|
|
Post by maninshed on Oct 18, 2010 20:10:04 GMT
Hi Can someone advise whats the best way of turning very small diameters. I seem to remember some where a tool designed for the job, where you had a brass insert in a tool holder which you drilled a hole through the diameter of the stock to be turned down. A small lathe tool was also mounted in the holder which could be moved by a screw to push it into the material to set the diameter that was required. I assume once the diameter was set off you go turning away. Has anyone got any ideas or can tell me which Model Engineer mag it may have been printed in. Or indeed any other ideas for turning small diameters.
Thanks Martyn.
|
|
chrisb
Part of the e-furniture
Posts: 345
|
Post by chrisb on Oct 18, 2010 20:32:59 GMT
|
|
jackrae
Elder Statesman
Posts: 1,333
|
Post by jackrae on Oct 18, 2010 20:33:48 GMT
Chronos Ltd sells the very tool you're looking for www.chronos.ltd.uk/acatalog/info_XC10____.htmlDon't know its quality but what can go wrong with a brass bush and a piece of HSS tooling, apart from they state it's out of stock jack |
|
|
|
Post by Tel on Oct 19, 2010 8:27:41 GMT
Doesn't take long to knock one up.   |
|
|
|
Post by Tel on Oct 19, 2010 8:29:29 GMT
|
|
|
|
Post by maninshed on Oct 19, 2010 20:29:43 GMT
Hi Tel once again you come up trumps, thanks mate thats the jobby I'm after, will have a go at knocking one up.  |
|
|
|
Post by Tel on Oct 21, 2010 4:18:05 GMT
Let us know how you get on. I see by that rather fuzzy pic that I made that back in '94 - probably only been used a dozen times since than, but indispensable when you need it.
|
|
Arnak
Seasoned Member
Posts: 146
|
Post by Arnak on Oct 21, 2010 9:56:37 GMT
Hi,
I assume that when turning with that attachment you would need to turn to the required diameter in one go as if you don't then you would need a smaller bush to support the first cut diameter?
Arnak
|
|
|
|
Post by Tel on Oct 21, 2010 10:10:17 GMT
Yes, it is single pass cutting, but seems to work out OK in most cases
|
|
|
|
Post by drjohn on Oct 21, 2010 11:21:57 GMT
So in my simplistic mind, Tel, you presumably have a specific bush for the finished diameter of whatever you're turning, or am I missing something?
Basically is it like a fixed diameter travelling steady?
DJ
|
|
|
|
Post by maninshed on Oct 21, 2010 13:02:06 GMT
DJ, no the bush is the diameter of the stock you are turning down from, as Tel says it's a single pass tool. You do have to get the tool setup right to cut the diameter you want, once it's and subject to tool wear you can turn away to your hearts content. I spose the idea is to use the nearest size stock material to the finished size you want. I want the tool to machine some 1.8mm stock to 1.6mm so I can then thread ends of it.
martyn.
|
|
|
|
Post by goldstar31 on Oct 21, 2010 14:11:16 GMT
The late Kenneth C Hart wrote as Martin Cleeve in a number of model engineering mags.
He had an ancient( even then) Myford ML 2 or 4 and could not get or afford the fixed steady.
He fabricated one to take bushes of varying diameters and went on to produce steadies to support his later ML7 which has a fairly poor set of bearings and went onto making a new steady for the ML7.
OK, does this apply( knowing the prattle that has gone on about DRO's)?
'Cleeve' spent the last of his years making a good income from bespoke nuts and bolts to all sorts of places.
Funny, does no one else recall the series?
Norm
|
|
|
|
Post by weldsol on Oct 21, 2010 17:15:31 GMT
I would have thought that the "turning box " is more akin to the travelling steady.
Paul
|
|
kingsteam9
Hi-poster
Enter your message here...
Posts: 160
|
Post by kingsteam9 on Oct 21, 2010 17:29:37 GMT
Norm,
I remember Martin Cleeve's 'Bushing Fixed Steady' very well indeed, even started fabricating one for my old (long superseded) ML2 after corresponding with him. The only drawback was the number of bushes (Martin used cast iron for them if I remember correctly) required. I like Tel's approach tho' but the only trouble is there aren't enough days in the week to make all these tools he keeps producing - it's slowing down the main job:-)
Robin
|
|
|
|
Post by jonkett on Oct 21, 2010 20:14:44 GMT
It looks a great idea to me, in reality it is a simple version of a roller box tool, beloved of Ward Capstan lathes etc.
|
|
|
|
Post by goldstar31 on Oct 21, 2010 21:16:57 GMT
Norm, I remember Martin Cleeve's 'Bushing Fixed Steady' very well indeed, even started fabricating one for my old (long superseded) ML2 after corresponding with him. The only drawback was the number of bushes (Martin used cast iron for them if I remember correctly) required. I like Tel's approach tho' but the only trouble is there aren't enough days in the week to make all these tools he keeps producing - it's slowing down the main job:-) I greatly admired his efficient but simple approaches. Years ago, I tried to re-publish his articles as an aid to younger people. It ended up with the threat of litigation from Magicalia. Add suitable epithet Norm Robin |
|
|
|
Post by drjohn on Oct 21, 2010 21:51:37 GMT
Thanks mainshed - I see from Tel's pictures that the bush is towards the chuck - not an actual upside-down Australian illusion ! ;D
DJ
|
|
|
|
Post by Deleted on Dec 16, 2010 15:30:00 GMT
Here is a gadget that seems to solve most of the problems associated with turning small diameters. The idea and the picture was given to me by Paul Clarke of Southampton SME: he used one for long 6BA bolts. Note the clearance hole drilled from the back before the flutes are cut, leaving about 1/8th bolt length of required diameter.  I decided to make a few! 8, 10 & 12BA, and 2mm:  They were pretty straightforward to make on the rotary table, just make sure that you are exactly on the centre height.  Five degrees front rake was applied.  Hardened, cleaned up, and that's 1.7mm at 1250 rpm!  Here's 1.3mm!  A very handy set of gadgets! JB |
|
|
|
Post by locoian on Dec 16, 2010 15:55:18 GMT
Re simply locos gadget, these are known as hollow end mills and used to be commercially avaible for use on capstan lathes for running down bolts etc. Cheaper than a roller box and did not need setting.
Haven't seen them for years
Ian
|
|
|
|
Post by maninshed on Dec 22, 2010 20:15:59 GMT
What a brilliant idea, simplyloco thanks for the detailed description of manufacture, I might have a go at one.
Martyn.
|
|
