geoff walker 1 | 27/04/2019 17:26:56 |
521 forum posts 217 photos | Hi All, I have a piece of BMS plate 1/8" thick and using it I want to make a cylinder end cap. The cap needs to be 34mm O/dia and have a spigot 20mm dia and 1mm long to fit the cylinder bore. Any ideas on how to hold and machine. I have an idea but thought I would ask first to see if anyone has a better idea. Thanks Geoff
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Nick Wheeler | 27/04/2019 17:52:48 |
1227 forum posts 101 photos | Wouldn't it be simpler to machine it from bar and part it off? |
SillyOldDuffer | 27/04/2019 17:54:31 |
10668 forum posts 2415 photos | If you mean like this: I'd saw a square out of the plate and take the corners off with a file leaving a rough octagon big enough to make a 34mm disc. Then I'd super-glue the octogon to a round bar held in the chuck. I'd turn the 1mm deep spigot first, and then round off the rest of the cap. Take it gently and the super-glue will hold the interrupted cut, (may not be necessary to file the octogon first, but it reduces the clonking!) Super-glued parts can be separated by boiling, blowlamp, or soaking in acetone (aka nail varnish remover). Dave |
Roderick Jenkins | 27/04/2019 17:56:24 |
![]() 2376 forum posts 800 photos | I'd make it as round as I can by hand, super glue it to a face plate and then creep up on it with a very sharp tool. A bit of warmth should break the glue joint. HTH, Rod Edit: Just like Dave really Edited By Roderick Jenkins on 27/04/2019 17:59:54 |
Emgee | 27/04/2019 18:04:58 |
2610 forum posts 312 photos | Roderick and Dave you have some excellent super glue, what make and type please ? Emgee |
JasonB | 27/04/2019 18:11:26 |
![]() 25215 forum posts 3105 photos 1 articles | Same as Dave and Rod, if you have any doubts about your glue the tailstock can be used to hold a pressure plate against the part while turned. I tend to use Mitre bond or the small 5mm bottles of Loctite superglue |
David George 1 | 27/04/2019 18:18:39 |
![]() 2110 forum posts 565 photos | Hi Geoff I would hold in 4 jaw turn boss leaving outside till later and counter bore a 10mm conterbore as deep as the boss for a centre support. I have a piece of 10mm dia. silver steel with a centre in it to push against jobs. Take out if 4 jaw chuck and hacksaw of corners clean up and glue to a bar with super glue. Hold in place with centre support and Finnish outside diamiter and face. David |
SillyOldDuffer | 27/04/2019 19:10:49 |
10668 forum posts 2415 photos | Posted by Emgee on 27/04/2019 18:04:58:
Roderick and Dave you have some excellent super glue, what make and type please ? Emgee I've done OK with cheapo Poundshop glue as well as more expensive brands. The trick is cleanliness and fresh, in-date, glue. Oil weakens super-glue severely, so any suspicion of grease and I wash the metals with warm water and a spot of detergent, then rinse and wipe off with Meths. Even clean metal is wiped with Meths before using super-glue. As often as not super-glue metal to metal joints are embarrassingly strong when I try to break them. Although cleanliness may be the most important factor, super-glue seems to 'go off' fairly quickly; for me new glue seems more reliable. Dave |
not done it yet | 27/04/2019 19:26:03 |
7517 forum posts 20 photos | I would not start with BMS - it will likely warp when you remove the surface skin and fall off its substrate. |
Speedy Builder5 | 27/04/2019 20:39:25 |
2878 forum posts 248 photos | As soon as you glued it to a boss and mounted into a chuck etc, bring a rotating centre up to bear onto the plate for extra support.
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geoff walker 1 | 28/04/2019 09:38:30 |
521 forum posts 217 photos | Hi All, Many thanks for all your replies, very useful. Would have replied sooner but we had a tribal tsunami (aka the grand kids) last night so not much time for internet chat! Yes I was thinking probably have to get it roughly round then bond the plate in place and as Rod said "creep up" on it and take by surprise. Will use the tailstock for support. I like Davids idea of using a shallow counterbore. I'll have a go in the week and report back Big T again to all Geoff |
Hopper | 28/04/2019 11:26:52 |
![]() 7881 forum posts 397 photos | You could soft solder it to a stub mandrel rather than glue it. Much stronger. You could hold your square of plate in the 4-jaw, face it, put the spigot on it then make a stub mandrel smaller diameter than the finished end-cover's OD. Then put a recess in the end of the stub mandrel for the spigot to fit into to help hold job in place. Then turn the square down round to finished OD and face the final surface. |
geoff walker 1 | 01/05/2019 14:10:12 |
521 forum posts 217 photos | Hi All, No big deal this but as you guys were kind enough to offer advice I thought I would show the results. I was surprised just how easy, by heating, it was to break the superglue joint between the cap and the boss. Jobs a good 'un, thanks again Geoff |
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