How is this filing rest used?

[ic0n]

There were couple of mysterious bits floating around in the bottom of a watchmaker's lathe box whose function escaped me. One was obviously a file rest, but I couldn't see any way of mounting it to anything. The other was just some random seeming bits of shiny metal:

The other day I was looking for some images of filing rests (the conventional double-roller sort) and google found me a post on Reddit where someone was asking 'what are these tools'. Among them was this image:

The person who responded said "It's a filing rest". I rushed to put my bits together and what do you know:

My question is, how is this mounted to anything on the lathe? The bottom 'cup' bit acts as a screw clamp, I think, but to what? The screw isn't long enough for it to open very wide. There's a couple of purposeful-looking 'nicks' you can see in the photo. I can find no other photos like it on google and it's not in Britten or any of the lathe books I have. Any ideas how it's used?

[ic0n]

Come on - have a guess! Someone must have a clue?!

[Neverenoughwatches]

4 minutes ago, ic0n said:

Come on - have a guess! Someone must have a clue?!

Ask me about the screw lantern in the top left of the second picture

6 minutes ago, ic0n said:

Come on - have a guess! Someone must have a clue?!

You can see the 2 rollers that the file rests on, what you dont see is the mount on the lathe.

[oldhippy]

Looks like something is missing. 

[Michael1962]

I am thinking that you are correct that the part you said looks like a cup bit and the other part with the cutouts attaches to some upright bolt on the toolpost of a watchmakers lathe.

 I just had a quick look online and I think you would want to mount it on a T bolt attached to something like the crosslide on this lathe. 
https://www.ebay.com.au/itm/125097830836?chn=ps&norover=1&mkevt=1&mkrid=705-159824-816807-4&mkcid=2&mkscid=101&itemid=125097830836&targetid=4585444532064602&device=m&mktype=&googleloc=&poi=&campaignid=412352395&mkgroupid=1309518645581565&rlsatarget=pla-4585444532064602&abcId=9300543&merchantid=136820&msclkid=e807fc1532a01c357b9099716690733c
This is total guess though.

 Is it possible that even though it is called a filling rest that it is possibly used with a Jacot tool and a burnisher?

Edited November 27, 2023 by Michael1962

[Neverenoughwatches]

1 hour ago, Michael1962 said:

I am thinking that you are correct that the part you said looks like a cup bit and the other part with the cutouts attaches to some upright bolt on the toolpost of a watchmakers lathe.

 I just had a quick look online and I think you would want to mount it on a T bolt attached to something like the crosslide on this lathe. 
https://www.ebay.com.au/itm/125097830836?chn=ps&norover=1&mkevt=1&mkrid=705-159824-816807-4&mkcid=2&mkscid=101&itemid=125097830836&targetid=4585444532064602&device=m&mktype=&googleloc=&poi=&campaignid=412352395&mkgroupid=1309518645581565&rlsatarget=pla-4585444532064602&abcId=9300543&merchantid=136820&msclkid=e807fc1532a01c357b9099716690733c
This is total guess though.

 Is it possible that even though it is called a filling rest that it is possibly used with a Jacot tool and a burnisher?

I'm not sure you would use it with a cross slide, what you are looking at in the link is a vertical tool post to hold cutters. I dont see why it cant be attached from the side locking nut through a hole in a flat post. There's a part that we are not seeing.

[ic0n]

This is tool fully dismantled:

 

It's only a single roller. It seems strange that the other one out there in Internet-land had exactly the same parts?

[Neverenoughwatches]

1 hour ago, ic0n said:

This is tool fully dismantled:

 

It's only a single roller. It seems strange that the other one out there in Internet-land had exactly the same parts?

Ah that makes more sense, i thought this ( see the picture below ) was another roller. I've seen them with 2. That part just swaps out for the t-rest then  doesn't it and drops onto a rod thats in place of the rest ?

2 hours ago, ic0n said:

This is tool fully dismantled:

 

It's only a single roller. It seems strange that the other one out there in Internet-land had exactly the same parts?

Seems a lot of kafuffle when a post on the bottom of the rest will do. What does your lathe setup look like ?

[ic0n]

My lathe is a 6mm Lorch. I actually do have a couple of filing rest options, but I'm just curious about this widget!

 

I tried the idea of using the tool rest, but it's too tall:

 

Anything on the cross-slide would definitely be too tall:

 

I have a few other bits whose function I'm puzzled about, but we'll come to those later!

[nickelsilver]

Try flipping the roller part over, and swivel the whole thing forward 90 degrees, so the roller is "facing up", would it fit then? I much prefer single rollers to double, at any rate you have another single there that works!

 

[Neverenoughwatches]

1 hour ago, ic0n said:

My lathe is a 6mm Lorch. I actually do have a couple of filing rest options, but I'm just curious about this widget!

 

I tried the idea of using the tool rest, but it's too tall:

 

Anything on the cross-slide would definitely be too tall:

 

I have a few other bits whose function I'm puzzled about, but we'll come to those later!

It looks like it needs to be on the other side of the post and the roller should be pointing  upwards on its frame. If its still too high maybe it was meant for a bigger clearance headstock ?

[ic0n]

I think Nickelsilver and Neverenoughwatches are saying roughly the same thing and I see the logic. The only thing that gives me pause is that mechanically, having the roller pivoted at the end would be an odd choice. Any excess pressure when you were filing and the damned thing would slip.

Well now I feel silly:

The 'system' merged my two replies - it made more sense when they were separate!

[Michael1962]

Try loosening the horizontal clamp and rotating the vertical clamp forward until the top of the roller is on the centreline of the lathe. If you can’t get it there, I would suggest that this rest is for a lathe with a higher centreline. 

[ic0n]

10 hours ago, Michael1962 said:

Try loosening the horizontal clamp and rotating the vertical clamp forward until the top of the roller is on the centreline of the lathe. If you can’t get it there, I would suggest that this rest is for a lathe with a higher centreline. 

Hi Michael - see my picture in the post above yours - it turns out to be a graver sharpening jig, not a roller file rest after all! And it does a very fine job of that.

[Michael1962]

Ah, I had seen your photo but did not look close enough at the item in the jig.

Well done Sherlock. Mystery solved.