By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by Allendale Jan 24th

Steel for machining

All Topics | Latest Posts

Search for:  in Thread Title in  
Involute Curve04/10/2018 18:23:04
335 forum posts
106 photos

Material Cast Iron, my guess is the original will have been hollow, in order to make to manageable.


Adam Harris04/10/2018 18:25:41
451 forum posts
19 photos

original is solid not hollow

Adam Harris04/10/2018 18:35:39
451 forum posts
19 photos

Or at least the early one (the more curvaceous one) is solid . The later model has a more angular and slightly more bulky one which may or may not be hollow

Neil Wyatt04/10/2018 19:06:32
17692 forum posts
697 photos
77 articles

Bloody 'ell!

I thought you were planning something like this:

For a lump like that, it's possibly worth making your own pattern and getting a casting done. I doubt the price difference will be huge as that will mean so much less metal.


JasonB04/10/2018 19:12:06
17806 forum posts
1948 photos
1 articles

Not so sure Neil, recently picked up some castings and the foundry were charging £10 a kilo, Alibre tells me a basic L shaped blank will be 40Kg and you won't have any offcuts to use for something else.

Adam Harris04/10/2018 19:16:08
451 forum posts
19 photos

Ha Ha Neill! That would indeed be a job! No this is quite a simple affair albeit more voluminous. Are you still recommending EN1A pb?

Adam Harris04/10/2018 19:18:15
451 forum posts
19 photos

Or if casting, what spec of material and anywhere recommended to do it within 100 miles of Oxfordshire?

Adam Harris04/10/2018 19:22:29
451 forum posts
19 photos

I thought a common commercial size billet cut down to rough size with my Rapidor saw which I hardly ever get a chance to use, would be the cheapest way but if casting is cheap then I am all ears...

Chris Evans 604/10/2018 21:52:59
1625 forum posts

Make a simple pattern from polystyrene which will be burnt out of the sand box. This is how I made my new lathe cross slide. Speak to Nigel at Coventry Castings.

Adam Harris04/10/2018 21:59:09
451 forum posts
19 photos

Thanks Chris, I will call him tomorrow. And what spec of material would you recommend casting with?

Marcus Bowman04/10/2018 22:25:54
162 forum posts

The ideal material for a real machine tool would be Meehanite, which dampens vibration, but I imagine that might be a tad expensive. In that case, spheroidal cast iron ('ductile' iron) would still give good results. I have no experience of specifying grades, but this site gives advice:


and I guess a foundry would advise. There seem to be plenty of companies advertising that they either cast from patterns, or sell large section bar. West Yorkshire Steel, for example, sell bar. I have no connection with them.

Bazyle04/10/2018 22:47:30
5125 forum posts
199 photos

I doubt the original would be solid. The big Elliotts use a hollow cast iron overarm with a hollow alloy drop arm (the bit Neil pictured) The drop arm is hollow to provide an oil reservoir.

Mike Poole04/10/2018 22:54:26
2538 forum posts
60 photos
Posted by Bazyle on 04/10/2018 22:47:30:

I doubt the original would be solid. The big Elliotts use a hollow cast iron overarm with a hollow alloy drop arm (the bit Neil pictured) The drop arm is hollow to provide an oil reservoir.

I was able to pick up the overarm for an Adcock and Shiply 1ES and install it so I think it was hollow, it would have been v heavy if solid.


Hopper04/10/2018 23:28:09
4378 forum posts
92 photos

Carving that "L" out of a solid lump is madness. Waste of material, time and machine/cutter wear. Much easier to fabricate it from two pieces of 5" x 2" flat bar, or whatever the size is. The end piece could be either bolted and doweled in position, or even welded on before machining.

The original would have been cast iron because it's more rigid than steel. But steel would do the job in most cases.

You should be able to mill the dovetails to a suitable finish for this purpose. It is not a moving surface under load, like say the ram on a shaper or even the table on a mill. One trick to milling dovetails nice and smooth is to do your finish cuts using only one surface of the cutter at a time. This involves machining to almost final size, then drop the mill table a few thou so the cutter cuts the angled face of the dovetail only for one pass. Then raise the table so the cutter then clears the angled face and cuts only on the flat end face of the cutter and take another pass to machine that face. Yes you end up with a couple of thou in the very corner of the dovetail that is not machined but the mating dovetail should have the matching corner relieved for clearance here so it does not matter.

Michael Gilligan04/10/2018 23:37:50
15427 forum posts
665 photos


I feel sure that you are familiar with the machine, but others may find this page useful for reference: **LINK**


Martin W05/10/2018 00:09:02
831 forum posts
29 photos

The overarm for the F3, see Michael's link above, is quoted to weigh 16kg or in old money 35lbs which is considerably lighter than the weight Jason calculated of 40kg for an L shaped blank. So either I am looking at the wrong thing, Aciera have machined a vast amount off the casting or it is possibly hollow as suggested by other posts above. It is also stored at the bottom of the illustrated tool cabinet as shown in the catalogue, no fork lift in sight wink to extract it.

Martin W

JasonB05/10/2018 06:55:07
17806 forum posts
1948 photos
1 articles

Three clues to it being hollow and scraped as I said earlier

Edited By JasonB on 05/10/2018 06:55:39

Edited By JasonB on 05/10/2018 06:55:58

Ian S C05/10/2018 09:17:18
7468 forum posts
230 photos

I'd say hand scraped, and hollow for that Jason.

If i was making it I'd fabricate from steel plate.

Ian S C

Baldric05/10/2018 09:27:59
149 forum posts
11 photos
For a foundry within Oxfordshire, there is Swan in Banbury, not used them personally but I know they do castings for preservation.
duncan webster05/10/2018 11:00:09
2528 forum posts
49 photos

Cast iron is not stiffer than steel, in fact it's Youngs Modulus in tension is considerable less. Considering that the load is put into the overarm via the much smaller arbor it is quite obvious that high tensile steel is not required, as others have said the original would have been cast iron. Using a 'better' grade of steel will not reduce elastic deflection. Making this out of one piece is just making life difficult, Neil's suggestion is far more sensible. I would just make it out of 2 pieces of EN3 (070M20) or S275, but the latter would not machine as well. If the OP really must have it from solid then a plasma cut blank would be a better starting point

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!

Find Model Engineer & Model Engineers' Workshop

Latest Forum Posts
Support Our Partners
Allendale Electronics
Eccentric July 5 2018
Eccentric Engineering
Subscription Offer

Latest "For Sale" Ads
Latest "Wanted" Ads
Get In Touch!

Do you want to contact the Model Engineer and Model Engineers' Workshop team?

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.

Digital Back Issues

Social Media online

'Like' us on Facebook
Follow us on Facebook

Follow us on Twitter
 Twitter Logo

Pin us on Pinterest