imperfect circles

[FineLineAuto]

Should we start a pool to see how long it's going to take Nate to refund Keith's money and another one to see how long it'll take to get these bad drives recalled and replaced? Oh. And those rack spacers?

Keith contacted me yesterday to initiate the return of the drives and the refund for that portion has been processed. For anyone else that has purchased a machine, if you do not want to wait for drive swap and wish to use CRP drives we will extend the same offer to you. The drives are valued at $110 a piece. If you choose to go this route we will send you a label and refund $330 for all 3 drives.

Regarding the rack and pinion fixes, this is not going to be a 1 week turnaround. I have a few prototype parts out for manufacture at the moment. I should get them next week and will need to do testing with them to determine which configurations work the best. Then I'll order an production run and should have them by the following week.

Regarding the gear spacers, it is on my list but not as high as the other rack and pinion fixes. I should have a better timetable on this by Monday.

[kebuttke]

Keith contacted me yesterday to initiate the return of the drives and the refund for that portion has been processed. For anyone else that has purchased a machine, if you do not want to wait for drive swap and wish to use CRP drives we will extend the same offer to you. The drives are valued at $110 a piece. If you choose to go this route we will send you a label and refund $330 for all 3 drives.

Regarding the rack and pinion fixes, this is not going to be a 1 week turnaround. I have a few prototype parts out for manufacture at the moment. I should get them next week and will need to do testing with them to determine which configurations work the best. Then I'll order an production run and should have them by the following week.

Regarding the gear spacers, it is on my list but not as high as the other rack and pinion fixes. I should have a better timetable on this by Monday.

This is very nice to hear. The drive issue in no way diminishes my satisfaction with the rest of the machine. It is/has been wonderful. I sincerely hope the drives can be improved and put on market again. This is the wonderful thing about the intimate nature of the boutique CNC machine market.

[coherent]

Yes. I will take some picture as a comparison when I get home, but there isn't the off kilter wear on the pinion like there was before. Removing the axial play using the drives with bushings made for almost zero play in either the pivot or the pinion.

If you get a chance and can post a photo or two where the pinion gear mates with the rack using the CNCRP drives I'd sure appreciate it.
Thanks!
Marc

[kebuttke]

If you get a chance and can post a photo or two where the pinion gear mates with the rack using the CNCRP drives I'd sure appreciate it.
Thanks!
Marc

Will do. Was under the weather past couple days. Will post pictures as promised.

[kebuttke]

I believe these are some of the photos requested. Please tell me if i missed any. This Nyquil is taking over...

[RCaffin]

While I have been following this thread with some interest, I have to say I know relatively little about rack and pinion drives. That said, I am left wondering whether far too much is being expected of them?
True, the pinions are showing an alarming amount of wear (middle photo), but even with hardened steel pinions I would not myself expect anything better than 0.5 mm accuracy - mostly due to inevitable backlash. On a manual lathe the rack&pinion drive usually has several millimetres of slop.
Do people find much better than this in the field?

Cheers
Roger

[ericclinedinst]

While I have been following this thread with some interest, I have to say I know relatively little about rack and pinion drives. That said, I am left wondering whether far too much is being expected of them?
True, the pinions are showing an alarming amount of wear (middle photo), but even with hardened steel pinions I would not myself expect anything better than 0.5 mm accuracy - mostly due to inevitable backlash. On a manual lathe the rack&pinion drive usually has several millimetres of slop.
Do people find much better than this in the field?

Cheers
Roger

Uh. Yes. Plain and simple. I have been running my rack and pinion machine for close to two years now on the same set of pinions. Mine haven't even begun to wear yet.

If you have poor meshing between the two parts wear will start almost immediately and you'll have all sorts of issues. The Joescnc.com forum had problems like this a long time ago. Because of similar issues. Ie. Not fully engaging the pinion into the rack, poor alignment, excessive wear, etc. Causing premature pinion wear. I for one lived through a bit of that when I owned my Joe's machine. So I'm speaking first hand here. The improvements and evolution of the cncrouterparts drives were a direct result of the issues we were having over there. Ahren was paying attention and fixed the issues for us immediately with no hassle to us at all. The latest and greatest edition of the drives from cncrp are what Nate was supplying at first. ZERO clue why he'd devolve the drives back to older versions. With terrible tolerances. I mean the pinions themselves are literally falling out of the pockets they're supposed to be PRESSED into. Again. Keith pressed them and the bearings out with his fingers. When I changed my cncrp pinions I had to use a 6 ton shop press from Harbor Freight and a half ton Arbor press to get them started back in....

Also it's a misconception that these pinions and racks are hardened. Most of the rack and pinion parts on the market are from Moore gear. Ie. Give them a call these things aren't hardened

Lastly. While the pinion gears are considered "consumables" they shouldn't be anywhere close to the type of wear you are seeing in Keith's photos in such a short period of time. Period.



Edit:

Also I've never had to put anything into my backlash compensation. Especially not .02 like with the drives Keith received. The cncrp system has a spring tensioner that is designed to take the slop out of the system by pulling the pinion into the rack. It acts as a anti backlash nut in a lead screw setup.

(This is all coming from a Virginia Tech educated mechanical engineer class of '05) so take it for what you want.

[RCaffin]

Hi Eric

Interesting stuff. Thank you.

Cheers
Roger

[coherent]

I believe these are some of the photos requested. Please tell me if i missed any. This Nyquil is taking over...

Thanks kebutte. The gear mesh in photo one is what I wanted to see. Definately a much more contact. Now if we can get some spacers to bring the rack out about a half inch think that would be the ticket.

[kebuttke]

Thanks kebutte. The gear mesh in photo one is what I wanted to see. Definately a much more contact. Now if we can get some spacers to bring the rack out about a half inch think that would be the ticket.

After I finish a couple other projects setting up the machine, some drop-in aluminum shims are on the list.

[difalkner]

I was thinking about 1/8" spacer behind the rack... that would allow the rack to be fully engaged by the pinion but yet not let the pinion hit the frame; or am I missing something? Going up to a 1/4" spacer will almost allow the pinion full depth on the rack but would leave about 1/8" of the pinion going past the rack toward the frame, again not a problem.

What lubricant are y'all using on the R&P? I'm using the same grease that I use on the linear bearings - Royal Purple NLGI #2

[coherent]

deleted... double post.

[FineLineAuto]

Here is an account of what we did with the rack and pinion.

I should have the spindle changes done this week.


Sent from my iPhone using Tapatalk

[difalkner]

That looks good, Nate. Are you also doing a spacer for the rack to move it away from the frame?

[FineLineAuto]

That looks good, Nate. Are you also doing a spacer for the rack to move it away from the frame?

Additional changes that are coming:
- either a spacer to move the rack out or a thicker rack. Looking at doing possibly a .75 or 1in thick rack. If we go with the thicker rack I will do a run of spacers for the current machines.
- the gear racks are currently not heat treated. All the racks in the class of machine are not heat treated. However, we are going to go to a heat treated gear rack. It will be quenched and tempered. I am looking into heat treating the pinion gear as well.

I don't have a timeline on these changes yet. Should have some more info in the next week on it.

[sybilsurf]

All the racks in the class of machine are not heat treated. However, we are going to go to a heat treated gear rack.

Nate, I would say that you have created a NEW class of machine between the existing hobby class and the industrial class of router. And made in America!

All these changes will definitely enhance the machine. In my opinion one impediment to new buyers might be the requirement of building a base.

I wonder if you sell out on the first batch of machines if it might be a smart thing to have a leg kit or tall base incorporated into the design. I now have $1000 worth of welder just sitting around...it WAS fun learning to weld though.....

Ward

[DDgitfiddle]

I hate to revive an old thread, but I'd like to get some information from other Saturn owners. Nate indicated that he was making some design changes to the system to fix the concerns described in this thread. I purchased a machine in June and some of the changes or "patches" were not implemented. Has anyone received spacers for the rack? I have tried emailing and calling Nate for the past month without a response, and I am trying to decide if it is time to give up.

Thanks,
Robert

[FineLineAuto]

I hate to revive an old thread, but I'd like to get some information from other Saturn owners. Nate indicated that he was making some design changes to the system to fix the concerns described in this thread. I purchased a machine in June and some of the changes or "patches" were not implemented. Has anyone received spacers for the rack? I have tried emailing and calling Nate for the past month without a response, and I am trying to decide if it is time to give up.

Thanks,
Robert

Robert,

I just got the spacers ready earlier this week. I'll connect with you today on them. I'll take some pictures soon for everyone.

In addition, we just got in the first batch of a custom turned shaft for the pivot point. This replaces the standard shoulder bolt. It's a much tighter tolerance than a shoulder bolt and does even more to remove flex of the plate.

The 3/4" wide gear racks are in process. They are taking longer than expected to produce. I expect to have them in September.

Regards,

Nate

[RCaffin]

Chuckle.

Learning exercise all around. These 'small changes' usually take several times longer to get right than expected. It happens.
But not contacting your customers to explain the delay - that is not so smart Nate.
Curiously, being upfront and honest even beats coming in on schedule.

Cheers
Roger

[FineLineAuto]

Chuckle.

Learning exercise all around. These 'small changes' usually take several times longer to get right than expected. It happens.
But not contacting your customers to explain the delay - that is not so smart Nate.
Curiously, being upfront and honest even beats coming in on schedule.

Cheers
Roger

We definitely didn't think it would take this long. It didn't help that we were already in the middle of addressing some of the other issues. On a positive note, we have another accessory ready to go and a few more major changes to the machine design to address issues raised. Should see a formal release by Monday on all this.

Some of the changes are retrofittable and some will not be without some modification.