trimming length of brass bushing

thomas harris · Post by **thomas harris** » Sat Oct 27, 2007 4:03 pm

What is the best trick to hold it while I face it off to the correct length? It has a flange on it to compound the matter. Couldn't get one stock in the right length.

SteveM · Post by **SteveM** » Sat Oct 27, 2007 5:47 pm

Make an expanding mandril that fits inside it, but far enough back to clear what you are trimming.

The mandril would be turned on the outside to the bore diameter of the bushing, with a shoulder for the bushing to sit on. Bore a hole in it (I think tapered might be better) and make a tapered plug to go in it. Slit the mandril crosswise so that when the plug goes in, it acts like a collet in reverse.

Drill the plug for a clearance hole and the mandril for a tap hole and put a screw in. Tightening the screw will expand the mandril.

Let me know if I'm not clear (wouldn't be the first time).

Steve

thomas harris · Post by **thomas harris** » Sat Oct 27, 2007 10:22 pm

That's what I figured more or less, but how will I slit the mandrel. I have no milling cpabilities. Any other "caveman type" way?

Post by **Harold_V** » Sat Oct 27, 2007 11:52 pm

You can bore a bushing made from aluminum or even plastic, that has a body diameter slightly greater than the shoulder diameter, which would allow your chuck to close on the bushing so it can be gripped in a three jaw, or even a collet. You may need to saw the bushing end to end through one wall, so it will collapse easily.

Soft jaws are the perfect solution to your problem. Does your three jaw chuck have master jaws? If so, you could hold the bushing by the head and face off the required amount. Don't try that without properly machined soft jaws, otherwise you'll destroy the bushing----guaranteed!

Harold

edit: deleted poor wording. Intent is unchanged.

fourjc · Post by **fourjc** » Sun Oct 28, 2007 7:53 am

You can also make a split bush, slightly larger than the head you your brass bush, insert you bush in it, chuck and face.

RET · Post by **RET** » Sun Oct 28, 2007 8:24 am

Hi,

If the finished length of the bushing is fairly long compared to the shoulder width, it would be simple to make a split bushing that just fits the OD. of the bushing body (not the head) and use that to grab hold of in either a 3 or 4 jaw chuck. Collets would be even better if you have them. Obviously the sleeve OD. has to be greater than the flange diameter.

The point is that because you are just cutting the thing to length & facing the end, it doesn't have to be concentric, it just can't wobble. As long as you can hold it securely so there is no wobble, that's all that's necessary.

After I wrote it, I see this is basically what Harold suggested, but with a bit better explanation.

Richard Trounce.

Jay, Idaho · Post by **Jay, Idaho** » Sun Oct 28, 2007 8:27 am

Slit the mandrel with a hacksaw, deburr with small files.

SteveM · Post by **SteveM** » Sun Oct 28, 2007 7:46 pm

If you can mount the work on the cross-slide at the right height, you could use a slitting saw in the chuck or a collet.

Just make sure everything clears before you turn the power on!

If you have a cross slide table on your drill press, you might be able to do it there, but go light - drill presses aren't meant for side loads.

Other than that, hacksaw blade and debur, as Jay says. Use a FINE TOOTH hacksaw blade if the wall is thin.

Steve

Anselme · Post by **Anselme** » Mon Oct 29, 2007 7:53 pm

What size bore does the bushing have? I've made a self locking mandrel by turning a bore size diameter with a shoulder ,then milling a flat on it and using a small dowel pin on the flat,the flat has to be just .001 or so larger than the dowel,a small clockwise turn on the bushing locks it on the mandrel.
Send me your e-mail and I'll send you a scetch.
Anselme

thomas harris · Post by **thomas harris** » Mon Oct 29, 2007 9:46 pm

It's done. Just used a tight fitting plastic sleeve and oh-so-carefully tightened the chuck onto both of them. Held fine for the lateral pressures needed to face a small sintered bearing. Thanks for the ideas. I'm sure for more demanding work the special mandrel would be the way to go. The fits on both sets of bearings were excellent.