|Mark Davison 1||18/10/2018 19:00:21|
|114 forum posts|
Newby after material selection advice.
I'd like to make a rear mounted tool post of a (soon to be new to me) MK1 colchester bantam. I've really struggle to find a used one and have decided making one could be a good first project.
My question is, what material for the main body? EN1 or EN3 mild steel seems easy to source, but I can't find a source for anything more exotic, not even EN8 (it all seems to be round bar). Would cast iron be suitable (I can find 60mm x 60mm x 6" on ebay)?
Example below from a Bantam 2000 which has incorrect centre height
Edited By Mark Davison 1 on 18/10/2018 19:01:17
|pgk pgk||18/10/2018 19:36:02|
|2605 forum posts|
should you want it m-machine show 2.5" square EN8. they also stock cast iron
|Neil Wyatt||18/10/2018 19:53:40|
19079 forum posts
EN1a should be fine unless you plan to use it day in day out.
|Chris Evans 6||18/10/2018 21:19:50|
2069 forum posts
I used an offcut from a flame cutting place, just mild steel and free. It was a pieces on the floor that I spotted when going in to order a piece.
|Rod Renshaw||18/10/2018 21:36:33|
|376 forum posts|
Some years ago a contributor to the ME press ( I can't remember which magazine ) detailed a toolpost for a smallish lathe which he said was made from a grade of steel which was stronger than ordinary mild steel and which machined easily to a good, bright finish which was fairly rust resistant. Sounds like useful stuff for things that get a lot of handling.
I seem to remember the author was based in the US. Does anyone else remember this article? What kind of steel was it and is there a UK equivalent available here?
2947 forum posts
Hemmingway's do a kit for rear mounted tool post to suit small / medium lathes. I made mine from the kit; have a look in my album 'Rear tool post'
|chris stephens||19/10/2018 00:07:24|
|1049 forum posts|
To make my rear tool post for my Bantam I used a top slide and part of the cross slide from , I think, a Boxford. It's useful because it still has its indexable four way tool post.
|larry phelan 1||20/10/2018 13:48:40|
|1192 forum posts|
I made two rear toolposts for my Craftsman lathe using nothing more than offcuts of BMS which were kicking around,nothing fancy,one was made from a piece of two inch box tubing,and I use it all the time.
I just cut the pieces to size and welded them up,drilled and tapped for Allen screws,and used a piece of 12mm threaded rod to clamp it to the cross slide.Bit iffy,like much of my stuff,but it works,and if you paint it to match the machine,who knows ?
I made another tool post for use from the front,this one rotates and locates,like the "proper" one. Reason was that I had tools set up in the proper post and did not want to upset them,but need to use other tools as well for the job.
Was not too difficult to make,cut out the location slots on the mill.,Works fine.
|jimmy b||20/10/2018 14:57:34|
793 forum posts
|EN1a should be fine. |
I've now got front and rear QCTP.
|Howard Lewis||20/10/2018 21:30:24|
|6317 forum posts|
The fourway rear toolpost for my BL12-24 was made from laminations of 1 x 3 inch BMS, bolted togeter.
My previous ML7 hasd one made from a piece of 2 inch Box section, with 5/16 plates welded on at top , bottom and part way (to act as the tool platform). Worked well.
Machined from a solid block of suitably sized steel will work quite well, as long as you don't use a grade that tends to work harden There lies disaster!, and several spoiled cutters!
You can either machine a keyway to siut the T slots on the Cross Slide, or make stepped dowels to fit the T slots. My fourway, locates against the back of the Cross Slide by two dowels, but is clamped by a two M8 studs in a long T nut. Just have to remember to pull the toolpost so that the dowels touch the Cross Slide when clamping.
With hindsight, should have made ring dowels to fit into the T slot!
|John Reese||20/10/2018 21:39:10|
1038 forum posts
I suspect it was a resulfurized medium carbon steel like 1141 or 1144. There are proprietary steels made by an elevated temperature drawing process. Examples are Stressproof (100Ksi), Fatigueproof (120Ksi), ETD 150 (150Ksi), and ETD 180 (180Ksi). Mild steel has a tensile strength around 60Ksi. Ksi is kilo pounds per square inch. These steels machine brautifully. Unfortunately they are only available as rounds,
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