My team is looking to get an arbor press and we’re not sure what to look for in the press to ensure it can broach 1/2" hex using the AM broach:
First, how many tons should the press be?
Second, how much space should it have to press down?
Third, any other dimensions that we should check for?
Lastly, anyone have a guide or video about broaching so I can show to my team?
Typically I dont think it requires a large amount of force. One of our mentors purchased a 1/2" hex broach a couple years ago for us and iirc we usually just put it in the lathe and chuck the part up and force it through like that. We do use a large lathe but the force isnt huge for aluminum. I probably wouldn’t recommend that, we broach very few parts.
I believe you have to push it pretty far through the part, nearly all the way.
I think any arbor press you find with enough clearance and travel to cover the 12" length of the broach plus your part will be strong enough. You’ll probably also find it exceedingly expensive.
We built our own broaching fixture from welded steel C-channel and a hydraulic bottle jack with about 18"(?) of travel. Works extremely well and several local teams come by to broach parts during build season.
You need a 3 ton or larger. Don’t broach in your lathe. That’s very hard on and potentially damaging to the lathe.
I think any arbor press you find with enough clearance and travel to cover the 12" length of the broach plus your part will be strong enough. You’ll probably also find it exceedingly expensive.
We built our own broaching fixture from welded steel C-channel and a hydraulic bottle jack with about 18"(?) of travel. Works extremely well and several local teams come by to broach parts during build season.
This!
If you have the money and don’t have the space for a tall press, rotary broaching is a very effective option. You can broach in a mill or lathe pretty easily, and much faster than using a large press. The caveat is that you can’t broach deeper than a bit over an inch or so, but for FRC that should be fine.
You can find 1/2" shank rotary broach holders for $200ish on ebay, and the 1/2" hex broach for another $70. 3/8" hex broaches are another $60-70. The total cost is less than buying two broaches.
Personally, I also find rotary broaching a lot less scary, but that’s just me.
It takes a little more time, but you can do it easily with a shorter travel press by doing it in 2-3 stages. 294 has used this Harbor Freight shop press (or a similar one) for broaching hundreds of parts in 1/2" and 3/8" hex over the last 8 years. https://www.harborfreight.com/12-ton-h-frame-industrial-heavy-duty-floor-shop-press-60604.html
This is the press we bought a few years ago to be able to broach. We also drilled a hole for the broach to sit in the press ram a couple inches, but it’s not required, it just helps for broaching some thicker items.
https://www.mscdirect.com/product/details/00231290?rItem=00231290
Wait for MSC to have a good coupon, we got it for $322 including shipping.
For the one you linked. it has enough working distance that you can just go once through correct?
We do this exact same setup as well. It works great but you cannot get in a hurry. I broached a part yesterday, it take about 3 steps. You can only go about 3-4 inches at a time. The entire broach is like 16” long. We made a custom adapter to attach to the press that then stepped down to the 1/2” shaft of the broach.
Stroke length scales with tonnage in a pretty predictable way across all brands. The “standard” 3 ton press is barely tall enough to handle a 1/2" hex broach. For tall parts, you can try to rig up an alternate lower point of support, or just use a mallet for the first few teeth – the middle of the broach is where the load is the greatest. Its a really bad idea and you shouldn’t do it, but I have broached all the way through aluminum parts entirely by hammer before in a pinch. With some persuasion we’ve been able to do everything we’ve wanted with a 3 ton, and we’ve been very demanding on our broaches relative to the average FRC team – one of my teams’ standard gearbox features over the past couple years featured a 2" long broached steel hex sleeve.
I have used larger presses and they make life easier, but a 3 ton should handle everything you need if you are space/budget constrained.
Make sure you have something under the table to catch the broach or allow the operator to pull it out of the part, so it doesn’t just crash to the floor.
Such lathe abuse should to be illegal. The most expensive part of the lathe is the headstock bearings, and you’re damaging them by doing this, no matter the size of the lathe.
That ^^. It will be perfectly fine, perhaps even overkill, for broaching of any kind. Under $100 with a coupon.
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Wat about for pressing in pinions? would it be too much?
Just because a press CAN generate 12 tons of force, doesn’t mean that it HAS to. You press the pinion with care, you’ll be just fine.
The broach we built is 42" to the underside of the broach stop surface (at the top of the press) and 44" overall. We broach our stuff “upside down”. The upside is we don’t drop the broach on the floor when it passes through the part being cut. 
The top of the piston to the underside of the stop is 14.5" and travel appears to be 16-18".
The bottle jack is a 3 ton unit and easily does all our 1/2" hex in Aluminum. IIRC, we bought the jack from Harbor Freight.
The Al linkage is just to move the pivot higher so the operator doesn’t have to bend over so far when the press is on the floor.
For best results, the broach stop should be perpendicular to the stop.
Sorry, no CAD file exists…
The broach we built is 42" to the underside of the broach stop surface (at the top of the press) and 44" overall. We broach our stuff “upside down”. The upside is we don’t drop the broach on the floor when it passes through the part being cut.
The top of the piston to the underside of the stop is 14.5" and travel appears to be 16-18".
The bottle jack is a 3 ton unit and easily does all our 1/2" hex in Aluminum. IIRC, we bought the jack from Harbor Freight.
The Al linkage is just to move the pivot higher so the operator doesn’t have to bend over so far when the press is on the floor.
For best results, the broach stop should be perpendicular to the stop.
Sorry, no CAD file exists…
I hope the photos come thru…
Was this question answered? I am searching for the same information but could not find an answer anywhere. Is there a way to press a pinion gear onto AndyMark Redline motor without an arbor press? We do not plan to do hex broaching and we are not a high resource team (particularly w.r.t space), so I would like to know if this can be done without an arbor press. Can the following bench wise be used to press pinion gear on to motor shaft?
Also, is there any other use case for an arbor press in FRC besides hex broaching and pinion pressing?
Andymark sells a pinion press tool you could try to use in your bench vise, as long as you do it slowly.
You can use a press for removing stuck bearings from shafts and pressing them into and out of plates. Fairly useful, but not necessary, per se. I use a vise as a replacement for a press often for low-load pressing applications.