# new roller part for jig



## marcros (3 Aug 2011)

I am making a small jig and am struggling to get a vital part. Part of the problem is knowing the correct term to use for searching.

I am looking for something like the rollers found on a roller table, but only about 50mm long. Diameter is not important, but approx 6-8mm would be ideal. They only need to be fixed at one end, but need to roll smoothly.

Any ideas?


----------



## paultnl (3 Aug 2011)

I am not sure if this is of any help http://www.vxb.com/page/bearings/CTGY/8 ... ionSystems


----------



## marcros (3 Aug 2011)

More like this but much smaller and thinner. 

http://uk.rs-online.com/web/p/conveyor-rollers/2548683/

I want to sharpen the end of a 3/8" brass pipe, so was going to set the angle and fix it, then roll the pipe on the rollers to sharpen all the way around


----------



## xy mosian (4 Aug 2011)

You know when something is tickling the back of your mind. It's just come through clearly  

Pinch rollers from a desktop printer. Hardish rubber rotating on a steel shaft. Now all you need is someone with a duff printer.

xy


----------



## marcros (4 Aug 2011)

That shouldnt be so hard to find.

Thanks


----------



## bosshogg (5 Aug 2011)

These are roller ball catches, I wonder if these would help?



...bosshogg


----------



## Eric The Viking (9 Aug 2011)

Similar to Bosshogg's thought...

... large ball bearings, or even marbles, would also work, if you can drill accurately-aligned pairs of holes for them to sit in.

This might also spark some ideas: 

I had to put accurate 30deg internal bevels on 1" brass plumbing fittings recently (to convert straight spigots to compression fittings!). 

Not having a lathe or a 30deg cutter, I made an MDF plate* angled at 15deg, with a hole in it, that sat on the router table, with a V-grooving cutter (45/90 degrees). There was a 1" hole in the plate near the bottom where it touched down. 

The plumbing fitting sat in the hole, and the highest point of the inside edge of it made contact with the cutter (that gave 30 degrees pretty accurately). I started with the cutter clear of the fitting, turned the router on, and slowly raised it with the height adjuster until it was just cutting very slightly. Rotating the fitting gave a clean bevel. 

Here's the essence in cross-section:






After that it was 'raise slightly', then 'cut until the bevel is clean', repeat, until I got the amount of bevel I needed. 

It worked a treat, and the fittings are now part of the central heating system!

Could you do something similar? You'd need a stop collar clamped on the brass pipe to prevent it slipping down, but that's easy, as long as you have a snug clearance drill for the size of pipe you're using.

I think I'm going to start a new blog on "Uses for the T11 the makers didn't intend"! 

Cheers,

E.

*It needed to reach the edge of the table, with 15 degree blocks glued on above, to give parallel surfaces to clamp it down so it wouldn't move - looked like a mini ski jump.


----------



## marcros (10 Aug 2011)

That idea might just work actually. I could drill a small hole and put a pin through to support the piece above the hole. Was it quite a quick opperation to do each fitting?


----------



## Eric The Viking (10 Aug 2011)

marcros":3mi8v7ws said:


> That idea might just work actually. I could drill a small hole and put a pin through to support the piece above the hole. Was it quite a quick operation to do each fitting?



Very. 

15 degree blocks cut on the bandsaw, hole to taste: position isn't critical as long as you can raise the cutter enough to engage with the brass fitting, so near the lower end of the board somewhere. 

The hardest thing was wedging the vacuum hose so as to grab the fine brass chips under the board (got most of 'em but still had a clean-up job afterwards). I didn't want brass chips going into the router motor, but that wasn't a problem - they are all arranged to blow out from the sharp end, and anyway most swarf got thrown sideways under the board. 

The actual thing is quite long. It looks like a ski-ramp because it runs to the edge of the table, so as to get a clamp on it to hold it well. My table isn't well enough made to clamp down using the T-track on its own (short screws into MDF, grrr! It's on the to-do list...) Nearer the cutter, I put a second block, and held it down with a bit of 2x2 across the table and clamps either side.

Overall, it's all down to having a router fitted in/with something that will work easily as a micro-adjustable lift whilst it's running. It's built into the Trend T11 (wot I 'ave), but at a guess, anyone's router-raising mounting plate ought to do. Obviously you have to arrange things above the table so you can get at the adjuster, but that's not a big deal. 

If the intent is to use the finished tube as a cutter (leather or similar?), you'll need a reasonably acute angle. I found out later that Wealden do a 30 degree cutter, so I could have avoided a bit of fabrication, but the board does give somewhere for the chips to go.

I got the hang of it with two scrap spigots as practice. The hardest thing of all was finding 1" BSP thread spigots that weren't tapered - they're usually used in the tapered thread pattern, so the workpieces were unusual. You won't have this problem!

Having said that, 3/8" doesn't give you much margin for error in aligning the pipe with the cutter. Whatever you use to hold the pipe needs to be Steve Maskery's 'Goldilocks' fit -- not too tight nor too loose. I got far better results than expected - the finished fittings sealed first time without undue tightening, nor recourse to leak-stopping goo (the olives and nuts were not removed from the pipe they were fitted to originally, just cleaned carefully with xylene to remove any congealed crud, then tightened onto my new adaptors with Boss White, as normal).

I wouldn't use a pin through the tube, but a collar clamped on. Drill 3/8" through a block, carefully perpendicular, slot it and drill for a clamping bolt. The reason is that the larger surface will mean it turns more smoothly - you need to keep a bit of downward pressure so it cuts evenly and doesn't chatter. I use soft pencil lead as lubrication for stuff like this, or greaseproof paper (if I'm not caught by the Domestic Controller!). 

I can't help thinking, for all the hassle, it might be easier to find a bloke (or lass) with a lathe. 10 mins. set up and he'll knock out as many as you could ever need, accurately and cleanly. 

Sorry - wittered on as usual. I could dig the remains of the jig out of the scrap bin, but it wouldn't tell you more than above really.

HTH, E.


----------



## CHJ (10 Aug 2011)

marcros":dibk7hqu said:


> I am making a small jig and am struggling to get a vital part. Part of the problem is knowing the correct term to use for searching.
> 
> I am looking for something like the rollers found on a roller table, but only about 50mm long. Diameter is not important, but approx 6-8mm would be ideal. They only need to be fixed at one end, but need to roll smoothly.
> 
> Any ideas?


Find yourself someone with a metal lathe and provide them with a sketch and quantity req'd. :idea:


----------

