4th Axis Rotab - Tail Stock

[Bob La Londe]

I bought the 4th axis 6" rotab back in March for an upcoming project. I unboxed everything yesterday in preparation for finally setting it up on the mill because I have started on the job. One thing I did was order the MT1 replacement sleeve (FROM TORMACH) for the tail stock so I could use an off the shelf MT1 revolving chuck instead of a center. I've found clamping up both ends of a piece of stuck results in less deflection and allows for a little heavier roughing cuts. On the other mills I'll often use two spindexers face to face for this reason.

Anyway, wow! The tailstock is much less than I expected in how its setup. Sure its fully adjustable, but what its not is really lockable or fine adjustable. It looks like you try to get it close and then fine adjust with a knocker or a hammer. That wasn't the big disappointment though. Its got an "18mm" (note the quotes) solid center in an "18mm" close slip fit hole. The replacement MT1 sleeve is 18mm (note the lack of quotes) so it should be an exact replacement. Um-Nope! The hole is slightly undersize, and the stock center is 17.98mm. Since I don't have a cylinder grinder to resize the new MT1 sleeve that leaves me looking for an 18mm reamer. Sigh!

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[Bob La Londe]

It seems the bore is actually tapered. My best guess is it was either bored without care for deflection, or reamed with a worn out reamer. Probably the latter.

[shred]

What did Tormach say about it?

I had one for a 8" 10 years ago and it doesn't look like they've changed any.

[Bob La Londe]

I figured it was the curse of the Chinese import ro-tab and that was what I had to expect. I ordered a "new" reamer to fix it from bice3054 on ebay. It was undersize, and they accused me of incompetence when I told them. So... I finally got around to contacting Tormach today. I'll see what they have to say. I may just have to buy a piece of stock and make a d-bit reamer myself on the T&C grinder. Kind of a PITA all the way around.

[Bob La Londe]

Well, I didn't get a response from tormach exactly. I received the link that I could click to go to a processor conversation or third or service or something which I clicked on. Then I had to sign up for a service. Then I finally got in and looked at it and nobody had responded to my problem.

I wonder if Tormach is AT&Ting Customer service. Make it such an involved process that people give up and go away. I hope not.

[machinehop5]

...can you Hone or Lap the bore to size? .02mm(.0007") is not much
https://www.mcmaster.com/laps/
https://www.mcmaster.com/hones/

[Bob La Londe]

I can. I was just going to ream it, but the "new" reamer I bought was undersized (and not that real sharp)..

I'll probably windup making a D-Bit reamer on the T&C grinder. Still it shouldn't be an issue to begin with. Its kind of annoying, and certainly not every other customer will have the ability to make special purpose single use tools. I'm overall pretty happy with the 1100S3, but I'm not thrilled with my experience with accessory equipment. My experience with customer service in the past has been mixed, but they usually replied in a business day or less before.

[Bob La Londe]

Maybe customer service is better than I thought. I was about to post a message in this thread saying I had not heard from anybody at Tormach when I received a call. I actually started to make this post before they called. They asked if I had received the message they sent on Monday. Well I didn't, nor did I receive a notification of a reply on their conversation platform I had to sign up with. That could be a failing in email. I'll give the benefit of the doubt.

They were quite happy to replace or credit my tail stock. Since I need to actually do the job we agreed on a partial credit and I'll proceed with my plan to make a custom reamer and finish it out properly myself. I was annoyed at that when I had not heard from them, but given their willingness to be fair about it I don't mind so much.

Actually now I am kind of looking forward to it. It will be great practice in working with my T&C grinder. Maybe I'll even take the time to dial it in a little better.... Or maybe I'll just do the minimum to get my tailstock to proper size for the MT1 sleeve. I don't actually need the solid center it came with. I already have tools to go in the MT1 sleeve including a carbide tipped half dead center. Mostly though I will use a small rotating chuck on an MT1 shaft.