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The Meticulous Z-Axis

I ran into that problem when I was helping someone out with a build awhile ago. I didn’t realize it myself until I looked at the specs for Rigid’s palm router. Suffice to say, I was a little annoyed they were so high speed. I just had a thought though, I wonder if they also have adjustment pots on the variable speed board like the R2200 has. That could solve that problem fairly easily. :thinking:

Most certainly. The big takeaway is that this would solve is that it lowers the CG, which we desperately need. The other potentially useful benefit would be that we may be able to push the Z-axis motor faster, which would speed up Z travel times. I do think that the current release of the Meticulous Z axis does a good job with this, but it would be awesome to get it going even faster.

For the sake of sharing information: Made a little more progress on the fitting of my Z-azis. I really like the printed clamp but it looks like (according to my measurements) the bearing on the ring system won’t clear the latch on the clamp by about 1/8th of an inch. Real bummer.

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a belt sander or grinder would trim off 1/8 easily

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Yeah that is what I have been considering doing, it will probably need to be 3/16 removal though, 1/8 is pretty much at zero. At some point I may modify the design of the clamp, if I do I will share with the community.

too bad you can’t rotate that bolt part of the clamp to the front/top where the ring is bolted so the rollers would never touch it.

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Another update:

So I trimmed ~3/16 from the clamp and solved that issue. I opted not to sand or grind it off as this is printed PLA, (layers of plastic). I used the bandsaw and sealed the cut area with CA glue.

I was then having trouble with the new Z-axis motor, nothing responded as expected even with the correct values entered. So a little digging and I came across this post:

I was having similar symptoms and my motor was manufactured by the same company and included the same diagram.

I can comfirm the correct wiring for this motor (in addition to the one in the post above) is same color to same color with the exception of the orange (original maslow z-axis cable) to Blue (motor wires).

So at this point things are getting better but the z-axis is not accurately traveling the distance I ask it to. I tried pretty much every work around people have talked about on this forum. It was moving about twice the distance I comanded.

I ended up doubling the encoder steps (after trying everything else in vain) and was able to produce repeatable accurate results and a speed more along the lines of what I expected.
The documentation: (http://www.cqrobot.wiki/index.php/Metal_DC_Geared_Motor_w/Encoder_CQGB37Y001)

It calls for 2688 steps per revolution. I double it to 5,376. Then I was getting 18 mm when I asked for 20mm. So 18/20=0.9, 1-.9=.1, 1.1x5,376=5,913.6, I rounded to 5,914. I know some of y’all are really sharp on this stuff, any suggestions are greatly appreciated. 5,914 is working really well and produces accurate results. The pitch on the lead screw is 8mm per revolution. Both Pulleys are 16 tooth, 8mm bore.

Here is the equipment I used in case it helps someone else.





(I only needed the female connector to solder the motor leads to in order to plug in the original z-axis cable.

I ordered all this stuff back in 2018, wow, I stay pretty busy but I didn’t think is was than long ago. But, except for changing some of the calibration numbers, (I still need to run calibration, but may just need to double check the distance from chain to bit center) this z-axis project is done. This setup is faster and more accurate than the stock z-axis but, not lighting fast. This is what I was hoping for and I am pretty satisfied so far, been a long road but I think I am there.

The clamp I printed and the discussion can be found earlier in this thread, if I get around to modifying the clamp I will post it on this thread.

Cheers!

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Need to say thanks to @MeticulousMaynard, I am really satisfied with the Z-Axis. It operates just like I wanted; smooth, precise, accurate, and plenty fast. I am beyond happy I finally found the time to get this project done. I am looking forward to getting a lot more use out of the maslow now!

First project with the new Z-Axis:

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This is with using 200mm rails. The 3/4x5.5"x 7.5" board the router attaches to takes up a lot of vertical space so the z axis adjustment range is only about 1.5". I think the next one I try I will make is shorter, maybe 4.5x7.5 wide. Just used some scrap 2x4’ s cut at an angel to mount it to my sled.

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What is your plan for bit changes? (no snark intended)

with the quick screw in front, do you pop the router to bit swap, then drop it back in?

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loosen thumb screw, raise router up 2 inches, change bit and lower back down. I supposed one could take it out as well.

Without examining the mount/holder/clamp, is it possible for slight variations in alignment of the bit? This is just a question that comes to my mind.

Next time use your printer and print schematic 1:1. Then glue it to wood. It will help You keep good angles.

Edit schematics and draw axis lines in center of all holes. It will be easier to center punch them later.

I have noticed that the 6mm Bore 30T XL Pulley is out everywhere, i did find one from china, but it may take a month before I ever see it.

I could use some guidance on a stand-in part.

Thanks !

Those pulleys are possibly one of the most difficult items of everything on the BOM. If you really want the 30 tooth, it’s probably worth waiting on it. However, if you can source a pulley with a different tooth count, all you have to do is change a setting in Ground Control.

You asked this question in your PM but I think others could benefit from the answer as well:

This is really easy, just requires a little math. The setting you need to change is for Z axis pitch. We need to change this value anyways to switch over the Meticulous Z-axis.


I’ve detailed the math in the Community Garden instructions page:

So, a 32 tooth pulley paired with a 10 tooth has a gear ratio of 3.2. We can plug that into the above formula:

Z = - ( 7.125 * 3.2 )
Z = - 22.8

And for a 40 tooth pulley, we have a gear ratio of 4.

Z = - ( 7.125 * 4 )
Z = - 28.5

I do want to make a quick disclaimer about the 40 tooth pulley. I don’t know of any machines that have used such an extreme gear ratio. Currently a 30 tooth is the recommended one and it seems to work pretty well. A 32 isn’t too much more, so it should be fine. Now, it’s entirely possible that the stock motor won’t care and work just fine with a 40 tooth, but I can’t guarantee that. If you want to test it, by all means, report back your findings either way. It would be greatly beneficial for all of us to know if it’s a possibility. I’ve been planning on testing it myself, but as I’m sure most people around here know, I haven’t had a lot of time for testing lately. :frowning:

Once you calculate the pitch, you need to confirm that the calculated pitch is correct for the actual machine. I detail the process of dialing that in the instructions:

Let me know if you have any questions, I’m here to help! :smiley:

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Couldn’t you just use a 60T with a 20T to maintain the same gear ratio? The belt would need to be a bit bigger. This is what I have on order for the setup I’m planning.

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Thank you for this !

Yes, using a 60 and 20 would also work. I had tried to keep the driven gear small just for simplicity’s sake.

It’s important to realize that there is a lot of things with the maslow (and the
meticulous Z axis) that are the way they are because they were the first thing
tried and it worked (so varients were not tested)

the gear ratio is one of these things. Given the power of the stock motor, I
expect that a MUCH higher gear ratio could be used with the Meticulous Z axis
because the friction it has is trivial compared to the stock setup.

David Lang

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I’ve noticed bits and pieces on back-order in Amazon, but here is a link to a pulley and gear set on amazon.
I just received it the other day:

Hope this helps!

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