Machine Selection: New vs. Used?

We purchased some Jet equipment for much the same use in our R&D department. We've had it around 3 years, and it has worked out OK for us. We got a hand brake/shear/roll former, a metal lathe, and a drill press with an X-Y table that can be used as a poor-mans mill.

I think I would go with the new, cheap stuff. If you opt for the used/higher quality, you may be buying someone's problem child.

Tom

Jesse,

I put in a similar shop in a research dept about 10 years back. I used a good bandsaw but the mill and lathe were similar to Jet. When I used them, I could easily hold 0.002-0.003 inch tolerance without any effort because I knew enough to always take up the backlash. The problem was with the "night nummies" - researchers who came in after I left and damaged the equipment becuase it wasn't quite sturdy enough. The mill was often broken, the lathe sometimes and the bandsaw never. You can break a Bridgeport or Hardinge, but you really gotta work at it.

Tom

". . . the mill and lathe were similar to Jet. When I used them, I could easily hold 0.002-0.003 inch tolerance without any effort because I knew enough to always take up the backlash." This is an important point, but going with used [or new!] equipment of better initial quality doesn't change the need to take up backlash if you want to get the best out of it.

On most of the small imported mill-drills, there is a BUILT-IN error on the vertical. On the X and Y axes, they can change the pitch of the thread to get 0.100" per full turn. But on the spindle advance, the use of a worm-&-wheel eliminates that option, and they put a 100-counts-per-turn dial on anyway. In effect, in the vertical axis, an "inch" is actually 25.00 mm instead of 25.40, and you're off by nearly 16 thousandths of an inch per inch of travel. And that "accuracy" is only if there is no backlash in the worm-&-wheel, which has never been my experience. This backlash will typically vary with location due to wear. Somewhere in mid-travel is usually worse than at the extremes, especially at the far downward, which is least often reached (the up-travel limit is often needed for changing collets, but usually with little or no loading). You can calculate the corrections, or measure every part before disturbing the setup, or add a long-travel dial indicator to the column so that you can ignore the graduations of their dial on the handle. Use it for setting zeroes if you want, but do NOT trust it for actual advance!

Of course, if you buy a metrically-calibrated machine, or one with a screw-driven vertical axis instead of the typical mill-drill setup, you can igneore this rant!

Well Said!

I have a 1954 Bridgeport. Works great.

All sound advice, especially :- "Avoid 3-in-1 machines"

I would only add NEVER by even a dual (or more) purpose machine ever......

For a manual mill, none has ever matched the Bridgeport. I have used all of the copies including the better ones like Lagun and Sharp. Some get close but never as good. A Tree mill was once considered a step up from the Bridgeport, but good luck in finding one. Personally I still prefer the Bridgeport. For total versatility a Bridgeport with a 9inch riser, and an Advance or Troyke rotary-table-cross-slide will allow you to any shape that can possibly be done with a manual milling machine. If you are looking at a used machine, check the wear on the ways, if most of the original scraping is still there, buy it. Even used at equal price of a copy you are getting a better deal.

For a lathe, if you are doing small precision parts, the Hardinge toolroom lathe is the king of all small lathes. Once you go bigger to an engine lathe, there are many good choices such as LeBlond, Webb, Mori Seiki, Sharp, Clausing, Monarch, and many more.

Hardinge recently bought out the Bridgeport company and is continuing the tradition of quality with greatly modernized production technology. I recently toured their factory in Elmira New York because I am shopping for a new CNC equipment (mill and lathe) for my own shop. While there are many good choices such as Mazak, Robo Drill, Matsuura, Fadal (I currently have a Fadal), I am convinced that the Hardinge Bridgeport is about as good a choice as you can make. If price is more important than quality and performance, then other choices start to look good.

For manual machines, condition is more important than age. There are some here who will suggest buying old CNC machines or doing retrofits. If you have a lot of electronics knowledge, and plenty of time to waste when you could be making parts then have a party. Personally I would not touch a CNC machine more than 10 years old, and would prefer less than 5 years old. New technology is developed for a reason, and there are advantages to using it.

For vertical bandsaws, DoAll.

The type of parts and materials you are going to cut will decide what you need more than anything.

Finally, don't let anyone tell you that a CNC machine is not appropriate for tooling and prototype. With today's machines and software, a competent CNC machinist will get the job done faster and more accurately at least 90% of the time. Yes there are exceptions, but not many.

First you have to decide in what you are R&D is tolerance going to be a big factor.

If so will you get the tolerance need to develop a good product from the equipment you are going to purchase. Have purchased the cheap saw that every one puts their name on and sells for $150.00 to $250.00. Don't unless you want to replace it in a year. Like me you have fits every time the blade comes off and you have to put it back on.

Use a 30 year old Bridgeport would not replace it with some thing cheap.

Would recommend that you not purchase Jet equipment. For what they are offering its over priced. The equipment the sell is being sold by others more economical

Thanks to all who replied. My co-workers just left to go look at a used Bridgeport machine. We've decided to go with used proven equipment instead of new import products. Now the trick is to find that machine that is not "someone's problem child" as TDESMIT put it.

Thanks again

Jesse

Keep your eyes open for auctions. I just this week bought a Bridgeport in pretty decent shape for $1700.00 at an auction. I was fortunate that thre were two others in not as good shape that were auctioned first. I was prepared to pay $2500.00 for the machine if necessary.

Hi Jesse: If you can get verified GOOD USED machinery, with the name brand, THAT HAS TO BE THE WAY TO GO!! (yes i WAS yelling; to make sure you heard) Junk will always be junk. Cheap clones ARE junk. Name brands WERE EARNED.

Make a concerted effort to cultivate a good relationship with a reputable used machine vendor, it WILL be worth your efforts (probably many times over)

(i'll say it again: Good stuff is worth it for a long time; Crap is junk out of the box!, & never gets better)

With a bit of luck, the used stuff could be cheaper, too.

The amount of money you will save on a used mill or lathe (in my opinion) will not be worth the potential headaches. A poorly maintained machine or a machine used by an untrained operator can be more trouble then you bargained for. If you must buy used stick to big names and make sure that a pro looks at it(master machinist or millwright) Stay away from specialist machinery some of its custom made and parts and tooling are difficult to find. Speaking of tooling keep in mind you will spend as much on basic tooling as you will the machine itself. Have fun.