Previous in Forum: stepper motor   Next in Forum: Manufacture Process
Close
Close
Close
14 comments
Rate Comments: Nested
Participant

Join Date: Sep 2009
Posts: 4

linear motion (stepper+rack and pinion)

09/20/2009 2:14 AM

how can we get the brass platform(10x3x1) to move 0.5-1 mm (linear)by using rack and pinion and stepper motor

Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

"Almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, vote them!
Guru
India - Member - New Member Engineering Fields - Electromechanical Engineering - New Member

Join Date: Oct 2006
Location: India, 200 Km. North of Delhi.
Posts: 1393
Good Answers: 53
#1

Re: linear motion (stepper+rack and pinion)

09/20/2009 2:23 AM

By fixing platform on rack and fixing motor on pinion, and using a stepper controller.

Register to Reply Score 1 for Good Answer
Guru
Popular Science - Biology - New Member Hobbies - Musician - New Member APIX Pilot Plant Design Project - Member - New Member Hobbies - CNC - New Member Fans of Old Computers - ZX-81 - New Member

Join Date: Jan 2007
Location: Centurion, South Africa
Posts: 3921
Good Answers: 97
#2

Re: linear motion (stepper+rack and pinion)

09/20/2009 3:49 AM

Assuming that the platform is in inches or cm and not mm or m.

First you need to attach some slides or linear bearings to your platform.

A standard stepper can do 200 (or 1.8deg per step) or more steps per revolution.

Then you need to calculate the movement per revolution of your rack and pinion. (in steps per mm or mm per revolution / step)

With this ratio you can achieve any movement.

Also have a look at a lead screw on the stepper. With 400 steps per revolution and a 4mm lead screw you van get 0.01 mm resolution. 5mm lead screw does well for inch moves.

__________________
Never do today what you can put of until tomorrow - Student motto
Register to Reply
Guru
Engineering Fields - Electrical Engineering - Been there, done that. Engineering Fields - Control Engineering - New Member

Join Date: Dec 2008
Location: Long Island NY
Posts: 15600
Good Answers: 981
#3

Re: linear motion (stepper+rack and pinion)

09/20/2009 9:49 AM

Lets not forget though that one can only approximate linear motion with a stepping motor. Stepping motors move in steps. A micro-step controller can minimize the size of these steps but they will still be steps.

__________________
"Don't disturb my circles." translation of Archimedes last words
Register to Reply
Guru
Hobbies - Fishing - New Member

Join Date: Jun 2006
Location: Rochester, NY
Posts: 867
Good Answers: 11
#5
In reply to #3

Re: linear motion (stepper+rack and pinion)

09/21/2009 7:57 AM

Depends on the transmission used on the stepper. You can gear the thing so that a single step is smaller than your gear lash.

__________________
Eric
Register to Reply
Guru
Engineering Fields - Electrical Engineering - Been there, done that. Engineering Fields - Control Engineering - New Member

Join Date: Dec 2008
Location: Long Island NY
Posts: 15600
Good Answers: 981
#7
In reply to #5

Re: linear motion (stepper+rack and pinion)

09/21/2009 9:25 AM

Not true, unless the gear reduction has some form of dampening factor built in to smooth the steps. But even if this is dampened, at some velocities the steps will reappear. You are correct that the non-linear steps will be smaller and possibly the gear chatter could be larger than the non-linear steps. But without knowing what the OP is doing with this stage, I would not claim that either of these will be insignificant. I believe it is better to warn somebody of a probably insignificant problem, than to ignore any aspect you noticed but that others didn't see.

__________________
"Don't disturb my circles." translation of Archimedes last words
Register to Reply
Guru
Hobbies - Fishing - New Member

Join Date: Jun 2006
Location: Rochester, NY
Posts: 867
Good Answers: 11
#8
In reply to #7

Re: linear motion (stepper+rack and pinion)

09/21/2009 9:55 AM

Are we talking about the static position resulting from a motion or a motion? If we're talking about moving the device and watching it as it moves you are correct. If we're just trying to hit a position then a stepper will work.

I guess I deal with moving things to a process position rather than dynamic motion....

__________________
Eric
Register to Reply
Guru
Engineering Fields - Electrical Engineering - Been there, done that. Engineering Fields - Control Engineering - New Member

Join Date: Dec 2008
Location: Long Island NY
Posts: 15600
Good Answers: 981
#9
In reply to #8

Re: linear motion (stepper+rack and pinion)

09/21/2009 10:05 AM

Precisely my point, the OP only asked for a stepping motor to move linearly with a rack and pinion translation. Operations could be anything.

__________________
"Don't disturb my circles." translation of Archimedes last words
Register to Reply Off Topic (Score 5)
Guru
Popular Science - Weaponology - New Member Safety - ESD - New Member Hobbies - Fishing - New Member

Join Date: Sep 2006
Location: Near Frankfurt am Main, Germany. 50.390866N, 8.884827E
Posts: 17996
Good Answers: 200
#4

Re: linear motion (stepper+rack and pinion)

09/21/2009 3:31 AM

Why ask the same question twice in two seperate Blogs???????????????

__________________
"What others say about you reveals more about them, than it does you." Anon.
Register to Reply
Anonymous Poster
#6
In reply to #4

Re: linear motion (stepper+rack and pinion)

09/21/2009 8:41 AM

Just to prove you're useless in every existing blog !

You never offer an answer, you always question the information provided by the PO. You're never willing to help at all or you are a complete ignorant and incompetent for any engineering matter. You are pretentious, selfrighteous and childish (you congrat yourself posting as a guest). you are the most anoying and stupid person ever born in the world, you're just a waste of breathing air.

Register to Reply Off Topic (Score 8)
Commentator

Join Date: Jul 2009
Location: italy
Posts: 58
Good Answers: 6
#10

Re: linear motion (stepper+rack and pinion)

09/21/2009 11:39 AM

I suggest you contact an OMRON dealer.

Ask for information on Linear motors (not stepper motors) . You can resolve your problem of precision (0.05 mm) , speed (20 meters/sec), acceleration on any single axis (20 G). This is relatively new technology. A limit would be the distance you can move the object.

cheers

Register to Reply
Guru
Popular Science - Weaponology - New Member Safety - ESD - New Member Hobbies - Fishing - New Member

Join Date: Sep 2006
Location: Near Frankfurt am Main, Germany. 50.390866N, 8.884827E
Posts: 17996
Good Answers: 200
#11
In reply to #10

Re: linear motion (stepper+rack and pinion)

09/21/2009 1:51 PM

I did not read 20 meters a second from the OP, where did you get that from please?

If true that is quite a speed to hit, a servo motor will be better in such a case I feel.....

__________________
"What others say about you reveals more about them, than it does you." Anon.
Register to Reply
Commentator

Join Date: Jul 2009
Location: italy
Posts: 58
Good Answers: 6
#12
In reply to #11

Re: linear motion (stepper+rack and pinion)

09/22/2009 5:05 AM

Andy, you are right, I must have made a mistake in filling up the performance sheet. However we applied this motor to shift the slot connection on a series of peristaltic pumps. The maximum displacement was 2 meters and this was done in 0.5 seconds with acceleration and deceleration. Incredible speed and precision.

Register to Reply
Guru
Popular Science - Weaponology - New Member Safety - ESD - New Member Hobbies - Fishing - New Member

Join Date: Sep 2006
Location: Near Frankfurt am Main, Germany. 50.390866N, 8.884827E
Posts: 17996
Good Answers: 200
#13
In reply to #12

Re: linear motion (stepper+rack and pinion)

09/22/2009 5:11 AM

Sounds expensive though, is it?

__________________
"What others say about you reveals more about them, than it does you." Anon.
Register to Reply
Commentator

Join Date: Jul 2009
Location: italy
Posts: 58
Good Answers: 6
#14
In reply to #13

Re: linear motion (stepper+rack and pinion)

09/22/2009 5:35 AM

Andy

Expensive is always subject to discussion. For us it turned out to cost just as much, if not less than the traditional system considering the money we saved in linear bearings, supporting platforms and transmissions. Above all we saved a lot of time to put things together and setting up the system. The maintenance time and cost is practically nil compared to a traditional system. We are controlling 60 pumps with two motors.

cheers

Register to Reply
Register to Reply 14 comments

"Almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, vote them!
Copy to Clipboard

Users who posted comments:

Andy Germany (3); angelo (3); Anonymous Poster (1); ca1ic0cat (2); Hendrik (1); rakesh_semwal (1); redfred (3)

Previous in Forum: stepper motor   Next in Forum: Manufacture Process

Advertisement