Adventures in Ogives

[Cane_man]

did you cut some relief behind the cutting edge of the reamer? i know i made that mistake, the relief was not enough and it was not cutting just rubbing the inside of the die... if you did it right you pull out the reamer and a pile of fine metal cuttings will be on top of the blade, not all along the blade but mostly near the tip section...

did you drill out the eject punch hole? the tip of the reamer will use this hole to center/feed itself....

i snapped several reamers, easy does it, literally millimeter by millimeter and pull it out often to clean out the cuttings... once the reamer 'grabs' and digs into the metal its all over...

maybe try some O1, i had some good success with it...

you aren't a swaging die maker until you snap a reamer! keep at it, you are educating yourself on how to get this done and what it feels like on the lathe... when i get frustrated with the dies i just walk away and do something else and pick it up again the next day, gives me time to think thru problems and get the enthusiasm back...

[customcutter]

Cane,
To be honest, you are the only person I have ever seen that has cut "relief" on the back side of the reamer. Everyone I have seen (not many) uses the full size reamer with both edges intact. I did see recently where someone said to leave the reamer slightly thicker than 1/2 thickness, supposedly to aid in cutting.

I didn't feed millimeter by millimeter, I was feeding thousandths by thousandths, or so it seemed. Watching paint dry or grass grow would have seemed faster by light years.

The ejection hole is drilled, has been all along. 1/16" IIRC. When I pull the reamer out there are extremely fine almost dust sized particles, I hesitate to call them shavings or chips they are so small. After 15 minutes of reaming I didn't have enough to cover a paper matchhead with on one side.

I've snapped 2 now and I still ain't no swaging die maker. I know experience is the best teacher, unfortunately it is sometimes painful also. Yes, when it gets frustrating time to back off and take a break, I knew there was no sense in sacrificing a 3rd reamer. I am seriously considering how to turn down my 1/4" carbide tree burr though, I found a small green carborundum wheel in the bottom compartment of my surface grinder the other day. Just have to come up with some way to mount it and turn it. Too small of a center hole to fit the surface grinder.

[customcutter]

I got to thinking about the relief on the back side of the reamer, and that may also hold the key. What may be happening, is that the tip is actually getting wedged in the hole and causing the reamer to snap. Maybe I'll go grind the backside of another one off and see what happens.

[teddyblu]

Customcutter Everyone has an opinion and I have mine, Do not grind the D reamer larger than half, one thousands under is best. an exaggatered example would be only 1/4 diameter removed and only thing that would rub is the fat sides, with under size the cutting edge rubs. and there is a relief on the cutting edge ground all the way from rear of reamer to ,under the point. It comes to 5-10 thousands to top of reamer and then a stone finishes the cutting edge. It should feel sharp to the touch. also a relief is cut on the back side of the reamer but does not come all the way to top.
If i could get a piciture of this relief on camera I will try.
Nothing wrong with your steel I use 01 and w1 with success. 4140t is even softer but will not a durable reamer.
Excuse the long winded post but we all have been where you are now and it will pass.

[teddyblu]

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On the cutting edge of the reamer you will see a shiney edge all along the reamer that is the relief, on the back side where it looks black is the relief just dark from the dikem.

Note I forgot ot mention earlier is to coat your reamer with dikem or black marker then a trial ream will show you where the reamer is just rubbing or just the cutting edge.

[customcutter]

All the pics I've seen of D-reamers look like the reamer is 1/2 round on the back no reliefs cut anywhere, and most people said they cut them to 1/2 diameter. Can't remember where but somewhere in the last day or two I saw where someone said to cut the reamer 1-2 thousandths more than 1/2. Maybe I mis-understood and it should be LESS. I figured I would try it and if necessary I could always take another couple thousandths off. What little bit I know about tool design on mills, drill bits, etc. there needs to be a relief angle on the back of the cutting edge or you can't get the edge to "bite, cut, etc". This is not happening with my 1/2 bit D-reamers, there is no relief to allow the edge to cut. That was one reason the first reamer I made was a 4 flute like KTN made. It had 4 edges to guide and center the reamer, but all of them also had a relief angle on the back side. Maybe I'll just go back to making a 4 flute reamer.

The W-1 reamers at close to 60RC shouldn't have any trouble cutting 4140PH at 35RC. It has to be the missing relief angle.

[Cane_man]

just like this and the pics teddy has above, that is how i did mine:



by "relief" i mean the way the reamer slopes sharply away from the cutting edge on the right hand side as shown in "front" sketch

nothing fancy, just take a fine small file to it and slope it back real steep, heat treat, then put a fine edge on it... one reamer that i snapped was so sharp that it was taking off shavings... it was nice until it dug into the blind hole and torqued off!

here is a really good thread on making these reamers for point forming dies:

http://castboolits.gunloads.com/show...ht=half+reamer

i dont really think it matters how close you cut over/under the diameter because you are going to make the real ogive profile when you do your lapping, that is when you really get down to business with it...

and yes, the 'small pile' of cuttings is like powder


now this "d reamer" i used just for rough hogging and to take out the steps from step drilling, i put a finishing cut on it using a two fluted reamer and it is made the same way as the d reamer but it is cut in half and has two cutting edges on it...


i think Buckshot did this and ground a relief on it, i just use a file:




here is that little forky i saw last week with his girlfriend:

[teddyblu]

You can use your existing reamer and modify it to the new specs. hone or grind from top to reduce diameter, nothing to lose.
You have a relief on the back of a 4 flute reamer .why not on the D reamer. Its a one flute reamer. What would happen if you put no back relief on a 4 flute, a spinning round tool cutting nothing, I use a bench grinder to cut the refief on front and back. amount is not critical just use plenty.

[customcutter]

I been in the shop, while you guys been posting. But , I went for broke and blacked the entire back of the D-reamer with a magic marker. Then I took it to my 2X72 belt sander that I used to grind knives with and used a 220 grit belt, and ground all off the black off except for the cutting edge about .015" wide on the cutting edge. I probably relieved everything by .010", then back to the hard Arkansas stone, and sharpened it up. Man what a difference a little relief makes. I honestly think if I drilled a 1/16 hole through the die I could cut the rest of it out with this reamer. It was feeding with almost no pressure at .001" every 5-10 seconds.

Thanks Cane Man & TeddyBlu, both of you kept telling me I needed to relieve the cutting edge, but I kept thinking back to the photo's I'd seen of other peoples reamers, and they didn't appear to be relieved.

Now I've got to make some laps and get some diamond paste ordered.

[teddyblu]

Customcutter; Cane man has lead you into the lapping, I orded some leather polishing cones to use with the diamond grits for final finish. I have not had the chance to try them yet. I ordered 8mm size and shaped them with the same ojive setup and sized to fit cavity. I dont know if they will swell with lubricant and have to adjust size.

[Cane_man]

teddy, i used those leather cones and i did not like the results... it is mostly due to me being a poor craftsman, but those leather cones are not the same shape as the ogive and it caused the meplat to flare and the turned my 6s ogive into a 9s ogive... i dont think you get around using near exact ogive profiles for your laps... for me i had to use the actual production bullet for my laps and it worked out really well

edit: never mind i see teddy that you shaped the leather cones to your ogive and i think that would work just fine

cc, great news, you got it now... time to wind down and celebrate this small success then plan of making that roughed out point forming die tomorrow... :takinWiz:


edit: you still got one problem, you have not made your core seating die yet... not a hard die to make but you need seated cores to see what your point forming die is doing

[customcutter]

Cane:
The roughed out point forming die is in hand. Good point on the core seating die, but as we know it's a piece of cake compared to the point forming die. I can start on that and hopefully have it done by the time the diamond lapping paste gets here. I sent your supplier and e-mail asking for price and shipping on 600, 2000, 8000 grit 50% diamond paste.

I need to make some brass points to use with the lapping compound. I also need to smelt some lead. See if I can get the Lee handles mounted on my molds I made a while back. Then plug in the Lee 20# bottom pour pot and see if I can cast some cores, test them for weight and see if I need to adjust the depth of the mold.

[Prospector Howard]

Curious what happened to customcutter. I was looking forward to seeing his finished dies. Maybe he's just too busy making money in his business. Hope he's doing OK.

[Cane_man]

i think he is coming back in November, just a guess... i told him i was going to start up again then after deer season was over, but i filled my tag on opening day and started up again the next day! i think cc will show up in a few weeks...

hope cc is doing well, i know he has a bad back, and he runs his own business

[customcutter]

Well I finally got some time in the shop today. I bored a hole through another piece of plate to hold the HF cutoff tool. Then I took a 1/2" bolt, and removed half of the head, so the grinding wheel would fit better. Then I put the nut on the bolt and turned down half of the nut and the threaded section down to 1/4" for mounting on the cutout tool. Everything looked good until I mounted it on the radius turning base that I had made earlier. The grinding wheel is no longer on the center line of the pivot point so there is no way to swivel around the ogive. I'll have to make another base that places the grinding wheel over the pivot point and can then be adjusted back for the different ogives. I also need another piece of 3/4" aluminum that's at least 5 or 6 inches square. Too late for pics, but I'll try to post some when I get the new base made.

Edit, I also figured out how to slow down the RPM's. Years ago I used a sewing machine pedal (rheostat, I think) for a variable speed control for a flexible shaft grinder. It works like a charm for the cutoff tool also.

[Cane_man]

hey cc where was that information you were sharing about how to evaluate the condition of a used lathe?

i am looking for a used SB 9" or 10" (Atlas or Logan would be fine also) on Craigslist

[customcutter]

CM,

I'm not sure where it was located. I'm pretty sure it was a reply to someone, not a thread I started. I'll try to look back through my post and see if anything looks familiar.

[customcutter]

Cane,

I think this is it.

http://castboolits.gunloads.com/show...uot-mini-lathe

[Cane_man]

awesome, thank you

now get back in the shop and finish that 0.224 pointing die...

[Utah Shooter]

Photos please.