Hello Guest it is May 25, 2019, 03:38:03 PM

Author Topic: Some starting advice for two steppers on one axis  (Read 8049 times)

0 Members and 1 Guest are viewing this topic.

Offline Davek0974

*
  •  2,509 2,509
    • View Profile
    • DD Metal Products Ltd
Re: Some starting advice for two steppers on one axis
« Reply #40 on: March 05, 2016, 03:17:41 AM »
Ok, cool, then its 99% a mechanical i.e. build problem. Forget about axis labelling it's irrelevant at this stage as you will need slaving on two axes but this is really simple - my breakout board can run two drives from each output as standard, not many can so that would work there.

Picture a bog standard x/x/z plasma table, then remove the frame between the two sides and chuck the torch out. make the side frames self supporting, I don't know if there is room to join them, maybe you need a crane or forklift to load the pipe?

So now we have two carriages running along two side frames on linear rail probably. On those carriages build another linear motion unit - a trapezoidal screw lifter would be good as it holds its position and does not self-drive from the weight on it, probably decent belt reduction from the stepper motor as speed is unimportant.

Now we have two points (the nuts on the trapezoidal screws) that can move in horizontal as well as vertical planes, separated by a distance that could theoretically be many metres, both these points will move in sync as they are both slaved.

Now we just need to bridge those points with a support, maybe a box section with triangulated support etc to keep it rigid and light, then fit some possibly nylon rack along it, build a carriage to hold the scanner, the traverse motor and coffee machine ;) then some type of cable manager under the rail and it will run up and down all day happy in the knowledge that both ends are perfectly in sync.

Is this a field or lab machine, as if field, dust and crud will need to be factored in.
Bridgeport Mill, Mach3 V062, CSMIO-IP/A controller, AC Servo Drives

Offline stirling

*
  • *
  •  2,188 2,188
  • UK
    • View Profile
    • www.razordance.co.uk
Re: Some starting advice for two steppers on one axis
« Reply #41 on: March 05, 2016, 04:57:51 AM »
My apologies for winding you up. That was definitely not my intention. Believe it or not - I was trying to clarify something.

I've attached a (crude) schematic of one of my routers. To give an idea of scale/size, the gantry is approximately 4 feet long.

Now this MAY be an unsuitable design for your purposes for details yet to be disclosed - but what I was trying to clarify/get across is that this does not have two TABLES - it simply has a master and a slave axis. As you can see the gantry is fully supported and hence there is no sag.

Anyway - as sometimes happens when conversing with text - what should have been a small point to try to clarify, has taken on a life of it's own beyond its usefulness - so I'll back off and leave you to it.

Again - My apologies for winding you up.
« Last Edit: March 05, 2016, 05:49:27 AM by stirling »

Offline Tweakie.CNC

*
  • *
  •  7,765 7,765
  • Super Kitty
    • View Profile
    • Tweakie.CNC
Re: Some starting advice for two steppers on one axis
« Reply #42 on: March 05, 2016, 08:01:50 AM »
My apologies to Sterling for following him around the forum but his diagram reminds me of Steel Nick’s excellent foam cutter design.

You just need to replace the hot-wire with a horizontal axis ??

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.

Offline Davek0974

*
  •  2,509 2,509
    • View Profile
    • DD Metal Products Ltd
Re: Some starting advice for two steppers on one axis
« Reply #43 on: March 05, 2016, 12:08:15 PM »
My apologies to Sterling for following him around the forum but his diagram reminds me of Steel Nick’s excellent foam cutter design.

You just need to replace the hot-wire with a horizontal axis ??

Tweakie.


Thats the one - exactly what i was trying to describe, just beef it up a bit and replace wire with beam/scanner :)
Bridgeport Mill, Mach3 V062, CSMIO-IP/A controller, AC Servo Drives
Re: Some starting advice for two steppers on one axis
« Reply #44 on: March 08, 2016, 07:36:14 PM »
My apologies for winding you up. That was definitely not my intention. Believe it or not - I was trying to clarify something.

I've attached a (crude) schematic of one of my routers. To give an idea of scale/size, the gantry is approximately 4 feet long.

Now this MAY be an unsuitable design for your purposes for details yet to be disclosed - but what I was trying to clarify/get across is that this does not have two TABLES - it simply has a master and a slave axis. As you can see the gantry is fully supported and hence there is no sag.

Anyway - as sometimes happens when conversing with text - what should have been a small point to try to clarify, has taken on a life of it's own beyond its usefulness - so I'll back off and leave you to it.

Again - My apologies for winding you up.

All good...  I have received the answer to my OP question, then some questions came along so I was answering them.  Glad to hear folks are interested in this project as I'm sure I will have more questions along the way.  As I said before, I have a good bit of experience with this but more than 4 axis was new to me.  I hope to post a general schematic for review to make sure I'm on the right path.  Also, I'll post some pics of our MSU magnet mapper when it is installed, maybe a vid or two of it in operation.  !!   
TheDude,