Travelling Steady Fixture for Thinning Narrow Diameter Bar

[klankParticipant @klank]

I need to turn down a length of 5mm silver steel rod over quite a long length to 3mm and 3.5 mm at various points. The problem is “springing” if trying to cut the work unsupported.

 

I can vaguely remember seeing plans/article for a tool post mounted fixture to act as a sort of travelling steady and cutting tool which supports the work as it is thinned in an old issue of the ME (?in the 1990’s?).

There was, I believe, a short follow up article, noting improvements to the original.

 

Such a tool/fixture is marketed by Chronos (usual disclaimer) – but “out of stock”!

 

Can anybody kindly tell me which issue(s) of the ME contains the article(s)? – it is difficult to find this item as there are so many “key words” to describe it.

 

Thank you

 

Peter

[klankParticipant @klank]

Help Needed To Find ME Article

[JimmieSParticipant @jimmies]

Hi klank

Issue 173 and 174 of Model Engineering Workshop have details on making and using fixed and traveling steadies by Harold Hall.

[JasonBModerator @jasonb]

Hemmingway do one that uses a small brass bush

  

J

Edited By JasonB on 05/04/2011 13:14:49

[klankParticipant @klank]

Thanks for the info. Jimmie.

 

Unfortunately a “standard” travelling steady with three “fingers” will not work for the very thin rod I need to reduce.

 

The item shown in the rather old ME article I am trying to find had a circular “bush” with a hole in it to act as the rod support on the end of the tool fixture.

[klankParticipant @klank]

Jason,

Just saw your kind reply – thank you – I didn’t realise such a “kit” was available – many thanks for the info.

 

If I cannot find the old article – that might be the solution!

 

Peter

[TerrydParticipant @terryd72465]

Hi Klank,

 

I’ve seen a simple hardwood or even thick ply steady made by bolting a suitably shaped piece to the steady holes on the cross slide and the cut applied by the top slide. The wood should be impregnated with grease at the bearing point of course. It is an old fashioned, but effective and perfectly acceptable method (inexpensive and simple to make as well).

 

Regards

 

Terry

Edited By Terryd on 05/04/2011 15:10:09

[klankParticipant @klank]

Thanks Terry – that is a neat idea.

I might try it if all else fails.

I like the adjectives “inexpensive and simple”!

 

Peter

 

[JasonBModerator @jasonb]

This post by Stew has a lot of pics of the chronos one, you should be able to work something out from them.

 

Tel’s one at the end looks the easier to build though

 

J

Edited By JasonB on 05/04/2011 13:25:44

[klankParticipant @klank]

Thanks for the kind help Jason.

 

Tell’s fixture is exactly the type of thing I was looking for – something similar, I think, in the ME article.

 

Enough in his photos to have a bash.

 

Thank you

 

Peter

 

 

 

[Gray62Participant @gray62]

Hi Klank,

Issue 85 of MEW has a very nicely designed small roller box

 

regards

 

Graeme

[klankParticipant @klank]

Hi Graham

Thanks for the link.

 

I had seen this article a while back – a very nice piece of kit – but too complex a challenge for the small job I have to do at this stage and possibly betond my present skills.

Maybe I will make it when I am more experienced.

 

A “screw push feed” hss cutting tool and bush fixture in the tool post, like Tel’s, is the sort of thing I would like to do and its the plan in ME I am looking for.

 

Failing that – a piece of greased wood on the cross slide (Thanks Terry) seems a likely cheap and cheerful alternative.

 

Anyway – I appreciate your reply.

 

Regards

 

peter

 

[chris stephensParticipant @chrisstephens63393]

Hi Peter,

What do you call a long length?

chriStephens

[JasonBModerator @jasonb]

Peter, Tel posts on HMEM and Model Engineering Clearing House, you should be able to PM him and get the details, he’s a helpful guy.

 

J

[klankParticipant @klank]

Hi Chris,

I need to turn a stock length of 5mm silver steel rod down to 4mm dia. for 38mm length and then a further 28mm length at 3mm dia. This is for a valve rod on a stationary engine.

 

Peter

[JasonBModerator @jasonb]

You should be able to get a ctr into that, turn teh 3mm bit first with about 30mm sticking out teh chuck then move the work out of teh chuck again to do the 4mm dia.

 

Unusual choice of material, stainless would be the norm.

 

Jason

[klankParticipant @klank]

Jason – yup – my mind is in neutral – the material IS stainless – D’OH.

 

I always assumed a ctr. would not be sufficient – I will try a test bit first – thank you.

 

Peter

[chris stephensParticipant @chrisstephens63393]

Hi Peter,

I did try to post earlier but the ‘puter froze up on me, again, and I could not post it.

The only bit of that post that would now be of any use is;

 

To reduce the tendency to bend under the cutting action, one trick is to support the work with a piece of oil soaked leather, held in the hand. If H&S are watching, “up yours!” it is perfectly safe, if done properly. Light cuts and very sharp tools are, of course, the order of the day on thin work.

 

Jason has already said the important bits, although I would have said collet instead of chuck, unless it is a four jaw or a grip-true.

chriStephens

[GoCreateParticipant @gocreate]

I machined some 3mm dia x 60 long valve stems in stst by first placing a piece of ali bronze in the drill chuck held in the tailstock, then drilled and reamed it 3mm. I turned the end of the stst bar down to 3mm for about 8mm long. Then I repositioned the bar so that the turned end ran in the ali bronze for about 4mm length. Just supporting the end was enough to prevent deflection with a sharp tool and light cuts.

 

Nigel

[klankParticipant @klank]

Hi Chris

 

Thank you for the tips – yes, I would use a collet, but never thought of oily leather – neat idea – could be used, I suppose, in conjunction with Nigel’s tip (posted below yours).

Thanks very much.

 

Hi Nigel

 

What an excellent idea – that’s the way I will go for this job – plus some oily leather just in case.

Many thanks.

 

Peter

[TerrydParticipant @terryd72465]

Hi Klank,

 

Just a word of advice, ignore if unnecessary, I don’t want to teach my granny to suck eggs, but do ensure that the tool is exactly on centre if you are going to machine thin sections without support. Even a slightly low tool can cause the work to climb it with bad results for the work.

 

The simple wood device I suggested would essentially have
the same effect as Tel’s device.

 

Regards

 

Terry

[Gray62Participant @gray62]

Hi Klank,

I agree, the complexity of the tool is ott for a one off. that said, I have built this tool and it has proved its usefulness on more than one occasion, in fact, I have built a scaled up version for more ambicious tasks and the fundemental design has proved itself very capable.

For anyone machining small to mid diameter bar, I would highly recommend this design. All complements to Mr Rawlinson for an excellent design concept

 

regards

 

CB

[NJHParticipant @njh]

Hi All

 

In a rush of enthusiasm a while ago I bought the Chronos tool shown in Jason’s post thinking ” that will be useful one day.” The day arrived recently when I needed some long 8BA studs – longer than any available commercially. The tool worked like a charm! I did look up the price of 8BA studding (!!!) and I think the tool has also paid for itself in this one exercise! The bad news for anyone wanting one is that it appears to be unavailable at the moment – this may be just temporary. You can of course make one!

 

Regards

 

 

Norman

[klankParticipant @klank]

Norman – I have done as you did – got one of those nifty little ready made tools from Chronos – (they just got new stocks in!).

As you say, it works a treat – job now done and no tears!. Added bonus of a usefu length of HSS tool steel in “the kit”!

 

Just remember to set it up carefully (on centre and in line)

 

Once again, thank you to all who so kindly offered help/advice – very kind.

 

Best wishes to all

 

Peter.

[mgjParticipant @mgj]

The Chronos thing is very good.

 

For this particular job, I think I’d have turned a spigot (for alignment) and silver soldered the 2 bits of stainless together.

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