[Fastest1]

well isn't this place for that kind of thing helping each other out?

On the other hand each thread is in regards to a "problem". It is simple to start one.

[CFLBob]

Hoss, I need a consultation.

I tried to make the ballnut removal tool and found it didn't work. The tool has a 0.400 ID over its entire length, but the Y axis leadscrew I have has a last section that's 0.500 OD and about 1.25 long (31.8mm). That seems to match the drawing you call "C7 ballscrews Y axis" - the non-ballscrew portion ("right end") is 97.8 mm long. The overall length seems to be 345.5mm and the length of the ball screw threads appears to be 247.7 mm.

My plan is for a front mounted Y-axis approach, but I see other ballscrews labeled Y axis and the dimensions of the non-ballscrew threaded portion are very different.

First question: does this ballscrew work for a front mounted stepper?

Second question is a bit rougher. I don't have a 3D printer, but I do have a good lathe, so I bought a piece of Delrin to make the ballnut removal tool. Long story shortened, at some point I pushed the live center into the open end a little too far and the plastic buckled a little where the 0.50 ID turned into the 0.40 ID. That tore the plastic a little, and created a gap where the 0.50" ID portion gets close to the ballnut threads. I really should have bought two pieces of Delrin in case I messed it up, but didn't. Is this usable? That gap is about .115 wide. My guess is "no". Since the ID has to be 0.505 or so and the OD about 0.530, that' about .012 on each side. Is plastic strong enough for that? Should I remake this in aluminum?

Attachment 341062

[hoss2006]

If you are doing the standard front mount the print won't say extension in the filename and the total length is shorter than the other 2 prints that have extension in their filename. Just wrap a little tape around the ballscrew and the removal tool, this isn't a critical tolerance tool. Many people use cardboard tubes, rubber tubing or tape wrapped paper for example, the purpose is just to keep the balls from falling out and it's not the end of the world if they do just a little bit of a pita to rapack it if so.
Hoss

[Fastest1]

If you are doing the standard front mount the print won't say extension in the filename and the total length is shorter than the other 2 prints that have extension in their filename. Just wrap a little tape around the ballscrew and the removal tool, this isn't a critical tolerance tool. Many people use cardboard tubes, rubber tubing or tape wrapped paper for example, the purpose is just to keep the balls from falling out and it's not the end of the world if they do just a little bit of a pita to rapack it if so.
Hoss

I used a piece of rubber hose, fuel line actually.

[CFLBob]

Thanks.

The only thing I have in the scrap bucket that's close in size is some 12L14 steel bar. Seems like a waste to use that.

[jalessi]

PVC Pipe will work with a small amount of machining.


¼" Nominal Pipe Sizes & Types

Outside Diameter Nominal Pipe Size Wall Thickness* Inner Diameter* Pipe Classification Pressure Rating @73F Color

.540" (13.72mm) ¼" .088" .344" Sch 40 IPS 780psi GRAY
.540" (13.72mm) ¼" .088" .344" CLEAR NSF Sch 40 IPS 390psi Clear/Blue
.540" (13.72mm) ¼" .119" .302" Sch 80 IPS 1130psi GRAY
.540" (13.72mm) ¼" .119" .282" CLEAR NSF Sch 80 IPS 540psi Clear/Blue YES

Thanks.

The only thing I have in the scrap bucket that's close in size is some 12L14 steel bar. Seems like a waste to use that.

[CFLBob]

PVC Pipe will work with a small amount of machining.


¼" Nominal Pipe Sizes & Types

Outside Diameter Nominal Pipe Size Wall Thickness* Inner Diameter* Pipe Classification Pressure Rating @73F Color

.540" (13.72mm) ¼" .088" .344" Sch 40 IPS 780psi GRAY
.540" (13.72mm) ¼" .088" .344" CLEAR NSF Sch 40 IPS 390psi Clear/Blue
.540" (13.72mm) ¼" .119" .302" Sch 80 IPS 1130psi GRAY
.540" (13.72mm) ¼" .119" .282" CLEAR NSF Sch 80 IPS 540psi Clear/Blue YES

Yeah... about that.

I checked with both my local orange and blue big box stores and neither had 1/4" pipe last week. Come to think of it, I didn't check Ace.

Is that stuff rigid enough to bore or drill out to 1/2" ID?

[jalessi]

Bob,

I believe you meant .400 I.D. , I would use a boring bar instead of a drill bit.

Jeff...

[CFLBob]

No, the last 1 1/8" in front of the ballscrew threads is 0.500. I used a boring bar on my Delrin piece, but the plastic is getting pretty thin by the time you have a 0.50 diameter bore and a .540 plastic wall.

[jalessi]

Steel pipe dimensions:

Steel Pipe Dimensions - ANSI Schedule 40

[CFLBob]

So I had some time today, and I'm sitting looking at that bar of 12L14 steel and it kept calling me. So..



I'll call it done.

[Ripthorn]

I recently did the direct drive Z axis conversion with the 570 oz/in Keling stepper. Every time Z axis retracts, I skip several steps. I have tried slowing down acceleration, but to no avail. After dropping several steps, it seems to then travel fine. Lowering the head is obviously not a problem. Short of getting a more powerful motor, what should I do? Gas spring assist? I would like to keep the solution simple and relatively cheap. Should I do micro stepping? Change motor current? I don't want to fry the motor or driver doing something stupid. I'm open to whatever advice.

[hoss2006]

<p>
Need a little info like what driver, power supply are you using, what do you have the driver set to for amps and microstepping, is this with ballscrews?</p>
<p>
Did you swap the spindle motor for a heavier one?</p>
<p>
Hoss</p>

[jbar]

Are the gibs adjusted properly? If they're loose they might grab when changing direction.

[bgriggs]

I suspect the Oldham coupling is slipping on the shafts. Place witness marks on the coupling and leadscrew with a Sharpie. Run the Z axis up and down and then see if the witness marks still line up. If not, tighten the set screws.

[jbar]

Hoss would you post the G Code you used to sharpen endmills with your 4th axis CNC?

[hoss2006]

Hoss would you post the G Code you used to sharpen endmills with your 4th axis CNC?

That was a long time ago I don't still have that code, it would all depend on the lead of the endmill anyway and wouldn't be the same for every endmill
Hoss

[Ripthorn]

Sorry for the delay in my reply. My controller PC appeared to have died, so I spent most of my free time this week in troubleshooting, resurrecting, and re-configuring the machine and software. Here is some basic info regarding my skipped Z steps:

- I am running a 570 oz/in Keling specified by Hoss
- KL6050 drivers, with DIP switches set to 01100000 (from 1 to 8), which, if I interpret the chart correctly, should read 4.5A current with no microstepping (2 pulses per step)
- Power supply is a 48V/8.3A ebay special
- I am direct driving the Z axis using an Oldham coupler that I machined. It fits very tightly with slip in the fit of the acetal disc and aluminum coupler body.

After re-configuring the PC, I decided to go ahead and tram the mill and put some lithium grease on the Z leadscrew. After lubing the screw, I was skipping fewer steps, but still skipping more than I am comfortable with, especially with some of the projects I have coming up.

To answer other questions:

- I will try witness marks on the coupler, but it was put on very firmly with thread locker on both the set screw and the threaded body portion
- The gibs might be a little loose, I will try snugging them up a little
- I am lubricating the Z ways with 3 in 1 oil. I know it's not considered the best oil, but a machinist friend of mine once told me it should be fine for this, is that not true?

Now, I have a couple other questions, as I think about this machine. I measured my backlash on X and Y and found .006" and .015", respectively. The Y axis seems way too much, but then again, I never adjusted the backlash nut on the stock machine (didn't see that step until the machine was all assembled...). Any ideas there?

With converting to ball screws, is it ridiculous to replace one axis at a time? I don't want to fork out for all three at a time, but if I could replace, say, just the Z axis screw to start, I might go onesie-twosie. Is that just a dumb idea?

I know I'm asking a lot, but now that I have almost a year with the machine and a little bit of a feel for what it can and can't do, I feel like I am ready to start taking things up a notch. Until now, I have not needed the utmost in precision because I was doing stuff that all had some hand finishing work or where .01" tolerance was ok. Now I want to do stuff with greater precision, but want to do so sensibly. Thanks!

[Signal9]

Hey Hoss,

On your Weiss motor, have your heard any squeaking sounds at low rpm?

Initially I thought it was the bearings in the spindle/quill or the head, but decided to remove the belt from the motor and just power it up without anything attached.

The squeal goes away at higher rpm's.

I don't believe this motor has any "maintenance options" i.e. lubrication.

Your thoughts?

I probably only have less then 24 machine hours on it.

I checked the pulley that's attached to it thinking perhaps the set screw came loose, but they are nice and tight still with the red loctite.

[DubMFG]

Hey Hoss,

On your Weiss motor, have your heard any squeaking sounds at low rpm?

Initially I thought it was the bearings in the spindle/quill or the head, but decided to remove the belt from the motor and just power it up without anything attached.

The squeal goes away at higher rpm's.

I don't believe this motor has any "maintenance options" i.e. lubrication.

Your thoughts?

I probably only have less then 24 machine hours on it.

I checked the pulley that's attached to it thinking perhaps the set screw came loose, but they are nice and tight still with the red loctite.

Clean your pulleys with alcohol to remove any gums or varnish. Make perfectly sure your belts are aligned and not overtensioned.