New CNC Membership Type Under Hobbies

Click here to get the Hobbies page.

Not much types of hobbies to choose from there should be at least an "other" button

Do you consider some of the new "3D printer" concepts germain to your hobby? much of the control hardware (i.e., stepper motors) and software would be similar- the main difference is the 3D printers add material rather than remove it. I have yet to build my own, although I am slowly accumulating components from dead printers and other equipment I come across. As to conventional machining, I have always preferred my manual lathe and mill- something soothing about watching a form take shape...Also, I am not much in to mass producing things- most things I make are one off, and it would take a lot more time for me to program a CNC rather than just start cutting...

I do see that 3D printers are in the same field, mainly because of the control hardware/software.

Actually, mass production is not my interest at all, but if you took the time to look at YouTube as I believe I suggested and see the beautiful work done with respect to printing and carving - which is where my interests lie.

Also, there are special ways of making 3D models from phots, once backlight, they look fantastic.....

My wife does some pretty funky cake decorating...I told her I'd make her a robot to help cut shapes out of fondant and do the monotonous piping of perfect patterns.

Then I haul it downstairs and strap on the ol' plasma cutter to save me from my sheetmetal cutting nightmares!

...I can't even convince my kids to be that helpful around the house!

Actually, that could be completely valid......!!

The size of it may give you away, so be careful......

For her stuff I'm actually looking at hacking a scrapbooking tool called the "cricut expression" (~$400) and an add-on program called "Sure Cuts a Lot" (~$100) and you have a very simple way cutting paper from any .svg vector file. Not a bad setup for <$500 if you watch for sales or used items.

http://www.youtube.com/watch?v=__Fya1crI-U

I'd like to take it apart and see if it can be modified to take other 'tools' than the default paper cutter that it comes with. I've seen someone take the top cover off and attach a etch resist marker and use it to trace circuit boards blanks before etching. Someone else was talking about a dremel but I'm not sure now stiff the rest of the structure is to deal with the vibrations. Neat looking little tool to play with...

My wife tried one the other day and liked it...I'm hoping she adds it to her birthday wish list...then I can add a hobbycnc driver kit to mine! :)

The only trouble with dremel is that once you have one, you realize you would ideally like to have ten of em.

I heard tell of a jeweler who set up his workshop with 20 of them (t-w-e-n-t-y!) They can do so many things and that is the problem: it's a hassle to change bits and setups for each different need. A set of hand carving tools is a set, ready to hand. You don't have to disassemble and make unready the tool you just used, in order to get the next one for your exact need....before going back to the first one....

Anyone who complains about their dremel is met with the phrase "Would you like to sell it?" Because we all want twenty of em, really. Get em cheap from those that will part with em.. (not so likely, although I suppose, on ebay??? you never know)...

I did manage to buy a high quality Proxxon from ebay, (Dremel like tool), that had a problem (it did not work!), I got it for €9,-. I sent it in to Proxxon who said it was unrepairable as it was the old model. They would send me a brand new model for €30,-. I paid.

In the shop the new model costs €75,-........

I do not know if Dremels are also "repaired" in this way, but if they are........

I have also had some Dremel look alikes, all broke within one hour of use, I also bought a Battery Dremel in the end, its still going strong.....

I love these tools, but two is enough!!!

If you like the Cricut for 2D look at the Sears Compu-Carve/Carve-Wright (3D) with a Dremel like device inside it. It does 3D with limited freedom of a depth of 1 inch.

Downside: It costs roughly $2200. It's computer controlled with included software but uses not so standard memory cards.

Just search google for a link. It's been out for about 2 years.

RAH

Count me in. The You Tube was convincing in the DIY. I like the idea of scavenging parts while I plan what to do with it. I read that old dot matrix printers are a great source of stepping motors and steel bar. I saw a laser on you tube that came out of an old CD burner.

After TexasCharley's thread about technogy that lets us down, I think it's time to make a machine from the scraps.

Great!

Count me in as well.

The other forum I would like is DEY (Do Everything Yourself), or is that the definition of a hobby?

Artsmit - nice machines are being made of scrap. (I think I have enough scrap in my 3rd garage to last me two lifetimes )

Perfect! You have the best attitude of us all, me included!

DEY makes perfect sense.. it's the aspiration to DEY that makes us lesser mortals crave the learning of engineers. DEY = D(I subone + I subtwo +....+ Isubinfinity)Y ??

The world we're living in is full of hightech scrap! Planned obsolescence and cheaper-than-repair replacements is generating the scrap we never dreamed of. I am a long way off in the DEY to be able to make something like a laser. But if there are good ones being tossed out with the trash, or lying idle in broken machines we can't bear to throw away, it will be very satisfying to use it as a part for a useful machine. (and think of the empty garage space...!)

I subscribe to a magazine called "home shop machinist" they also have a sister publication called "digital machinist" dedicated to cnc machining for diyers.You might find this of interest.

oilcan13

Hi,

firstly I would like to re-state that I am also a beginner here, my first machine is not yet finished, so what I am writing here has not been put to the full test as of now, but I thought that you might be interested anyway.

The "proper" threaded rods are heavy and expensive and to my mind, the distance "traveled" is too far per revolution (pitch) for fine work, so I decided to use 8mm (0.315" somewhere between 1/4" and 3/8") threaded rod from DIY sources. I actually bought stainless steel rods on ebay quite cheaply.

A standard 8mm thread has a pitch of 1.25mm per turn, which conveniently translates into 8 turns per cm! (if you want to stay with inches, pick a non metric thread! but in fact all good CNC software can switch between both, even though the threads are either metric or not!)

Using stepper motors with a 1.8° step, this means that I can break 1.25mm into 200 separate steps of 0.00625 mm.(0.000246 inches...) which is pretty damn fine!!!!

When you also know that with most stepper motor driver electronics you can also break each step down even further, often into 1/16 step.....it starts getting ridiculous!!

Most hobby CNC people will not use threaded rod as they are not "cut" threads, they are "rolled", the problem is that they are relatively inconsistent in thickness, and what you need for a CNC machine is complete consistency.

I decided to re-cut the threads myself using standard thread dies. I was appalled at just how inconsistent the rods were. It takes me about an hour per rod to cut off all the excess metal using a 6mm die. Its quite amazing just how much is eventually removed!! The first time I wondered if they would be any good at the end, but they turned out to be perfect.

I used plenty of cutting oil and got myself really dirty in the process!!!!

For the nut, I used a "long" nut I have no idea what they are called, some have flats and some are round, they are about 3 cm or just over an inch long. Also stainless. I welded it to a piece of flat stainless that would allow me to attach it to the CNC machine with screws. I first cut this nut's thread with an 8 mm tap, so that this thread was also exact DIN standard (or as near as I could get). There was not much metal removed here, it was already fairly accurate.

When I tried this nut on my newly cut rod, there was a little too much play, about 0.06 mm if I remember correctly. So I made a cut along the length of the nut, completely through one side. I ran the tap again through it to get rid of any metal pieces that could block the thread, then I used a vice and "Squeezed" the nut a little bit, till it was free on the rod, but I had reduced the play to less than 0.03mm. I also plan eventually to use hose clamps to keep it slightly tensioned and stop the slit opening up under duress.....also as it wears, I can retension it a little as well.

Now the nut would run the complete length of the rod without any tight spots and with very little play.

By the way, all the good CNC programs can be set up to negate any play in any part of the mechanism.

I have played with the idea of tightening it some more and then using metal polish to polish the two parts one against the other to get the best possible fit, with minimum play. Later maybe. Lets get the machine finished and running first!

If any points are not clear enough, please just ask and I will do my best to explain better....

If anyone is interested in my ideas, I can make a picture of the nut and put it in the blog. Just ask. In fact, I will make pictures of any part if requested.

Next post will be with regard to the bearings of the threaded rod.

If I get boring, tell me and I will shut up completely......

Here is a simple picture showing the nut that runs on the threaded rod:-

Andy-

I have seen a similar approach to a nut on a machine somewhere that used two small cap screws through the cut to allow for adjusting for backlash and wear, which worked quite well. One might need a thicker body on the nut that your drawing shows, and I am not sure how to drill a small hole off-axis in a round part (although I have accidentally done this on occasion!).

Got you, but you would need to make the whole piece, still not too difficult and worthy of thinking about if my idea does not work out.

The reason I did it the way I did was to try and use parts that I could (cheaply!) buy in a DIY market or on ebay!!

Naturally I could weld a nut and a loop above the cut on each side, but I want to see how it works out with the hose clamps first.

Many thanks for the idea though, that is EXACTLY what I need, active help and ideas from people like yourself....keep in touch.

Good Stuff Andy We are now getting into the nitty gritty I was also thinking along the lines of making my own lead screws and now you have started to quantify the solution as regards stepper motors and lead screw pitches. My main worry was making a viable chassis and it now seems to be coming my way. This is a realworld discussion far removed from the blue sky theorists which to My mind means cool . I am very interested to hear that you cut your own threads I will ask you more about lead screws also how I get on, mind you I will be doing a fair amount of theorising myself as i cant get into practical doings as i am pulling down one workshop as the wood has gone rotten after twenty years and putting up a new one and fitting it out

You are most welcome here, it sounds as though I need you too as you are already in areas that I have not yet reached!!!

The reason that I used 8mm threaded rod was that skateboard bearings, the cheapest bearings around, happen to have an 8mm hole through them......but other bearing sizes, if bought judiciously on ebay, will be acceptable too. It is maybe a good idea to go a bit thicker on the thread.....

The reason for re-cutting the threads is that "rolled" threads are not consistent enough in diameter, and the rider nut you make, will be tight in some areas and slack/loose in others if you use them as they are....simply not good enough for a CNC machine.

I used stainless steel, I would not use it again as it is difficult and time consuming to re-cut. I would use a reasonable quality normal steel, it wears better and re-cuts easier I have found....

Whereas in a professional machine built by a company, the threads are doing two jobs, guidance and movement, in my design the threads only do movement, the guidance is done by the "rail" system at each side of the main base.....good Acme threads are very expensive too.....so are the other bits you need to use them!!!

Keep in touch as I think we can help each other - a lot!! I must apologize as I am working very slowly on my machine at this time.......

The threaded rods must be properly supported, so that there is no radial or axial movement of the threaded rod, but the rod must be able to turn freely.

I use the following construction of one radial and two axial ball bearings. It looks something like this:-

The only thing I have not shown is the fact that I use plastic water bottle caps, drilled in the middle to cover each axial bearing to protect it from dust and dirt. They are held in place by the nuts on each side.....they go between the nut and the axial bearing.

The radial bearing used is the cheapest ball bearing (I believe) available in the world today, from skateboard and inliner wheels. This is a bearing with an 8 mm hole, outside diameter of 22 mm and a thickness of 7 mm.. I sometimes buy 8 bearings on ebay for €1 plus postage!!! Make sure that you get the ones with the sides protected either by plastic or metal covers. Not open.

This fit perfectly on my 8 mm threaded rods. They are also used in the linear bearing design I use.....you need a lot of them, 30 in fact!

The axial bearings are not quite so easy to find, but also available on ebay if you look long enough!! You only need 6 per machine.

The radial bearing outer edge is cleaned with methylated spirits and glued in the middle of the plywood former with good quality epoxy 2 part glue. Do not use too much as it could damage the bearing. I use a simple nut and bolt with enough washers to place the bearing in the middle of the wood and not skewed. I leave it for 12 hours on a radiator to harden off fully....

Each threaded rod axis only needs one of these bearings (2 x axial, 1 x radial) at one end of the rod, the other end only needs a single radial, not the axials.

The nuts must be both of a type of locknut that has a circle of nylon (Nylock) to stop them moving while the machine is running.

How long are your threaded rods? Any problems with sag, especially when working mid-span?

Great question, its something I intended to cover during the next couple of days anyway. So here goes:-

Firstly, the 8mm rods I use can be bowed from new slightly, but are easily straightened if you have a good eye....but even if you don't, it really does not matter as the rods are "kept under control" by the two end bearings and the nut that runs up and down.

The x,y and z axis are kept "on the straight and narrow" by the way I have made the linear bearings and rails. (Which will be my next post.) The z axis is quite short anyway....

The 8mm rod is simply not stiff enough to cause any problems, but stiff enough to be self supporting eg. not to bow any further. I am expecting that it will get "ironed out" to straightness by the bearings and nut!

On my X axis I will be using about 75cm long rod, but I anticipate no problems in using 1 meter lengths (on my next machine).

I have not found any sources of rod longer than 1 meter up to now, but eventually I will have to source longer ones next year (2010) if I am to achieve my goal.

But I don't let it bother me for this year!!

Great set of posts Andy, for the excellent links and also describing your choices in the design.

There's a nice picture of a system for keeping the threaded rod anchored and freely turning, using skate bearings and straps, here. http://lirtex.com/index.php/cnc

I'm still at the stage of deciding on design and making a list of stuff to rustle up.

It appears that the 'Easy-to-make desktop' design at the Instructables link relies on sliding rather than rolling, and involves far fewer bearings as a result (unless I'm missing something). Obviously rolling is better, I just wondered, What do you think of this approach? It looks surprisingly functional.

You must chose your own method, but may I recommend mine as it holds the threaded rod securely in one position, but allows it to turn easily.....

The method shown on the Lirtex web page (a good website for most things), will eventually ruin the bearings as they are bearings for Radial loads only, Axial loads will wear them out. For a tiny CNC machine probably OK, but not for the ones I am building.....too big and heavy.

We can discuss this further if you wish....

thanks Andy

I am probably looking at building a relatively tiny machine, but that doesn't mean it wouldn't benefit from better design.

I would really appreciate any photos of your designs: I am a bit 'diagram-dumb'. Photos are easier to understand, for me. This is one reason I like the CNC scene as you presented it, because there's lots of video and photos for us dumb critters....

You make a good point, I will do my best to make some photos that are easily understood.

f you want (or anyone else for that matter) copies at the full original 5 mega pixels of my camera, we can organsize that off line via our own email addresses, as the quality here is abysmal....sorry CR4!!

I will try and get onto it sometime in the next week.....remind me if I forget please.

Thanks Andy for the drawings and that goes for everyone I am working on the chassis at the moment between sorting out my new workshop will send some photos as the work progresses so that you can see what the router looks like I am working on full size templates at the moment they need such a lot of fiddling about in solid works moving around and getting plan perspectives. I have got the scale worked out and should be able to get a good finish on the parts. Using a router bit and a pillar drill

Hello again i would like to experiment by running a die on a piece of rod one could I suppose achieve quite a fine thread after a few passes of the die I have not yet scaled the rod into the size of the machine but we are open to a wide choice Here is My Z axis side for the gantry scaled from solid works I think I will use 1/4 inch lead screws more drawings and photos to follow I have made a DXF drawing of this one

Here is Joes Router With some of the dimensions

Great links- especially the Instructables, and the supplimentary data on drivers for the stepper motors. One of the things I have found with my salvaged parts is that some of my motors are 24 volt, and I either have to build my own driver circuits or figure out how to address the original boards (assuming they are salvageable). I also have had trouble, when salvaging parts, identifying the items- sometimes, manufacturers remove all original markings and specifications from the parts they incorporate (including electronic components), and their internal part numbers are pretty useless for identifying just what it is you have. Also, although I will try to salvage anything I can from "dead" equipment (i.e., anything that no longer functions as it was originally intended), I find modern "surface mount" electronics pretty useless- when you need a microscope to identify components, they are pretty hard to modify!

For electronics development, I have a nice little prototyping station that incorporates a power supply, signal generator, a variety of switches, pots, and such, plus an LED bank that comes in pretty handy for monitoring output, to determine if the system does what I intend it to do.

The old Centronics parallel printer port was a great tool for digital control- I still mourn the passing of that feature on newer computers. The GPIB interface was even better. I have used RS-232 for similar purposes, using the control lines for sending digital signals, but even that is fading into obscurity. I haven't figured out how to get the flexibility I like out of USB yet..

The Instructables site is phenomenal- the only complaint I have about them is that I have downloaded far more "projects" than I will ever have the time to play with...

Somehow, I feel I could have written your whole post, if I was going to be fully honest.... But I am not going to be fully honest either.........!! Too embarrassing!

I can put you (or anyone else if needed) on the path of an excellent power supply that can be set up for anything up to 40 volts with the standard chips, or 65 volts with the uprated....its from Elektor and is a Switched Mode Supply with 85+% efficiency and up to 10 amps. I would recommend such a power supply as a basic part of the setup. I would NOT recommend old PC supplies except for very tiny CNC machines.

With regard to stepper motors only (I have not used servo motors as yet privately) they can be driven at far higher voltages and currents than the label suggests with no problems. Was the motor you mentioned a stepper motor?

Small CNC machines can be easily built from parts salvaged from printers, scanners and the like, the bigger the better!

If you or anyone else has any questions, please feel free to ask, I will do my best to find a good answer as far as possible.....

I will be posting again this evening on how to make Linear bearings quite cheaply.

Here is my favorite forum for CNC stuff, it has everything. Electronics, free schematics and lots of artwork and and and........

CNCZone

Sadly a lot of the other forums are in German, but if anyone would like some of them too, just ask. CNCZone also has multilingual areas as well.....

The actual bearings of the linear bearings are made in the same way as shown on that website. 4 x skateboard bearings per side of linear bearing. 2 x needed for an axis.

You will notice in the following sketch that the bolts interfere with each other and need to be offset when using aluminium angle, so that you can put a locknut on each screw. Even 3mm thick angle will not allow a reliable thread to be cut. You need at least 5mm or more.

With steel angle of 3mm or more, you can cut a good thread and the screws can be cut shorter so as not to interfere with each other.....use Loctite and lock washers.

The length of the angle needs to be at least 1/3 rd the width of the axis, to give the greatest stability. Sometimes a further set of ball bearings are needed in the middle to correctly support the weight of the axis....

Make yourself a guide so that the pilot holes for the bolts can be drilled always exactly the same distance from the middle of the angle. I used a small off cutoff Aluminium angle to allow accurate marking.

I forgot the simple drawing, sorry....

Here is a place to buy some of the electronics at a reasonable price. They have a good reputation too....

Linistep Kits

Do you mind to do this project from start to finish?

You do not touch on the electronics and the computer to drive interphase, that is what I am interested in. The mechanics is the easy part.

I will try and put something together for you in the next week, don't let me forget!

A good Forum to join is this one from Ivan Irons:-

http://www.cncinformation.com/

I have made a few pictures of various parts and the way I designed and made them. The designes are not entirely my own, I used some basic ideas from several web sites, to whom I am most grateful indeed.

This is a picture of one of the special "Nuts" that run along my 8mm stainless steel threaded rods. All these parts are also stainless, but its probably not completely necessary as long as parts are given something to discourage rusting.....the reason that I bought stainless was that I found that stainless on ebay was as cheap as normal steel in a DIY shop.....

The rods have been re-cut by mayself to make them more accurate, it takes about an hour and a lot of oil. The problem being that the rods are rolled, not cut and prove to be over thick and inconsistent in their thickness.....you would be amazed at just how much metal gets taken off with the dies.

I then cut the "nuts" with a tap and often they are also oversize. But then the nuts are a little too loose on the threaded rods, so I make a long cut on the nut and squeeze it a little together till it fits better with less slack. I then put two hose clamps, one on each end of the nut, to hold the adjustment better. I can get the slack down to about 0.04mm (0.0016" aproximately) good enough for woodworking.

This picture shows how I make my rails. The fiber board (?) is cut using a wood router with a 45° bit, with a small ball bearing on it, a standard type. The router is adjusted so that the ball bearing is in the middle of the fiber board and a cut is made. I started by screwing the alumium rail to the fiber board, I now use special glue that glues metal to wood with no problem....

In the background, you can see an unfocussed linear bearing that I make myself.

Here is a better photo showing the angle and the skateboard bearings mounted on it.The angle on which it is mounted is wider than the side cheeks, to make everything as solid and stable as possible.

This shows the Proxxon router that I am using at this time, clamped in a caravan clamp for the jockey wheel for a European Jockey wheel.

thank you for the photos, andy!

What I failed to mention before is that the "Rails" are all hi density fiber board, with a plastic skin. I use 3cm thick for the "Y" or the work area. This must be cut exactly parallel at the sides, I got a firm to do it and I was not able to measure any error with a steel rule. Its certainly well under 1 mm ......

The middle of the side is not cut by the 45° router, it allows good guidance of the router via the small ball race, from both top and bottom.

I am amazed at how heavy the "Z" axis has become, about 2.5 Kg with router. So I am at present designing a counterweight system to reduce the extreme load on the stepper motor when driving upwards.....I have cast the lead weight, but I now need to adjust its weight carefully by drilling holes in it....

The weight will slide up and down on two extra long wood screws, that I have turned off most of the thread and will remove the heads once the are correctly mounted....

For heavier routers I will make up some lead "Rings" to allow future easy adjustment of the counter weight.

I have not see a "Z" axis with a counterweight up to now.......but my motors are only 1.8 amps....we will see.....

I thought I should try and continue with a few tips for when designing your own CNC Machine, so here goes. Please drop me a line if I don't get it quite right for any reason whatsoever!!

1) Except for very small CNC machines say for making PCBs, do not design a machine where the workpiece is moved. It ahould remain still at all times.

2) Make sure that you balance the weights of the parts of the machine so that the weight is transferred to the middle of the linear bearings, not at one end. Here is a simple side view (not to scale) that shows how the Y axis rail should be placed somewhere in the middle, to allow the weight to be fully supported. If this is not exact, it does not usually matter, eye balling is close enough....

3) If you have the slightest thought that the gantry may prove to be heavy, add extra bearings in the middle to support the weight better.

4) Make the bearing carriers as wide as possible, so as to add stiffness to the design.

The wider design is more dificult to design for, but pays dividends in the end.

5) The bearings must be held in tension so that Y (and Z axis) can move freely, but not tip or move out of being parallel. This is exceedingly important.

6) There are some excellent threaded inserts for wood that can be used to make the base usable with bolts to hold the workpiece down. They look a bit like this:- (if no one recognises them, I will make a photo as I haven't a clue what they are called!!)

I used one with a 5 mm thread and drilled about 50 holes.....I also used a strong Epoxy 2 part glue to make sure that they do not drop out in usage..

Such a CNC will be excellent for PCB making, wood working, plastic and light metal working (but without liquid cooling), use forced air cooling if needed.

Excellent tips for design, thank you Andy.

I have a few more things I will post shortly, its just getting time to do it!!!

If you or anyone are starting a build, let me know and I will try and speed up a bit!!! You need to know as much as possible before starting.....

If you or anyone else have any ideas or tips, please post them here as well for us to learn from you. Its a 2 way street here....Thanks in advance.

Hi Andy I am also A Newbie and at the moment just making sense of the solidworks models of Joe's 06 router extracting baselines and bolt hole sizes by tracing bitmap images in turbocad and making full size templates I think that I have arrived at the true scaling but it is a long and laborious process .I would like to collaborate on things like the lead screws and nuts and whether threaded rod outside the kit manufacturere domain would work just as well the threaded rod prices seem very reasonable .I am thinking of cutting out the machine parts in MDF using a router bit in a vertical drilling machine to achieve the fineness of finish and tolerance I think a router bit would be more controllable than an ordinary router as they have a will of their own and much of the workpiece is obscured by the body of the router. I hope we can keep up the thread and for it not to get lost amongst a plethora of postings after all we are pioneering practical work designs Best Wishes John M

This is JUST an idea I had a few days ago. I thought I would run it by you Guys to see if you think it might work/ be useful.

I did the diagram in paint, its not very good, I just hope that it gives you enough of an idea....please ask me if any points are still not clear.....

I use 8mm threaded rod as the lead screws on my home built CNC machine (by the way, they only move the axis, the guidance is done by ball bearings on angle.....

I have used another system to take up the slack on my present machine, but it struck me that one could use the "difference" in pitch between two different thread sizes to take up the slack and to readjust when wear takes place.

I bought today, some 8 and 12 mm "Connecting Nuts" (that is the translation from the German, what they are called in English I cannot say, sorry!) They look simply like really long nuts, over 3 cm long in fact.

Look at the diagram above, the green is an 8mm long nut (from now on called a LN), that has been welded or glued into one end of a 12mm LN (Blue).The beige 8mm LN has been turned down in a lathe and given a 12mm thread on the outside for 3/4s of its length. It has been screwed into the unused end of the 12 mm LN.

Where you see 2 small red "X"s on the 12mm LN, are two grub screws to hold the beige LN fixed in position, once the correct adjustment has been reached.

You only need to turn the beige LN relative to the blue LN to tighten the two 8mm LNs one against each other, because one is welded to the Blue LN and the other turns only with the thread pitch of the 12mm thread which is 1.75mm per turn, against the 8mm thread pitch which is 1.25mm per turn. A difference of 0.5mm per turn.....

Therefore one can pull apart or close up any looseness in the 8mm thread. This is important to make the CNC run as accurately as possible....

Naturally one could fill the center with grease or oil before inserting the beige LN for good lubrication. Also, one should not make it too tight, just enough so that it is tight on the thread and loose enough to allow the 8mm lead screw to turn easily.....

This assumes you have very, very good threads over the length of the threaded rod! The less slack you have, the more exacting your threads must be cut...I have seen something similar (not exactly the same, but the same basic idea) somewhere in the past. Another alternative is to use a "split" nut with a set screw for adjusting the fit...

I use home made split nuts at this time, well lubricated, on my DIY machine.

The rolled threaded stainless steel rod that I bought turned out to vary its diameter over its length, normal for such things I guess, so I bought some new 8mm dies (outside threads) and re cut the whole length of each axis, it took me 2 days.....it turned out that they were well oversized as well.....I cut a lot of metal off, far more than I thought possible.

By the way, I will never buy stainless threaded rod again, it was a pig to re cut, getting hot etc...the next time I will just buy normal steel threaded rod....and keep greased to stop any possible rust.

I used some good metal polish mixed with lube oil to "Lap in" the nuts, running each axis from end to end many times. I then cleaned the mixture off well and then just used a good light oil for the moment as lube.

(By the way, I am still looking for a high performance oil or grease to use on the lead screws, any suggestions anyone? I thought of maybe silicone oil or grease, but need a name that I can buy in Europe! Something that lubes well and gets into the metal's surface)

Now my split nuts (sounds awful!!) run beautifully from one end to the other with no tight or loose spots!!

Try this:

http://www.lucasoil.co.uk/products.php?page=products&subpage=product&product=29

Or there are lithium-based greases that seem to adhere longer than most types of grease...

Many thanks!

Depending on how far down the line you are, you might check out Mechmate. They are a great group, very helpful, but are focused on making a large scale CNC machine. Even DIY it will cost several thousand dollars ($3K to $8K with $5K US being typical) that does sheet work nicely (think generically 4x8' sheets of plywood, but you get to scale it to what you need). It is based from an old Shopbot design way back when, but has been enhanced and beefed up, and is working in shops around the world. ... BTW, the design, documents, and support are free. It is NOT 'open source', but if you want to build them for others for a profit, they are willing to talk. Design from South Africa, but support people all over the world, literally.

Hi C.W.

It nice to see ithis blog "awake" again. It blinked once the lights were on.

I had almost forgotten it myself......

The link you posted is a really good and useful bit of software, so good that I am told many professional shops use it!!!

Yes, good site. Home of the EMC2 software. Very robust and well maintained. Run under Linux with real time kernel.

Its nice to see the blog in use again.

I do have a load of updates that I could pop in if there is enough interest out there.

Could all of you Guys who are still tracking this blog please just put a very short post in it (one word like "Hallo" for example) just to show you are still interested.If I see more than say 5 posts, I will do some serious updating for you all, OK?

The reasons (sadly) that I have not been updating here are twofold:-

1) I have found many CNC based Yahoo blogs that cover most of my interests and most are still very active. I can post some links here if anyone wishes it, but it feels like I am stabbing CR4 in the back a bit and I would never want to do that, ever. But we do post links for other good web sites.....

2) The interest, except for a "hard core" few here, was apparently very limited.....So Guys (and Gals"!), please prove me wrong and post to let me know just how many are interested in continuing......

I have changed the heading to be a little more accurate....please use the new heading.

Does anyone know exactly how to re-introduce this blog on the "Daily Digest" again? I have seen it done many times, but never (needed to) do it myself.....

Maybe I will start a new Blog and just post the link here.....

Hey Andy,

I'm still in! I haven't done a thing with it at this point - but I'll certainly read the blog if it's active and admire any pix of the work any of you've done. Great linux link there, cw, thanks. I'll be needing that!

With a name like yours you are most welcome!

(You are most welcome anyway, I just like the name as well!!)

Hi Andy - must've had enough interest shown by now - post some photos!

(If you're still deep in the design stages, that's OK. Bin there - not trying to embarrass you).

Great stuff Andy, just the sort of think I like.
I've got too much stuff on at the mo' to actually join in, but I'll watch with great interest from my secret cat nest.
Del

Thanks Del, you are a good reliable friend to all of us here, (in spite of leaving paw prints and scratch marks on EVERYTHING!!! At least you do use the Kitty Litter Box....... )

No seriously, interest is enough, anyone else interested enough to post once here?

By the way Del, would a long slim CNC Router be able to cut out a suitable blank for carving? If yes, not difficult to make!!! I am sure that you could use a marker pen to mark the wood even and follow it with some simple opto electronics.

That way the CAD/CAM part is not needed even, AND you can follow the grain by eye first much better!!!

Just a thought!!

You can make things like large wooden carved snakes on it when no new bow is needed..... or Dildoes? Really big ones!!!

I'm lurking - but you can keep your sex aids to yourself (or maybe give them to friends for Christmas presents?).

Good stuff as far as I've read - will see about reading all the posts at the weekend (then I can start wading in and telling everyone where they're going wrong ).

I recently bought a bandsaw off E-bay, it's saved me a lot of axe work, great for roughing out bowstaves (sakes and dildoes too).
I've just been tidying the garage and I've used a load of old plywood to make a nice run of 7 drawers for my archery bits & pieces (I can't seem to contrive a Snow Wite and the 7 drawers joke...but I'm sure someone will come up with something).
The bandsaw and tablesaw made it a relatively easy job. I've been meaning to make those drawers for ages, I can store my flights, points, fletching jig, tools and stuff nicely now (arrows are mostly 5/16" or 11/32" so at last I can separate the differnt points nocks and tools).
Dunno how I missed this blog before and gawd knows where this mythical 'hobby' section is..I had a look around the blogs and couldn't find it... maybe CR4 is a bit like my garage and needs a good tidy up.
Actually, now I've given up golf, I'm sort of wondering what I could convert my homemade electric golf trolley into.... I'm sort of pondering a little traction unit to assist my son's wheelchair if he goes off road, sort of tractor on a stick!
Del

I am in the midle of building, been there a long time as I have simply run out of space in the cellar and I need to sell my Kit car and make some storage space in the garage for a lot of computer equipment that I have....

If you look back through this blog, you will see I posted a lot of actual build pictures a long time ago.

The major changes that I am planning mechanically is to double up on the bearings on each machine screw. Other than that I have remained true to my original design mechanically.....

Look here for the genius that inspired me personally:-

http://buildyourcnc.com/default.aspx

Hi Andy

Thanks for the info I have just got my new workshop together wired etc still very much interested in CNC after cutting out the parts for a 1/7th scale model Hawker Hurricane CNC router would be very useful I shall be cutting out my machine I have decided on using aluminium for the chassis and wil be doing it piecemeal together with building this aircraft .Nice to hear from you.

Very Best Wishes John M

Hi Andy

Could you please circulate some programs that would be useful to us CNCrs I've found a really good practice one for a CNC router it has a really good practise demo but it is not free but priced very reasonably it also has some very good online tutorials it 's an interface creating it's own G Code .

Still not built a machine yet but I still keep an interest

Best Regards John Mason

Basically we have 3 areas, CAD, CAM and actually driving the steppers.

Do you mean all or just particular areas?

Hi Andy

I have the drawing situation sorted I use turbocad cut2d works great with PDf files but will not work with autocad drawings generated with turbocad but thats not a great problem I am from a engineering drawing office background and have been building model aircraft for many years I have also lofted and made a 16ft canadian canoe so drawings do not create any challenge what is required is CAM but none of these programs are free I have mentioned that CUT2d does a very good trial version. that creates very good machine code and it will also work off PDFS.

I dont want to go the MDF route because I think that by it's very nature will create intolerances I think going the alumiium route is the way to go and the kits are a ridiculous price so the chassis will have to be made with surface plate protactors vernier and mike and hacked out from the raw material

Best Regards John Mason

There is great middle route that may appeal to you even better, that is using an MDF or chipboard core (I use plastic coated chipboard and paint or seal the cut areas) with Aluminium rails glued onto the MDF/Chipboard with modern adhesives......to take the wear and tear of the linear motion via skateboard bearings.....

I use a product here in Germany that is similar to "No Nails".....it will glue anything to anything!!!

The trick is to get all the boards that will carry rails to be cut for width on a professional circular saw so that the sides are as near as dammit parallel.

Then you get a router and using a 45° cutter with a tiny ball bearing st to the middle of the chipboard (use as thick as you can get, I use 30mm Chipboard), you cut a 45° chamfer on the top and bottom of both sides, leaving just the middle 5 mm uncut for the ball bearing to ride on.

You then use denatured (Methylated) spirits to clean the insides of the aluminium angle, keeping your fingers away from the surfaces. On these cut edges you glue two alu rails. I tap each one with a rubber mallet to make sure that it is seated as closely as possible onto the freshly cut 90° (2 x 45°!) edges.

The variation on width across the rails, when done carefully, is REALLY tiny, as good as unmeasurable.....with normal tools anyway. Though I am busy thinking of a way to measure up to 1 meter with a micrometer, I have an idea, I just need the time.....so that I can check the accuracy better......

Here are a few simple sketches:-

The drawing is not to scale.

If you go on-site here:-

http://buildyourcnc.com/default.aspx

You will see where I got some of my ideas!!! The Guy is a genius!!

If you have any further questions, please come back, I will do my best for you.....

I will explain how the other side (the bearings) are built to run on the rails so produced above!!! Using a bit of thick alu angle or similar and a few skateboard bearings, attached to 8mm machine bolts.....

The beauty of the system is the accuracy is really good, and the parts are all available at most DIY stores.....the only "specialist" tool required is a wood router.....and a 45° cutter with bearing.....many would say "that is a normal tool to have!"

http://www.cambam.co.uk/ is the home of CamBam that allows 3D modeling and editing, but does generate g-code directly as well. There is a free version (older version) but the 'production' version is still being updated and developed, there is a good support forum, and (tada) it is 'reasonably priced', especially when compared to almost any other commercial software.

I am a happy customer, no more, no less.

My only reservation is it is a windows based program, and I am trying to get to be a 'Windows Free' environment. But he keeps saying a Linux version is forthcoming, but the time frame keeps elongating ... Such things happen in a small development shop (been there, done that - not a complaint, just an observation).

Thanks I am amazed shall definitely try it and see if it will work with turbocad DXFs

Hi thought that one got the driver software when one bought a a motor kit such as Rockliffe .It's making a chassis of good mechanical integrity is the prolem GBam software is looking promising and you get forty practice goes before purchasing Cut 2D which I have tried is also good

I don't know how Rockliffe package their products, but generally speaking, you buy or make hardware and you buy or get for free the software......

There is some cheap and some free software for creating G-Code files, when I next have time I will post all that I know about...

Hi I have been playing around with cut 2D just practising marking out aerofoil sections and have downloaded CADBAM at the suggestion of fellow member Servant. It seems quite good to me and one has forty goes at it I expect that it can be downloaded again for some more goes before purchasing, at first glance it looks that you can place multiple parts on one sheet which is extremely useful and sensible. I will start cutting out bits of aluminium for joes router of which I have a full set of plans that will need laying out on the material will do this bit by bit as I get on with other shopwork it's nice to have my workshop up and running

Best Regards John M

The Story Continues

I found a g/m code language description and used a text editor that will edit flat files. it worked well for me. ... Learning g-code writing is a simple process, but start with a simple tax (mill an outline of a square that is 1/4" deep or something) and progress from there.

Once you understand g-code at that level, learning g-code with 'higher level' methods makes more sense, and you can figure out how to debug code that has gone haywire too!

Cut 2D I find is highly suitable GBam I think has a high learning curve but Cut 2D generates GCode for a huge variety of machines running quite a number of driver software and is relatively cheap costing about 248 dollars which is 200 and something British Pounds it will translate DWGs DXF and PDFS it works very well with PDFS generated in 2D turbocad. It seems to me a very quick way to get up and running after you have built your machine and bought power source driver software and motor kit . I am longing to get going but have not yet built a reliable router chassis. All of this for me is in the theoretical stage . But I think it could be quite possible to build an accurate machine out of aluminium using a scroll saw and suitable blade for cutting. This is my presis of the situation and will have a stab at it as soon as I have finished all the other jobs that I have on the go!

Ps it will not accept DWGS and DXfs made in turbocad but does great with PDF s created in the same

I actually have two CNC blogs running on CR4 (show off!!), if you want to look at the other as well, look here:-

http://cr4.globalspec.com/thread/59111#newcomments

I found this place interesting : phlatboyz.com

They have a forum that shows lots of stuff they build from CNC cutting flat foam and folding it into various forms. They focus mainly on making 'foam airplanes'.

But one of the most interesting items is their software. You can download it for free. It integrates with Sketchup and outputs g-code ... It is free for non-commercial use. Yes, they want you to purchase their machines, but it is not a requirement.

Thanks I will go and have a look at this site