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ibewgypsie
01-20-2005, 08:07 PM
I cut my first tempered steel today. I had on a denium apron, saftey glasses. I cut my first dovetail, the swarf or shavings that came off that steel are like needles.

Geeze, my vacuum sparked when I turned it on, I had to undress at the back door, Worst thing I have found yet in the shop.

How do you deal with it? I found myself running the mill manual with the joystick, stretching the cables as far as they could to distance myself. All the magnets, including the one on the joystick box is "dangerous" now like a porcupine. Not sure how to clean them since.

Dovetail was fantastic thou, I finished it about 2 thousandths over and hand file fitted it. That steel cutting makes you appreciate ALuminum.

Is it supposed to be shavings that small? I thought I was supposed to cut long curls with the drill and the lathe too. I get a smoother finish.

(still learning)

------------------
David Cofer, Of:
Tunnel Hill, North Georgia

Spin Doctor
01-20-2005, 08:21 PM
Side milling in steel with shallow depths of cut often produce long needle like chips. This happens even with end mills providing the length of the cut is long enough (top to bottom). Yah they are a PITA but I have yet to find a way to eliminate the problem beyond the use of roughing type mills which one could do in a Dovetail cutter by hand with a lot of care.

BillH
01-20-2005, 09:06 PM
I just made some out of brass the other day.
And for some reason I dont know, 4 flute endmills work like crap in brass while 2 flute make all the difference in the world. ATLEAST on my micro mill.

spope14
01-20-2005, 09:43 PM
Brass and soft materials I tend to gravitate to 2 flute end mills on 1/2 end mills or less, and for the most part even on the larder diameter end mills. The reason for this is the chip removal of the flutes. Soft materials tend to fill the flutes faster on 4 flute end mills. The smaller the end mill, especially like you may use on a micro mill, the more pronounced the problem.

As for the needle chips, and sorry to chime in, a dovetail cutter tends to lead to these by the cutting action of the multi flutes of the dovetail. Many of these have more than 4 flutes to prevent the intermittient cutting action that may occur otherwise, say in where you may have cut a slot with a straight mill before dovetailing. In a slot where the cutter hits on both sides during the cutting action, you want to have a cutting edge - tooth cutting in both slots at the same time at as much of the time as possible, or deflection occurs.

Smaller chips result, and there is a larger cutting surface area due to the full edge.

there is also the human factor that we tend to run the feed on these slower.

Observations from years of cutting these, looking forward to other observations.

PSD KEN
01-20-2005, 09:56 PM
My introduction to sharp little shavings was a profound experience, akin to hand-to-hand combat w/a porcupine!

toolmakerjim
01-20-2005, 10:21 PM
thats why i hit the power feed and walk away a safe distance...jim

ibewgypsie
01-21-2005, 01:48 AM
Perhaps I used the wrong term? I laid the head over on a degree matching the lil plastic angle finder I got at sears. Cut a "outside" dovetail or "slide" and then filed it so the piranaha break-die would slide on.

Not a true {tee) slot.. Just a dovetail.. what else do you call them? Kinda like the V-ram on the bridgy.

Black betty (cnc) ran like a dump truck tonight. I was running a 1" two flute mill. It shook the machine so hard it went out on "limit estop" twice. (shaking them micro switches a little hard and it tilted)
I changed over to a 4 flute but it was too short to reach all across the angle cut, so I did most the cutting with it, then went to a 2 flute ball end mill and side milled the rest down to a couple thou.

One thing about a Vram machine, you can pivot, angle, or extend the head to meet the work. It is "looser" and not as rigid for sure thou. You lay your hand on the "knuckle" as you drill 1 1/4 or so holes and you can feel her "flex". Scary, thinking that head might just break off there and come down and "whip my ass".. (bear hugging a twisting cutting mill as it slams me into the concrete?)

Nahh, I'll probably get killed doing something stupid instead of some accident. Hey watch this.. http://bbs.homeshopmachinist.net//biggrin.gif You should've seen me with the nunchukas.. whipped my own butt.. I used to be able to..... yep... used to..

David

Forrest Addy
01-21-2005, 10:58 AM
Yup. You're doing OK. Side milling and slab milling in light cuts does make long needle-like chips and that's normal.

There's chips come off machine tools that make a razor wire entanglement look like a feather bed.

I recall years ago when rolling with my sweety in front of a roaring fire on a frosty nght she rose up with a gasp. "Aha!" I thought, "We're getting somewhere." But no. She in her shapely backside had been stabbed with a long monel slab mill chip I'd tracked home from work. I had to pull it out with pliers. No more romance that night. She ever after regarded my carpet as one would a minefield.

[This message has been edited by Forrest Addy (edited 01-21-2005).]

lynnl
01-21-2005, 11:31 AM
I've gotten similar chips from parting off operations on the lathe. Murderously painful little hairlike chips that you can barely pluck out with tweezers. Eventually I learned it's an indication of poor technique/setup.

Spin Doctor
01-21-2005, 06:45 PM
<font face="Verdana, Arial" size="2">Originally posted by Forrest Addy:
Yup. You're doing OK. Side milling and slab milling in light cuts does make long needle-like chips and that's normal.


There's chips come off machine tools that make a razor wire entanglement look like a feather bed.

I recall years ago when rolling with my sweety in front of a roaring fire on a frosty nght she rose up with a gasp. "Aha!" I thought, "We're getting somewhere." But no. She in her shapely backside had been stabbed with a long monel slab mill chip I'd tracked home from work. I had to pull it out with pliers. No more romance that night. She ever after regarded my carpet as one would a minefield.

[This message has been edited by Forrest Addy (edited 01-21-2005).]</font>


Now thats adding insult to injury http://bbs.homeshopmachinist.net//frown.gif http://bbs.homeshopmachinist.net//frown.gif http://bbs.homeshopmachinist.net//frown.gif

Rustybolt
01-21-2005, 08:05 PM
Dave, using coolant will keep the chips down. I've also made temporary sheilds made out of a handy cardboard box. I also keep a speaker magnet in a plastic bag to mow up all the needle like chips.

Don't use the airhose!!

Used to use a rotary carbide burr in a profile grinder.

beckley23
01-21-2005, 09:28 PM
Several years ago I bought a #4 Cincinnati horizontal mill that was on mostly used on SS. You only had to look at the mill and the little invisible splinters would get you. That was one nasty clean up.
Harry

ibewgypsie
01-22-2005, 12:48 AM
My vacuum cleaner, well the 5hp? 7hp? 4hp?, sucking monster had it's match.

The coolant soaked chips ball up right in the 90 degree angle where the hose enters the container. I cut the restriction out. I see I have to build something better. Modified super vac. Perhaps with a 35 gallon drum.

The Gast 1/2 hp 3ph blower is hooked over the door to exit the welding smoke. Unfortunatly it pulls the heat outa the building in about twenty seconds. And, it sounds like a jet turbine to boot, the whine can be heard for a half a mile. It may be incorporated into a super shop system vacuum later. Right now, it is just hangin there. I think the legend plate says 55" h20 vacuum on there. That turbine blower is not designed to blow solids thou. It'd die rapidly with shavings going through it.
Where the 1 1/2" pipe exits the building, to be a "crapper" I put a plastic bag over the whining exhaust and let it flutter for about ten minutes. I was looking for a whistle, only got a squeal.

It took me about 3/4 a hour this morning to get "99 percent" of the needle like shavings up. geeze, they are everywhere. The magnets look furry, not tackled them yet.

[This message has been edited by ibewgypsie (edited 01-22-2005).]

madman
01-22-2005, 02:46 AM
Toolsteels like D2 when grinding with carbide burrs suck. I just wear Good sealed safety glasses and blow them of with the air hose in a safe direction.