European Source for gear-transmission?

[Retro]

Hello there,
i'm still having issues with my steppers and the wobble of the gear since i have no option to tighten the stuff. Also i want to reduce my driver to overload an shut down in the middle of cutting.

So theres Avid-CNC and their 3:1 gear (https://www.avidcnc.com/pro-rack-and-pi ... -1388.html). I remember there was an cheaper version of those but it seems, it isn't available anymore.
Now my question is: Is there a cheaper version AND is there a european seller where i can buy it? The shipping costs of those parts would be equal to the worth of it.

Any suggestions for me?
The Cut-Quality increased since i have the Hypertherm (but the issues are gotten somehow worse and i'm still in the learning process) but this "little" issue with the wobbly gears is the bigger problem.

Btw: Currently there are 3 Nema 34 steppers straight to the rack and pinion. The racks aren't straight. I can't remember the english term for not straight. It's not gay, thats something i know...

[adbuch]

Hello there,
i'm still having issues with my steppers and the wobble of the gear since i have no option to tighten the stuff.

Perhaps post some photos of your steppers and gears so we can see exactly what you are dealing with.
Thanks,
David

[Retro]

I attached the pics of the gears.
The Y-Axis is the biggest problem. The X-Axis works ok, it still has 2 mm wobble i think in it. Since it sits on Al-Extrusion, i think, i can manage the wobble. But Y-Axis won't work out that way. It sits on 80x80x3 Steel Beams and is drilled by hand with the threads cut into it.

20240908_095309.jpg

20240908_095417.jpg

20240908_095439.jpg

20240908_095450.jpg

[adbuch]

Hello there,
i'm still having issues with my steppers and the wobble of the gear since i have no option to tighten the stuff.

When you say "wobble", do you mean that the small gear on the motor is not centered on the motor shaft and has some run-out?
David

[Retro]

No, the transition from small gear to rack.

[adbuch]

But Y-Axis won't work out that way. It sits on 80x80x3 Steel Beams and is drilled by hand with the threads cut into it.

Perhaps you could shim your gear rack (shims between gear rack and steel beams) so that the teeth are flat with respect to the xy plane of motion. Of course this won't help you to achieve your desired gear reduction. Perhaps you can install a gear reduction box onto the end of the stepper motors with your small pinion gear attached to the output shaft of the gear box.

David

[Retro]

Shimming won't do anything i think. With a shim between rack and beam nothing changes in terms of "slop". I would need to get it down but that won't work out.
I thought of the gear reduction unit because it has a spring that keeps a consistent load on the rack. And i assume my machine would be more silent after that since the stepper will work on a higher rpm.

[adbuch]

https://www.amazon.com/Nema34-Planetary ... J3XW7?th=1

gear box.jpg

[adbuch]

Shimming won't do anything i think. With a shim between rack and beam nothing changes in terms of "slop". I would need to get it down but that won't work out.
I thought of the gear reduction unit because it has a spring that keeps a consistent load on the rack. And i assume my machine would be more silent after that since the stepper will work on a higher rpm.

These would be small shims placed at strategic locations to effectively level the rack. If you want it spring loaded, then you will either need to design and construct something or purchase one similar to the Avid. I own two of the Avid Pro series tables with Nema 34 motors so I am very familiar with those gear drives.

David

20200111_004634_resized_2.jpg

[Retro]

But a shim would just "relocate" the rack in direction of the arrow?

The spring loaded thing would be one part that my machine is missing to make it better.

[adbuch]

no shim.jpg

[Retro]

Ok, so i wasn't wrong with my thinking.
So: Is there a european version of the avid cnc parts? Or should i pay someone to machine me those parts? I can't make everything on my own.

[adbuch]

Ok, so i wasn't wrong with my thinking.
So: Is there a european version of the avid cnc parts? Or should i pay someone to machine me those parts? I can't make everything on my own.

I am not aware of the Avid equivalent sold on the European market. You may have to design something and have a local shop machine parts for you.
Assuming that you have that capability.

David

construct.jpg

[adbuch]

price.jpg

Where are you located?

[Retro]

I would pay the 199 bucks, but the shipping will be the same. 150 per set would be nicer tbh.
I'm located in bavaria, germany.

[adbuch]

The cost to ship a 19 lb. box size 12" x 12" x 6" to Europe is around $130. You could fit at least 2 or 3 of these Avid kits into a single box. So a cost of around $42 per kit is very reasonable.

David

[Retro]

It's still a lot of money afterall.
I found smth from a different manufacturer: https://www.finelineautomation.com/prod ... ion-drive/
But how would i replace the straight pinion with my angled one?

[adbuch]

It's still a lot of money afterall.
I found smth from a different manufacturer: https://www.finelineautomation.com/prod ... ion-drive/
But how would i replace the straight pinion with my angled one?

gear replace.jpg

[Retro]

With this one it looks easier, yes. But with the Avid one it seems like the parts are made for the transmission.

[Retro]

I found the old style of the avid ones: https://fab.cba.mit.edu/classes/865.21/ ... and-pinion
Wonder if they still have those in stock.

[acourtjester]

You have a slanted tooth rack and spur gear, this may be causing problems a with the torque at the start of movement. You will need to change both rack and spur for that change in drive assembly.

torque.JPG

[Retro]

On the X-Axis (picture) i already have 2 linear bearings. But i can't change the position of the rack since its a big cutout actually and i wouldn't get the bearing tight after that. I have no problem with the torque in general. Its really just the slop between rack and gear. I can rock it 5 mm in total. The parts are ok sizewise. At least ok for my purpose - but if i can get it better, why not?

[adbuch]

On the X-Axis (picture) i already have 2 linear bearings. But i can't change the position of the rack since its a big cutout actually and i wouldn't get the bearing tight after that. I have no problem with the torque in general. Its really just the slop between rack and gear. I can rock it 5 mm in total. The parts are ok sizewise. At least ok for my purpose - but if i can get it better, why not?

Then simply modify your motor mount plate to to add a spring loaded element. I expect that either Tom or myself could draw something up for you.
David

[Retro]

I attached the PDFs of the drawings of the parts. I hope you can see, how the NEMA is mounted on the Al-Plate.

3-1 Pos1-Motorhalterung-Pos2-Montageplatte.pdf

3-0 Z-Achse Baugruppe.pdf

[acourtjester]

You have slots for adjusting the motor position but if the rack mount is not straight, the motor will be tight on one end and loose on the other.
As David said you may look at adding a pivot point in the motor section with a spring tensioner to hold the motor to rack flexible along its travel.
Here is how I mounted the motor and drive gears, and I used a secondary shaft for the gearing reduction in the drive assembly. About 3 to 1 ratio.

rack and spur gears.JPG

DSCN4028.JPG