making a mould

[jimkim]

I have a friend that owns two tool and cutter grinders. Where can I get prints for cherries? Is there anything I would need to know if we did manage to grind a few? I would be the one milling the moulds if we made our own. It would be the first time I made one. Any tips? Thanks, Jim

[deltaenterprizes]

You are going to want a vise for the mill that closes the jaws so that they meet in the center,Grizzly sells one that can be modified for this task.
Get a sample of the bullet styles you like and take measurements from the bullet and make your own print.

[44man]

I just draw up my own cherries. I have to use end mills and files to finish them. The very hardest part is figuring out the diameters for different calibers to allow for shrinkage, etc.
Lucky you to have someone with tool grinders! :drinks: A bad cherry is not as big a loss as two days work. A loss of mold blocks hurts though. Sometimes cutting scrap instead for the first one is better. You can clamp the pieces together, heat it and cast one to see the diameter.

[jimkim]

Thanks. For the info. DE why cant I just find the edge zero the table and cut one side at a time? Not being smart if that wont work I want to know. I was thinking of making a wax bullet with a lathe then getting the measurements from that. If I had to I could use those big crayons for round stock.

[deltaenterprizes]

Closing the blocks around the cherry produces a truer cavity and thus a truer bullet. It won't cost a whole lot to try it the way you suggested and the small amount of error may be acceptable,but the errors may multiply,2 errors finding edge +2 errors cutting cavity= ?????

[JIMinPHX]

why cant I just find the edge zero the table and cut one side at a time?

If you can hold 1/2 a thou (& most decent machinists can on a good machine) then that is an acceptable method. Just make sure that your inspection methods on the finished parts are good.

[Buckshot]

..............An option instead of making a full reamer would be to make a form tool that in simpler terms ends up being a silhuette of the design. Looks kind of like a key. You would make a fixture to clamp to a rotary table, clamped to the bed of a milling machine.

Drill or bore out the minor ID of the cavity. Then swap out for the form tool. Introduce it full length into the cavity. Retract the X or Y axis to cut, then rotate the rotary table. Repeat until the cavity is fully formed. You'd want to use HP air or a cold gun to keep the chips down so you aren't recutting them. However, the form tool is basically a single flute so there is lots of room.

Via this method you can use the same form tool to cut similar designs into a wide number of calibers. You will also have to spend some time beforehand understanding what, if any changes are made when you tie down the X, Y, or Z axis before machining. Because you WILL want to do that. Even if equiped with a DRO, it probably won't pickup these changes.

.................Buckshot

[Cap'n Morgan]

It's not that difficult to cut the cavities in two operations. The trick is to cut the cavities *before* you drill/ream the holes for the guide pins - since the cutter will flex a little. You can then use two cylindrical pins, same diameter as the cavities, to keep the blocks aligned when drilling the guide pin holes.

Nowadays I use CNC and helical interpolation when cutting molds, but back in the good ol' Bridgeport days I would cut the mold halves slightly deeper than 1/2 diameter, and then trim the blocks to size on a plane grinder. This would guarantee a sharp parting line.

[44man]

Some of you just have too fancy of machines to use! [smilie=1:
Yeah, I get jealous! :mrgreen:

[Southern Son]

+1 to 44man's comment, the flashest bit of gear I have is a cordless drill, but my missus keeps hiding that on me cause whenever I use it I damage something (usually one of my digits).

[BABore]

Tight tolerance machines and digital readouts have been around for a long time. There is a good reason why molds are either cut by lathe boring with the blockset held together, or cherry cut on a mill with each block half clamped and indexed together. If it was as simple as indicating in a block half and side cutting into it, don't you think it would be done like that. Molds are cut with the alignment pins in place.

[jimkim]

Sorry I asked. I didn't mean to stir all this up. I thought it was a simple question. I can do it either way. I can hold plus or minus .0005" it wouldn't be the first time. God willin' it wont be the last either. Honestly I was just exploring different options. I really didn't mean to start trouble. Jim

[45nut]

Jim, I don't know where you are seeing trouble in this thread, I have seen trouble a few times myself and just do not see it in these posts.

[BABore]

Sorry I asked. I didn't mean to stir all this up. I thought it was a simple question. I can do it either way. I can hold plus or minus .0005" it wouldn't be the first time. God willin' it wont be the last either. Honestly I was just exploring different options. I really didn't mean to start trouble. Jim

Nope! No trouble intented. Just wanted you to think on it some.

You can hold a half a thou as can I and others. There are several problems with trying to cut each block half, one at a time. Number one is side flex on the cutter. Yes you get the same flex on lathe boring, but you are inside a closed block set. deflection is equal all around. When working on only a half block it tends to egg out on you. You also have to consider how your going to measure your cutting depth to account for tool flex. It not exactly easy to get an accurate measurement on a half circle when bearing bands, lube grooves, and GC shanks are involved. Second, the finished mold locates on its alignment pins, not the block edges. Ideally the alignment pins are put into the block halves as a set. Drilled and reamed though one half and into the other. You can also do them one at a time from an indicated edge. When done this way the block halves must be machined as a set first. Even when everything is machined to less than 0.0005, and the pins/buchings are installed, the block ends don't always match up perfect-like. They have to be dusted or honed into submission prior to clamping into a cherrying vise. If not perfect they can bind on the pins when clamped. Finally, I see a large stackup issue even when holding +/-0.0005". Block edge to cherry/form tool alignment. Block width. Remember, the second half has to be flipped around and indicated off the opposite end. Then block end to alignment pin centers. I'm thinking you have the potential of +/- 0.0015.

[jimkim]

I've seen a regular discussion get too heated on other post. I have become hypersensitive to it. I keep forgetting how different the people on here(and the Casting Assoc.) are. I guess I have been around too many powder kegs. lol

[jimkim]

I think I will do it the easier way and use a modified vise. Thanks.

[leftiye]

This approach - cutting one block at a time has another possibility. Don't use a cherry. Drill a hole with a partial ogive in it where you want the cavity to be (clamp both blocks together and scope the dividing line at the center). Make that hole the diameter of the bottoms of the grease grooves. Use a tool like a reamer or endmill with some of the flute ends removed to leave something analogous to a keyway cutter with 15 degree tapered sides to cut the land grooves, and a formed variation on this to finish the ogive. Out of round can be avoided by cutting maybe a hair deeper, and letting the cutter dwell in the groove. Within reason, make the grooves a thou or two bigger in your calculations for shrinkage as sizing can correct a little oversize.

[Willbird]

Machining an assembly is an old old practice that DOES work. I seriously doubt we will ever see important items that come apart in halves finish machined as seperate halves. Connecting rods, main bearing bores, and the ring gear in your Jacobs chuck are just 3 examples.

On the Connecting rods, BMW has a process where they machine them, then BREAK the caps off the rods....the fractured surface realigns itself exactly, Jacobs does the same thing with the ring gear in your Jacobs chuck.

Most of our bullet molds make round bullets, no matter who made them, a very common problem is that the round cavity is not exactly on the parting line of the blocks, this causes cursing :-).

I have flexed my brain for years in idle time thinking about how to make bullet molds in THREE pieces to avoid this problem :-)...one of these days I will make one just to prove it can be done. The die that Federal Mogul (they own Champion spark plug) uses to swage the plug wire terminal onto spark plugs is made in 3 equally sized pie sections, I used to make them in a former job, the tolerances are held very closely when they are assembled, and they are finish ground as an assembly.

Bill

[leftiye]

Lkie Cap'n Morgan said, cut the locating pins AFTER you make the cavities. Make (machine) a surrogate bullet out of aluminum or brass, clamp it in the cavity to locate the blocks, then drill the locating pin holes. Then (when you've got the locating pins in, and with the bullet still in the cavity) take a finish cut on the sides of the block, and cut your handle grooves and screw holes. Please look at this not as an argument, only as a possibility. There are more than two ways to skin anything, I am only forwarding this as a way to make one-off molds without too much tooling up.

[jimkim]

Thanks I just didn't want ya'll to start arguing. Like I said I have been in forums where the people were kinda young or something, not really sure, but they would get into a "scrap" at the drop of a hat. I got where I just didn't post anymore. I love debate and discussion. I hate arguments and drama. I keep forgetting the level of maturity that I have encountered on this forum. I also love figuring out new ways to do things.

[leftiye]

Sounds like maybe a problem with telling the difference. Technically, argumentation is used in both debate, and discussion. And a good argument can be fun too. Guidelines might be "fun" and it being over the line when angry attacks are made. Most real conflagrations start by someone being insensitive, or personally insulting, or refusing to allow that it is possible for them to be wrong.

[Buckshot]

.............jimkim, naw just guys discussing various ways to create a mould cavity. Different ways to do the same thing. How one goes about it will vary depending upon experience (I'm doing it so and so way because it's worked before) and by the machines available. If we were a bunch of African bush blackfellas discussing moulds one would say he sticks his thumb in the mud and another would say he uses his big toe to form the cavity. Then you'd have differing thoughts on the best mud to use and why :-)

Someone with a CNC would clamp a couple blocks into a fixture and transfer the desired mould info from his computer to the lathe and punch the green button. Go make a PB&J, pour a glass of milk and amble out into the shop to remove his feshly machined blocks out of the fixture. Maybe take a nap after that hard work :-)

...............Buckshot

[jimkim]

Next thing. Ready for this. Have any of you seen a mould made from Graphite? I saw a mould on another site and I think they said it was machined from graphite. Is this a prototype or is this something new? Would it not crack?

[deltaenterprizes]

Sounds possible,I heard about a manufacturer trying tool steel,I think both would be brittle,stainless would be nice! Tell me about this other site.

[Cap'n Morgan]

Jim,

When calculating the shrinkage I multiply the desired bullet diameter with a factor depending on the alloy - normally between 1.005 for "hard" alloys, and 1.01 for pure lead. For an 1:20 tin/lead alloy I use 1.007. This takes the guesswork out of the design, and will work with any size bullet. Example:

Desired bullet diameter: .431
Alloy: 1:20 = shrinkage factor 1.007
Mold size = .431 x 1.007 = .434

If you have a decent round table for your mill, I can wholeheartedly recommend Buckshot's approch. You are not dependant on the cherry being dead-on size, and you can cut a multitude of different bullets with the same tool. Add leftiye's two tools solution (nose cutter/ groove cutter) and you have an even larger number of design possibilities.

[jimkim]

This is the only thing I could find with a regular search. For some reason part of the article is missing. http://www.realtechnews.com/posts/1487 The other site was one I found by accident. I was looking for something else and stumbled across it. I think I will Email lyman or somebody and ask. I'll keep looking. When I find something I'll post it.

[Willbird]

Next thing. Ready for this. Have any of you seen a mould made from Graphite? I saw a mould on another site and I think they said it was machined from graphite. Is this a prototype or is this something new? Would it not crack?


Jim, are you sure it was not Meehanite ?? That is a trademarked form of cast iron that has been used for bullet molds.

Graphite is used for RAM EDM electrodes, it would stand up long as a bullet mold I would not think. It MIGHT be a good prototyping material for a cnc program used to machine a bullet mold.

Bill

[jimkim]

It could have been a prototype. I remember it saying graphite mould.

[44man]

Need graphite for the high temps of silver.

[JIMinPHX]

I really didn't mean to start trouble. Jim

You didn't.

I might though.

As far as the locating pins go, I would pop the holes into the blocks first & then use them to locate the blocks on a fixture that I had made special for this purpose.

That’s just the way that I would do it though. As others have said, there is more than one way to skin a cat. The best way for you to do it depends on what machines, tooling & experience you have.

[JIMinPHX]

+1 to 44man's comment, the flashest bit of gear I have is a cordless drill

You have a CORDLESS?????

I'M jealous!

;-)

[JIMinPHX]

Someone with a CNC would clamp a couple blocks into a fixture and transfer the desired mould info from his computer to the lathe and punch the green button. Go make a PB&J, pour a glass of milk and amble out into the shop to remove his feshly machined blocks out of the fixture. Maybe take a nap after that hard work :-)

...............Buckshot

The guy that own the CNC shop I used to work at always used to say that he'd rather die of lung cancer than a sore back. He spent a lot of time rolling up some of Dewey Eggbert's finest.

[jimkim]

There is an article here on mould making.
http://www.castbulletassoc.org/forum/view_topic.php?id=2659&forum_id=10
It is from Handloader magazine. Jim

[jjamna]

I didn't think I would ever be able to make my own mold. No access to milling machine- However after reading this thread I may be able to after all. I do have access to a lathe, I just never thought about putting the blocks in and the boring it.
Thanks guy's
Jeff

[jimkim]

Did you see how the guy in the article did it?

[Cap'n Morgan]

Here's a pic, showing the principle behind making a WC (or the groove part of a boolit) on a lathe.



http://img106.imageshack.us/img106/9542/moldturningxo8.jpg (http://imageshack.us)

[Southern Son]

Captain Morgan, I understand know what you meant on your earlier post, but I think that bit would woble like hell in my cordless drill, if my missus would give it back to me. :kidding:

[tn gun runner]

Here's a pic, showing the principle behind making a WC (or the groove part of a boolit) on a lathe.



http://img106.imageshack.us/img106/9542/moldturningxo8.jpg (http://imageshack.us)

I put a mould in a lathe with a 4 jaw chuck and dial it in make 2 tool like your ,
1 for nose and the other to cut the bands . use a old mould single type , like a
30 cal and drill and cut to this 40 cal 400 gr which is 3 different dia bullet .

http://i189.photobucket.com/albums/z195/dukeboy51/Picture073.jpg

[Shotgun Luckey]

unfortunately, to get a new mold, I have to BUY it....I envy you machinists

[Buckshot]

unfortunately, to get a new mold, I have to BUY it....I envy you machinists

................Naw, heck you can make a mould on a lathe just using a faceplate and a couple small angle plates.

http://www.fototime.com/025DBFFE3B48D69/standard.jpghttp://www.fototime.com/096CE7F75FAF235/standard.jpg

I made the above 3 cavity core mould just like that. Two angle plates on a face plate. I'll admit that merely boring 3 cylilndrical holes is a lot simpler then boring and then cutting features into a set of blocks for a boolit mould, but it DOES work and the process is VERY similar. The making of the core mould started out as just a kind of an exploratory deal. I just wanted to see if I could do it and how it'd turn out. As it was, it turned out great. I was prepared to learn and scrap a couple along the way.

You could get one of the 7"x12 machines for less then $500. Another hundred and you'd have the tooling to do it yourself. Not only moulds but then size dies, nose punches, M die sizers, etc & etc.

..................Buckshot

[44man]

I do things a little different because I use scrap aircraft aluminum and it is large enough. I have enough for 13 more molds, then I will have to use thinner stock.
I make my blocks in one piece then drill the pin holes. I then saw the block in half and mill the inner surfaces and put the vent lines on. I usually just vent one side. The pins are installed next.
After I clamp the blocks in the vise I mill the top again so it is at right angles to the mill head. I never remove the blocks until the cavity is finished, doing my de-burring with a stick I tape fine emery to.
I use pins and setscrews for the handles but I drill a small hole all the way through first, then the pin size hole a shorter distance and tap the lower end for the setscrew. If a pin sticks in the hole I just take a little allen wrench, stick it in the top hole and push the pin out. Makes life easier when I have to change handles. I use Rapine handles.
Here is where I am now. I have started milling the scrap. I still have a lot of cutting to do on the bandsaw and have to mill the ends.

[44man]

I now have all of the blocks sawn up ready to finish mill. I also found another piece so I have 14 blocks.
Bandsaw blade got dull again so I have to sharpen it again with my Moto tool and the wheel I shaped to the gullets. 720 or so teeth, yeeeeoh! :???:
You might be interested in how I keep my cherries from warping when hardening. I put it in my drill press and turn it when I heat it. This keeps the flame even. Then I stop the press and open the chuck to drop the cherry straight into the oil can. I put it in my kitchen oven at 300* for an hour and shut the stove off to let it cool slowly as the oven cools.
I tried one without tempering and edges broke off.
I HATE making cherries! :mrgreen:

[leftiye]

Tn Gun Runner,

I really am impressed with your mold! Please edimicate us on your technique in making that nice ogive, and them nice round grooves (pretty please).

44Man,

Thanks for the overview of your heat treating. What type of metal are you using for your cherries? How do you control your max temp?

[44man]

I use oil hardening. I just soak with the welding torch, bright orange. I use a carbonizing flame, less oxygen. I drop it into transmission fluid.

[WildmanJack]

God I wish I could do this stuff. You guys talk about x and y axis like it was a peanut butter and jelly sandwich. I was a fire/medic, so I could read an EKG and give you the right drugs but man when it comes to machining something, I feel like a caveman!!!! I am truly envious of you guys...

[deltaenterprizes]

God I wish I could do this stuff. You guys talk about x and y axis like it was a peanut butter and jelly sandwich. I was a fire/medic, so I could read an EKG and give you the right drugs but man when it comes to machining something, I feel like a caveman!!!! I am truly envious of you guys...

Got to school or get some books and start reading or check out the Home Shop Machinist and Pratical Machinist web sites.Then spend between $5000 to $10,000 on tooling and after making a bunch of mistakes and making piles of scrap you will be able to do it too! You were not born a medic were you?

[deltaenterprizes]

I downloaded the article on making a mold but the pics were kind of dark,I sure would like to see some clear pics on how to sharpen the cherry.I made a rough one of a 38 wadcutter and cut some aluminum but the cavity came out full caliber on the width but not full caliber on the depth going into the blocks. It cut nice small chips.
Can anybody post some pics?

[44man]

Yes, tomorrow when I am on the downstairs computer where the pictures are. It sounds like you were trying to cut cavities by running the cherry in like a drill bit! Not good that way! [smilie=1:

[deltaenterprizes]

God I wish I could do this stuff. You guys talk about x and y axis like it was a peanut butter and jelly sandwich. I was a fire/medic, so I could read an EKG and give you the right drugs but man when it comes to machining something, I feel like a caveman!!!! I am truly envious of you guys...


Yes, tomorrow when I am on the downstairs computer where the pictures are. It sounds like you were trying to cut cavities by running the cherry in like a drill bit! Not good that way! [smilie=1:

No,I closed the blocks on the turning cherry.

[44man]

OK, I have a few pictures that were sent to me. I have to try and get them here. It is the same as I do it but I use a 4 flute end mill.

[44man]

That picture was the start of a flute. I usually cut slow until I am about .070" deep. I use six flutes and then file only three to the nose. Four flutes works good too.
I had to take a picture of the paper I have to show angles so I don't know how it will come out.

[44man]

Now if you can see it on the picture you will see the small flats at the edges. These must be filed from the cutting edge back for a relief or they will just rub. Like sharpening a knife. You don't want to get into the cutting edge with the file, just barely reach it. The nose edges need done too. Just leave a few thousandths left at the cutting edge. Then stone them sharp with a fine stone like ceramic.
I don't have a picture showing this. An easy way to see this is to study an end mill. Since we don't have the grinder setups used on cutting tools we need to do the best we can with hand tools.
My camera is not that good but I took a picture of a few cherries.

[deltaenterprizes]

Thanks! I will give it a try.

[tn gun runner]

Tn Gun Runner,

I really am impressed with your mold! Please edimicate us on your technique in making that nice ogive, and them nice round grooves (pretty please).

44Man,

Thanks for the overview of your heat treating. What type of metal are you using for your cherries? How do you control your max temp?

The tools look like inside thread cutting tool . you can control band wides and depth and distance
between bands and the same thing with ogive and dial indicator help on the control feeds
I'm a self taught gunsmith and machinist .
http://i189.photobucket.com/albums/z195/dukeboy51/web/moldturningxo8-1.jpg


http://i189.photobucket.com/albums/z195/dukeboy51/web/bullets.jpg

[tn gun runner]

How do my molds shoot
http://i189.photobucket.com/albums/z195/dukeboy51/web/Picture073.jpg

http://i189.photobucket.com/albums/z195/dukeboy51/target32-40.jpg
http://i189.photobucket.com/albums/z195/dukeboy51/Picture049-1.jpg

and one of the gun I built to shoot it

http://i189.photobucket.com/albums/z195/dukeboy51/Picture060.jpg

[Boomer Mikey]

Excellent writeup tn gun runner!

Nice work, and excellent results... especially with a rifle you made. It doesn't get much sweeter than that.

I'll bet that perfect score is in the future.

Lathe boring is looking easier all the time.

Boomer :Fire:

[tn gun runner]

Here the 40 Ibuilt

http://i189.photobucket.com/albums/z195/dukeboy51/400gr.jpg

http://i189.photobucket.com/albums/z195/dukeboy51/40-60maynard.jpg

[44man]

TN, you have it all together and I applaud you. GREAT job! :drinks:

[jimkim]

What is the ideal thickness for the sprue plate. I'm thinking of building one for my ranch Dog mould. I was thinking of making it .375" thick and connecting the pour holes with a shallow channel so the lead would flow to the next cavity once the first is filled. I believe having it shear one large piece may produce more uniform bases. My thinking could be off, since I am new to this. I would value any input. Thanks. Jim

[deltaenterprizes]

.250 is plenty thick enough,that is what H&G used.

[jimkim]

Thanks. I tend to over engineer everything. I don't know if you can tell. lol

[Echo]

Envy is one of the Seven Deadly sins, and Boy, am I a Sinner! That is beautiful work, TN - someone a lot smarter than I once said 'Beauty Is, as Beauty Does'. Those Beauties Do, Big Time!