Meticulous Z-axis - partially cut, manually aligned, sniping/biting when cutting

Troubleshooting
1

TLDR: Partial cut of Meticulous Z-axis, manually aligned/centered/finished, test run scary; bit sniping/biting causing torque flex in router clamps/backing plate leading to very rough cuts. Any ideas to fix?

I anticipated that the standard z-axis kit would have increasingly worse tolerances or fail completely on the Ridgid R22002 simply because it is not designed for continuous use. So I got the parts to build the Meticulous Z-Axis which is much more robust. Thanks to all those involved on this project and for providing it to the community.

I only managed to get through part of the cutting process, when lo and behold, the z-axis failed! The orange button thing got stripped during tool changes as the z-axis bottomed out, due to difficultly in aligning it between tool changes.

I tried to make the best out of what was already cut. This involved many hours spent releasing partial depth cuts with jigsaw, aligning router backing plate to sled frame, aligning router ZX/ZY to backing plate, and centering Ring frame (which is not circular?) to sled base. I used a magnetic digital angle gauge and true square metal block spacer to align router ZX/ZY to sled base. Got perfect on ZY and 0.05 degrees on ZX. Used a router bit with string to draw circles to align the metal Ring.

Once it was all glued up, 24 hour dry time, I performed centering test by dropping Z into stock and manually rotating the sled 45 degrees left and right. This showed good results that deviated less than 1/32" oval in X & Y.

I then ran through the whole Maslow calibration process using measurements I previously made that worked great before. Ran the calibration alignment test which was off by less than .5mm. I then ran test cuts for the pieces that did not complete like the dust chute.

At this point it got down right scary. During the cut the router bit would catch / bite / snipe at certain angles, which caused the lower router clamp to torque flex, which also made the carriage plate flex at the bottom. This resulted in many scary noises, like the whole thing would disintegrate, and very uneven cuts in XY. I was standing a safe distance away, out of XY cutting line (bit breaking), with fire extinguisher on the ready. Yeah, it was that serious. XY cuts were terribly fluctuating nearly 1/8" where as Z axis was perfect.

Has anyone experienced something like this?
Can I recover from this by adjusting something or should I cut all meticulous z-axis parts from scratch?
Thanks for all input!

2

if you can get access to a 3d printer, you can print a replacement

there should not be significant play in the router, the fact that you are
getting such play indicates something is very wrong. figure out what part is
flexing and how that part is mounted to the base.

David Lang
k

3

The router was not moving in the clamps. The lower clamp was torque rotating because the backing plate that it attaches to was flexing.

I have hand cut v2 clamps (which seem beefier) and a square backing plane out of highest quality birch ply. Going to try changing the rail mount position too, moving it lower and less space between end rail mounts, to see if it will reduce flex.

Thanks for the link to STL files. Unfortunately I do not have access to 3D printer but might get one soon.
I did however find the part for $0.75 + $5.95 shipping on 1800TOOLREPAIR. So I bought 10 for a grand sum of $13.95! https://1800toolrepair.com/513396001/

4

Damn, I’m sorry to hear of your troubles. Something seems horribly off. What material did you make the spindle clamps from? What grade of plywood did you use for the carriage? Was the plate flexing along the Z axis of the machine, or the Y axis?

Well, at least we got that going for us :upside_down_face:

My only worry here is that you might loose a lot of Z travel. Bit of a moot point if the whole thing brings your machine down, though.

PM me about 3D printed parts. I just got a new Ender 3 and it’s kicking the butt of my old printer. I’ll try to get you back up and cutting.

5

Everything was made from 5 ply AB grade marine Douglas fir originally. The new clamps and backing plate, I have yet to test, are from 7 ply AB grade birch.

The plate, and lower clamp, was flexing around Z.

Yep, but its easily adjusted and will rule out flex in the rails.

Thanks for the generous offer. I still have my old sled and should be getting replacement router orange button part soon. I will first try the changes on the meticulous z-axis sled. If that does not work then I will recut and build a new one using the old sled. If that still has issues then I will contact you. Thx again.

6

This is an issue that @dlang and I had speculated on in the development thread, and we concluded that plywood, particularly anything that has voids in it, would not hold up the structural demands that the spindle clamps would be under. To me, this is likely evidence that those conclusions hold true. It’s possible that a high quality ply, like Baltic Birch, which has no voids, may be better. I have also heard people have had some luck with solid wood clamps. From what I’ve seen, it seems like most people head in the direction of 3D printed clamps. Even PLA seems to work well for that use.

Like, flexing around the lead screw? I’m surprised marine grade ply is holding up so poorly. It’s hard to say exactly what is going on, but when I have a chance to do some testing I’d like to see if I can recreate what is happening here.

This is true, and has been another point of speculation in the development thread. If you do find the rails flexing, that would be very useful data as I continue to improve this system.

Good luck on cutting the new parts. Hopefully it goes better the second round :crossed_fingers:

7

I am very happy to report that I finally had time to test the changes and the Meticulous Z-axis is working meticulously!

I ended up re-cutting the spindle clamps and backing plane in 7 ply AB birch. The spindle clamps split when tightening so I manually cut them again using well seasoned Oak on band saw. I also changed the backing plane to be a rectangle - removing the notch cuts at the bottom on both sides and moved the bottom rail mounting posts to about 1" above the sled. I doubt I will cut any stock thicker than 3/4" so I thought that having the posts so close to the cutting range should reduce flex. This also adds a modicum of safety as the router collet cannot touch the wood stock, which could possibly start a fire, as the rails will bottom out first. I also moved the top rail clamps down about 1" to reduce flex on the rails at the expense of z-axis travel. I have 1" travel down from z-axis zero and about 1.75" up.

The difference is astonishing:

  • No more terrifying noises - actually sounds like its cutting smoother than it ever did.
  • No visible twisting/flexing action - Still some vibration in the rails but it does not seem to affect the quality of cut.
  • Very good consistency during multi depth passes - Got a small, <1/32", lip on the 4th pass that had tabs but first three were absolutely perfect.
  • Depth on pocket cuts is almost perfect - imperfection probably caused by cheap CD test stock.
  • Overall the cuts are are the best quality that I have managed on the Maslow.

Met_Z-axis_fixed
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^ Using 2 flute up cut bit provided with Maslow kit. Only light sanding to remove squirrel tails, for better visibility, none of the plane surfaces have been sanded!

Thanks for all the support! Your input was very valuable in helping me fix the problems and getting great quality of cut.

Just to clarify - The original flexing occurred on the z-axis of the router bit and not the lead screw. The backing plane was twisting, the metal rails were bending, and I think the spindle clamps were not holding well.

Will be back at it again tomorrow running full calibration and hopefully cutting a full project. Tried my first Perspex/Plexiglass test piece and was very happy with the result. Seeing so many possibilities opening up!

2 Likes
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Glad you’re up and running now. I know, finding time can be very tricky!

I guess its better than plywood, but even solid wood clamps still make me nervous. :sweat_smile:

That should be the case already if it’s assembled correctly. The bottom rail block should act as a hard stop. However, when I look at the model now I see why people have had issues here. Because of the vertical spacing between the clamps, the user can mount the router lower in the assembly than I planned. As I have it drawn, the clamps are centered on the round section of the router. In this position, it shouldn’t bottom out the spindle first.

image
image741×668 108 KB

For what it’s worth, I still haven’t seen any reports of the rails flexing under normal operating conditions. There was something very wrong with the previous setup that was causing significantly off-nominal results. Obviously, erring on the side of caution is the correct approach, but I do have to wonder how much flex you would see on those rails now that the whole carriage has been improved.

I still see the carriage as the weak link in the design, and I will be working on improving that in the future. If you have any ideas to improve with the entirely Maslow-able version down the road, I’d love to hear them.

Happy chip-making!

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having had an solid oak set of clamps crack along the grain and send a larger
router bouncing around the shop, I ould trust good plywood over solid wood, but
it’s far better to get something that can’t let loose of the router if it’s
grain/layers/whatever fail

David Lang

10

Thinking back on my first iteration; I think the rail flex was my fault. I purchased the longer rails and mounted the bottom rail mounts at the sled base and not 1/3 up as in spec. This is also why the router collet could hit the work piece without bottoming out. This probably created the rail flex.

Cut a few more pieces and did not see any rail flex. Really happy with how its performing now. Pocket cuts are way more even and overall everything is better.

The only thing I did that may help is removing the bottom notch cuts on the router backing plate. But this may interfere with the non-ring sled mounting option, sorry can’t remember what its called - holley?, which I am not using. In my first iteration I noticed that the router bottom clamp was twisting the backing plate when the router bit sniped/caught. Here’s my crude work in progress:

Met_Z-axis_back_plane_change
Met_Z-axis_back_plane_change1218×1828 242 KB

Thanks for the heads up. Will keep an eye on the clamps for signs of cracking. So far everything seems good. Will try to stay out of harms way but nothing has freaked me out like it did before.

1 Like
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I’m glad to hear it’s working better now. :smiley:

Those are clearance notches for one of the old linkage systems that I use on my machine. Removing them should have no affect to the ring system, so you shouldn’t have a problem.