The Meticulous Z-Axis

Yeah, I’ve been meaning to get to that but it’s been slow going. Good news is, most of my sled is together and I should have some good progress pictures soon.

I’ve seen @bar post the OnShape document, the model for that just needs to be overlayed with my model and the holes need to get transferred. It’s not terribly hard but not something I’ve gotten done yet.

The link I provided for the Amazon item ships from China? I thought I had picked a US seller for those that didn’t want to wait for China shipping times.

Also, if you’re handy with Fusion360, I can share the file with you and we can go through the changes that I listed above. PM me if you’re interested and we can work out the details.

Not sure if I am seeing the pictures correctly. It looks like the inside corners on the vertical supports are not dog-boned. Is that correct?

Yeah, I had dog-boned them at some point but it doesn’t look like that feature made it to the program I cut. I will be making sure they are in the revised DXF on the community garden.

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I have already completed the transfer of the holes in fusion 360, and the file I got from your link earlier in this thread had the dog bone fillets and v2 or v2.1 of your dust collector. (I remember there was some discussion about what version you had posted). I decided to do the sled as ring system only so it has fewer holes.

My router body is so bad that I’m waiting for Teflon adhesive sheet and UHMW tape before I can start cutting the sled. Last night / this morning I was putting a BL Touch on my older 3d printer but I’ll try to finish up in fusion 360 and share the sled.

I have a linkage kit and a ring system kit but I’m pretty sure I’m going with the ring system.

As far as Amazon goes, you can never be sure if it is a China shipper or not. eBay is very good about it though. Best way to tell is by the cost of expedited shipping.

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Here is the link to the A360 version of the sled that is compatible with the ring system.

https://a360.co/2MT5auS

I guess I just added the three holes used for indexing the ring system brackets. So depending on which version you are building, you can just not path the holes you aren’t using when you do the CAM.

There are two counterbored holes on the sled centerline, their purpose is beyond me. I am not pathing them on mine but maybe I’m missing their purpose?

I’ll try to whip up the brackets when I get the chance, I definitely want to print as many components as I can until I get this Z-axis workable.

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Thanks so much for adding in the ring system holes!

The counter bored holes you see along centerline are for one of the linkage systems. You won’t have to worry about them since you’re using the ring.

Don’t worry about the spindle clamps, I was able to do most of the modeling for them last night. I still need to add the holes for heat-set inserts to connect them to the carriage plate. I’ll shave to upload pictures later when I’m not on mobile.

These are loosely based on the previous version, but don’t have the nubbin sticking out where it can get in the way of the ring system. As I previously had mentioned, there are a few holes missing but it gets the idea across. I will be trying to make one of these for my own build soon. Updates as I get them.

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That looks great. :slight_smile:

Hey I was thinking, I feel like I could 3d print the carriage plate & the spindle clamp halves that screw to it all as one piece. That would also let us do some filleting where the spindle clamps meet the carriage to help increase the stiffness. After this any flex would probably be from the smooth rods themselves.

I like that idea a lot! That simplifies the carriage by reducing the number of parts, plus then we don’t have to bolt the clamps onto the plate.

I’m not sure if the carriage will need stiffening, however. Over 250mm, the 8mm linear reasons have no noticable deflection, and the carriage plate from 3/4" ply is very stiff as well. Now, the plywood may warp over time, so switching to a plastic plate would be a good idea. I don’t know how much a print would deflect, but we could always experiment with different infills. We could also just add some gussets, like you were suggesting, just to be safe.

The 8mm smooth rods on the y-axis of my Prusa i3 deflect significantly when a load is applied to the bed, I had been using the nozzle to probe the bed until the x-carriage wouldn’t move down any more (at that point a microswitch was triggered) and the deflection from the rods was screwing that probe cycle up. That’s why I finally put the BL Touch on there. It surprised me but I watched it with my own eyes. I still use the nozzle-crashing-into-bed method for the Z-endstop though, it works great for that.

I hope that we don’t have any issues with the meticulous z-axis doing that, The rods on the Prusa i3 are making a 330mm span on that axis, so hopefully the 250mm span we are doing here ends up being much stiffer. The loads are certainly going to be higher (just from the weight of the router alone). let’s say if you were rough cutting with a pretty high feed rate and going from one radius direction to the other, we may see the router transferring all that to the linear rods.

Anyway both the printers are running at 100% again and I have what I need to jerry-rig the R2200 into working for me so hopefully I can get going on this project this weekend. Do you have a new link for the new brackets or is it in the same project file you shared previously?

Thanks,

Quinn

Those brackets are in the Fusion file. I’m not sure I will have time this weekend though to make the 1 part version of the carriage plate.

I will be testing using 1/2" cutters with the new sled, so I’ll certainly be putting it to the test. We’ll see how well the rods hold up to some serious loading. Worst case scenario, I’ll have to upgrade to larger diameter rods.

Sled Update! :smiley:

Cut my spindle clamps this afternoon! Totally cheating on this one, I have to admit. In my new job, I’m a prototype machinist for a robotics company, so I have access to some really nice machines now. We had some 3/4" 6061 aluminum scrap that we were going to throw out, and rather than let it go to waste, I would put it to good use!

So I threw it on the waterjet and 35 minutes later I had these:

I still have to have to put them in the mill and add all the secondary features. I made a spare just in case I mess up the first one :wink:

My sled is mostly together at this point. I have a couple of things I still need to tweak but it’s coming along well:

We’re slammed at work right now, so I’m not sure how long it’s going to take me to finish this. Hopefully I can stay late another couple of days and get the clamps machined.

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My jealousy at this point is intense… very nice!

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I drew this up. Will take about 10 hrs to 3d print if you use a 0.8mm BIG nozzle. That’ my standard nozzle because most of the stuff I 3d print is prototype stuff that doesn’t need fine detail.
I’m thinking of putting in a heat set nut and thumb set screw to hold router in place.
I think the main benefit of 3d printing this is it allows one to get the router pretty close to the z axis rod so there is less torque alignment issues.

In looking at the original design, I’m wondering why the router is so high? Is that to make router bit changes easier? seems like it could be lowered a good 2 inches easily?

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That’s exactly it. It is a lot harder to take the router off of the sled every time for a tool change so I tried to make it easy to just change the bit out without having to take the router off.

I’m curious to see how your interpretation of the Z-carriage will turn out. It’s pretty cool to see all the variations in the design, it should help us dial in a good design to implement for the new and improved community Z-Axis! :smiley:

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Got the Z-Carriage and clamps combined and filleted. I just need to put the bushing block and Z-bracket holes in, which could go fast or could be a pain depending on how easily I can find those dimensions.

I’m not entirely convinced of the benefit of a redesign of the carriage, beyond merging the bodies like this. The print time of this is only 4 hours longer (with a 0.4mm nozzle, at that), and will have an incredibly higher stiffness because of the thickness.

One thing that I have noticed is that people go to great lengths to reduce print time and most of the time those attempts generate an increase in perimeters, where as blocky designs like this are mostly infill so print blazing fast. If time was the issue I think you could print this with no top/bottom layers and 10% infill.

Bryan, we have room to thru-bolt the clamp now that it is rotated 180 degrees, or we can add a nut trap. What size bolt did you have in mind? is the hole already the correct size for tapping? If the threads ever stripped you could just blast the hole through with a drill and put a nut on the back.

Thanks,

Quinn

I do like the idea of ditching the bushing blocks and having the carriage ride on the rods directly, maybe we could incorporate printed bushings like these: https://www.thingiverse.com/thing:2202854

Having the plywood version and the 3d printed version closely related geometrically should make it easier on the community though, and since most of us have to buy the linear motion leadscrew kit we will have bushing blocks anyways.


Every time I make a model I have to tweak it. This is my 3rd version. (8hrs , 75% infill)

My main worry is the weight of the router and how easily it will slide up and down. I read other topics where people tried a z asis and said it just was not stiff enough.

I think I might add 2 brass threaded lead nuts. Not sure one will be strong enough.

this version will fit inside a 4x6 aluminum channel for good support. has left and right carriage rails balance around center of router and z axis screw as physically close as I could get it.

Will be using two set thumb screws to hold router in place, which allows for easy bit changes. I want the supports to be as low and close as possible

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I think once I get my Chinese 400mm kit, I will cut it in half to make two 200mm rails. and remove the bushings to insert into my 3d printed carriage. I thought about using oil on the rails, but wood dust would probably build up in no time even with a good vacuum.

I planned for M8 x 1.25 for the spindle clamp. The largest heat-set insert I could find was an M8 so I went with that. The imperial option would be 1/4"-20, which would probably be strong enough, but you would need to offset the walls to the right diameter.

You can tap threads in 3D prints, but I feel like this is an application where you want the stronger threads of the insert.