We currently have a part we run that has a broached hex put into it. Currently we run 3 varied sizes of this part. ON the smallest part we punch broach from the 20 tools into material gripped by the main spindle. On the larger sizes we use a stepped pickoff collet and broach from the 30 tools into the back spindle. We are considering buying another L7 to replace one of our L5's and the owner has some concerns about broaching with a new machine.
Currently on our largest part we actually grind off 3 of the corners our broaching tool and index the part and punch it multiple times. This works somewhat ok to relieve some of the pressure needed.
We would use a rotary broach, but this part also requires that the hex be oriented against another part feature (Drilled hole during main operation) and we are not aware of any way that would accurately orient a rotary broach between parts.
I was hoping someone may have any suggestions on tooling or processes we're unaware of that may help. We are only broaching a countbore that is approximately .040-.050 deep.
Picture a stepped .500 OD washer .200 in lenght with a .400 square shoulder bore to a .170 depth. The remaining .030 is what we broach--and we do pre-drill it to the largest size allowed by the hex flats.
Any suggestion/information is well appreciated--even if I don't get a chance to respond for a while.
The way you're currently broaching the job is the cheapest and easiest way of doing so when you have to time the broached profile to other features on the part. It can be tougher on the machinery when you're just punching, like you have already stated.
I've successfully set up rotary broaching jobs that required orientation in CNC Swiss type machines. Send a print to firstname.lastname@example.org and we'll see if we can set you up for it.
Polygon, I'm not sure we'd have the clearances and movement to do that. Plus, the tool itself is stationary, so I wouldn't be able to pull the tool off of the fixture afterwards.
Scott, I'll probably be emailing you fairly soon. If I'm not mistaken I think we actually got our rotary broach tooling from you guys.
Just my two cents:
The L7 ('09 and up from my experience), can broach comfortably up to 3mm full form, and if you index the broach, you can easily broach up to 5mm.
Here is a Macro that i use if you are interested:
T3400( 4.0MM BROACH )
G1Z.___F4.0 <--Depth you wanna go
#520 being a vaiable at the beginning of the program on $1 to control the times in which to index. This can also be used on full form broaching to help prolong life of it as well.
Check out Broaching ~ Horn USA, Inc.
Might not be the fastest way of doing things...but you get all the control in the world..I've used these before trying broach hardened nickle/cobalt/chrome..gave us the ability to peck away at each corner to reduce load..and you can get a range of differant hex size out of one tool, depending on pre drill tolerance...
weve also cannulated the broach (a hole through he center of the broach all the way through it, or with another hole at a 90 degree angle to it so u get an "L" shaped hole on the broach) to releive pressure. and we normally bore the max I.D. hole, with a slight taper towards the bottom of the hole, bell shaped if you will,...so when the broach gets to the bottom of the hole, it also get less pressure.