Carriage stop..................

I am trying to avoid feelings of guilt about not working on the next model by knocking up a bit of tooling. A carriage stop is on the cards as next job. I would like to incorprate a micrometer head like this:

**LINK**

but as it will be installed on the left side of the carriage/apron the readings will be upside down. I have had a pretty good search but cannot find any supplier who sells these heads for the opposite "hand".

Are the upsidedowners available?

Rik

Rik

I've just pm'd you my dwg for my carriage stop which uses a common hex head bolt, (if you must have a mic barrel, & have difficulty reading upside down), set your tool to the shoulder / depth you need, measure with a depth mic or vernier & lock the hex head bolt up in that position you should get repeatability at that... & save y'self a tenner plus.

Cheers

George

Edited By mechman48 on 21/09/2013 19:53:22

Somewhere, in the far off recesses of my aging brain I seem to recall micrometer heads engraved the other way around? Maybe from bits of apparatus in a research lab. Anyone remember?

Norman

This micrometer is almost 'normal' right hand but if you click on the picture you get an enlargement that shows it has two sets of engravings. On that basis you could just get a standard one and re-engrave it yourself.

I imagine the intention of having a micrometer, as is how I use my standard Boxford one, is to make a cut and then make an increment on that cut of a precise small amount for which a fixed screw stop is no use. It enables you to make accurate shoulders without using the topslide which can be left set over for threading.

But you can also get ones that turn the other way

Edited By Bazyle on 21/09/2013 23:06:34

Thanks Bazyle

You have accessed those parts of my brain unused for some time! Of course these micrometers were used primarily, not just for measurement, but to accurately position items on experimental rigs. I'll bet that they cost a bit more than the ARC offering that Rik has found though!

Rik

I don't know what lathe you have but you might try design based on THIS item supplied by Hemmingway for the Myford 7

N

I have just added a new article to my web site about my take on lathe carriage stops. I have never been a great fan of using micrometer hard stops as it is too easy to damage the micrometer should the carriage make a heavy contact. Once a stop is initially set and locked I use the compound slide to make fine adjustments should that be necessary.

The other thing I also wanted from a stop was the ability to use it with power feed operational, as in the case of screw cutting or even normal turning. My article describes a new simple attachment I have devised to do this which helps enormously when judging the correct instant to operate the GHT retracting screw cutting tool or in the case of normal turning under power feed to disengage the feed.

link:

http://www.homepages.mcb.net/howe/lathe%20stop.htm

Graham

Mitutoyo do a few models with reverse reading if thats what you are after. Series 150 is a standard head available with reverse reading grads.

Raymond.

Thanks everyone. Graham, the link does not work for me.

Rik

Hi Rik

I think do it yourself stop is a better choice, a micrometre is not strong enough.

A high tensile cap screw with the end ground flat maybe set into preloadable half nuts to allow you to take up the slack and reduce the backlash similar to the way a micrometre works, or alternatively a simple lock nut to lock the setting.

If you have a dividing head you can make up an engraved thimble.

I have a VDF factory made stop for my VDF lathe it is just a well fitted screw and a lock nut with a graduated thimble. It clamps on the bed, One thing I would like to change is the method of holding it on the bed. I picked up a stop for another unknown lathe in an auction junk box. This stop has teeth, a short rack, that engage the bed rack that is used by the carriage drive. This would provide a rock solid mount there would be no possibility of slipping. If you marked the teeth where you placed it, it would go back in exactly the dame place each time. One day I will get around to making one............

Regards
John

Edited By John McNamara on 22/09/2013 09:35:48

Edited By John McNamara on 22/09/2013 09:38:30

Sorry, I disagree with John's opening statement.

I have a cheap Chinese micrometer head on my 7" centre height TOS lathe which is used daily in a jobbing shop operation so it does get some use.

I do have a clutch on the feed shaft but it's set quite high as 4 mm deep cuts under power at 1,000 revs are quite normal on this lathe.

I've crashed it many times, bumped hard onto the stop and after about 10 / 12 years this is still working as it should.

The work mine has done so far must equate to more than a lifetime in a home shop and small machines

Well John - the voice of experience! How though do you get over Rik's original problem of the micrometer readings being upsidedown if installed on the LHS of the saddle?

N

Hi
For short lenghts's to a shoulder. Bring carraige to the fixed stop with top slide set at zero . face job .say you want to move 4.20" move away from job wind the top slide in 4.20" and away you go to the shoulder using the carraige . The stop I use is adjustable ie can slide to a postion and lock it . Under it is a rule for setting and a platform i can introduce slip gauge's ie face job slide stop to the gauge block lock stop remove slip and you can turn down to the shoulder
Nobby

Back to the start. As the ticks stay the same and only the digits have to change how about a thin brass sleeve to overlay the original numbers. If you can't engrave perhaps Letraset would do. Also the digits do not need to be absolutely precisely positioned (unlike the ticks) so various computer printing options are possible.

Moore and Wright used to make Imperial micrometer heads with "inverted" readings. I have one on the carriage stop that I made for my lathe (Engineers Tool Rooom BL12/24 - Warco BH600/ Chester Craftsman lookalike).

The end thread, which secures it to the stop body is 1/8 BSP, if you manage to find one.

Maybe they no longer manufacture such things.

If you want to be really modern, you might be able to fit a digital depth gauge, and set the Zero at the one end, and then work off the Minus reading on the display? Although Murphy's law says that the display will still be upside down, unless you can find some means of using the other end of the probe against the saddle.

But being ingenious is one of things that makes Engineering so special.

Howard

is there such a thing as a left handed micrometer - Its probably what you want, then modify it.

Here is a left handed vernier

**LINK**

I have a M&W internal micrometer that is 'left handed', at least if you mounted the bit with the fiducidial line to a stop, the bit the thimble moves in and out would be on the right. A range of 0.250" might be a bit limiting though.

Neil