Home machining questions

I clamped the head on the table and a Dial Test Indicator on the quill, then ran it all the way across the head both ways (X and Y), and it had less than a .0005 variation.

It is an old mill, 1939-1940 close as I can figure (Gorton 8D) spent the last ten years in a guys shop with zero use because he paid a GM Industrial Electrician to convert it from 440 to 220 and the guy butchered the wiring and never got it to work right, took me ten hours to do the research and fix it right (I'm not an electrician). The prior 40 years it spent in a woodworking shop, seems like it was never used much. My lathe (a Sebastian 12 x 36, 40" between the tip of the chuck jaws and the tip of the tailstock) was made in the same timeframe, no detectable wear on the ways so I guess it was never used much either. Both are 220V 3 phase.

pretty good guess there is no power feeds on the mill, I think you should use a milling head larger than the width of the motorcycle head, this will insure a flat even surface.
when you try to bore the cyl, you are going to need a steady feed, othere wise you will not get a straight bore.
set up is the most important part, it will eliminat vibration, chatter, and give you the best finish

Power X feed (left to right in case I got X and Y mixed up), it was one of the things butchered by the so called "Industrial Electrician", but I should have it fixed tonight if I can find the right size taper pin for the motor drive gear. 9x24 table travel, so I don't think I will be able to do a 750 four head, but I have not measured one yet.

Yeah, I think I am going to have to make a larger flycutter, it takes me three passes to cover the entire surface. I did not like the results so I made one pass directly over the combustion chambers that extended about 3/4" past the chambers on each side, and then made another pass on each side. Got a blood blister on my right hand fom all the cranking
The longitudinal (X?) drive "will" be fixed before I do this again

The current flycutter only cuts a 3 7/8" path, but the set of three only costs me $10 including shipping from eBay.

I have a lot of leeway because I don't work on anyone else's stuff, just my own, and if I screw it up I either fix it or drag out a spare

you might want to get a machinists hand book, its kind of outdated for most of the new cnc machines but it has some good info in it

We made our own flycutter. It is 8 inches in diameter. It uses a 1" square tool that takes replacable carbide inserts. It can do an FJ Yamaha in one pass.

Jay

BSKZ650 wrote:

you might want to get a machinists hand book, its kind of outdated for most of the new cnc machines but it has some good info in it

Already have "The Machinist Handbook" along with a few others, it took me six months to get the mill and lathe moved to here, so I had plenty of time to study, but nothing beats hands on experience

We made our own flycutter. It is 8 inches in diameter. It uses a 1" square tool that takes replacable carbide inserts. It can do an FJ Yamaha in one pass.

Yeah, that's what I plan on doing, but only 5" in diameter

I'm working strictly on my own stuff (obviously I'm not qualified to do machine work on anyone else's), 750 twins and fours.

Think 5" will make it across the cam chain area for complete clean up?

Jay

APE Jay wrote:

Think 5" will make it across the cam chain area for complete clean up?

Jay

If I stick the cutter in sideways and it extends 1" out to the side that will make it effectively 7" in diameter and should be large enough to reach. But that's only a guess and I'll measure it to make sure before I start making one.

My mill is a Gorton 8D that stands 68" tall, has 9x24 table, and a B&S #7 taper in the spindle, the B&S #7 collets have a max size of 1/2", I am using a 3/4" endmill holder to hold the flycutter right now.
I'm just not real comfortable having a 8" diameter hunk of steel hanging on such a small spindle. I might try the other style of flycutter that is like a square horizontal bar with a cutting bit at the end since it's lighter.

I'd like to find a Gorton 9J (the largest Gorton mill), but it stands almost 8' tall and weighs over 3000 lbs, so I have to find one local as shipping would be a tad expensive

I have less than $500 in all the machines right now (including tooling), drill press, tool cutter grinder, mill, and lathe (all industrial machines, not cheap home stuff), and it is going to stay a budget operation

Post edited by: steell, at: 2006/06/13 18:56

Man, I've not seen a gorton mill in machine shop or factory enviroment in over 20 yrs. I do know some guys that have bought some of the older ones and they all have real short X travels in them. Now, take your actual X travel minus head length, that will give you max flycutter dia. I would take another 1/2" for good measure, take table all the way to the end, point cutter towards head and move head to within an 1/8" and you will go all the way across the chamber area with no problem. Now you need to lower table and work on the areas that the fly cutter didn't get and it isn't near a critical as the chamber area. You can fudge just a little. Machine just enough that you can't catch a fingernail on the machine line and you should be good.
Good Luck

The bigger Gorton mills (8 1/2D and 9J) have a lot more travel than my little 8D

I'm watching a flycutter with adjustable width on eBay right now, if it don't go to high I should have it in a week or so

After I cut .045 off the head with the flycutter there were a couple of lines remaining on each side of the combustion chamber, but not enough to catch a finger nail. I have been thinking about using a piece of glass with 120 grit sandpaper on top of it to wet sand the head a little smoother.
I have been working on the ports also, I figure I'll either gain a noticable amount of power, or lose a noticable amount of power, but I have more cylinder heads and gasket sets so if I don't succeed the first time I'll try, try, again

That's the coolest thing about the 750 twins, parts on eBay are really cheap.