HELP fixing Fowler thread micrometer

[oldplanecollector]

HELP. Does anyone know how the anvil lock works on these micrometers?


I picked up a thread micrometer at the flea market. It has the replaceable anvils so it needs to be recalibrated after changing anvils. The anvil that goes in left end is adjusted by hand in or out as needed to re-zero and locked down with the thumb lock. The lock however doesn’t work and I can’t figure out how it is supposed to work.


I’m trying to understand how the locking mechanism is intended to work, but I’m at a loss. There’s nothing that bears down on the replaceable anvils to lock them in place. Nothing appears to be missing from the mechanism.
The thumb lock appears to do nothing. It doesn’t enter the barrel and doesn’t even arrear to contact the barrel at all.

There is a moveable ball bearing that is a perfect slip fit on the inside of the barrel.

 

[awander]

Email Fowler, and I bet they will help you out.

I had an interchangeable anvil micrometer that I broke through sheer stupidity, and they sent me a new piece for it, taken from one they had lying around.

I was quite impressed with how helpful they were. It was totally my fault that I broke the tool and they went out of their way to help me fix it.

I corresponded with:

Dave Leboeuf
Service Manager
Fred V. Fowler Co., Inc.
66 Rowe Street
Newton, MA 02466
617-332-7004 ext. 337
www.FVFowler.com
DaveL@fvfowler.com

 

[oldplanecollector]

I feel foolish now. I figured it out. I thought the anvil itself was locked in the barrel when re-zeroing, but I finally discovered that the anvil seats all the way in the barrel and stops against the ball bearing and the BARREL moves in/out to zero. My barrel was frozen and wouldn't move. I added a couple drops of tool oil and let it soak in and freed it up. Now it makes sense why the thumb lock locks down the barrel and not the anvils.

BTW, thanks for the response about contacting Fowler. Sometimes when I buy stuff at the flea market I miss the obvious resources. If I had bought it new from a distributor, contacting Fowler would have been top of my list. But for some reason when I only paid $20 it didn't even occur to me to contact the manufacturer. Go figure.

 

[RWL]

Does your micrometer thimble turn easily when closing it, or does it 'catch' at certain points? I've got the same micrometer and it gets tight at certain points and then moves on from there. It feels as though something internally is catching. I don't know if it's just mine or whether all of the Fowler thread micrometers do this.

 

[awander]

It's a simple 40TPI thread-shouldn't catch at all.

Check for dried lube or possibly burrs on the split nut(if it uses one-I don't remember).

 

[RWL]

It's a simple 40TPI thread-shouldn't catch at all.

Check for dried lube or possibly burrs on the split nut(if it uses one-I don't remember).

My intuition is that the catch is occurring in the gears that control the digital readout. I've been hesitant to open that without knowing more about what might be inside.

 

[Bill Gruby]

My gut feeling on this is that you are correct. The hang up is in the digital read out. Be extremely careful taking it apart. Things sometimes pop out when you don't expect it. A trick I learned is to use a large clear freezer bag. Take the mike apart in the bag. The parts are confined and will not become part of the floor.

"Billy G"