Finding a professional model engineering service

[SillyOldDufferModerator @sillyoldduffer]

Lawrence (toptracks) has a nasty problem.

8mm Dia (No machining required). Part off / cut to lengths of 10mm, 12mm, 14mm and 16mm. 400 off required.  Maybe another 1000 later.

Do-able on a Myford or a mini-lathe except the number needed means the job is very tedious.  Making a few thousand would drive me mad.

A capstan, turret lathe or CNC with a bar feeder would do the job, but only if you have one, and they’re not cheap.  I don’t have room for one, and buying in just to make a few thousand slugs is uneconomic.

Outsourcing is nasty too, because a few thousand is low profit for a professional operation, and they may well not be interested.  The customer has to find a firm, explain what’s needed accurately, and not have a heart attack when he gets the quote!  Likely to include a heavy up-front set-up cost, making the first few hundred slugs expensive.   Only after the set-up has been paid for does the per slug cost drop, which it does dramatically as the thousands rise.

There may be a way!  I always recommend everyone buy a copy of LH Sparey’s “The Amateur’s Lathe”; he covers all the basics.   Chapter 16 is “Production Methods in Small Lathes“.   His opening example is rather more complex than toptracks’ slugs, but the way they are made is similar.   Done with stops and a few simply made special tools, nothing complicated, and knocking out slugs that don’t need to be machined accurately to a good finish is simpler.  Stops speed up positioning the material and cutters considerably – they remove the need to measure and reduce the skill required.

The Chapter covers various other production methods that Sparey applied to his Myford, but the techniques can be applied to other lathes.

I think Sparey is a good compromise – Lawrence takes on a mild-tooling up job, and then bangs out slugs.  Still tedious, but much faster than machining each and every one individually, and practical without breaking the bank.

I recently annoyed someone by daring to say that Myford’s aren’t ideal for production work because they are too light.   In this case production only runs into low thousands, so not a problem, but I hope it’s clear that making 100,000 slugs on a Myford would be asking too much.  It will wear out the lathe!  When volume production is needed, outsource or cough up for a hefty capstan or turret lathe that’s designed and accessorized for that type of work.

Dave

 

 

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