imperfect circles

[beltramidave]

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

Nate,
I am also still waiting for the spacers. Are you going to send out new shafts to your existing customers as well?
Dave H

[FineLineAuto]

Nate,
I am also still waiting for the spacers. Are you going to send out new shafts to your existing customers as well?
Dave H

Dave,

Spacers will go out no charge. The new pivot shafts are an optional purchasable upgrade.

[beltramidave]

Dave,

Spacers will go out no charge. The new pivot shafts are an optional purchasable upgrade.

I am still getting the squeaking from the X axis timing belt pulley, mainly noticeable at low speeds, that we had discussed quite a while back. I have tried a larger washer between the large timing pulley and the bearing, but hasn't made any difference. Other than that, pretty happy with the machine itself. Wish it could correct my mistakes, though....

On another note, what type of grease did you say we should be using? Thanks

[FineLineAuto]

I am still getting the squeaking from the X axis timing belt pulley, mainly noticeable at low speeds, that we had discussed quite a while back. I have tried a larger washer between the large timing pulley and the bearing, but hasn't made any difference. Other than that, pretty happy with the machine itself. Wish it could correct my mistakes, though....

On another note, what type of grease did you say we should be using? Thanks

This is the new pivot shaft for the rack and pinion.



Here's the gear rack spacers. The spacers are half the size of the 54in gear rack and you will need to install 2 per rack. They just drop in behind the rack.



Here's a few shots of them installed on a machine.

[sybilsurf]

Those spacers look great, Nate.

Ward

[difalkner]

Dave,

Spacers will go out no charge. The new pivot shafts are an optional purchasable upgrade.

Looking forward to getting them, Nate.

Thanks!
David

[beltramidave]

Spacers will go out no charge. The new pivot shafts are an optional purchasable upgrade.

Not sure how other owners of the Saturn machine feel, but I think that if improvements are being made due to quality or safety issues, they should be made available at no charge. Not any different than buying a new car and having a recall.

[difalkner]

Not sure how other owners of the Saturn machine feel, but I think that if improvements are being made due to quality or safety issues, they should be made available at no charge. Not any different than buying a new car and having a recall.

I agree.

David

[FineLineAuto]

Not sure how other owners of the Saturn machine feel, but I think that if improvements are being made due to quality or safety issues, they should be made available at no charge. Not any different than buying a new car and having a recall.

I agree that identified safety or quality issue should function like a recall. It's basically what we did with the rack and pinion drives. The spacers would fall under correcting a intermittent quality issue with some machines.

The new pinion shafts are considered upgrades. While the tolerance is slightly tighter, the primary purpose for the change to make it easier to remove and install the rack and pinion drives. The R&P drives perform within spec with the original shoulder bolt, so it's strictly considered an upgrade.

[DDgitfiddle]

Not sure how other owners of the Saturn machine feel, but I think that if improvements are being made due to quality or safety issues, they should be made available at no charge. Not any different than buying a new car and having a recall.

I purchased my machine with the realization that it is still somewhat under development. Like all of the current owners (I believe) I also purchased the machine at the discounted intro price. I am willing to accept some of the growing pains and even a little additional expense because of that. That said, I do appreciate that Nate has been willing to supply updates at no charge. As "upgrades" become available, I will decide whether they are worth it to me.

-Robert

[Erik F]

Hey Guys,
This thread is kind of old, and I'm pretty sure I have the newer version of the drives, since I have the spacers on my machine as well. I have been cutting a group of 1" squares to try and get things dialed in. My parts are measuring 0.015"-0.020" to large or too small. I have cranked down the pinions temporarily just to try and eliminate backlash, but still seem to get the same issues. I have run a calibration with a steel ruler and I seem to be spot on position wise (well at least over a 1' range). If I really pull and push on the router head I can get it to flex the amount of error that I am seeing, but when released is back in position ( I did this while I was calibrating with the steel ruler). Nate has seemed to gone MIA on me, so I figured I would ask around here for ideas. Eventually I know Nate will come out of his hole, but until then...I would like to start doing some cutting, since I got the machine in October and am finally together enough to start making some parts. I was running 10x micro stepping, but have since set it back to 5x hoping it would give me a little more torque and positional holding power. Belts are tight, pinions are extra tight (for now). The only thing I can think is maybe I am binding somewhere. I have measured a few time with tape measure and feel like my Y rails are not perfectly parallel, but Nate seems to think with these linear bearings, even if they were slightly misaligned I would get major binding (my machine seems to move up and down the Y axis with out issue). Any ideas would be great. Thanks folks.
Erik

[RCaffin]

If long distance calibration seems OK, then you have the steps/mm in Mach set correctly. That should be easy enough.
If you have small errors over short distances AND you are cutting wood (yes?), then you have some sort of backlash. Even if you cannot feel it.
Check tightness of all pulleys and motor mounts and nut mounts.
It does not sound like electrical noise just yet.

Then check what sort of belts you are using. If they are the old trapezoidal ones, they can/will introduce backlash. If they are GT2 and are moderately tight, they will be OK.

Cheers
Roger

- - - Updated - - -

If long distance calibration seems OK, then you have the steps/mm in Mach set correctly. That should be easy enough.
If you have small errors over short distances AND you are cutting wood (yes?), then you have some sort of backlash. Even if you cannot feel it.
Check tightness of all pulleys and motor mounts and nut mounts.
It does not sound like electrical noise just yet.

Then check what sort of belts you are using. If they are the old trapezoidal ones, they can/will introduce backlash. If they are GT2 and are moderately tight, they will be OK.

Cheers
Roger

[Erik F]

Roger thanks for the response. (and anyone else) I have the HTD belts on mine. I'm not doubting you, but could those account for all of the issues I'm seeing? Just curious since I don't know that much about the belt issue. What is the major difference between the HTD and the GT2 belts that would cause all the back lash?

[ger21]

Are you cutting all those squares at the same time, without moving the board? It looks like linear error in the rack or pinion, as each group of squares in the same X or Y location are the same size. Meaning both the X and Y axis are consistent in specific areas.

How confident are you in your measurements, especially with all that fuzz?

Are you cutting everything in the same direction? All CW, or all CCW?

[Erik F]

I have the CAM program set to conventional cutting. Yes, the squares are all getting cut at the same time, it is set up as a group of 9. I cutting in two passes the material is only .22 inches thick. Using a 1/4" upcut two flute spiral. I am pretty confident in the measurements, the caliper is a cheapy though but I would say has been reliable. I have done the same cut file before this in two other places with similar results. The square are cut left side first then the right side and the middle row last if memory serves. I would hope this machine should be able to hold +/-0.005". My hope when I got it was to be able to mill some aluminum parts with a fair amount of accuracy, but given its current state, I wouldn't even feel great about running wood projects. Thanks again guys.

[FineLineAuto]

Are you cutting all those squares at the same time, without moving the board? It looks like linear error in the rack or pinion, as each group of squares in the same X or Y location are the same size. Meaning both the X and Y axis are consistent in specific areas.

How confident are you in your measurements, especially with all that fuzz?

Are you cutting everything in the same direction? All CW, or all CCW?

Can you post the steps per inch you are using? With 10X microstepping your steps per inch should be 1909.9861 or real close to it. Also, the Z-Axis should be 10160 steps per in.

Also, as Ger says can you give us an idea of the tool path for the squares? The one thing that stands out is the consistency in how far things are off.

Is there any way you can setup a dial gauge to get a measurement without cutting?

[ger21]

The fact that the error is consistent in both rows and columns would lead me to think it's a mechanical issue. I can't see the rack or pinion being .02" out in 2 inches.
It's also strange that the squares get larger in the Y axis in each row, from top to bottom.

I doubt that you are seeing backlash, but something is going on.

[FineLineAuto]

I have the CAM program set to conventional cutting. Yes, the squares are all getting cut at the same time, it is set up as a group of 9. I cutting in two passes the material is only .22 inches thick. Using a 1/4" upcut two flute spiral. I am pretty confident in the measurements, the caliper is a cheapy though but I would say has been reliable. I have done the same cut file before this in two other places with similar results. The square are cut left side first then the right side and the middle row last if memory serves. I would hope this machine should be able to hold +/-0.005". My hope when I got it was to be able to mill some aluminum parts with a fair amount of accuracy, but given its current state, I wouldn't even feel great about running wood projects. Thanks again guys.

That cut profile makes sense given the pattern of measurements. I am not sure it’s backlash because if it’s backlash I expect variations in measurement. But each row and column have very similar measurements.

Let’s make sure we got the settings right first.

[Erik F]

I have a cheap dial some place but haven't seen it in years. The control program I'm using want to know two things. Steps per rotation and distance per rotation. I am currently using 5x micro stepping. 3.14159/3 gets me to 1.04719 inches per rotation. So I am telling the control software 1.04719 inches per rotation at 1000 steps per rotation. I did dial in the x axis a little closer so now the distance per rotation is 1.048xxx but I haven't bhad time to make any cuts and Y seemed to be good at the 1.047xx number. This was done over a steel ruler with 1/32 markers on it. X was only off by about .010 over 12" and was spot on to my eye after the adjustment.

[Erik F]

Was trying to load the NC file but would not post up here. Please let me know if this link works to download the .NC file.

https://drive.google.com/file/d/1Rho...w?usp=drivesdk