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DMS

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#31
Is that rebound tester a commercial unit, or is it shop-built?
 

Ray C

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#32
Commercially available. About 90 bucks on eBay but some dealers are asking way more.


Is that rebound tester a commercial unit, or is it shop-built?
 

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#33
BTW: Here are examples of the testers I have. These are just the 1st ones I grabbed pictures of on ebay. Shop around. Both can be had for 1/2 of what these dealers are asking.


Question: If there's any interested in this turret head, I'd be willing to make an additional one and sell it at auction here with 20% of the proceeds going to support this site. Let me know if there's any interest in that -but you'll probably want to see what it looks like first understandably.


Ray

http://www.ebay.com/itm/MILLER-ENGI...203?pt=LH_DefaultDomain_0&hash=item3375d8b003

http://www.ebay.com/itm/Portable-Br...153?pt=LH_DefaultDomain_0&hash=item2a146d84b9
 

Dranreb

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#34
BTW: I got an unusual PM from someone about this and some of my other demonstration projects so let me explain... I'm well aware that nothing I'm showing is rocket science and I try to give decent verbal descriptions and show pictures to help some of the folks that are learning this for the 1st time. Some people learn with pictures some folks need written words etc..

Ray
And as one of your target audience I thank you for that Ray

Bernard
 

Bill Gruby

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#35
Ray, I'd like to have a nickel for each PM I got saying I was getting too simple in my explanations. You are correct, not all have seen some of the things we do done before. Keep doing what you are doing and ignore those others. Bang up job on this one I must say.

"Billy G"
 

Ray C

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#36
Thanks, Bill -that means a lot -and I appreciate it.

It was bang-up all right... When I was setting the plate down for the 1st time on top of the shaft in the rotary table, it was a tight fit and suddenly the plate just dropped into position -Right Smack On My Finger! -Finger is still banged up! :bawling:. Man, I can read my pulse by looking at my finger...

Ray




Ray, I'd like to have a nickel for each PM I got saying I was getting too simple in my explanations. You are correct, not all have seen some of the things we do done before. Keep doing what you are doing and ignore those others. Bang up job on this one I must say.

"Billy G"
 

Ray C

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#37
Quick update:

Minor snag today and I had to surface grind the plate after all -but not due to warpage or heat distortion... When I pack carburized this big piece, the foil would not seal well and chunks of the carbon stuck to the surface. Tried scraping, wire wheeling and sandblasting -no luck. Some of it chipped off but other pieces were too stubborn and seeming hard as diamond. In the grinder it went and I took off just enough to get all the bumps off. I checked hardness after the grinding -no difference at all. Naturally it's harder toward the outer diameter and in the areas where the holes were clustered together. In those areas, it's RC 42, in the center RC 32 and at the edge of the center hole, back up to RC 40. I don't know if this is acceptable variance but suspect it's within the realm of acceptable -definately OK for this non-critical part.

There's a big learning curve with this. I've done several smaller parts and measured them precisely before and after treating -there was no measurable difference at all. Wasn't expecting the carburizing material to stick like this; no doubt due to oxygen exposure. Next time I get into a situation of not being able to seal the foil, I'll shoot the oven up with CO2 during the process to see if that helps.

Grinding that big monster is a real chore... Here's the top side.

Hard and Ground.JPG

Ray

Hard and Ground.JPG
 

DMS

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#38
Well, as consolation, it looks real perty now ;)
 

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#39
And here it is with black oxide. Next up, start working on the adjustable pedestal or possibly, make a couple of the holder blocks. Haven't decided which to start with yet. Makes no difference; I'm working from a CAD drawing.

BTW: The black oxide looks splotchy in the photo. It was still drying.

Black Oxide.JPG

Ray

Black Oxide.JPG
 

itsme_Bernie

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#40
WHOH Ray! That is beautiful!


Bernie
 

Ray C

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#41
Thanks. We're heading into the juicy humid weather. Wanted to hurry and get that over with.

So what do you want to see next; pedestal, taper blocks or switch back & forth?

Ray

WHOH Ray! That is beautiful!


Bernie
 

pboulay

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#42
And here it is with black oxide.
BTW: The black oxide looks splotchy in the photo. It was still drying.

Ray
So what potion do you use to do the black oxide?
Paul
 

Ray C

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#43
Caswell. Cheap, easy, good quality, no muss, no fuss, no deadly chemicals. Surface prep is everything. Sandblast first (not required) followed by a rinse with rubbing alcohol and blow dry. Handle parts with gloves as the smallest amount of skin oil will show up as fingerprints. Must use clean shop towels etc when handling. I use both the glossy sealer and matte sealer depending if the part is visible or not.

http://www.caswellplating.com/metal-finishing-solutions/black-oxide-kits.html


Ray

EDIT: PS: Forgot to mention. Use Distilled Water! -Not tap water.



Thanks. We're heading into the juicy humid weather. Wanted to hurry and get that over with.

So what do you want to see next; pedestal, taper blocks or switch back & forth?

Ray
 

Tamper84

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#44
Wow Ray looks great!!!! I do have a question/maybe helpful tid bid. But I was watching a knife making show on Discovery channel. (I forget the name of the show) Any hoo, He was heat treating a knife in a foil pouch, and in the pouch he put two small pieces of paper. He said that when the paper burns, away goes the oxygen. Dont know if that helps/hurts or anything. Just passing it along.

Chris
 

Ray C

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#45
Much thanks Chris...

I'm using powdered charcoal with potassium nitrate which has the same effect. The potassium cooks off around 600 degrees and produces carbon monoxide which A) uses-up the oxygen and B) is carbon rich and saturates the metal.

The darn problem I had was not being able to seal the foil very well because the part was a little big to handle in this setup. Pretty sure I mentioned this before but, next time around, I'll fill the oven box with Argon and give it a refresh squirt every 10 minutes or so. One other fellow suggested using CO2 and indicates good results but even my meager chemistry background says that's reactive and in theory, should not work very well.

Ray


Wow Ray looks great!!!! I do have a question/maybe helpful tid bid. But I was watching a knife making show on Discovery channel. (I forget the name of the show) Any hoo, He was heat treating a knife in a foil pouch, and in the pouch he put two small pieces of paper. He said that when the paper burns, away goes the oxygen. Dont know if that helps/hurts or anything. Just passing it along.

Chris
 

Ray C

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#46
Looks like we're going to make some blocks for the tapers first.
Here's a nice hunk of 4140 (or maybe it's 4145, I'll have to look at the receipt). This thing was probably milled in big honk'n horizontal mill. The tooling marks are darn near 1/8" apart and 1/16" deep. A big face grinding bit probably nibbled that thing to size in a few moments.

Blob of 4145.JPG

After cutting off a couple inches it gets milled to make it fairly square. The bars in the jaws are used to keep the piece from getting cockeyed when the jaws press as the initial geometry of the piece was a little off.
Milling.JPG

And here it is all nice with rainbow colors on four sides. It's pretty square now. I was running a 1" facing endmill, carbide inserts, 1900 RPM at about 20 thou depth and cranking the table about as fast as I could. Didn' bother with coolant, just a spritz of WD. The slight scuffs at the bottom are when the side of the cutter starts dropping off the edge of the piece and the inserts aren't being supported evenly. Purely cosmetic. You can't feel it; it's just an optical effect due to different spectral reflection. We're talking surface differences on the order of angstroms...
PrettyRainbowColors.JPG

Next, I'll put put it in the 4jaw, drill a hole and start working on the taper. I won't worry about precise positioning of the hole or even if it's perfectly straight. That will get fixed much later on... This piece will get heat treated and will need a couple passes of seemingly redundant operations. I'm just play'n around...

Ray

Blob of 4145.JPG Milling.JPG PrettyRainbowColors.JPG
 

itsme_Bernie

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#47
Thanks. We're heading into the juicy humid weather. Wanted to hurry and get that over with.

So what do you want to see next; pedestal, taper blocks or switch back & forth?

Ray
Wow- switch back and forth sounds interesting!



Bernie
 

Ray C

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#48
OK, the backyard deck is done so the turret project can resume.

First Pic... The block from earlier was carefully setup in the chuck. It's mounted with a 3/8" offset because I want a slight lip to overhang the plate. The block was set perfectly flat and checked ad-infinitum with a TDI lengthwise on all four sides. After that a hole was bored down the middle. In the photo, a travel indicator is setup at the left of the carriage and a TDI riding on the compound. We're setting up the angle for MT 3 taper which is 1.4377[SUP]o[/SUP]. I'm checking by running the carriage 1/2" (as measured by the travel indicator) and watching the deflection on the TDI. 1/2 x TAN 1.4377 is 0.0125" so, the compound angle is adjusted until the deflection reads that amount. This is a basic Rise-over-Run Tangent slope calculation... How much the needle rises when the carriage is run 1/2". I could have used 1" as the amount of travel but, the Tangent of 1.4377 is 0.025" and the TDI doesn't read that high so, 1/2" was used instead.

After a few adjustments, it was reading dead on. Not shown is the use of a boring bar to start making the taper. I'm just using the compound crank to move the bit in and out. A taper attachment would be a better choice but, it hasn't arrived yet. At the wide part of the taper, the diameter will ultimately be around .98" (around there, can't remember at the moment). For now, I just opened up the hole enough to see how things were looking.


Taper Setup.JPG


Next pic: I purchased a store-bought MT3 reamer set (I hope to make these in the future for other taper angles) and here, it's inserted in the hole with a little pressure from the TS ram and twisted a few times. This is just a spot check to see if the compound setup agrees with the store-bought taper cutter. BTW, the taper set has both a rough cut (shown) and fine-cut tool.

Taper Check.JPG

Third pic: Here you can see things are well in agreement. The reamer is shaving evenly on the inside of the hole. I'll go back to widening the hole with compound cuts to the desired diameter then, I'll clean-up the hole with the rough reamer. After that, the block will need a little milling and holes drilled/tapped -and then a heat treat to about 30 RC. BTW: The block is 4140 so it should harden nicely. Once it's treated, I'll need to touch-up the taper with the fine cut reamer.

Tapered Hole.JPG

Ray

Taper Check.JPG Taper Setup.JPG Tapered Hole.JPG
 

Tamper84

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#49
You are a talented man sir!! Do you get nervous with all of that hang out and no support?

Chris
 

Ray C

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#50
I appreciate the kind words but guys like Bill, and the folks making knives are doing stuff that requires skill and creativity I also feel that CNC programming takes talent because you have to program a machine to do what humans do naturally and with the help of the sense of feel and sound... What I'm doing is basic stuff to hopefully give people ideas.

Anyhow... Nope, not worried one bit. If you felt it, you'd know its solid as the Rock of Gibraltar. It's not going anywhere and yes, I do give these things consideration and not take it for granted. I am paying extra close attention to where my fingers and hands are as those corners would make mince-meat out of me if we tango'd at high speed.



Ray

You are a talented man sir!! Do you get nervous with all of that hang out and no support?

Chris
 

Ray C

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#51
Cruz'n right along...

Here's the bottom holes of the taper block which are lining up quite precisely with the bolt holes and registration pin hole. Haven't made the pins yet (we'll get there) but, I used a drill bit for a test and it was dead on (wheew!).

Threaded Holes.JPG

The bolt at the top is a tang keeper. MT has a tendency to spin so the bolt can optionally be screwed in lightly up to the tang to keep it from spinning.

Tang Keeper.JPG

And of course, MT's tend to get stuck so there's a threaded hole in the back to push out a stuck taper piece.

Knock Out Hole.JPG

Here it's just sitting in position to give some perspective. The disk accommodates 6 attachment pieces. Perhaps the pictures are clear enough to see a rounding bit was used to break the corners of the block. Quite necessary to do that or this thing would be a knuckle widow maker.

Positioned.JPG

Now it's time for heat treating which I might start tonight -possibly tomorrow. After that, we'll black-oxide it then clean-up the taper and holes after treating.

Ray

Knock Out Hole.JPG Positioned.JPG Tang Keeper.JPG Threaded Holes.JPG
 

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#52
Heat treating went very well -amazing what happens when you follow the instructions exactly... I was working during some intense rain and windstorms in the area and keeping my fingers crossed we didn't lose power. -Got lucky today.

I made a change of plans on the final Rockwell by testing some old MT tapers. Of course, I went through a mental exercise wondering if the taper block should be harder or softer and since I couldn't make-up my mind or find info about it, decided to make it the same as the tools which were about 45 on average.

Also, I used argon gas this time around and no foil wrapper. I rigged a steel tube in the heat oven, calculated the amount of cubic space and squirted gas in long enough (with a little extra for good measure) to theoretically displace the same volume. During the process, I gave it a 5 second shot about every 15-20 minutes. This seems to have worked very well. The part is 4140 which calls for a 1575 degree soak until the part is thoroughly heated (which is roughly 30 minutes for a part this size) followed by an oil quench. When the door was opened, there was no scale or decarburizing on the surface at all -just a glowing red/orange object with no flakes peeling off. I used 2 gallons of trans fluid in a steel bucket with a piece of bent-up expanded steel in the bottom. Much to my surprise, it brought the oil temp up to 350 degrees. It was constantly agitated. The part air cooled to 150 and tempered at 700 for 2 hours followed by a fast water quench. After the oil quench, the part turned black but that's just oil burn-off that came off easily with a few moments of sandblasting when it was all done.

The Rockwell near the edges and next to holes was 47 and the thick cross sections were 44. It hit an average of 45 almost on the nose.

The part dimensions were measured very precisely before and after treating. No change whatsoever. The finish reamer was used to clean-up the taper. No metal came off, just the black coating from the oil. All the MT centers and drill chucks etc fit like a glove -just like a store-bought unit... Happy camper tonight!

Tomorrow: A little more sandblasing and then black oxide.

HeatTreatedMTBlock.JPG

HeatTreatedMTBlock.JPG
 

Ray C

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#53
Today I made three more taper blocks; one is for 5C taper and two more MT3. To see pictures, just look at the last post 3 times.

I also normalized the pieces of 1x6x8" 1018 plate that will be used for the base. Can't open the oven door to take pics -they need their privacy until they've cooled down to below 300F.


Ray
 

Ray C

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#54
Today, the three blocks were heat treated and it was no picnic quenching all of them. On the first one from a few days ago, the quench left the oil at 350 degrees so this time around, I put the bucket inside a large flowerpot filled with ice water. This time, I was able to keep the final oil temp at 170. It took 3 large bags of ice; one for each quench.

Also, here's a pic immediately after the final tempering -and this is what it looked like after the quench. I used a little more argon (and more frequently) when treating today and it came-out a cobalt blue color. If you look closely, there's no sign of scale or decarburization. The exact same recipe was followed and the Rockwell results on these were dead-on compared to the first one. 45 +/- 2 RC.

All that's left now is a light finish pass in the surface grinder followed-up by grinding the bases to proper size.

Soon we'll start working on the base/pedestal portion.

Ray

Cobalt Blue.JPG

Cobalt Blue.JPG
 

n3480h

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#55
Ray, thank you for a very interesting thread. I appreciate the knowledge you are sharing with us.

Tom
 

Ray C

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#56
Here's just a tiny bit of eye-candy... I only had time to do some finish surface grinding today. Here's the bottom of the taper block and man, this piece of treated 4140 is both hard and tough! It's been giving the surface grinder a run for it's money and I've tried several wheels. Any downfeed more than a thou and you can hear the (1HP) motor slowing down. On this one, I didn't mill the step as closely to spec as the others and I had to take 10 thou off to allow the centerline of the taper hole to be at 1.125". Took a long time to take that 10 thou off. The walk-over was limited to much less than 1/8". -Won't be making that mistake again.

Anyhow, it looks really nice to see in person and it's a real pleasure to hold something you made that is unbelievably hard and tough...

BTW: The chafed areas around the bolt holes are from the sandblaster held at very close range to clean-up the threads. For the most part, normal sandblasting doesn't phase this piece of metal.

Ray

Hard and Tough.JPG

Hard and Tough.JPG
 

itsme_Bernie

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#57
Ray I am LOVIN this thread


Bernie
 

Ray C

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#58
OK, decided to make one more taper block. This one will be a 5C collet holder.

Once the metal block is square (which I should give a description of how I do it -I'm sure there are many ways) it is placed in the lathe. The piece needs to mount in at an offset because I make a ledge on the bottom with about 1/4" overhang. The center height of all holes must be 1.125" from the base as that's what I've chosen and it will also allow taper blocks up to MT4 with plenty of meat on the sides to drill the hole and not interfere with the bolts. I designed this in Alibre CAD so there is no thinking/measuring on the fly.

The part has to be flat in the lathe for the starting hole to be straight. A travel indicator is used and by running the carriage back-forth and by checking all 4 sides, adjustments are made until the part is "perfectly" flat. In all reality, I quit making adjustments when the indicator shows under a thou from front to back. No doubt, the hole won't be perfect no matter how hard I try.

This alignment is done while checking to see the offset center is still perfect with the tailstock. The center mark was pre-struck on the bench.
Squaring-Up.JPG Find Center.JPG
I'm making this one today (took a vacation day to pick-up the new tool grinder) so I'll take more pics of drilling the hole etc later on.

Oh, here's a sneak preview of the metal for the base...
Metal for Base.JPG

Ray

Find Center.JPG Metal for Base.JPG Squaring-Up.JPG
 

Ray C

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#59
As promised, here's a few more shots.

First the hole was bored. I want a very tight fit -and I got what I wanted and managed to get the collet a little bit stuck. The part was warm and I bored it to 1.25" -knowing well that it's going to shrink about 0.0015" when it cools down. My plan for this one is to make a 1.25" power reaming bit. [BTW: I picked up the tool cutter from the terminal today. It's going to be a few days before I get to it.] Anyhow, I went inside for a cup of coffee and when I got back the collet was pretty stuck in the hole. A few moments of heating the outside got it unstuck.

For reference, I found this collet chart on google images.

See that kitchen magnet on the ways? That was my depth stop indicator when power boring the hole.

BTW: That boring bar is home made. Works just peachy.

Boring hole.JPG ColletDimensionsMedium.jpg In the truck.JPG

Next, the compound was set to 10[SUP]o[/SUP] and the 5C taper was cut in. That took all of 2 minutes. Mondo got smart and heated the block a little for another quick test fit. Looks good. Mondo was real smart and didn't get coffee before removing the collet.

Basic Shape.JPG Seated test fit.JPG

And finally, I wanted to get an idea of the concentricity of the hole. That's pretty important here. The inside calipers along with inside telescoping gauges (not shown) showed the diameter to be very consistent. -That's not too important now because it will be reamed. The important part is knowing if the hole is straight. Using the long (chopstick-like) calipers, I could pinch from the inside of the hole to the outside of the side and it showed no gross error from front to back. There are other ways to do this (based on the same theme) and I'll do a more precise job once it's reamed.

Chopsticks.JPG

That's it for today...


Ray

Basic Shape.JPG Boring hole.JPG Chopsticks.JPG ColletDimensionsMedium.jpg Seated test fit.JPG In the truck.JPG
 

Ray C

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#60
Moving very slow today but got my morning chores done and also cleared the area for the new roof. Work starts on that Thursday.

Anyhow... Here's the start of the drawbar for the collet closer. Easy enough. 24TPI and something like 1.055" diameter according to my measurements. Just using a piece of 1045 for the threaded end and a scrap laying around for the drawbar. I'll heat treat it next time the oven is hot. BTW: That's a fast & hot carbide cut on the shoulder. About 900 RPM, 25 thou DoC with probably 0.007 IPR. Just guessing at the IPR as I usually don't mess with it all that much.

Endcloseup.JPG Threaded End.JPG

Here's the drawbar. The shoulder on the threaded end fits precisely into the 5C hole. That will keep it aligned when it's tightened. The collet is not screwed on all the way for demonstration purposes. The back end of collet seats against the shoulder to help keep things square.

Drawbar.JPG

Here's a quick preview of the setup. I'll be making a new base but now, it's just sitting up there to see what it looks like.

RoughLayout.JPG

And here's yours truly commemorating what is probably my three hundredth shaft with a threaded end. -Pretty sure I can do them in my sleep now.

Me.JPG

OK, maybe when it cools off later today, I'll do some more on it.

Ray

Drawbar.JPG Endcloseup.JPG Me.JPG RoughLayout.JPG Threaded End.JPG
 
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