Adventures in Ogives

[customcutter]

I got the bright idea back when Cane Man and I were both trying to make reamers that I needed to make a radius cutter (aka ball cutter). I'm still trying to cut ogives and he's finished his point forming die. Go figure, but here's to you Cane Man.:drinks:

I couldn't make any of my 3 different tool post holders work to cut an ogive so I decided to make a radius cutter. There were several issues, but one of the main ones was that the pivot point for the compound was short of the center line between the chuck and tail stock. So I made a new base and moved the pivot point closer to the rear of the lathe. Unfortunately, I forgot to figure the extra offset for the ogive. But no problem, I finally figured out I could run the spindle in reverse and put the radius cutter on the back side.

Here are some pics of the radius cutter. It didn't work well, so I decided to try a radius grinder.

Edit: Should have taken more pics but that 4" disc started as a 4X8X.75" block of aluminum. My first attempt at cutting a circle from a square. I cut 8 sides with the band saw and chucked it up in the 4 jaw and had a lot of "interupted" cuts. Also had to bore a 1" hole in the bottom plate and set that up in the 4 jaw but only had 3 jaws holding it, so I clamped it down tight and turned it at 70RPM.

[customcutter]

There was too much deflection with the radius cutter, so I decided I would try to modify it to make a radius grinder. I spent all morning machining a holder for a small pencil grinder I had bought with intentions of using it to lap the point forming die once I got it reamed. Still working on that reamer though. I tried mounting the grinder as low as possible to stiffen everything, but it created a problem with the center part of the diamond wheel not having any diamonds to grind with and also the center bolt to hold the wheel to the shaft was a problem, so I had to mill a slot and raise the holder about 1/2-3/4". I also milled a shallow slot in the grinder holder so that it could be attached to the fixture with a single screw and be a solid fit.

You can see there is one picture where I was trying to see if I could grind an ogive and ran out of room. It was really a set back for me because I thought that the fixture still wouldn't work. I thought there was something wrong with my dimensions, off set, design, or something. I spent an hour or so trying to figure it out and finally decided to simply raise the grinder to where I could cut with the lower part of the diamond wheel and it worked.

[customcutter]

Here are some pics of 2 different laps that I made using the radius cutter with a carbide insert. Then there are a couple of pics of the 2 points that I made using the grinder. The point that looks the closest to the factory 55 grain ogive is 6X the radius, the longer point is 6X the diameter. The same is true of the shorter points the smaller one is 6X the radius, the longer one with the ugly tip that has a booger on it is 6X the diameter.

These aren't going to be used for lapping but simply to confirm the procedure. I'll need to find a way of using a cut off wheel or maybe making a disc that I can attach 120 grit, 220grit, and 400grit silicon carbide too to polish the final laps and reamers with.

Here's the pics of the points.

[plus1hdcp]

I find these "how to" threads incredibly interesting. I am both glad and sad that I am not in position to try this in my shop. Maybe someday. But thanks for sharing and keep up the great work.

[Cane_man]

cc, looks like you are making good progress, that radial attachment looks great :awesome: now chuck some O1 and see if you can grind an ogive on that... you will have to polish it smooth for your reamers, but you can leave it rough like that for the laps as it helps them to hold polishing compound and they get smoothed out anyway while lapping...

[teddyblu]

When you get the shank to size and start the radius, I have used superglue to glue a serria 52 hp to end and held in place with carriage till glue is thourghly set, Then you can adj the grinder to follow the ojive. When you have it like you want then just hand pull off the bullet.

I use a wider wheel and prob 120 + grit and grind with surface of wheel. I lock the grinder in place and use it to grind the shank to size like a tool post grinder.

You are getting it done looking good.
Larry

[customcutter]

Plus,
Just wondering why you aren't able to attempt them in your shop? Thanks for the encouragement, it helps keep us "rednecks" motivated.

Cane,

I saw those shallow groves in the point that I ground and was wondering if it would help hold the lapping paste also. I think that diamond wheel was either 60 or 80 grit, a little to rough possibly. Once I start making progress again I've got to get some ordered. What grits did you use?

[customcutter]

Larry,
I had the pencil grinder and modified my radius cutter. It is on the weak side to say the least. I've also got a slight issue with the hole that I bored in the rectangular base. The hole is slightly tapered, the only thing I can figure is the compound wasn't square to the hole. I should have set the compound and fed with the carraige instead of the compound. I may try reboring it and inserting a bushing or maybe a bearing. It works for now I just have to keep downward pressure over the pivot point while turning the points.

I looked at several rotary tools last night at HF trying to figure out another way mount something with a small grinding wheel like you used. Finally decided to just go with what I had for now. Maybe I'll look at something else if I decide to do this long term.

[Cane_man]

the first grit i use for lapping is the "course" valve grinding compound you can buy at the auto parts store just to get all the rough cuttings off...

then use 600 grit diamond paste, until you get to within 0.002 of your final ID, then heat treat...

that final 0.002 use 2000 grit to size and 8000 to polish...

it helps a lot to make a 0.223 test inserts to see how close you are getting, just get a brass rod and turn one to 0.221 and another to 0.2230 for testing... when the 0.221 can slip into the die the ID will be close to 0.222 and you can heat treat, when when the 0.223 inserts slips in you will be close to 0.224

here is the lady i get my diamond polishing compound from:

http://www.ebay.com/itm/5-gram-Diamond-paste-compound-polishing-lapping-from-14-000-Grit-to-400-Grit-/230692095923?pt=LH_DefaultDomain_0&var=&hash=item35b65207b3

when you make your reamers, they will ream about 0.004 too much, also you want to leave about 0.004 for lapping, so make your reamers have a shank OD of 0.224 - 0.004 - 0.004 = 0.216 and it will put you where you need to be starting at about 0.220 and give you plenty of room for lapping and polishing...

i used three sizes of laps, 0.210, 02.15, and 0.220 as you have to leave some room for the lapping compound


dude, i am getting pumped, you are taking serious steps to make this happen... wont be long now :guntootsmiley:

[customcutter]

Cane,

Thanks, you really got me motivated with that last die and bullets. Those look better than any I've every bought. I only get to put in a few hours during the week and about half a day on Saturday. That's all my back can handle. Don't know why but just standing in one spot really strains it. I've had 3 herniated discs for almost 30 years now. Bouncing on the mower doesn't help any and I was thinking of getting into machining, beings I have a few pieces of equipment. However, this is showing me that maybe that isn't the way out. Maybe I'll finish them before the fall. But then I'll have to start on some dies for .40, .45, and 9mm. Maybe 6.5mm, 7mm, and .30 also.

Thanks for the tips, I know they will help lower the learning curve.[smilie=l: I couldn't get both brain cells to fire at the same time this AM, and it had me stumped for a little while.

CC

Edit: Did that modified tree burr do anything or was it a waste of time?

[Cane_man]

cc, the modified tree burr worked really well for rough hogging the die... i sort of abandoned the idea when i decided to do the rough hogging out with the d-reamer and finish ream with the 2-flute reamer... i ended up grinding down the burr until the max OD was about 0.210 or so, but one problem is that is leaves a really rough finish... it is worth looking into

[aaronraad]

What is a tool post grinder worth?

[customcutter]

It would depend on the make, model, manufacturer, condition, etc.

[customcutter]

Got back into the shop for a couple of hours and decided to try and make a couple of points to make D reamers with. I sat up the .250" W-1 exactly like I did the .250 brass. I cut about 1.5" down to .218-.219 and proceeded to install the radius cutter. The abrasive wheel is offset 6 X the radius of the pivot point, then I advanced the crossfeed on the abrasive wheel till it just barely made contact with the .219 rod. I moved the carriage feed toward the chuck until the abrasive wheel made contact at about a 45* angle to the rod. I started grinding the ogive, swinging around the pivot point and advancing the carriage slightly till I got a very small meplat. It didn't look right (looks like a 3-4 ogive)so I decided to reverse the rod and make another on the other end, but trying for .220" this time.

Same set up as before except that I hit .220" instead of .218" after filing. Set up exactly the same on the radius cutter, and this one looks fatter than the first one. Maybe a 3 ogive.

I would say this is because I need to have 6 X the diameter instead of 6 X the radius. But the 6 X radius in the brass rod at .250" looks perfect. Is the .030" affecting the ogive that much? EDIT, brass rod was set up at 6 X .112"

I guess tomorrow, I'll chuck them both back up and turn them at 6 X the diameter. Sorry no pics for now, got to get ready to take the wife and her best friend out for supper.

CC

[Cane_man]

imo, i think you need to aim for 0.216 as these reamers tend to cut oversize by about 0.004 or 0.005, this way you will have plenty of ID for rough sizing, then heat treating and any warping that may occur, and then to final lapping... make your die ID test probes as you dont want to get this far and then oversize your die, ask me how i know :killingpc

did you get your diamond lapping compound yet? $22 gets you the three grit sizes you need and you are good to go

[customcutter]

Haven't ordered the lapping compound yet, But maybe later tonight. I thought some of the other threads had said to try for around .220, but I'll go with .216. You can always take more off, but it's hard to put some back on.

The only other thing I noticed was the diamond wheel has a slight grove worn in it where the diamonds are being removed. I may try moving the wheel up or down to a "fresh" spot with lots of diamonds. I still may try and make a disc that I can mount silicon carbide sand paper on.

[teddyblu]

Customcutter I mentioned glueing a 52 hp to the end of your sized shank, then see if your ojive setup will trace the outline, adjust or change until it will.

[customcutter]

Teddyblu,
I had to pull a 55 gr bullet from a loaded round to have one to compare to the brass ogives that I cut. As stated the 6X radius was almost a perfect match. I used the same set up for the W-1, and it looks like it's cutting a 3X ogive. [smilie=b:

Thanks for the tip, I may have to try that.

[customcutter]

OK, I adjusted the pencil grinder up about 1/16", also found that the pivot rod had backed out about 1/2 turn due to vibration from the pencil grinder. Left it at 6X radius, and tried regrinding both points. They look much better. I think the pivot point backing out had elevated the upper part off of the base and exaggerated the "rocking" possibly, causing it to grind something other than 6 ogive.

Back to the garage to see if I can grind them in half + .001-.002 , heat treat, temper, and make a couple of D-reamers now.

[customcutter]

NO JOY[smilie=b:

Got 3 points made, ground them in half +.001" (ie, .216" point ground to .109"). Heated them to orange for +/- 30 seconds, dropped them into a 5 gal bucket of water (W-1). Stuck them into the oven for 1 hour on 350*. Polished all the scale off and sharpened them up on a hard Arkansas stone. Placed the smallest one in the drill chuck in the tail stock on the lathe and put the step drilled die into the 3jaw chuck and started it up at 70rpm. Filled the die with cutting fluid and started feeding the reamer in. I attempted to ream the hole for probably 15 minutes and all I was getting was very light scrappings near the tip of the reamer. Kept pulling the reamer out inspecting for shavings, blow out the hole, and reapply cutting fluid. Applied just a little more pressure with the tail stock and snapped the D-reamer. 70rpm and feed rate incredibly slow (IMHO immeasureable). I grabbed a Nicholson file and easily cut the die, tried it on the reamer, and probably could have cut it, but wasn't going to be easy. I'm just thinking I should start over with another die material instead of the 4140PH? It cuts easy on the lathe, drills easy with some cheap chinese drills I have (109pc set, I won years ago at a vendors party).

This die is killing me.:groner:

[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! :D 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.:lol: I know experience is the best teacher, unfortunately it is sometimes painful also.[smilie=b: 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]

79415[ATTACH=CONFIG]79416[/ATTACH)


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.:confused: 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:

http://www.fototime.com/822F5471FA0DC35/standard.jpg

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/showthread.php?58410-swaging-dies/page3&highlight=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:

http://i913.photobucket.com/albums/ac331/johnelway/0-relief_zps89832fda.gif


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

http://i913.photobucket.com/albums/ac331/johnelway/0-deer008_zpsb7e88529.jpg

[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 [smilie=w:, 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, :drinks: 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/showthread.php?205203-Harbor-Freight-25-off-July-4th-time-for-a-7-quot-x-12-quot-mini-lathe

[Cane_man]

awesome, thank you :happy dance:

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

[Utah Shooter]

Photos please.