How Would You Make This Part?

Let me rephrase:

I WANT MY PRIZE!!

Thank you.

DT:

My question was how would OTHERS make this part, not how *I* made it. So EVERYONE that posts a viable process for making this part deserves a PRIZE, eh? The "PRIZE" would consist of the respect of your peers for formulating a well thought out & reasonable plan to produce a good part to print. So those that posted, or possibly will post, a procedure the could make the part is an automatic WINNER! I'll relate my own trials and tribulations (boo-boos & corrections) concerning making the part probably later today.

Yeah, yeah, yeah....

So will my prize at least be bigger than the other prizes??

Can I request a substitute? How bout a 5 gal pail of Prep H? I'm running low.... been a rough week....

Plus with Palin, I think ahma really haveta slap dat H on thick..... She scares me so bad, I just sent the Obama-rama-ding-dong camp another $50....

What are the corner radiuses?

Tom:

I'm sorry, I forgot to put than in the original data. They're 1/16"

Step 1.) Square up the two blocks on a mill, finish the thickness to size, leave the sizes .1 big approx or more. Leave an extra .5 on the long side for holding purposes later. While in the mill cut the 2/4 pockets in the corners and do the holes. Lay the block on its side and do the 2 tapped holes on the side.

Step 2.) Wire edm 1 pass finished with the reisitivity set high so the aluminum wont ruin the resin. (try to use at least .010 diameter coated wire if possible, and if it doesn't have to be dimensionally accurate, cut the wire feed speed in half to save the wire material). Cut the part off from the stock you left on the long side with the wire. At the last 1/2 of the cut have it leave .001 stock, so when it comes off you can file that grand off smooth. (Should be able to wire each one in a half an our a piece max.)

Better idea, make it as one piece, slice it off with the wire when done. One setup vs. 2.

1) Hold in vise, square and machine blanks a) 6.000" -.001" x 3.000" x .750" b) Machine 1/16 Outside Corner radiuses. 2) Hole in vise, stand part on side (6" side up) c) Machine tabs drill and tap to finish dimensions

Soft Jaws

3) Install Soft Jaws, chuck on .100" spacers a) mill pocket 6.001 +.001" L, 3.000" W, .650" deep.

Well Bob. I think it's time you tell us what revolutionary way to machine this part you used. Jerry

I'll bet he used a vaccum chuck and had it done before the wire guys could get their finger out. I know I could have.

Jerry:

Nothing revolutionary about it, just regular stuff. Actually I used bits and pieces of some of the various replies that have been posted here. I'll start writing it up after I'm done watching the Ryder Cup.

Thanks to all who replied and for the alternate procedures to possibly doing this part. Not to put too much on it, but I liked hearing all the options people posted. If I had to do more than two parts I would have done them differently.

First, one of the manual guys squared up the blocks and finished ALL the outside dimensions, while I programmed. (We needed work for the manual dept. and it shortens the lead time) I used a 6.5" X 3.5 X .5 alum block held in a vise as a subplate/fixture. I figured I'd hold the parts down by 4-40 screws with plastic washers to not mark the finished surface. Drilled and form tapped the holes in the fixture, plus drilled and reamed some

3/16" holes for dowel pins to locate the parts. 2 pins wide spread on the back X axis, and one pin in the middle on the left side. Put the blank against the pins, and held it down by a couple of Kant-Twist clamps, then drilled all the holes, and tapped the two 4-40 Heli-Coil holes half way through with a cut tap. Didn't want to form tap them since there was too much chance of the form tap deforming the already finished outside surface. Took the drilled blank off to remove the long chips from the two tapped holes, chamfered the holes and put the blank back on and screwed it down with the 4-40 screws and squished the plastic washers snuggly. Used a .250 two flute high helix end mill to radius the four outside corners then used a .500 two flute end mill (7,500 RPM @ 80 IPM and .050 DOC) to rough out the center leaving .050 on the walls to finish. Then went in with the .250 end mill again leaving about .005 on the walls to finish and roughed out the inside front notches as well. Finished with a .125 high helix end mill 7,500 RPM 20 IPM and .050 DOC. The notches in the front were finished with a .125 3 flute ball end mill, profiling the floor.

Doing the holes was a 4 minute cycle time, the pocketing & finishing of the walls was a 34 min. cycle time.

Checked the part and the center of the right side wall was .058 and the center of the back wall was .059 (they were supposed to be .050 +- .010. The walls were within print BUT just barely, and I don't like being on the edge of a tolerance since it can adversely affect other operations down the line. So I added two more 3/16 dowel pins, one in the center of the back wall, and another at the center of the right wall. Did another blank, the walls now came out fine (within a couple of thou) BUT the front left corner was being deflected by the last pass with the .500 end mill since it was pealing up the last .050 of floor and the plastic washers weren't holding the part securely enough to resist movement. SOOO, I changed the program to only leave .010 on the floor and used another op. to take the .010 off, plus I switched to steel washers. I didn't originally want to do that at first since I was afraid that at 7,500 RPM the steel washers would notch the .125 end mill, but I went with them anyway. That's my two original blanks down, so I had Salvador make another two blanks while enduring all the resultant kidding for scrapping his first two blanks. "Hey Salvador, I'm giving you job security, right?" LOL

Anyway, put another blank in and ran it, and it was dimensionally fine, with no feelable notching of the end mill. So ran the second one. Deburred the parts, flipped one over, put a Jo block stack between the front "pincers" and screwed it down to do the notches on the back side... well now the top side.

Next were the two front edge 4-40 Heli-Coil holes. We have some 3"+ tall vise jaws that have a series of .250 dowel pin holes in them. So I put a couple of dowel pins in to locate the side wall of the part, and put another dowel in so that the underside of the where the tapped holes would go would be supported. Put the jaws in the vise and a part against the dowel pins and tightened the vise. I put a Kant-Twist clamp near the top of the jaws to more securely hold the part and edge found the the jaw and part and was ready to machine. The holes were blind with .250 worth of material but the callout wanted .190 min. full thread depth. So I programmed to drill within .020 of breaking through, then helixed in with a .094 end mill to get a flat bottom and machine tapped down .150 and finished the tapping of the holes manually. Ground a tap flat on the end to get another couple of threads in the hole.

And that's pretty much it. Geeze, that was an awful lot of writing for such a simple part. And I even left out a few things. LOL

I was assuming making it on VMC and not having a vacuum chuck. (Only running two parts I error on the side of caution.)

Op # 1) Hold in vise, square and machine blanks a) 6.000" -.001" x 3.000" x .750" OP # 2)

Hold in vise, stand part on side (6" side up) c) Machine tabs, drill and tap 4-40 X 2 Pl

Tooling: Soft Jaws

Install Soft Jaws, chuck on .100" spacers, mill pocket 6.001 +.001" L, 3.000" W, .650" deep. Over cut the corners so part is being clamped on sides not corners, remove spacers.

OP #3)

a) Drill & ream .157 dia. thru holes , drill & tap 4-40 thru holes, Drill and Tap the two clamp holes as shown. b) Rough and finish bosses & all 1/16 corner radiuses with lead in and outs enough to blend with next (larger diameter) tool. c) Cut wall profile leaving .060" floor. OP #4) When cutting the part out can plan on leaving breakaway tabs to secure the part or pour fusible alloy to a level under the tapped holes on side. I have fusible alloy so I would use it, and as an added safety measure I would place 5/32" dowel pins in the .157 dia. X 5 PL thru holes to secure the part as well. a) Carefully clamp the part and bolt cut out down, install the dowel pins. b) first part of the program will finish the boss on the side

4-40 holes then cut out the part. Tom

Typo?

Think it S/B 6.5" x 3.5" x .750"

Tom

Sorry I should have read your whole post first.

Tom:

Cripes! You even DREW the thing, top and bottom! Sorry Mr. PV, Tom gets the PRIZE.

Are you looking for work? I'll send you the next part like this I get. LOL

It was a quick and dirty taking less time than trying to type everything out. Ole lady is on an Alaska Cruse with family, I am home alone (if you don't count 9 pets). I have every thing I need on my laptop so I was sitting here watching the boob-tube drawing it up.

You should see the documentation I send to a shop floor...LOL.....even a near-blind-one-arm-wino should be able to run the job.

Tom

Since we're talking money here, how 'bout "swindle"?