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View Full Version : Need a bit of help please (milling)



torker
08-31-2007, 08:32 AM
Hey guys! Haven't been around much lately but my new business is starting to fire on a couple of cylinders...even getting to do a bit of machining now. I need to mill .005 off two sides of 3/8" square mild steel. I need to do about 24 feet of it and havent figured the fastest way to do it. The stock needs to be cut into 2 1/2" long pieces at one time or another during the process. I'll have to use my mill/drill to do this as my horizontal mill is tore down so I can move it to my other shop.
Make some soft jaws for the 5" Kurt and do a few pices at a time or do a 10 ft length and keep sliding it ahead....or what? How would you tricky devils do this?
Thanks!
Russ

Evan
08-31-2007, 08:46 AM
Take your mic down to the supplier and buy a piece of undersize stock.

I would mill it with my shaper. :D

tattoomike68
08-31-2007, 12:22 PM
Saw it into the short peices. When you mill on 2 sides it will stress relieve and warp like a banana.

Carld
08-31-2007, 12:34 PM
Mill/drill huh, well, cut it into 32" lengths and clamp it down on the table and flycut a section and move it and flycut a section until the length is milled. Roll it over and do the same. Then cut it to required lengths. I doubt taking .005" off two sides will cause much warpage.

Do you have a surface grinder? That may be a good way and more accurate.

There is no easy way.

Evan
08-31-2007, 12:45 PM
There is an easy way but I am pretty sure Russ doesn't have the equipment. If the entire length is stretched about 1.5 percent it will be the right size. Straight too. It would require around 10 tons of pull.

Do you have the Hairy Kanary running yet? :D

gzig5
08-31-2007, 01:03 PM
Put the horizontal back together, gang two cutters on the arbor with the right shims and go at it.:D

I think Carld has the most sensible solution. Cold roll will warp, but taking five thou off opposite sides it shouldn't move much, if at all.
Greg

LastOldDog
08-31-2007, 02:51 PM
Torker, you did not mention which two sides, opposite or adjacent, I read this as taking .005 off adjacent sides, as in 3/8 - .005, square like undersize key stock. Not opposite sides. If tolerance is required, my fave would be the surface grinder. For 100+/- pcs @ ~1 sq in per, load up a 6"x12" or 18" with 50 pcs.

If this is hot roll, nasty scale, and you have a shaper, gang several of them, set the cutter to just clean up. Then for the opposite side set the cutter to the finished height and go, no reason to then adjust anything. Rotate them 90*, and do the same.

I think for .005 the easiest would be touch them on a 6x48 abrasive belt to remove a few thou. A simple MDF fixture,guide against the miter gauge, touch one side, flip, do the other side, handled once, a little rough, but quick
Lloyd...........

Forrest Addy
08-31-2007, 03:41 PM
Take it to a woodworking shop and ask them to blow out their TimeSaver wide belt sander and run it through. They may not because the sparks will pose a hell of a fiire hazard but with the machine blown out and the blast gate closed there should be no real probllem for a piddling 0.005 per side on stuff that narrow. They could do the job in 4 passes and you don't have to cut the stock in little pieces except for convenience in handling.

mochinist
08-31-2007, 03:48 PM
The best way(imho) would be a surface grinder with a table big enough to fit them all at once, a 2.5" piece isn't going to warp any noticable amount in a short piece like that and would most likely only be a problem if you took all the material off of one side. That really isnt that many pieces, and not sure how big your vise is but you should be able to do four to five at a time and skin them with a shell mill or a nasty ol flycutter.

mochinist
08-31-2007, 03:50 PM
Take it to a woodworking shop and ask them to blow out their TimeSaver wide belt sander and run it through. They may not because the sparks will pose a hell of a fiire hazard but with the machine blown out and the blast gate closed there should be no real probllem for a piddling 0.005 per side on stuff that narrow. They could do the job in 4 passes and you don't have to cut the stock in little pieces except for convenience in handling.Oh I forgot about those machines, I had a local wood working shop do pretty much the same thing on some G10 years ago, finish and thickness were both really good for as quick as they did it.

Carld
08-31-2007, 03:51 PM
Actually he said .005" off two adjacent sides the way I understood it. I have machined .020" off one side of 3/8 keystock without it warping so I guess he's safe but he may get a piece with stress in it. Keeping it cool helps.

mochinist
08-31-2007, 03:56 PM
Hmm I guess you could read it either way, still I wouldnt be to worried about them warping from that small amount.

Evan
08-31-2007, 08:20 PM
It's adjacent sides. What would be the point of taking off .005 from opposite sides instead of a single op .010 from one side?

Your Old Dog
08-31-2007, 09:08 PM
I'd farm that puppy out to Sir John. If it ain't done the next day I'd call'em up and ask "what the hell?" We're talking tall buildings in a single bound here so that stock of your should pose no problem :D

Good luck with the new business Russ.

mochinist
08-31-2007, 09:24 PM
It's adjacent sides. What would be the point of taking off .005 from opposite sides instead of a single op .010 from one side?The print could have called out for a specific finish on those two surfaces, and there could be numerous other reasons for doing it that way. But you know all so end of story

beckley23
08-31-2007, 09:52 PM
I would cut the material to length first, then do the milling. I've done similar jobs and have been faced with the same issues.
Harry

wierdscience
08-31-2007, 10:56 PM
Cut it up first,then setup with a carbide endmill spun up full bore.Mill the face so the endmill is turning away from you and into the fixed jaw of the vise on the first pass using the powerfeed.Once it clears the end of the piece stop the mill and roll the part.

That way when you roll the part for the next side roll it towards you then reverse the feed,doing that the first burr is milled off on the next pass leaving a sharp corner and only one burr to remove with no lost motion on the table.

It'll take longer to deburr the one edge than it will to mill both sides:D I got to go now,I'm having short run production flashbacks:D

torker
09-01-2007, 11:51 AM
Thanks guys! Lots of good ideas. I need to take .005 off of two adjacent sides so the square stock will slide into 1/2" square tubing. Tolerances don't need to be really tight. A taxidermist uses these things to make the antlers removable on his display mounts. Ha...halfway through the job and I'm finding I bid it a bit too low. Must be part of some kind of learning process I guess.
The first two months of running the new business have pretty much been a disaster but it's starting to get better. Relying on straight motorcycle/sled part sales isn't cutting it but as I move more of my equipment up to the place it's getting better. I added a heavy flux core wire machine to the stable and it's my money maker now. The lathe and milling machines are going to be pretty busy by the look of it. Have two very good machining jobs next week. I'm thinking I may just cut these 3/8" pieces to size and try that.
Thanks!
Russ

Evan
09-01-2007, 12:07 PM
Go check your stock again Russ. I wouldn't be surprised if it comes from the same source mine does. I just had a look and the 3/8" sq I have will fit nicely in between the 1/2" walls without the seam. All that needs to be done is to take off one side of the 3/8 to accomodate the seam bead.

jkilroy
09-01-2007, 12:13 PM
Torker,

Remember, if you find yourself winning all, or most, of your bids you are not charging enough.