Tags: 4th axis
- CurtParticipantJanuary 24, 2016 at 3:01 pmPost count: 173
I had a friend stop over today and really liked the mpcnc and the laser. He has a small side business that he would like his company name etched on a wood dowel. Anyone have any ideas on how to add a new stepper to rotate the dowel after each line etched?
Curtvicious1KeymasterJanuary 24, 2016 at 3:18 pmPost count: 2669
There are a few stepper driven axis on thingiverse, they look like a lathe. You can just substitute that for one of your current axis and have rotation.
I think it should be just fine. Worse case fusion360 can handle an actual rotating axis but I don’t think you need it with a laser since there is no depth change (if that even matters).karltinslyParticipantJanuary 24, 2016 at 5:00 pmPost count: 279
I am also interested in this (Curt and I seem to share a lot of interests!). This is the only one I’ve found on thingiverse so far: http://www.thingiverse.com/thing:144156. It’s laser cut, but we should be able to do that. The main problem is I’m not sure what to search for. I found this one with a search for “rotational axis”.CurtParticipantJanuary 24, 2016 at 7:41 pmPost count: 173
Thanks for finding this item. like you I do not know what to look for. I think this is close to what I might need but I need something for smaller dowels. (3/8-1/2″ dowels)vicious1KeymasterJanuary 24, 2016 at 7:45 pmPost count: 2669vicious1KeymasterJanuary 24, 2016 at 7:48 pmPost count: 2669
I don’t think that is complete, sorry. Nothing else is coming up. I guess I have a new project.
I thought that one had a lathe chuck that fit it and a live end, he must have changed it.CurtParticipantJanuary 24, 2016 at 7:48 pmPost count: 173
Hmmmmm. Thanks. This gives me a place to start. CurtTonyParticipantJanuary 25, 2016 at 9:21 amPost count: 15
Have a look at this forum thread for an idea to use our Y axis motion as a simple 4th axis, no additional stepper motor required. Pretty ingenious idea!
There are some cool modifications to Bob’s idea further down the thread.
I can’t wait until someone adapts this idea to work on our MPCNC. I’ve been mulling around a few ideas but don’t have a prototype yet.vicious1KeymasterJanuary 25, 2016 at 9:42 amPost count: 2669
So how about using this, http://www.thingiverse.com/thing:624625.
First off is that too much too complicated? If so we can just make some sort of plate you can screw mount things too instead of clamping.
Then rig up the gregs wade gears to run it, or I guess to make it really simple custom gears so the steps per mm would not need to be changed in the firmware. Then CAD up a stand to hold the stepper, gears, chuck/plate, done! Then just plug and play. as for the other end it can either be another chuck/plate or 2 bearings v holder to hold the stock since force will only be applied mostly in 1 direction.
hmm dang it I want to prototype but I have to pack boxes.TonyParticipantJanuary 25, 2016 at 10:05 amPost count: 15
I’ve been looking for a reason to make one of those chucks. I think I’ll try to make it work with Bob’s 4th axis idea so I don’t have to incorporate another stepper.
Also, THANKS for all the work you’ve put into the MPCNC project!vicious1KeymasterJanuary 25, 2016 at 10:14 amPost count: 2669
Glad you enjoy it!
This might be a really cool add on, can’t wait. I’m sure there will be a few different kinds now. That makes it fun.CurtParticipantJanuary 25, 2016 at 10:20 amPost count: 173
What is the gear ratio for the X & Y axis? I am not sure if I want to start with the files that you linked or the one that Karl linked but I will gear the stepper appropriately to rotate the same distance as my x axis would move for one line.
I am looking forward to seeing what Tony, Karl and I can come up with!!vicious1KeymasterJanuary 25, 2016 at 10:27 amPost count: 2669
The stepper is set at 200steps/mm, the pulley is 16 teeth.Leo69ParticipantJanuary 25, 2016 at 1:40 pmPost count: 344Farrell PiggParticipantJanuary 25, 2016 at 2:03 pmPost count: 7CurtParticipantJanuary 25, 2016 at 2:44 pmPost count: 173JasonParticipantJuly 22, 2016 at 5:47 amPost count: 333
Going to revive an old thread here but has anyone made any progress on setting one up for the MPCNC?CurtParticipantJuly 22, 2016 at 6:49 amPost count: 173
With help of my buddy who made the request we were able to use a single stepper to turn the dowel. The dowel we are using nearly perfect match up to the belt/gear ratio Ryan set up. I will post some photos of the holder and the dowel after a laser burn. CurtJasonParticipantJuly 22, 2016 at 7:32 amPost count: 333
Interesting… I guess yea every time you use a different sized material your steps would change.
I would like to add the ability to laser engrave or mill round stock as well.Leo69ParticipantOctober 12, 2016 at 5:59 pmPost count: 344
@Curt : Any follow-up on the laser engraving of dowels? Pics? I’ve found the hardware set-up to be simple but am working through debugging and modifying some open source gcode wrapping software to work with MPCNC and this will take a little time. Just wanted to see what you’ve worked on so we don’t duplicate efforts. I should have more free time to work on this so let me know what toolchain you’re using when you get a chance.CurtParticipantOctober 12, 2016 at 6:59 pmPost count: 173
The setup we have is for a specific diameter of dowel but with a little time it could be turned into a roller setup. I simply unplugged my X axis and plugged in the stepper rotating the dowel normal Gcode will move left and right burning the image and when the CNC thinks it is going up (plus X) it rotated the dowel and burns the next line. We determined that the dowel my buddy needed was almost the exact diameter as the gear used to drive the belts so we did not make any scaling changes. THe image is slightly compressed but on the dowel it is not noticeable.
I will get it out in the next few days and get you some photos.CurtParticipantOctober 14, 2016 at 9:17 amPost count: 173Leo69ParticipantOctober 14, 2016 at 7:28 pmPost count: 344
Looks similar to some designs I’ve seen on Thingiverse. Cool. How bad is the stretching/compressing of the image due to the straight tool path?CurtParticipantOctober 15, 2016 at 1:18 pmPost count: 173
I will print a a test box or something later on a flat surface and on the rod to measure but it was not off by much. The dowel he needed is almost the same size as the drive gear so when he did the math he laughed and said close enough.Leo69ParticipantOctober 15, 2016 at 1:30 pmPost count: 344
No worries, don’t want you wasting material to draw a box. I understand the concept, the wrapping of the toolpath is done by carefully selected gearing so no software needed. A change in stock diameter would just need a gear swap then right?
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