Micrometer Travel Stops

[Anorak Bob]

I'm thinking that the Hercus tool and cutter grinder could possibly benefit from having a pair of micrometer table travel stops in place of the existing stops. Now, I imagine a few lathe owners have saddle stops that incorporate standard micrometer heads such as the Mitutoyo illustrated below. Stops using similar heads would be a fairly simple thing to make but as usual there's a but. A lathe's saddle can be brought gently to bear against the micrometer's spindle end. On the T and C, the table moves effortlessly, a single finger can easly move it, a gentle push of the table will send it to the full extent of its travel and the table, naked, is heavy. Heavier even still with attachments added. That weight can cause the table to smack hard into the table's stop.

Hercus provided a micrometer saddle stop for their lathes. It is robust. The spindle has a 7/16" x 20 thread. Stops based loosely on the Hercus design become a touch more complicated because there is limited room on the table's side the mount the stop. It is about 10mm down from the top face to the 8mm wide tee slot and another 20mm below the slot to the bottom of the table. I imagine I would have to come up with a design that features a drilled through tee bolt along the lines of the Y stops I knocked up for the mill, pictured below.

So I end up with a couple of questions.

Do any T and C owners have mic stops on their grinders? If so, do they think an over the counter micrometer head with its delicate 40TPI thread would be up to the task?

I should point out that Peter Fou owned the machine previously and had no cause to change the stops but Peter owned other grinders, surface, cylindrical.....

BT

[kwijibo99]

G'day Bob,
With regards to micrometer stops on a lathe, I never really saw the value in them and always thought they were a bit of a gimmick (of course this might just be because I don't own one).
If I need to set or adjust a stop accurately I use an indicator to determine the initial position of the saddle, move it as required then adjust and lock the bolt on my normal stop. To check it, I just move the saddle away and back against the stop and verify with the clock that it repeats where I want it.

Granted this is a bit more fiddly than just twirling a thimble but I don't have to worry about damaging a petite micrometer head and perhaps more importantly, the accuracy is not dependant on a micrometer which is constantly exposed to collisions with the saddle.

Perhaps an idea might be to make a holder for an indicator that could be positioned behind the hard stop and bares against the end of the stop bolt itself, this would allow you to see immediately if the stop moves while insulating the precision bit of the arrangement from any direct impact. Of course this setup would require more space which might be at a premium, that's why I haven't made one up for my lathe yet, although they are on the to do list for my mill.

P.S. I love your little mill stops and might just have to steal your design when I get around to making some for mine.

Cheers,
Greg.

[Anorak Bob]

Some good ideas there Greg. Thank you.

The indicator is something I should have thought about as an option. I had thought and done something about a similar setup for the 13 -

http://www.woodworkforums.com/attachment.php?attachmentid=181092&stc=1&thumb=1&d=1315214065

An indicator with a rubber boot on its stylus is probably a lot more impervious to the damage caused by grit that a dainty or oily micrometer.

More to ponder.

BT

http://www.woodworkforums.com/showthread.php?t=140683&p=1370920#post1370920

[Michael G]

Bob, is it worth doing something like this?
341051
The dial coupled with the micrometer head should allow you better visibility and allow you to slow down in time. (I've half made one of these but am yet to put the graduations on the micrometer barrel). I have the appropriate taps (metric or imperial) if you want to make up the micrometer bit.

The other possibility is a damper of some sort (fluid filled). With the right needle valve you should be able to adjust it so that by the time it gets to the micrometer it has very little energy left.

Michael

[Michael G]

Incidentally, in post 3 you linked to another thread where you contemplated making some extension pieces for your DIs but did not because you didn't have any M2.5 taps. I bought a tap and die in this size some months ago to repair an insert holder. If you think they would benefit from a small holiday let me know.

Michael

[Anorak Bob]

Incidentally, in post 3 you linked to another thread where you contemplated making some extension pieces for your DIs but did not because you didn't have any M2.5 taps. I bought a tap and die in this size some months ago to repair an insert holder. If you think they would benefit from a small holiday let me know.

Michael

The damper sounds like neat idea Michael.

I must have acquired an M2.5 tap and die because I did end up making an extension. I had long forgotten about their existence until the other day when I made an elephant's foot for my Compac. It's funny how looking for something can become a voyage of discovery, finding stuff you'd forgotten you had.

[Peter Fou]

Bob,

As you have said, I had other grinders including 3 other T&C grinders. The Kao Ming, Makino C40 knockoff, had a ball race table like the Hercus but it had spring cushioned stops. The only time I could have done with a micrometer stop was when cylindrical grinding a shaft with a shoulder which then had to be faced. For the normal run of cutter grinding the table stops sufficed.


I got my container over at last and my gear into the new workshop, a lot of sorting out to do before swarf can be generated. One job will be to resume the resurrection of the Cincnnatti Monoset, quite a lot of scraping to do!

[Aussie Bruce]

Normal micrometer heads are not strong enough to deal with the impact loads a tool and cutter grinder can impart

I pirated some off a lathe that was being scrapped and a tool and cutter grinder as well they are so heavily built in comparison

Bruce

[Stustoys]

Normal micrometer heads are not strong enough to deal with the impact loads a tool and cutter grinder can impart
I'm not so sure about that.....

Having said that. As yet, I've not been able to bring myself to use one as a lathe stop.......... even though one was supplied free of charge for that express purpose :-(which also doesnt please me)

Given I can't imagine ever wanting to dial on 1/2" of feed o the nearest 1/10th. Much more likely you'll want to dial on something less that 0.004"/0.1mm. Wouldnt any old normal thread, say 1mm pitch for the metric inclined be "close enough" over the distances we're likely to be talking about?

I believe the name of the device Micheal is talking about is a dashpot. I doubt any that I've seen on carbys would be big enough, but then I've never tried.

Stuart

[WoodBee2]

Hi Bob,
As it happens I have a AI Hembrug universal grinder and it's documentation.
The standard stops are spring-cushioned but have a threaded (m8x1mm) bolt to "fine tune" the setting. There is also a real micrometer stop for this machine. These machines were not designed and built on a small budget, so I am sure both types of stop will prove strong enough.
I have taken some pictures of the manual parts and the standard stop.
I also have one micrometer stop somewhere. If you are interested I will try to locate it and take it apart for a picture.

Peter Heuts341157341158341159341160341161341162341163

[Anorak Bob]

Thank you very much for the dissection Peter.

Correct me if I am wrong but the set screw E076915 is used to lock the plunger and override the spring. Neat. And simple.

If the micrometer adjuster availed itself for photos I would love to see them. I and I'm sure others would also like to see some images of the Hembrug grinder.

Bob.

[WoodBee2]

Bob, you are right about the function of the big setscrew. The small one rides in the groove and limits the travel of the plunger. I will search for the micrometer stop and post pictures.
I will also post some pictures of the grinder in a new thread. I will post here if I have.

Regards, Peter

[WoodBee2]

Bob,
I found the micrometer stop.
341284
It's the bottom one. The top one is another incarnation of the normal stop.
I have taken it apart:
341285
341286
341287
341288

The micrometer stop is quite similar to the ordinary stop. The thread pitch is 1 mm with a diameter of 10 mm. The part just below the micrometer head is a bit bigger diameter. The micrometer head (diam. 20 mm)is divided in 100 divisions, which gives 1mm per turn and 1/100 mm per division. The extra screw is to fix the micrometer head to avoid losing your setting.

A drawing with sizes is probably not needed, because of the different machine you have, but feel free to ask anything if you want to know more.

Regards,
Peter Heuts

[WoodBee2]

Hi everyone,
I promised to show some pictures of my Hembrug universal grinder. I have started a new thread for this:

http://www.woodworkforums.com/showthread.php?t=192936
AI Hembrug universal grinder

I look forward to your replies!

Peter Heuts

[Anorak Bob]

Outstanding Peter. Thank you.

I imagine the graduated collar is screwed in close to the line marked on the sliding piece 075848 to enable reasonably accurate readings ?

Bob.

[Big Shed]

Hi everyone,
I promised to show some pictures of my Hembrug universal grinder. I have started a new thread for this:

http://www.woodworkforums.com/showthread.php?t=192936
AI Hembrug universal grinder

I look forward to your replies!

Peter Heuts

Thank you Peter.

BTW I thought where you live was spelled Alphen aan de Rijn, or has that changed?

[WoodBee2]

Fred,
It has always been "Alphen aan den Rijn", but "den" is the old dutch word for "de" which means "the" so there is not much difference.
literally translated it means "Alphen at the Rhine", and that is "the old rhine", not the one coming from Germany.
Originally it was a Roman settlement called "Rhenum Trajectina". :rolleyes:

Cheers,
Peter

[WoodBee2]

Bob,
That's right. The turning piece is made in one piece, so the collar moves from the reference-line if you screw it out. I personally think this part could be improved. Either another way to fix the reference-line, or a graduated collar that does not move with the "anvil".

Regards,
Peter

[Big Shed]

Sorry Peter, I misspelt mine. I said Alphen aan de Rijn, it wasn't "de" and " den" I queried, it was your "Alpen" as against my memory of "Alphen".

Phew, that was a weird sentence:rolleyes:

If you look at your location in your profile, you have "Alpen aan den Rijn" - I thought it was "Alphen aan den Rijn"?

[WoodBee2]

Fred,
Confusion all around :eek::)
And yes, you are right, I must have made an error when I made my profile.
I will correct it, thanks.
Peter

[WoodBee2]

Fred,
It's done. How come you remember the city name anyway? Dutch roots?
Peter

[Stustoys]

Bob,
That's right. The turning piece is made in one piece, so the collar moves from the reference-line if you screw it out. I personally think this part could be improved. Either another way to fix the reference-line, or a graduated collar that does not move with the "anvil".

Regards,
Peter
My Huaser have a way of doing it. Not sure you could if it to what you have but BT may be able to work it into his design.

BT can supply pictures :D

Stuart

[Anorak Bob]

One of the numerous adjusters on Stuart's Hauser jig borer. What is interesting about this one is that reference line is marked on a spring loaded bar that constantly bears against the graduated thumbwheel. One photo shows it pushed up to reveal the shoulder on the bar end. The entire machine is festooned with wonderments. Typically Swiss.

BT

[WoodBee2]

Hi Stuart and Bob,
Thanks for the interesting info. That feature might even be added to my current stops I think (a small version that is). Is the plunger with reference mark only prevented from turning by its shoulder, or is there some other locating feature?

Thanks,
Peter

[Stustoys]

Is the plunger with reference mark only prevented from turning by its shoulder,
I believe so. I'll check tomorrow.

[Stustoys]

yes, just the shoulder(though it is machined to mate the radius of the thumb wheel)

Stuart

[RayG]

I might have know they would radius the underside of that spring loaded pointer ... :) We should start a thread for obscure examples of Swissness....

Ray

[WoodBee2]

Thanks for the picture Stuart. Although nicely made, not too complicated. I should be able to use this design.

[Michael G]

We should start a thread for obscure examples of Swissness...

I think the Hauser is there on several counts - I can't get over flaking a surface that is not in contact with anything and in normal operation is covered from view by a solid door.

Michael