Gunsmithing Hydraulic broaching machine

[maccrazy2]

I am going to help a friend move a couple machines tonight. I have been offered a hydraulic broaching machine. Does anyone use one for making actions? I know bighorn uses wire EDM on his. I am tempted to pick it up just because if the price is right. I would like to build an action for the fun of it but have no intention of doing it as a business.
Any feedback from anyone who has used one is appreciated.

 

[MOAxp]

Tooling cost will eat you alive for a one off

The 50 receiver I am working on the EDM cost was very reasonable $150-175 IIRC

 

[6.5 sender]

How big is it? lets see some pics if possible.

 

[LRI]

Lookin at around 10 to 20 K to get a broach made. Lean on the pen and make 2 copies!

 

[maccrazy2]

Holy cow I did not think it would be that much for tooling. I will see what it looks like tonight.
Looks like EDM would be the way to go for a one off either way.

 

[LRI]

EDM is cool, provided that the shop doing the work has a SUPER high end machine.

The wire likes to "bow" and deform a bit due to the need for increased water circulation and because it's such a long length of cut. Water circulation is a must for chip evacuation. More pressure you run, the more it's likely to distort the wire and cause a machining error. The wire doesn't actually contact the part, if it does, the machine alarms and stops. It's the arc that does the whittlin.

You can bump up the tension on the wire only so much, then it starts to stretch or break. Again creating errors and a whole lot of cussing. Been there, done it... Best left to the expert who's perfected it:

Ken Frankel, Three Sigma Machine in Kent, WA. He does about 90% of the better actions out there.

Good luck.

C.

 

[maccrazy2]

Thanks Chad. I will look him up if I try to build one.
I went and moved the lathe and mill and checked out the rest of the equipment. The machines were built and used for broaching but were really basicly electric/hydraulic presses. he had 3 of varying sizes. 2 were just hydraulic rams to push directly on the workpiece. 1 had a toolholder on a track that the ram actuates. I had envisioned a machine that pulls a broach down thru the workpiece based on what I was told. The largest one sold while I was there. The small ones only had aprox 4-5in stroke.
I ended up with a machinist box full of carbide/hss cutters, drills, mini gun drills, boring bars, allens, tools, measuring tools and set up blocks as well as a large assortment of t nuts, studs and hold downs for my mill and a small metal shear all for the high price of $85!! The guy just wants the place cleared out.
there were 2 machineshop owners there today so most everything is gone now but the scraps.

 

[bohem]

Ken Frankel, Three Sigma Machine in Kent, WA. He does about 90% of the better actions out there.

I will second and third this advise... If he has the time to do it, Ken is absolutely the guy to see but like all good shops he's super busy.

 

[glbreil]

The wire Bow thing is why the blanks are cut in multiple passes. The rough cut is is made with high pressure to clear the kerf as it cuts, then the slug is removed and multiple Skim cuts are made at very low pressure to clean up and make the internal finish nice. The EDM can provide a great finish with no visible tool marks.

Gary Breiling