Spindle problems . What is the runout on your spindle?

[eltejano]

Runout test bars are $$.
Try a name-brand round bit of (ground) tool steel - say 10.0 mm or 12.0 mm. Very very close!

Cheers
Roger

A runout test bar is a lot more expensive that a Tormach spindle.

[RCaffin]

A runout test bar is a lot more expensive that a Tormach spindle.
True, but do I need a test bar accurate to 0.1 micron? Or would 1 micron suffice?

Cheers
Roger

[MichaelHenry]

For quick and dirty tests, I use a length of Thomson 60 case 3/4" in the Tormach Master Collet - they are pretty expensive and have decent straighness and roundness specs.

http://www.thomsonlinear.com/website...dard_shaft.php

[eltejano]

For quick and dirty tests, I use a length of Thomson 60 case 3/4" in the Tormach Master Collet - they are pretty expensive and have decent straighness and roundness specs.

http://www.thomsonlinear.com/website...dard_shaft.php

I was

Also, I recommend you toss that Tormach r8 collet, I was checking the contact patch on mine and it was terrible. I also checked the collet from a different machine and it was bad, too. Contact barely 1/8 inch wide uneven patches next to the slits only. This is bad for the spindle taper since you are exerting a lot of pressure onto such small areas equal a lot of concentrated PSI. It starts doing damage. Get Hardinge collet and grind it down. I clamped my bench grinder on my Bridgeport and put a 3/4 inch delrin slug in the collet to close it down on then just slowly took very shallow passes.

you can get them here:

https://www.shophardinge.com/product...17570019007500

If they are out of stock the have a week or less lead time.

Test the contact patch on yours, hopefully yours will be better but I doubt it.

[MichaelHenry]

I use a length of Thomson 60 case 3/4" in the Tormach Master Collet - they are pretty expensive and have decent straighness and roundness specs.

That should have been pretty *in*expensive!

[MichaelHenry]

Test the contact patch on yours, hopefully yours will be better but I doubt it.

I did that a few months ago and thought that it looked pretty good, but it's hard to tell from the pictures I took. I''l try it again in a couple of days and post the results here. Do you have pictures of good and bad blued collets that you could share?

[Steve Seebold]

Was that the initial finish out of the box, and a new quality belt fixed the issue, or was the belt a recent fix, i.e. your belt was worn and due for replacing?

I replaced the drive belt within about 3 months after I got the machine.

[IMT]

If the spindle taper has runout it is possible to re-cut it in place. Check out this post.
Can You Really Regrind Your Spindle While It's On the Machine? - CNCCookbook CNCCookbook

[eltejano]

Well, maybe they will not be replacing the spindle. I sent videos of the spindle and they seem to be not sure if it warrants replacement. I have been back and forth with 2 people. One went on vacation, another took over so started everything off again. Thought we were gaining ground now I am back to the original person, picking up where we left off. I am pretty much over it. I am just going to send out the spindle. I asked them to just give me the bearing sizes so I can let the grinders know. Right now, time is of the essence, and it is much more important to fix this than the money. Plus the guy I spoke to will only regrind it if they change the bearings to some of their higher standards.

I was going to buy a second 1100 real soon and a lathe but I dont think this will happen. I would never tell them this to try and get this resolved sooner, though, just wanted it resolved. Having to mark the spindle and mark my holders to line them all the same every time is a real pain, especially when I have a lot of tool changes.

Oh well, if this is not resolved by the end of the week I will start to refocus towards something different and bigger. Maybe a VF2 or a Speedio.

I'll still keep the machine for prototyping and teaching my kids but no more Tormachs in my future.

They should really offer upgraded spindles with a certificate of concentricity to within a tenth or less with American bearings. I would gladly pay extra for that.

[popspipes]

Just curious what everyone else's spindle runout was. I measure mine at the taper and got about .0008, almost a whole thou. Does this seem a bit excessive? My gear had mill drill was almost completely still when I took a reading with the indicator at the taper, and it was from Harbor Freight. My Bridgeport is almost as good as it.

Seems to get worse the further out. I was using an 1100 at Techshop Austin and when I try to run the exact same parts toolpaths, material, everything, I get a poorer finish and its a bit louder. Especially on a 1.5 by 3/8 keyseat cutter run on aluminum, I can hear it hitting one side and not the other. At the techshop one, the runout sound was there but barely and I got a great finish.

Here is a pair of parts that I made on either one. Both of these were made with the same exact program. On the rough one, I actually had to slow down that top pass because it was getting real loud, I thought my 3/16 bit would break.

Attachment 356788
Attachment 356790

Pretty much has been a struggle to make parts, having to modify all my programs cause I have broken 2 of my 3/16 high helix Destiny tool cutters when I tried to run them at the same speed as I did on the other 1100.

Anyone know a good spindle grinding shop in case I get no help from Tormach?

BTW, this machine is a few weeks old. and it reads almost perfect on the outside of the spindle nose, just off inside on the taper.

Thanks

My finishes looked similar to this when I first got my 1100, the problem turned out to be severe vibration, I balanced the spindle PDB nut, drive motor fan, and changed the belt to a Fenner link belt, my finishes went from bad to good immediately.
I havent really checked for runout of the spindle on my machine, but my finishes look more like the top photo.

Keep us posted on what you find thats causing the problem.

[eltejano]

My finishes looked similar to this when I first got my 1100, the problem turned out to be severe vibration, I balanced the spindle PDB nut, drive motor fan, and changed the belt to a Fenner link belt, my finishes went from bad to good immediately.
I havent really checked for runout of the spindle on my machine, but my finishes look more like the top photo.

Keep us posted on what you find thats causing the problem.

The previous machine I used had the exact same setup as mine. The only difference was that mine has runout at the taper and the other one had almost none. I have a part I was making where I was running a real nice high helix 3/16 cutter no prob on the previous machine that will snap it almost immediately on mine. You can hear the individual hits where only one side of the cutter is hitting. Plus I have measured it.

On one part, I run a 1.5 inch wide by 3/8 DOC keyseat cutter that has a little runout on the holder, nothing bad, like most tools on er collets. On one machine, no prob. On mine, you can hear the clunk, clunk, clunk... Its hitting on one side only most of the time unless I line the tools with the spindle just right so that the high side of a cutter matches the lowside of the spindle runout. Vibration from the belt is one thing, a tool running non-concentric is a whole other story


I have had 3 other milling machines. 2 bridgeports and a smaller mill, and 3 lathes.I have had a bunch of different pieces of machinery. I am not a great expert but i have been doing this for some years. I just got the Tormach to ease into the CNC world.