Buying manual mills and lathes for a VoTech shop

[Joe Henderson]

Wells Index used to offer to rebuild BP heads and entire machines. I don't know it they still offer that but it's worth a try. Hass used to offer a manual lathe I think but even good imports are expensive.

 

[michiganbuck]

I just wrote this for another thread so should also post it here.
Drawing at 10x scale.
A very good way to visualize part-to-cutter contact is to draw a part at 10 x scale, with the intended insert also drawn (or whatever the subject of investigation).
So the 1" dia lathe held part would be drawn a 10" circle..to see how the insert .187 drawn at 1.87" and set at part centerline has or does not have proper clearance.

A 5-minute drawing exercise can show a lot.

Every machine shop class student should be given this assignment.
( I had Smith Hughes vocational machine shop and was not given this important exercise.) You can trig it, but that will not have as much impact as drawing it yourself.

note: Careful drawing with a sharp pence at 10X can show .001

 

[Toolmaker51]

I just wrote this for another thread so should also post it here.
Drawing at 10x scale.
A very good way to visualize part-to-cutter contact is to draw a part at 10 x scale, with the intended insert also drawn (or whatever the subject of investigation).
So the 1" dia lathe held part would be drawn a 10" circle..to see how the insert .187 drawn at 1.87" and set at part centerline has or does not have proper clearance.

A 5-minute drawing exercise can show a lot.

Every machine shop class student should be given this assignment.
( I had Smith Hughes vocational machine shop and was not given this important exercise.) You can trig it, but that will not have as much impact as drawing it yourself.

note: Careful drawing with a sharp pence at 10X can show .001

note: Careful drawing with a sharp pence at 10X can show .001
Many will find that hard to believe, until countered with the logic how every mold was drawn, detailed and so built, especially dependent on use of shrink rules. Not just plastic molds, everything. Rubber, cinder blocks, phenolics, aluminum, glass, lead;........ all depending of course on the end use determining precision required.

 

[john.k]

Theft from school machines is nothing new.....back in the 70s/80s Id buy Colchester Students and Bantams from govt schools with the tailstock quill missing,or even the whole tailstock..............ebay and facebook have made theft very easy and profitable ......put the pics online,if it doesnt sell ,then dont bother stealing it.

 

[michiganbuck]

I would have a belt lathe for getting started because they are harder to break. Perhaps a change-gear so students understand gearing.
Have at least one lathe with a taper attachment and steady.
Have a bench grinder so the student can grind a HSS tool bit.
Be sure to teach picking up and existing thread.
I think a surface grinder or a TC grinder(that can be used as a surface grinder in a pinch with just leveling a mag chuck.) is good for a tec shop.
Good to have the student design a screw thread perhaps a 5/8-16

 

[michiganbuck]

"used to be" that some machine tool companies were eager to place their machines so students would be familiar with a certain brand....might call around to some of the sales reps and see if they offer any type of promo machines---stripped down CNCs.
And....at one time while working for a state agency found out certain vendors could supply a pre-written purchase proposal that was known to move through the budget guys/approval process based on their knowledge of gov't purchasing.

That is how we filled our shop class, think we had about 10 high-class lathes from an 11" Sheldon to a very big (?) gear head machine. two surface grinders, a number of mills, a horizontal mill, one or two shapers, a heat treat room, a few drill presses \], pedestal grinders, a cylindrical grinder, and more....and..all in very good usable condition.