|John Haine||14/01/2020 16:44:13|
|3252 forum posts|
I want to roll a bezel for the dial of my next clock, from brass strip say 5 x 10 mm. I believe this can be done using a set of rolls but I don't want to either buy or make this just for a one-off. I sure sure I have seen somewhere details of how a simple lathe fixture can be made so you can use a roller in the headstock against two other rollers on some kind of bracketry. Does this ring any bells for anyone, if so could they remind me please? Alternatively if you have direct experience please share?
|John Reese||14/01/2020 22:42:35|
|845 forum posts|
You could probably roll it around a mandrel like winding a spring. I think a simple roller on the toolpost would work to form the dtrip to the mandrel.
Things to consider"
Are you roiling it the easy way ao the hard way? If the hard way the material may try to twist.
Allow for spring back. The mandrel will have to be undersized.
You will be rolling a helix. Can you fet it flat enough afterwards?
Does your lathe have the balls to pull it off?
|John Haine||14/01/2020 22:58:26|
|3252 forum posts|
|Bob Stevenson||14/01/2020 23:35:12|
|424 forum posts|
Cut the brass carefully to the right length for the finished diameter using rxpi (at 3.142) file edges nicely as this will help later.....place on hearth and heat using a 'brushy' flame...keep the flame moving until the piece is just glowing..ie not too bright or red......if the torch is small it's ok to start at one end and work to the other but keep it moving.....allow 'glow' to go and then cool under the tap.....
Find a suitable former for your diameter...ideally a little smaller than the finished diameter.....a lathe chuck can be good but always use several layers of gaffer tape to get to the exact diameter...this is both for exact sizing and also to protect the brass surface using just your FINGERS bend the brass round the former in one operation...use a hardwood block to get the ends to meet nicely, or use the clamping of a 'workmate'.
Carefully file the join using a flat file (I use a warding file0 until there is no light coming thru the join when you hold it closed.......silver solder. In all probability there will probably be some slight heat distortion so return the piece to the former for final pampering....If the walls twist use padded pliers to gently untwist so that a perfect fit onto former.
18598 forum posts
As seen on Traction Talk only a couple of days ago using two freely rotating rollers and the mill on slowest speed For your size of strip a couple of bearings would do as rollers.
Edited By JasonB on 15/01/2020 08:11:35
|John Haine||15/01/2020 08:41:07|
|3252 forum posts|
Thanks Jason! I knew that bending rolls would do the job from an article in HJ but not wanting to buy a set just for one job I need to improvise the same method. I hadn't thought of using the mill but that looks much better than the lathe. I've got a couple of big bearings too.
Thanks also for the other suggestions.
|Clive Brown 1||15/01/2020 08:54:38|
|477 forum posts|
Bear in mind that the set-up shown in Jason's post will leave a short straight section at each end of the strip, perhaps to cut off or re-roll after joining. GHT addressed this issue with his design in ME using pinch rollers. This much reduced this effect.
|Martin Kyte||15/01/2020 09:20:40|
1998 forum posts
That sounds suspiciously like employing a filing rest as the other pair of rollers. I have never heard of it before but filing rests were popular at one time with clockmakers for putting squares on the ends of arbors and other sundrey tasks. It's not any great leap of imagination to repurpose a filing rest on a lathe into a light duty ring roller for clock bezels. Not sure I would be happy doing this with anything other than thin brass strip.
|Andrew Johnston||15/01/2020 09:21:53|
5635 forum posts
You get the same flat, but only on one end. So the work needs to be swapped end for end on each pass.
|Roger Hart||15/01/2020 09:37:27|
|118 forum posts|
I once made a bezel for an old French mantle clock, about 150mm dia with bevelled glass set in. This was not an easy job and I would not try it again!
Cut 3/8 square brass to length, anneal, bend into ring and silver solder. Use oak former to make round. Set into grooved oak plank on faceplate, clean up front and back and use form tools to make nice rounded bezel shape. Cut groove for glass and clean up inside. Then silver solder on hinge and catch and re-true up and cut snap groove on inside rear. Then cut glass and bevel and polish.
This worked but was 'difficult', good luck with your bezel.
|104 forum posts|
In May last year , I needed to roll some “T” section brass to support the roof of a loco cab.
Not wishing to purchase gear specifically for the job , I made a set up similar to that detailed by Jason , and it worked very well indeed .
As will be seen , a roller with a groove in it was mounted in the milling machine spindle , and a number of roller bearings mounted on the table , slowest speed and reverse at each end .
|John Haine||16/01/2020 09:47:33|
|3252 forum posts|
Thanks everyone for the suggestions, especially Jason and Mr. Godley for the photos of setups. I'll report back on progress when I've tried it, one way or t'other!
Please login to post a reply.
Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!
You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.
Click THIS LINK for full contact details.
For subscription issues please see THIS LINK.