Enco/Gamet Boring Head

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ccfl
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Joined: Wed Jun 01, 2016 9:14 am

Re: Enco/Gamet Boring Head

Post by ccfl » Sat Aug 19, 2017 4:53 pm

The 4 screws on the vernier side, those hold the vernier/leadscrew/ratchet assembly plate to the body. That is a separate piece, if it's never been disassembled before the seam may be invisible, but it's there. The one centered above the vernier... no idea. I do know it's not the lock for the arbor thread, as that one is visible in one of your earlier pictures. It is possible it is an adjustable limiter though. It looks empty - if you thread in a long screw there, and crank the vernier, does the screw move with the slide or does it stay stationary?

The screw on the opposite (back?) side is the over-travel limiter, it only stops the slide from flying off at speed if the autofeed keeps going until the slide comes off the end of the leadscrew.
"Never trust a man who puts a witty quote in his sig line." -Mark Twain

spro
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Re: Enco/Gamet Boring Head

Post by spro » Sat Aug 19, 2017 5:06 pm

This exploration of the automatic boring heads is fascinating. I can see how they are most useful for inside grooves or facing inside a precise surface.

spro
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Re: Enco/Gamet Boring Head

Post by spro » Sat Aug 19, 2017 7:28 pm

There is probably a book about these things and how offset tools fit the offset holes for surfacing. I don't know enough to ask the proper question but it is so much different from a lathe.

spro
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Re: Enco/Gamet Boring Head

Post by spro » Sat Aug 19, 2017 7:53 pm

Please read ccfl's information above.

ccfl
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Re: Enco/Gamet Boring Head

Post by ccfl » Sat Aug 19, 2017 8:15 pm

You know what's funny about all this, I have this fancy automatic boring head, I've rebuilt and repaired and tweaked and improved it, know its innards like I know my hand, yet I don't have a machine capable of running it! This boring head is one of the primary motivations for me building a beefier spindle for the drill press, so I can finally use the thing.
"Never trust a man who puts a witty quote in his sig line." -Mark Twain

asallwey
Posts: 177
Joined: Sun Dec 31, 2006 6:49 am
Location: N. Virginia

Re: Enco/Gamet Boring Head

Post by asallwey » Sat Aug 19, 2017 9:00 pm

ccfl,

If you didn't get my PM, I would like a copy of the website you mentioned. asallwey @ yahoo. com

"The 4 screws on the vernier side, ... the seam may be invisible, but it's there." Boy if there is a seam there it must be a perfect fit.

"The one centered above the vernier... . It looks empty ... ." Yes it is empty. It goes in about 1 3/8" and at the rear looks to be 2 threads - maybe the arbor?

"... does the screw move with the slide or does it stay stationary?" No screw in there and no movement when the carriage moves. But as I said there appears to be a thread at the back.

The screw on the opposite (back?) side is the over-travel limiter, it only stops the slide from flying off at speed if the autofeed keeps going until the slide comes off the end of the leadscrew." Ok, I remember reading about that feature in the Enco manual.

Spro,
"There is probably a book about these things and how offset tools fit... ." I have found a little bit of info on these heads, but usually it just how it was used to do something. Not on how to set them up and their features. Youtube has a couple of videos of folks using them on projects, but I'm digging for info on how the head works and how to set it's features.

One feature that I'm not sure I have, or if I do how to set them, are the stops for automatic feed. The manual recommends using the head at 100 rpms so the clicks can be counted. Each revolution (on the base setting) give 1 click, and increases the hole 0.0025". My Millrite has a lowest speed of 250, so the clicks come quite briskly. Might just be one of life's challenges!

spro
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Re: Enco/Gamet Boring Head

Post by spro » Sat Aug 19, 2017 10:00 pm

Right there you gave more information. These are intriguing in the way they work. I have also been confused by some surface finishes. A fly cutter or a set facing head tool would introduce a series of semi circles . It has all been faced to the same level and that is fine.
There is another thing which explains, I think, a different pattern. The facing tool is set offset the axis yet it will still cut because it is not dependent upon the axis of a lathe. It is dependent on its grind angle throughout the feed and when it advances there are different patterns. There is a different offset in the side holes at each end which are there for a reason. I just think there is a lot of stuff going on.

ccfl
Posts: 118
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Re: Enco/Gamet Boring Head

Post by ccfl » Sat Aug 19, 2017 10:47 pm

Email sent - check your spam folder, Yahoo may not like attachments.

Your head does not have any of the parts needed for the adjustable stops. The hole above the vernier sounds like a second lock for the arbor, 90* from the one above the gib screws.

I just checked MSC and these things are one thousand dollars for the big one, seven hundred for the little one. Yikes.
"Never trust a man who puts a witty quote in his sig line." -Mark Twain

asallwey
Posts: 177
Joined: Sun Dec 31, 2006 6:49 am
Location: N. Virginia

Re: Enco/Gamet Boring Head

Post by asallwey » Sun Aug 20, 2017 7:55 am

I received your email, it's great and thanks!

It is clear from the pictures that I do not have the stops, as you point out. Apparently there were a couple of versions of this head brought in by Enco (some Enco/Gamet and some just Enco). My label clearly says Made in France under the Enco name. But there is no model # or other writing on the head. I believe mine is at least 30 years old.

I hadn't looked at MSC, but your comment sent me there. Apparently these 2 (this size and a smaller one) are the cheap ones, with the others jumping to $3k, $5k, and above. Folks look up Automatic Boring Heads on MSC.

Thanks to all who helped on this. I think it is time for me to go practice counting clicks.

Alex

ccfl
Posts: 118
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Re: Enco/Gamet Boring Head

Post by ccfl » Sun Aug 20, 2017 8:07 am

250 RPM won't be that bad. Slower would be better, but I think it should be manageable. It's only 2.5 times a second. Plus, you don't have to hold the ring and make the cut all in one go. You can start the spindle, grab the ring when you're ready, click-click-click, let go and let it coast, hold again, click-click, let go...

Just run it for a while with no tool mounted, run it through its full travel a few times and get used to the timing.
"Never trust a man who puts a witty quote in his sig line." -Mark Twain

asallwey
Posts: 177
Joined: Sun Dec 31, 2006 6:49 am
Location: N. Virginia

Re: Enco/Gamet Boring Head

Post by asallwey » Sun Aug 20, 2017 10:18 am

That's the game plan. Plus I will start with a scrap piece until I get comfortable.

The driving force behind using this is I have a shaft cover plate that needs a seal installed (was felt). The seal will sit into a ledge that expands outward into the plate about 3/8". The ledge is slightly wider and deeper than where the felt was. I didn't know I was embarking on a major hunt for info on the tool, but it has been fun and very informative.

ccfl
Posts: 118
Joined: Wed Jun 01, 2016 9:14 am

Re: Enco/Gamet Boring Head

Post by ccfl » Sun Aug 20, 2017 10:44 am

(By the way, the 250 RPM = 2.5 per second is correct, since I have switched over to the much more practical metric time. The old 60/60/24 system is antiquated and obsolete.)
"Never trust a man who puts a witty quote in his sig line." -Mark Twain

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