Ancient milling device

[tinkerer]

This mill came with the lathe, but the dovetail is too small for the cross slide and too big for the compound. I think the pieces in the dovetail are sacrifical parts, but the ones I have don't really secure it. Can I make larger ones? What do I make them out of. Any suggestions? Getting this in service would speed up my process of making more tooling. I need a QCTP and a mill would help. None of my cutters are on dead center. I have stacked a skill saw blade a parting tool blank and a .005 feeler guage to get three of the cutters dead on.

[sbwhart]

Hi Tink

You can make the gib strips from brass or steel, there should be some screwed holes in the front so you can tighten down on them, if you look on Johns thread "Fixing Darrens Lathe" he makes some a bit more complicated than you want but it will give you the idea of what its about.

http://madmodder.net/index.php?topic=627.0

Hope this helps

Stew

[tinkerer]

Thanks Stew. I reread the thread. I remember the first time I read it, I was very impressed with John's thought process. I didn't have any brass or a way to machine it, so I grabbed a piece of hard aluminum and set the table on the sander to 60 deg and lots of dust and hacksawing later ( I hate aluminum) had formed a piece .63 wide .30 thick with two 60 deg angles and a little over an inch long. The mill has an excentric bolt for tightening. I mounted it and it is solid. I don't expect the aluminum to withstand a lot of the stress for very long, so the first thing I have to do is get a piece of brass to mill another gib strip. I know I will take a couple and post them later.

Friday night lights coming quick and I have neglected preparations too long, so it will be next week before I can get back in the shop.

[tinkerer]

I took the pictures. My plan is to get the brass gib strips made. I will make one for each side if that is the proper thing to do.


I think I will drill this and bolt it to the mill and then make a holder for the brass and bolt it on. I plan on replacing this with steel angle plate after I make the brass gibs..
 
I will post pictures as I progress. If anyone sees something I am doing wrong please jump in.

[sbwhart]

Hi Tink:-

One tip when milling try and get your set up as ridged as you can, a milling cutter doesn't cut continuosly so you get a fare bit of vibration, try and minimize overhang etc, and always feed into the cutter to avoid the dreaded climb milling.

John did a thread on climb milling so you can do forum search for it.

Don't forget you can use your tool post to grip work for milling.

Have fun

Stew

[bogstandard]

Tink,

That dovetail fitting you have on there is a definite no-no. Lash ups like that are courting disaster.

The difference in size is way too much for a gib strip. The way it is, it would be liable to come off at any sign of milling pressure.

If you want to use it on your lathe, you will have to fill part of one side of the dovetail with a bolted in and rigidly fixed filler piece to reduce the larger size down to somewhere near the smaller dovetail, then make a small gib strip to fit.

It is not the sort of job you should attempt to do without the correct experience and machinery to do it.

Sorry to be the bearer of bad news, but in this case, and as always, safety comes first. We wouldn't want to see you getting hurt.


Bogs

[tinkerer]

Bogs,
Thanks for the heads up. So I need to make one for each side and drill and tap the one opposite the excentric side to be on the safe side? I womder if a handplane would work on brass. If not, I can build a fixture to get the 60 deg angle and use a belt sander. I might be able to build a holder and use my table router with a mill chucked in it.

Again , thanks, that is what I am looking for, keep my butt safe and the rest of me too.

[bogstandard]

No Tink,

You have to keep one side of the original dovetails in contact with each other because of the difference in size.

If you look at the crap-o-cad drawing, it shows what I meant.


Bogs

[tinkerer]

No Tink,

You have to keep one side of the original dovetails in contact with each other because of the difference in size.

If you look at the crap-o-cad drawing, it shows what I meant.


Bogs

Cool, that makes sence and is what I will do. Thank you. I am going to read your post on climb cutting. If it is the same as on a router, I know it can eat your lunch and some of your body parts, if not careful.

[tinkerer]

Bogs,

I read the entire thread on making the flywheel and forgot my original intention of looking for climb cutting until I got to the part where you talked about it. Fantastic description of the process, even I understood the steps you took and why.

Climb cutting is the same as on a router table, it can be done, but is best if you don't without knowing what can happen.

Tink

[tinkerer]

I needed clearance on the back side, so I turned the piece around and mounted it and matched the angle. With much trepidation, I began to mill it a little at a time. It seemed to be solid with the small amounts and feed speed I used.

The angle on the back side is different than the front and I didn't want to get any closer to the casting.

I removed it and went to the sander for a final fit. The clearance will ggive me more Z travel.
It just clears the casting. Now to make a holder and a brass gib strip as Bogs showed.