# Roto-Mike



## GT-6 Racer (Sep 21, 2022)

For you metrology buffs out there, how about this.  It’s a Roto-Mike. Use on surface plate to manage angular setup.  I snagged it at auction for a few bucks because it looked so cool and was in fantastic condition. anyone ever used one?  I’ve only found a couple setups that are interesting, easier than a sine bar.  Can be used horizontally or vertically


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## markba633csi (Sep 22, 2022)

Whoa- I'll bet that cost a freaking _fortune _when it was new
-M


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## GT-6 Racer (Sep 22, 2022)

Yes, I expect it did cost a bunch. I haven’t found any literature or anything for it. Saw one listed on eBay finished listings. That’s about it.


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## pontiac428 (Sep 22, 2022)

Does it have a Vernier scale to divide degrees with?  Looks like it could be useful, then again looks like a RT at the end of the day, unless you can resolve some very close radians with it.


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## GT-6 Racer (Sep 22, 2022)

Yes it does have a vernier, the knob on the back is fine adjust.  It is strictly for setup. Parts in grinding vices, angle plates etc.   much lighter than a rotary table of similar size, but still heavy.  Limited versatility for sure. I suppose that’s why there aren’t many around. If I’m going for angular accuracy it’s the Moore rotary table for sure.  I’ll post pictures of it in the machine accessories thread.


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## C-Bag (Sep 22, 2022)

It certainly is beautiful, what does it do?


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## GT-6 Racer (Sep 22, 2022)

It simply allows you to mount small parts into grinding vices or onto angle plates by mounting the vice to the Roto-mike and using it to set a precise angle. Then indicate the part to the surface plate.  Then remove the ”fixtured part” and go to the grinder. I’ve also used it to measure angles by mounting the part to the roto-mike and indicating parallel to the plate and reading the angle from the vernier.  Mostly for reverse engineering repair parts.


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## JRaut (Sep 22, 2022)

Hey, I've got one of those too!

Also picked it up at a local auction, for the same reasons as you. Too cool looking to pass up. Mine came with the original wood case plus all the hold-down gear.

I've never used it. Probably never will either.


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## GT-6 Racer (Sep 22, 2022)

Beautiful, you need to play with it and find some uses.  I have the box and triangular drawer for mine too.  Next time I use mine I’ll post some pictures.


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## pontiac428 (Oct 13, 2022)

I just found one locally...  Haven't pulled the trigger, just reckonin'.  Would it be a cardinal sin to use it as a mill fixture, or is it too weak?  For one or two cut angle setting in the horizontal it could be nice to have, and it's a drop in the bucket on cost compared to a 12" Troyke, though clearly a different beast.  I admit it's a shiny object, but would it be useful?


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## GT-6 Racer (Oct 14, 2022)

Hi Pontiac 428
It’s really a setup fixture for working on a surface plate.  I suppose you could mount a part at the angle and do some light milling then rotate to a new angle.  But it’s likely to be very cumbersome.  Won’t replace a proper rotary table for sure. If it’s cheap though, I’d buy it just for fun and great for setting stuff in a grinding vise.


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## pontiac428 (Oct 14, 2022)

Yeah, it's got that clean-room look to it, low holding power, and no good clamping points.  It just looks so much like a RT (I see a horiz sine setup when I look at it) and has such nice mounting holes, I can't help from trying to think up ways to use it.  Ah well, I've lived without it this long and didn't even know they existed until recently...


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## C-Bag (Oct 14, 2022)

pontiac428 said:


> I admit it's a shiny object, but would it be useful?


That is a really tough one. If it was super cheap I’d be a goner. But it mostly just appeals to my TAS as I don’t have a surface grinder or do super accurate angle setups. I do appreciate it being posted that’s for sure. It’s always good to know about these kinds of tools.


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