Tips/Techniques Dan Gelbart shows how to test lathes and mills

Tips/Techniques
Dan Gelbart in his bat cave discusses how to test lathes and mills. Of course his equipment is amazing (and pricey!). CNC gear but with manual handles for all the axis. I almost hate to try these tests on my machines. Performing these tests while inspecting a potential purchase could be quite helpful. Maybe I'll try a few of those tests and post results - be interesting to see results from other members.

He also explains the advantages of the 3D metal printer he designed. Maybe the forum could buy one! just $200K. Really good content from Dan as usual.

 
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Susquatch

Ultra Member
Moderator
Premium Member
Sorry for the bad inference. blame Covid. I was just up from an 8 hour nap...

Noga is far better than I deserve. I've used a Fisso in a metrology lab (they are too expensive for an average shop floor) and I found it... amazing.

That's an amazing testimony coming from you! I hope I get to see a Fisso someday. In the meantime, I do love my Noga. It is sooooo much better than my other holders that it is hard to believe anything can be better yet!

Hope you feel better soon!
 

DPittman

Ultra Member
Noga is far better than I deserve.
I guess that might be why I don't own a Noga. Initially it was because I was cheap and ignorant. While the ignorance has improved slightly, I am still cheap, and likely will NEVER "deserve" one. I do however yearn for a quality dial test indicator and stand. Maybe someday my stars will align. :rolleyes:
 

Susquatch

Ultra Member
Moderator
Premium Member
I don't think his spring is all that accurate.

He did say that it can be calibrated. And it can. 100kg is nothing for a pair of short flat bars like that.

But I agree, the exact amount is not critical. I think the 100kg is just the number he uses for his own comparisons. Note the pressure pads. He didn't make that test bar for just one use.

You could use one Janger instead.
 

Susquatch

Ultra Member
Moderator
Premium Member
Re Noga DI holders: KBC has one for $168 on sale supposedly. Is that a good price? There are some on amazon for less but I assume they are sh*T knockoffs.

I got my Noga at KBC for the same reasons. But if I were you I'd hold out for the Noga double adjusting versions. There are three sizes.


436L76_AS01.jpeg

They have fine adjustments at the base and at the indicator and fit a multitude of indicator types.

The other members on here talked me into getting one after I tried to find an Erick & a US General. I LOVE THE NOGA. Maybe the Fisso is better, but it's a bit hard to believe, and even if it is, I just can't justify the coin.

Thread 'US General 387 indicator holder' https://canadianhobbymetalworkers.com/threads/us-general-387-indicator-holder.4237/

A lot of guys spoke highly of the Erick too. I ended up getting one on ebay. It's a beautiful holder that works better than the US General, but...... the Noga is better yet.

What originally caught my eye about the US General was its "Swing into and out of action" capability. Well it really can't do that as well as I hoped. But the Erick is pretty good for that.
 

PeterT

Ultra Member
Premium Member
I've heard knockoffs are starting to invade Ebay/Amazon space so beware. The machinery supply outlets are safer because they are dedicated distributers. But check prices & shipping as they vary & have sales etc. I've noticed sometimes Thomas Skinner has competitive prices, but their online catalog went vapor a few years ago now & they haven't replaced it. But if you call they will email you a quote. I did buy a Noga mini mag through Amazon, but it was a Travers (or someone like it) storefront.

One thing you have to pay attention to is not all indicator dovetails & stems are the same. You read this all the time where people have a lot of N-Am indicators & then complain a certain holder is not worth the money because it doesn't fit as well. Yeah, 6mm is not 1/4", one would think machinists know things like that LOL. Same goes for dovetails. Actually with Noga you can buy various heads to solve these issues, but it may not be on the particular common model.
 

johnnielsen

John (Makonjohn)
Premium Member
Ok I’m trying the first test he showed which illustrates how round your lathe is turning. I turned a lump of ground drill stock and then sanded it with 80 and 400.

I got out the 0.0005 dial indicator. I don’t have a 1 micron indicator - roll eyes. The two pictures show the dial indicator with the min and max deflection. I read that as maybe 10% of the graduations. 0.00005”?

Dan’s is 1 micron which is about 0.00004” or an order of magnitude better.

0.00005” C0636
0.000004” Dan Gelbart's

My lathe is C0636 modern tool 14x40. I bought it used a few years back. I am actually quite impressed considering I bought it for about $3700. Good and fortunate timing not bragging. I got lucky. This was before everything went up so much. How about your lathe? @johnnielsen how about your big German iron? I imagine it's a lot better. @kevin.decelles you have the newer version of the C0636 try yours! @Dabbler please try your Monarch Leblond. Bert's lathe - that's a monarch isn't it? Somebody on here has a 10EE. Try yours.
I am housebound for another week but I will give it a try then.
 

Rauce

Well-Known Member
Premium Member
That's an amazing testimony coming from you! I hope I get to see a Fisso someday. In the meantime, I do love my Noga. It is sooooo much better than my other holders that it is hard to believe anything can be better yet!

Hope you feel better soon!
My experience with the FISSO was that’s it’s noticeably more solid than a noga. The arm segments are significantly beefier.

The fine adjust wasn’t much different. I have two nogas that I bought with my tool allowance at my last job and a mitutoyo that I got used for a good deal. The new mitutoyo articulating stands are very good. The older ones had a tendency to leak from bad seals (they were hydraulic, not sure if the newer ones or any other articulating indicator stands are)

Also I’d like to point out that it appears the link to their website has brought FISSO here, they liked my last post haha
 

Susquatch

Ultra Member
Moderator
Premium Member
Ok @Janger, you have done it now!

I did a few tests tonight per your request. Didn't get very far.

Spindle Runout - basically not measurable. Less than a micron.

Spindle Play with 100kg load - I hit a snag. Seems to be about 1 micron of play and 3 microns of hysteresis (4 total). I fiddled with it a bit trying to figure out where the hysteresis was coming from. First I moved the indicator to the actual spindle, not the chuck. That brought the numbers down to a micron. But again with hysteresis. The difference is likely the chuck distorting and angular distance magnification. But why hysteresis? Thought for a few more minutes, then threw my milk at the lathe, and closed up the shop for the night. I'm not allowed to have coffee after noon hour. SWMBO Rule.

I think there is a blood thirsty zombie down that rabbit hole. I can't believe I let you talk me into this!
 

garball

Active Member
Ok I’m trying the first test he showed which illustrates how round your lathe is turning. I turned a lump of ground drill stock and then sanded it with 80 and 400.

I got out the 0.0005 dial indicator. I don’t have a 1 micron indicator - roll eyes. The two pictures show the dial indicator with the min and max deflection. I read that as maybe 10% of the graduations. 0.00005”?

Dan’s is 1 micron which is about 0.00004” or an order of magnitude better.

0.00005” C0636
0.000004” Dan Gelbart's

My lathe is C0636 modern tool 14x40. I bought it used a few years back. I am actually quite impressed considering I bought it for about $3700. Good and fortunate timing not bragging. I got lucky. This was before everything went up so much. How about your lathe? @johnnielsen how about your big German iron? I imagine it's a lot better. @kevin.decelles you have the newer version of the C0636 try yours! @Dabbler please try your Monarch Leblond. Bert's lathe - that's a monarch isn't it? Somebody on here has a 10EE. Try yours.
Janger, I watched this video a few weeks ago and thought it was fantastic. Tons to learn here. One thing that struck me is you don’t even have to run up a lathe to test it. There’s a lot you can do to ‘read’ a lathe without power.
 

Susquatch

Ultra Member
Moderator
Premium Member
@Janger - I tried hard to get this off my mind for a few days. Today, I was taking a photo for another post and decided to do a few more tests.

The hysteresis appears to be bearing related. After the lathe and bearings warm up, there is no longer any hysteresis and just under a micron of play measured at the spindle nose itself. Since there is a fair bit more at the chuck nose, I would bet most of the 1 micron is in the headstock structure. Can't complain about that! Mine is no R&D shop lathe, but it does appear to have excellent spindle run out by Dan Gelbart's standards. It has also done everything I ever asked of it.

For the time being, I'm gunna stop testing here lest I get sucked down a bigger hole and come to hate you.
 

Janger

(John)
Administrator
Premium Member
2nd point - I respectfully disagree. The indicator was mounted on the side of the head stock. Pressing on the chuck should indicate the flex of the spindle to the head stock. I think the way Dan tested with the big spring could show the problem with the test you indicate.
I thought about the test Dan did some more. Instead of zeroing the indicator and then measuring the movement when applying the spring to the spindle he did it backwards. Apply the spring, then set the indicator to zero, THEN release the spring. This shows the spindle to headstock movement as the spindle moves back to its unloaded position. I think doing it that way should eliminate any problems of saddle, cross slide, and saddle springiness issues. Dan seems to be pretty damn smart.
 
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