Who machines cherry cutters for molds?

[Viagrow]

Who offers the service for making the commercial milling cutter (cherry) used to make bullet molds. I have seen videos where DIY folks turn a bullet profile on a lathe and then mill a portion out for side cutting, probably okay if you make one mold only. The commercial cutters look more like a hardened end mill.

I'm looking on making some custom molds for a shooting club I belong to. I have access to a CNC mill. However, I don't have a source for a commercial quality cherry maker.

Any help will be greatly appreciated.

Regards,

Viagrow

[country gent]

I would imagine that most of the mould makers using cherries still have a in house tool room and cutter grinders ( Trade) that grind and sharpen them. Any shop that does cutter grinding should be able to make them. We ground some from 4 flute end mills at work. A lathe and tool post grinder to rough them out with then back them off by hand with a fine stone. Our cutter grinders were top notch craftsman, especially when it came to govt jobs. LOL.

[Grmps]

You could contact a saw sharpening shop that does custom profiles for routers and shapers. They can program in the shape you want and cut it for you to your specs

[Viagrow]

Gumps,

Thank you for the reply, would you be able to point me in the direction of a saw sharpening shop?

[Viagrow]

Thanks country gent,

I will do an internet search along the lines of cutter grinders and see what pops up. Much appreciated sir.

[Grmps]

It depends where on the west coast you are the 5 is a long stretch of road. PM me

[John Boy]

would you be able to point me in the direction of a saw sharpening shop?

Give David Mos a telephone call. One of the best skilled mold makers still in business that cuts with a cherry...
His phone number is 479-394-5895

[Viagrow]

John Boy,

Thanks for the reply. Other than boring with a lathe, is there another method for cutting a mold other than with a cherry? Any help is greatly appreciated.

[Nobade]

If you use a cherry you'll need a double closing vise as well. That's what keeps me doing them on the lathe. Those things are expensive! With a CNC mill you may be able to use a D reamer and orbit it in the pre drilled hole. I haven't tried that, might be worth a try.

[country gent]

with the cnc mill a form cutter can do the flat orbit and cut the cavity very true and it can give a very nice finish. The drawback is depending on the "offset required for size from the undersized cutter to the mould size you get a flat on the nose that big also. The D reamer will work but a multi flute cutter gives better chip removal and finish.

If your mill has a good digital readout then the blocks can be spaced open on long pins for alighnment and known spacer blocks, clamped tight in the vise. swing the spindle in to center of the gap with an indicator and zero y axis. Cut to the numbers each way in Y axis. a little more work, But more room for chip clearance and removal. This works better for base pour moulds than it does for nose pour moulds, simply because the cutters shank is bigger and solider.

[Viagrow]

county gent,
Thanks for the info. What you say is very interesting and enlightening. I am not a machinist so this is new challenge. From a video I saw on Mihec's youtube channel (mihecp72) it looks as if he works on half a mold black at a time. the cutter is driven into the face of the block. He has video labeled CNC interpolation and another one labeled CNC mill that show one technique for molds. Is the technique used in the videos how most commercial makers produce their molds?

[Viagrow]

Nobade,

Thanks for the insight. Using a lathe to bore and profile did cross my mind, but it would still have a small flat spot at the tip. What does a double closing vise run? Will the vise be accurate enough to close evenly as both molds halves are driven against the cutter. Last time I tried that my cavity turned out slightly oblong....LOL. The sizer took care of it in the end...LOL

[country gent]

When using the 1/2 each way method I described there are several little diffrences compared to the double acting vise. 1 thread play needs to be taken out between halves. on machines with ball lead screws or good digital read outs this isn't as big an issue. 2 a short pause at the end of each cut to allow cutter to "Idle" and remove any flex from cutting forces that were introduced. On the double acting vise the vise is closed while chips are removed with coolant or air pressure the set up is critical. Blocks are bolted into the fixture and as the vise closes the cutter cuts the cavity in both blocks evenly reducing cutter flex. With the vise chip removal is much more critical.

On the flat orbit the small flat can be removed with a second cutter after the cavity is cut. This is similar to ball mill and just reaches in and removes the flat The flay orbit is probably the faster way to cut a mould block set. I did a couple of balls in a cnc edm. The electrodes were machined from copper tungsten material and .010 under sized. used 2 electrodes 1 roughing and 1 finishing. This made very nice blocks and was very accurate. As it was an electric arc doing the cutting there was no cutter forces to deal with.

[Viagrow]

country gent,

CNC EDM, wow that's hard core machining. I don't have access to anything like that. The methods you described earlier are very useful and descriptive. I'm surprised a commercial mold maker hasn't posted a video detailing the process they use to cut the mold cavities, I guess it's a trade secret or something. Thanks again for sharing your knowledge with those of us who wish to learn.

[Nobade]

Nobade,

Thanks for the insight. Using a lathe to bore and profile did cross my mind, but it would still have a small flat spot at the tip. What does a double closing vise run? Will the vise be accurate enough to close evenly as both molds halves are driven against the cutter. Last time I tried that my cavity turned out slightly oblong....LOL. The sizer took care of it in the end...LOL

I was wondering the same thing, so just looked it up. MSC has the 6 inch Kurt for $2868.60 in the new catalog. Think I'll hold off for a while.

[Chill Wills]

In my experience, bullet designs with small flat on the nose have been very accurate and have not hurt the long range usefulness.
I would not rule out trying something if that was the only hitch.

Consider, all the Hoch nose pour molds have a small flat.

[country gent]

I believe the kurt has take up adjustments for the jaws. But that's one thing you really need on the double acting vise, this allows you to keep side play out of the jaws. This allows for better alighnment of the blocks when closing on the cutter, lessens the chance for chatter to start, and just allows for a better finish. We had one for doing multiple parts with centered milling. Made things a lot easier for it. as the vise compensated for the few thousandths differences in the parts.

[kywoodwrkr]

Project from previous times. Blank was to be held between outside steel pieces and middle piece.
CNC milling then performed milling in each mold half, chips flushed with coolant. Not proven so not sure how well it will, could have, maybe would work.

Attachment 243211

[RED BEAR]

You can always go back in with tool to remove the flat nose and replace it with a point or round nose .its not that hard it using a cnc machine it's a piece of cake.

[tecdac]

I don't know if Magma cuts a cherry or sends it out to a third party but you could call them and ask.
MagmaEngineering.com