So what am I supposed to do if I have an older machine (shapeoko 3 xxl with belt drive Z axis) and need parts, shell out 450$ that I doubt many people have to keep using my machine? Oh I know how about I just blow another 2 grand that nobody has on a whole new machine that will lose support in parts in another few years ago I have to go through this all over again.
Updated, Belt drive not bent.
It’s been more than a few years since we sold a belt-drive Z-axis machine (more like 5 or 6).
We offered the Z-Plus upgrade until quite recently, and the normal wear parts are still in our shop:
I suspect if you ask, that there will be someone here who has upgraded a belt-drive or Z-Plus machine to a Z-Plus or HDZ and would be able to sell the left-over parts at a reasonable price.
That said, what parts are damaged that you need to replace the entire Z-axis? Upload a photo? The usual damage is to the aluminum V rails and can be addressed by filling in with a metal-impregnated epoxy such as J.B. Weld and then filing smooth.
What’s wrong with your machine? What parts do you need that aren’t available from Carbide 3D? Someone on this forum might have what you need. I recently sold a complete belt Z axis to someone here.
One of the bottom v wheels fell off the other night and on inspection it looked like the home the nut sits in was damaged like the nut hadn’t been sitting in the hole all the way. When I got it back in the nut doesn’t keep the v wheel tight to the rail.
If you have the original eccentric nuts (machine sold pre 2020), the newer style is beefier and may solve your problem.
If the problem is with the threads in the PEM nut it should be possible to use a “Helicoil” or other thread repair kit.
Do these fit the belt driven z axis? I was reading other posts saying the newer ones were only for the upgraded gantry.
It’s not the threads in the nut, it’s the hole in the plate the nut sits in.
I defer to @WillAdams on this question
Usually this is secured by the nut on the other side.
Post a photo?
I believe the HD eccentric nuts can be used in some positions, but not in others on machines earlier than summer 2016, for an XXL which would be summer 2016 or later which has PEM nuts (unless upgraded from an earlier Standard size machine), they should work everywhere, except maybe for the vertical movement of the Z-axis, it’s really tight.
Mine would be for the X travel wheels
I have an SO3 XXL that originally had the belt Z. I upgraded to the HDZ and love it. Of course that is around $450 for the HDZ. But to your point about the upgraded eccentrics they fit on the older SO3. The eccentric is the same size just the nut that you adjust was increased in size. Depending on your skill you could remove the Z and drill a new hole and move the v-wheel over about a half an inch. Or as @WillAdams suggested drill the existing hole out and put a sleeve in that would allow you to use your original bolt, washer and eccentric.
Since I have an SO3 XXL that suits my needs I intend to keep as long as it runs. So C3D still supports the SO3 with most parts but they did discontinue the belt Z and are no longer making the Z-Plus but get a list of parts you need and people here on the forum would likely help you out with any parts that C3D no longer make. The SO3 is an excellent machine but unfortunately time marches on and OEM machine makers have to sooner or later stop supporting older machines. That is just an economic reality. As demand diminishes so does support. But C3D stil supports the SO3 in general but eventually they will stop making parts. However most of the parts for an SO3 also are in an SO4 with some exceptions.
So ask the forum for help with specific parts and you might be pleasantly surprised what you get.
Are you able to take a picture?
It sounds like it’s the z-axis carriage plate has issues with the hole that the eccentric nut goes into?
I converted my SO3 XL to linear rails along the X-axis so I may have the parts still.
I’ll take a picture as soon as I can, I need to take the wheel back off. I need to do a whole realignment of the whole machine.
So I think the wheel that I put back on is holding but I am running into another issue where when I machine into a pocket the z axis is getting stuck and not retracting above the stock before moving on to another to path. It’s acting like it is hitting the upper limit but it’s still in the pocket. I can’t even jog it up but it’ll jog down further. I end up having to loosen the bit so it’ll clear the stock and reinitialize the machine. I’ve tested the limit switches and everything works fine. It’s only even I machine into a deep pocket. But when I run other tool paths in that same pocket with other bits it retract just fine and moves out of the way when the job is finished.
Very similar to what is happening here
The belt Z machines biggest issue was that it lost steps when under stress. The belt mechanism has an idler that is the tensioner. Taking the Z mechanism is not too hard and would recommend that and look at the condition of your belt and the adjustment of your belt tensioner.
After inspecting reassemble and the Z should move up and down quite easily. If you find any rough spots figure that out.
To remove your Z just remove your bottom v-wheels and lift the Z off. You would need to disconnect the electrical connections. Upon reassembling the v-wheels at the bottom have the eccentrics. To adjust them there should be a bolt and a washer and then the v-wheel. The washer spaces the v-wheel off the Z frame and is very necessary. So loosen the bolt and use a wrench to tighten the eccentric until your v-wheel is able to move the z by pushing on the wheel. Do not over tighten. Then hold the eccentric with your wrench and tighten up your bolt. If you do not hold the eccentric in position you will over tighten the v-wheel because the eccentric will move from torque of tightening the bolt.
Here is a picture from an old post.
I would suggest posting photos of the current state of your machine.
If you haven’t done a rebuild using a Maintenance Kit:
do that, and post in-process photos and the state after finishing.
Is it possible you skipped steps, then it didn’t fully retract? When I had my belt driven Z SO3, I removed one of the two return springs as when extended father down, they over powered the Z stepper causing skipped steps.
You could raise the router in the mount a bit…
