Help repairing Fowler dial caliper

C

clevinski

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Hi, All,

I can't remember the last time that I completed a project without having to fix some tool, fixture, or machine in the middle of it. Today is no different. I am making a couple of simple aluminum spacers, and was measuring my progress with my 6 inch, Fowler dial caliper (the S/N is G9058374, if that tells you anything about the model) when it suddenly stopped moving. I assumed that some swarf got into the gear, but couldn't see any. I used a compressor to blow through the gear so that the chip would go back out the direction from which it entered, if there was a chip, but that didn't help. I got it to move a bit, but it feels very rough and keeps hanging up.

So I did what I always do when something's not working; I started disassembling it to get to the root cause of the problem. After removing the "tail" (used to measure hole depth, etc.), the travel stop, the gib and all the other screwed-on parts, I'm left with the body of the caliper (which includes the rack), and the moving jaw (which includes the dial mechanism). Looking down from the end of the rack, it looks to me like the pinion on the dial is only engaging the rack by 30-50%, and I suspect the problem is in there somewhere.

The question is, how do I get the dial mechanism off to take a look at it? The rack doesn't have teeth all the way to the end, so I can't just slide the moving jaw off. I'm guessing that I'll have to remove the cover from the dial, remove the needle and the printed scale to get at it, but I'm not sure, and I can't see how to remove the cover. :help:

Also, does anyone have any experience as to what can cause my original issue? Even with everything off, I can apply a little pressure to keep the gear in the rack and slide the moving jaw back and forth, but every so often it hits a spot where it definitely want to stop. The rack looks clean, so the issue might be inside the dial mechanism itself.

So back to my little project now with another caliper, but I'm bummed, because the Fowler is my favorite 6 inch... :bawling:

I'm hoping that I can get this repaired with the help of the many experienced machinists here... I appreciate all your help!
 
Phil Perry a Moderator in the machine Scraping Forum has repaired one of my Inter-Rapids. PM him and see if he can help you. Rich
 
Our college book store started stocking Fowler 6" dial calipers for machine tool students. The whole batch that the store received was defective and has to be sent back to the supplier. Fowler calipers used to be a decent tool but we no longer recommend this brand.
 
atwatterkent said:
Our college book store started stocking Fowler 6" dial calipers for machine tool students. The whole batch that the store received was defective and has to be sent back to the supplier. Fowler calipers used to be a decent tool but we no longer recommend this brand.
Click to expand...

Hi...

This particular caliper was 20+ years old... It's worked flawlessly until now. Now it's in the junk pile...
:thumbzdown:
 
Gentlemen, et al,

Once upon a short time, I worked for Fowler (1976). Taking apart calipers was the first thing I learned. They got a lot of them back for repairs. Mostly Helios, I think. The bezel, unless it has 3 set screws, prys up, (yes - that's what i said), with a screw driver on each side. Just lever it up.
The base under it is plastic. Don't take out the lens. You need special dies to put it back. The lenses start out flat. OK, there are hand pullers made. http://www.ebay.com/itm/like/370908034088?lpid=82 They hook around the side of the hand, and you push down on a knob that extends a pin, to push the pinion out. But, you can make a simple one out of brass or steel. File it out to fit around 2 sides of the hand, tap a smal hole / 0x80 or 1x72 / file down the tip of a threaded rod, or screw, to fit into the hole. OR, take 2 jewelers screwdrivers, and lever it out with a quick snap. Careful to cover the face first - the dial, not yours:)-

Now it gets interesting - there's a retainer for the pinion! It holds it in place. The gear has a groove in the center, that retainer fits into. That's easy, isn't it?? One more thing, as i remember, there may be paper or plastic shims behind the rack. be sure to put them back in the same positions.

Best,
Payson.
 
clevinski said:
Thanks, kd4... that helped me get the crystal off. Unfortunately, it looks like I broke the shaft for the pointer during disassembly...

Oh, well...
Click to expand...

clevinski said:
Hi...

This particular caliper was 20+ years old... It's worked flawlessly until now. Now it's in the junk pile...
[/QUOTE

Payson Greene said:
Gentlemen, et al,

Once upon a short time, I worked for Fowler (1976). Taking apart calipers was the first thing I learned. They got a lot of them back for repairs. Mostly Helios, I think. The bezel, unless it has 3 set screws, prys up, (yes - that's what i said), with a screw driver on each side. Just lever it up.
The base under it is plastic. Don't take out the lens. You need special dies to put it back. The lenses start out flat. OK, there are hand pullers made. http://www.ebay.com/itm/like/370908034088?lpid=82 They hook around the side of the hand, and you push down on a knob that extends a pin, to push the pinion out. But, you can make a simple one out of brass or steel. File it out to fit around 2 sides of the hand, tap a smal hole / 0x80 or 1x72 / file down the tip of a threaded rod, or screw, to fit into the hole. OR, take 2 jewelers screwdrivers, and lever it out with a quick snap. Careful to cover the face first - the dial, not yours:)-

Now it gets interesting - there's a retainer for the pinion! It holds it in place. The gear has a groove in the center, that retainer fits into. That's easy, isn't it?? One more thing, as i remember, there may be paper or plastic shims behind the rack. be sure to put them back in the same positions.

Best,
Payson.
Click to expand...

Payson

Is there any hope for the caliper now if the shaft is broken?
Click to expand...
 
Of course. Call Fowler. They're near me, in Auburddale, MA. 1-(800) 788-2353. speak to the parts dept. All those parts, hand, pinion, pinion holder, should be available. Maybe digital has taken over, but i still see dials for sale.


Indicators are fun too!
Payson.
 
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