300 blk case cutter test 2

[jmorris]

Yes, the UHMW can only move linear. Tooth count is 225 IIRC, have to double check to be positive.

[angus6]

Thanks , thought it was but couldn't tell for sure

[jmorris]

It is actually a piece of 1x2 box tube with one side mostly removed and slots machined into the plastic to ride in the "rails".

[shangrila]

Hey Jim, could you post your saw arbor design? I've got a good handle on the other components, just didn't know if you did something different for that. Thanks!

[jmorris]

I don't have it here but I can tell you that was where the work was. Started from a 4" billet of steel, machined down to 1/2" on drill press side and a .020"x 1" shoulder for the blade. Drilled and tapped for 1/4-20 bolt. A machined washer on the bottom 3 or 3.5" too.

keeps the blade from flexing due to load.

There are easier ways to do it but don't "hack" this part, you have a 5" blade spinning over 3000 rpm do it's only .025" thick, if stuff starts flying, you wouldn't want to be around.

[W.R.Buchanan]

Jim: a DIY manual version might be a big seller? Clamp to the DP table. Instead of the motor drive you'd just use a lever to move the slide in and out between stops. Everything else the same.

Randy

[jmorris]

I figure the small volume guy's would just use one of the inexpensive jigs (or make their own) with the cheap HF chop saw. The next gen I am putting together now uses linear slides larger motor, more RPM, etc. Also more expensive but they are telling me the 300 blk is the most profitable ammunition they produce.

Manual feed would likely just make for feed rate variables anyway.

[Bzcraig]

Amazing talent here and some ingenious fabricators!

[M-Tecs]

As always very nice!!!!!!!!!!!!!!

[M-Tecs]

I am going the Honey Badger/Titian Weapons route but this router motor would make a great start for a cutoff type if 8,000 rpm is not to fast. Currently $50.00 off on orders over $200.00

http://www.amazon.com/gp/product/B00...ilpage_o00_s00

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http://store-hdcduy.mybigcommerce.co...-starter-pack/

http://fastandfriendlybrass.com/shop...er-adapter/34/

[jmorris]

Still two passes through the machine?

[W.R.Buchanan]

Jim: I have ran similar "Chop Saw" jobs both on my mills and Lathes using a 6" fine blade between 4" aluminum "washers" ran in an Angle Head or setup in a lathe.

The manual feed is never a problem as the blade has such fine teeth and is spinning so fast that your part is separating in less than one revolution. Chip load per tooth is practically nil.

When cutting Brass on any machine there is no speed that is too fast. B&S Screw Machines making Brass Bushings run at 6000 rpms (which is the fastest speed available) and do a Feed to Stop, Drill, Ream, Chamfer and Cutoff in a 2 3/4 second cycle time!

Cutting Cartridge brass is essentially like cutting tubing, so it is not going to take much power or feed pressure to do the job as long as the part is fully supported.

That's why I suggested a manual feed fixture to simplify the design.

The beauty of your design is that you have gravity doing the feeding into and ejection out the bottom. The down side is the necessity for a dedicated spindle motor as opposed to using a common machine. The manual fixture could be ran on any drill press or mill.

However on a dedicated machine this is just part of the design and as long as it pays for itself, it is worth doing. Lots of suitable motors out there for cheap.

The operative point here is "Pays for itself." And as long as the demand is high enough and the numbers of product produced great enough then it is a no brainer to make a dedicated machine.

If the numbers are in question, then a more simplified approach is prudent and then if the numbers materialize further automation or a completely new machine would be in order.

I actually wouldn't mind doing this if I could find a good source for Ex Mil or LE brass. I would set up my DSM59 with a saw in the spindle and a small fixture on the cross slide and have at it.

Or more properly I would hire a kid to have at it.

I like your machine, it probably doesn't take breaks, go to the bathroom, or eat lunch...

Randy

[M-Tecs]

Still two passes through the machine?

From Fast and Friendly Brass "To make .300 blk correctly, it has to be done in two steps. Attempting to do it in one step means that the trimmer engages the brass before the brass engages the die. This induces spin as he brass enters the die, prematurely ruining the die and shell plate."

[captain-03]

Now that is just amazing!!