5804 is looking at getting a manual brake this summer to help with sheet metal fabrication. Baileigh is one of the companies we’re looking at, specifically their box and pan brakes.
I’ve worked at a fab shop with multiple hydraulic press brakes (some cnc, some much older than myself with dial back gauges) for about seven years but I’m still definitely limited in my knowledge of sheet metal bending and press brakes. I do know enough though to know that there’s a lot that goes into the process. A good amount of my time at this shop has been spent doing drawings for bent parts from .060 aluminum all the way up to 3/4" mild steel so I’ve had to pick up on bend allowance rules, material properties, crowning, etc. You didn’t say in your post if you have any background with brakes or bending but if not, I would definitely encourage you look more into it all. I’m sure the machinery’s handbook is a good place to start on that (just like everything in the shop), in addition to I’m sure an endless stream of knowledge from around the web, and the sponsors in your community. You can also PM me if you have any other questions and I can either answer them or, more likely, ask one of the greybeards at the shop.
As for the brake you’re looking at getting, I’d be wary of a hydraulic press in a high school shop as far as safety goes, but I’m also wary about the manual brake we’re getting. As with any machine tool, there’s a lot that can go wrong with a hydraulic brake from the obvious pinching (read: removing) fingers and extremities, to splitting dies and showering all those around with metal shrapnel at crotch level. The latter may be less of a concern with newer tooling that is only hardened on the very surface where it contacts the work, and then softer throughout but is still always a worry in the back of my mind. I know I plan on being extremely strict about usage of our brake by students and will always have tight supervision by myself or another mechanical mentor while using them, and the chances of catastrophe on a manual are far less than on a hydraulic in my opinion. Or at least the catastrophe will happen in a more slow and controlled fashion ::ouch::.
What is it you’re trying to do with this brake that you don’t think you’d be able to do with a manual brake? You can certainly get a manual brake that will do up to 1/8" aluminum or mild steel, 90 degree bends, some sharper bends depending on what you need, and even some pretty tight reverse bends (~.625"). I don’t think you’d be able to find one able to hem but I also don’t think I’ve ever seen a use for hemming on any robots I’ve been a part of or seen at competitions so I bet for the 25 grand price difference, you could get away without it. For lexan, I’ve actually never seen a press brake used to make bends.It may be possible and from my reading, it looks like it is, but any time I’ve ever needed to bend plastic sheets, I’ve just sat it on a plastic bending heat strip for a few seconds and then bent it around a template (usually a 2x4 or something simple).
All that being said, if you can treat this machine as a learning device for students, I would say it is most certainly worth it. My shop and many shops around the country are hard pressed to find skilled labor whether its welders, machinists, brake operators, what have you. If, in your opinion, this brake and the knowledge that will inevitably come with it will positively impact more students in your area than a manual brake would, I would say definitely pull the trigger on it.
If you do go with this baileigh or any hydraulic brake for that matter, you’re going to probably need additional tooling. The thicker your material, the wider bottom dies you will need to make bends and you can find charts like this around which will show you what die to get for the thickness material and given tonnage of your press. You might also want some gooseneck punches for tight return bends, some hemming tooling and then maybe even some horn punches which will allow the back end of a bent part to swing back through the space created between opposing horns towards the front/back of the machine. Using the correct tooling is pretty dang important on hydraulic press brakes (see paragraph 3) so definitely don’t skimp on this stuff and always, ALWAYS make sure they’re seated correctly and tightly before bending anything.
If you end up getting a brake of any type, make sure you pay attention to your alloys for aluminum. While I don’t think you’ll run into it much, some alloys are not formable and will crack or split if you bend them past a certain point. Formable alloys include 3003, 5052, or 6061 while you probably want to stay away from like a 7005 alloy. Most of what you commonly come across is going to be 6061 anyway though so like I said, you probably won’t have problems with it most of the time.