[Gooserider]

bigben2k: Hmmm... seems like your table isn't level, or your drilling head isn't perfectly vertical.

Well, I thought it was... my initial checks seemed to say that it was OK, but I don't have the worlds most accurate tools.

The most obvious thing that comes to mind, is that your mounting rig (where you put the block) has to be perfectly clean. Is it?

As far as I can tell, my mounting surfaces have been as clean and dirt free as I can get them.

You can use a locking washer, to help prevent those screws from coming loose from vibrations.

I may try that, or Blue Locktight, assuming I can FIND the damn screws... Lock washers will be a problem on some of them as they are recessed screws, but I'm sure I can get them with Locktight.

Good luck with the hold down clamps: it looks more promising

That's what I'm hoping. I know that part of my problem with the flycutting was that my vise lifted the part up when I clamped on it. I figure if I use hold down clamps at least the blocks won't be able to move.
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MMZ_TimeLord: Two things... One: Your mill head shaft is not at 90° to the table surface. This is causing your milling head to cut only on the back half.

Makes sense, It's what I was starting to suspect when I saw the cutting pattern.

Solution one: See if there is an adjustment on the table or mill head neck to adjust the angle.

There is no documented adjustment according to the manual...

Get out a carpenters square (big one... 18" on a side at least) and adjust the head shaft to 90°. If there is no adjustment, I don't know how to correct it unless your table is bolted to the frame of the mill.

The challenge with that is that there isn't really a place to measure against. There is a big flange around the bottom of the mill quill, so I can't get straight on that shaft. Before I found what a peice of .... this thing is, I would have assumed that the quill was parallel to the side of the head, but these days I'm not putting bets on it.

The only adjustment that I can see is a hairy one. There is a big block bolted on top of the lathe head. The block has a column sticking out of it that the mill head slips over (The mill head resembles a drill press head on steroids) Possibly I could slide the mill head up the column far enough to unscrew the bolts holding the column block on, and stick some shims under it. Possible, but it would really be a B!^C# to do, and I don't know if it would cure my problem.

At least I'm at the point now where I'll be using mill bits, and I don't think there will be a need to be quite so fussy. The measurements inside the block have a bit of flex to them in so I'm not to worried about a few thousandths here and there long as I don't poke through a wall or the bottom of the block.

If so, you MAY be able to shim the table to compensate. Two: Your feed rate could be too fast. Are you using an electric feed motor or manual crank?

Neither, sort of... The way my model Smithy works is that there are two motors, one for the mill head, and one for the lathe. The mill head motor just spins the mill bit; the lathe motor spins the lathe and drives the power feeds on both the X & Y table axiis (as needed for making screw threads, etc.) I was run the mill motor for the flycutter, and the lathe motor for table movement.

The lathe uses a change gear box, and a 3 speed gear selector. I am using the slowest spindle speed (160RPM)
and the lowest speed gear set, giving me the following speed options: (I/R = Inches/rotation, I/M = Inches/min, M/R mm/rotation, M/M mm/minute)

Gear...I/R...I/M.....M/R....M/M
..L.. .002". .320". .05mm.. 8mm
..M.. .004". .640". .10mm.. 16mm
..H.. .008". 1.28". .20mm.. 32mm

When I've been doing my cuts, I mostly use L speed, which seems pretty darn slow to me, it takes about 10-15 minutes to go from clear on one side of the 80mm block to clear on the other. I had trouble at times even seeing the table moving.

In concept the Smithy type multi function machine is a neat idea. Take a lathe, turn the tool rest into a table, and put a mill head over it. Get the function of your two most important metal working tools in the floor space of one. Unfortuneately, it seems the implementation is lacking.

Solution Two: If you are using a motor, see if you can lower the feed rate. If you are using a hand crank, try and half your RPM when turning. Hope this all helps...

The speed I'm using now is as low as it gets, I think my problem is more the tilt on the mill head than anything else. However I'll probably be scribing the layout for my blocks on the rougher side of each one tonight and starting to mill the passages tomorrow, something I expect to be less critical.

I also think this machine may end up on E-bay before to long...

Gooserider