tricky tooling question for you sinker EDM gurus

[hkfanatic]

i think he was useing 5 deg. as a example to set up and do this on a non CNC sinker the part that makes this messed up is that the flutes cannot extnd all the way out to the breech face.

im working on a print of the chamber right now.

[HKgunslinger]

I was just thining about this today,...this could be done on an older machine even with a shallow Z-envelope and a small worktable area. Using a rotary indexer clamped to the table, muzzle pointed straight outwards (tank door open obviously), true everything up, with your electrode at 90 degrees from vertical, 6 burns per barrel with a 2-flute electrode, only thing is you would have to lead the electrode in the barrel with the Y screw for each barrel. Very do-able. Obvisouly same as the other idea, you would have to have your loc-lines set for flushing the burn area, as it is not possible to fill the tank with the front door open.

'Slinger out.

[TAB]

I think there are number of good options on this board.

I have two options which have not been suggested.

First this could be done using a manual machine that was equipped with an orbiting attachment similar to this (not affiliated with this product just a link for demonstration purposes) http://cgi.ebay.com/Edm-orbiting-hea...QQcmdZViewItem. You could build simple electrodes and do one flute at a time or build more "complex" electrodes with all the flutes on a 360 deg pattern and do them all at once.

The second way to do this would be using a CNC EDM machine. this would allow you to do this very easily and would be how I would recommend doing this in any kind of production.

I would also suggest that you might want to insert the electrode in the breach end rather than the nozzle end as this will be easier and also provide a higher accuracy and quality end result.

good luck.

Todd

[PinnacleMachine]

I was just going to say orbit them in but was beat to it. Pretty easy from my standpoint. I'd make and electrode that has all 12 ribs on it at once.

JP

[Andre' B]

Here is an idea of what you would get doing all 12 slots in a 0.5" hole using a 0.005" overburn and a 0.04" radius orbit to get a slot 0.03 deep. This is with an electrode that only has 0.005" per side clearance to get into the hole to start with.

[rwkjr]

hkfanatic
How u doing on the print/data for chambers? you could send me a part/sample I could do print and/or sample burn, hard part is fixture barrels especially if they are tapered,probably be best to do edm before finish ops, right after broaching and the chambers are in, what do you think? what is your process for these,where does the edm work fit in?
RK

[hkfanatic]

sadly i have been rushing to finish a project for a recent show which i just got back from today, so i havent had time to really get into it.

im fairley confident that i could get measuerments as far as depth and width but its the way the chamber ramps up and necks down to follow the bullet shell.

unfortunately the EDM'ing will have to be done as the last operation, the barrel manuf. it doing everything including profiling they're coming from germany and they do not have the EDM capabilitys to do this.

first order is 42 units 21of one outer profile 21 of another

Rwkjr i would be more then happy to send you an .IDW (if you have autodesk inventor) of the outer profile of the barrels

and I would love to send you a cut up unit, i would obviously pay you for your time to at least to do a print and a test burn for me. i could ship you out a barrel blank (unfortunately it will just be a straight profile and will not match the actual product)

i belive you gave me your contact info before i will give you a call tommarrow to discuss things

thank you!!

[robinhood2b]

i was involved with the manufacture of most of the plastic parts for the SA80 standard issue rifle to the nato forces and got to visit the factory at nottingham and see the whole process.
they produced there barrels by making a male manderal and loading an over sized tube on it, this was in turn loaded on to a modified lathe which had an equivalent of a club hammer bashing away at the tube as it went round ( made one hell of a racket) they then rough turned the outside and the removed it from the machine and twisted the manderal out.
they then loaded the barrel on a capstan press with a light box at one end and turned and twicked the barrel so that it was straight and finally they finished turned the outside.