[phansen39]

Ok softer sacrificial wear makes sense. Sounds like the brass is the way to proceed. Tried to get a small some turcite but is only sold in larger quantities. At this point I doubt this mill will be cnc. Just won a spectralight with the high speed spindle, but no control box. $200.00 school auction. Electronics are not a problem for me though. Might keep or repair and flip the spectralight. The spectralight will used to make the small parts for sure. Then who knows.


I can get brass strips locally. But not 0.020 thickness. Would you go thicker or thinner like 0.016 or 0.025? Thinking the 0.025 would last longer.

[handlewanker]

Hi, .025" would be less likely to crinkle.....I think we used .020" for the lathe build....it's just a barrier between the steel faces.

The brass does require a stable background to enable it to work the same as a slide without it, otherwise it will just make spot contact with the high spots where it touches.

I would definitely, and without a doubt, ensure that the two slides mate together first without the shim......bit of filing and scraping called for here to get the base slides dead flat and parallel, then mate the saddle to it as the shim is of uniform thickness..... just fit the shim between the faces.

If the base slides are too far out on the contact faces you might have to give them a lick with a flycutter in the mill.

I couldn't be sure, but some thin sheet aluminium between the faces might also work if the slides are a good fit initially.....heavy question mark on that proposal......the ally might be too soft and smear, causing it to partially weld particles to the stationary slide and eventually seize up.

Practically all model aero engine had/have main bearings directly in the ally casting, but in that case the crankshafts are hardened and ground.

You'll have to fit the screws and/or nuts after the shim is fitted as it will put them off centre by the thickness of the shim.

As it's not intended for CNC, I don't think seizing up will come into the picture due to the intermittent and fairly slow travel speeds.

You could stick the brass to the saddle slides and gib with impact adhesive or epoxy resin, as there is not that much force on the slide longitudinally, and it makes securing it much simpler.

BTW, with box slides only one slide is used to guide the saddle longitudenally on all faces and has the gib, the other slide only has the top and bottom in contact, so you need to attach brass shim to 4 faces on one slide, one being the gib, and two faces on the other slide.
Ian.

[phansen39]

The saddle faces are definately flat and true. Spent hours on them with a files and dremel. Does have a couple oops on a couple surfaces though slipped with the angle grinder. In other news I will be picking up my Spectralight mill later today.

[Marcus4ar]

In other news I will be picking up my Spectralight mill later today.

[phansen39]

HeHeHe picked up to mill and sold it before I got it to the van. and made 50.00 on it to boot.

[handlewanker]

Hi, just Googled the Spectralight mill....pretty small and basic model.....OK I guess for learning what makes the wheels go round etc.

I think you did OK to get an extra $50 for it.
Ian.

[phansen39]

The super high tech brass shim alignment jig.
Attachment 186678

[handlewanker]

Hi, are you gluing the shim on, hence the clamps etc?

On the lathe build we bent the shim up at the ends and held it in place with some small screws, otherwise it tends to drag out of the slide.

The lathe was only 7" swing, and the bed was 3" wide made from 1/2" thick X 3"wide cold rolled steel bar with a base structure made form 4" channel iron, back to back with spacers welded in.

The brass shim was thought of when it became obvious that the steel on steel would probably cause a problem from lubrication failure.

Initially, the saddle was "designed" to be made from a block of cast iron scavenged from some machine part at the local scrap yard, but as it meant machining, where none was available, this was redesigned to totally using cold rolled material in various sections, hence the need for a sliding medium that would not seize up.

With advanced design criteria in the mind, I recently came into possession of a roll of Stellite 6 Mig welding wire, and as my main welding source is a plasma welder I want to .....one day......experiment with coating a steel slide with Stellite and using it after rework as a slide medium for wear quality etc......it just depends on the ability to add enough Stellite to enable a surface flatness of some quality for a slide.

The problem would be that the other slide would have to be case hardened and ground to make the method work.....probably more trouble than it's worth.

BTW, you could still have used a slab of aluminium for the saddle, with the brass shim interface for wear resistance, as it's so easy to work with.
Ian.

[phansen39]

Yes epoxied on. Well I'm glad I got the knurling tool. Took just a little bit to much off. Seem to have a bit of a taper too. Need to check that tail stock.
Attachment 186740

[phansen39]

There fixed it. Squared up that tail stock. Cutting square now. Lost 3/4" but won't lose any travel on the z axis. So all good.

[phansen39]

Well I have decided to build a mill you must have a mill. So I bought a project. A little sieg x1. Guy I got it from was trying to retrofit a sherline spindle into it and also eliminate drill press function. For some reason he cut the middle out of the spindle sleeve instead of shortening it and turning new bearing cups. So todays project instead of the bigger mill we'll work on the micro first.
Attachment 188382Attachment 188384Attachment 188386Attachment 188388
So carefully clamped the 2 halves together and tack welded. Welded the spindle sleeve around fully. Dialed in on the 4 jaw turned the weld and the shoulder down. I even checks square. So I'm happy. Took me like 30 minutes to clamp the thing together. Have a couple welding voids but not worth fixing.

[handlewanker]

Hi, I hope it's "man " enough to mill what you need.......looks a bit on the light side.

Does that mean there is no more quill function and it now rides on the column vees for the Z movement?

When you come to sell it you might make more than $50 if the build goes right.

I think the column will give you a headache....it looks like a pencil on a plate.....LOL......you might have to add a thick steel sub base with a square steel tube behind the column to beef it up a bit.

How far did the original owner go in the build?

It looks like a stepper is already in place for the Z axis, and two more under those covers on the X & Y.

Ball screws would be a Rolls Royce feature.
Ian.

[phansen39]

Its really lite. Yeah no more drill press quill function. The quill sleeve had the middle 1/3 or so cut out. He got about as far as you see in the 4th picture. The mill is cnc'ed but was never completed. I think all the parts are all their except the original quill and of course the quill sleeve. Not worth the cost of replacing though. I'm thinking when I'm done using it as a mill refit it as a router with a laminate trimmer router motor and have a little cnc router.

This is what it looks like complete:
Attachment 188426

With cnc kit: