Printable View
I am working on the armour for our Beetleweights and my we are thinking to A: save money on the cut, B: reduce the amount of welding and C: make the body stronger... what would be needed to properly fold 1.2mm Grade 5 Titanium?
Is it with the effort given the above advantages or is it easier to just weld it all together?
Bending titanium cold is difficult and usually needs quite a large radius to avoid breaking - I think the radius is 10 x the thickness without looking it up. Bending it while its red hot is much easier. If you have a propane or MAPP gas torch, a vice large enough to hold the sheet and a BFH, you can get the job done without much trouble.
Heating ti is derecommended. It weakens the stuff.
How so? Grade five is always supplied in the annealed state and I have re-heated and either bent or beaten out dents many times. Unless you get it hot enough to cause hydrogen enbrittlement (IE welding temperatures) there shouldn't be a problem. I got my info from page 23 of this manual: http://www.timet.com/images/document...abrication.pdf
Notice that table 18 for cold forming recommends a bend radius of 9X the thickness for grade 5 thin sheet, while you can get down to 2X the thickness at 816 Deg. C. I try to get the titanium to a dull red and do the forming in several stages with a final heating to take out any work hardening.
Trev has bent Ti sheets as the lids on Mini Mighty Mouse, might me worth giving him a shout?
If you look at them up close they're utterly beautiful pieces of art.
In short, it sounds like an awful lot of work... we don't have any gas torches that would be big enough, nor a press or bender so l thick that is out.
What's the length of the bend? I have been going seriously low-tech with just an 8" vice, a basic MAPP torch and a big hammer. Welding is usually a better result but bending is so much cheaper and quicker that its often the better choice for thinner sheet and I have done up to 9mm with a slightly larger torch. If you have some scrap sheet, at least give it a test...
Attachment 4663
That is the new chassis design so the longest folds would be 238mm long. There are a lot of long fold in the build if you were to do it like that and they all meet at sharp corners.
The issue with heating titanium is if you do it in an oxygen environment. Just like when welding you want to heat it in an inert atmosphere. Titanium should be the same slighty shiney but dull colour. If it goes blue then it's been oxidized and will in all likelyhood fail.
In terms of bend, you should be able to bend 1.2mm by hand. I bent 2mm grade 2 using a vice and a hammer for hornet 2. I had a fairly sharp right angle at the rear of the plate. Grade 5 can fail in a brittle fashion when bent whereas grade 2 is more ductile and will take a bend better.
Binky and Conker 2 are Grade 2 so we can bend them back into shape if we have to. There are people and places we know of that might have an argon tank so its possible but I am now leaning towards just getting it welded.Quote:
Originally Posted by typhoon_driver
At work we dont ever heat titanium to bend it, and its perfectly possible to bend it at 1.2mm thick using a proper bender, but having said that for your application heating it will make your life much easier and the effects of heating are negligible for our use...
Looking at the design, the corner seams need welding so you might as well weld everything. Its really hard to get that tab & slot construction to line up properly when you are bending a frame like that, making welding even more attractive.
With hot bending, I am only going on what the manufacturer recommends - they just mention that scale may form after heat bending and to remove it; nothing about inert atmospheres. As I understand it, you only need gas if the Ti is molten, which is a much higher temperature. Everyone using titanium should memorise that linked manual - its good stuff!
On Mr Mangle, I bent these 4mm brackets with a vice, an adjustable wrench and a torch you'd get from any hardware store:
http://www.nswrfc.org/Nick/P6300831.JPG
It was quick & easy, although better equipment would have given a bit better result.
TIL how to titanium properly.
The Tabs are there because that is the welding version. its that shape I am trying to create. If were to bend it I would make a netted version with the same geometry. Thats just gives you an idea of what I am trying to make.
Cough*storm 2*coughQuote:
Originally Posted by Eventorizon
Looks really solid tho
Seriously? So if I had 4WD would you complain it was a Tornado copy? You try and come up with making an effective rambot that doesn't look like either machine that has 6 or 4WD.Quote:
Originally Posted by Mega Masher
Aside from that, storm 2 is slightly longer than it is wide in my memory.
Most designs have been done before in varying degrees of succes.
Coming up with something completely new or different is quite difficult and often not the best way to go about it.
Sorry, but I thought that would be a complimentQuote:
Originally Posted by Eventorizon
Only trying to be nice
What motors are you using btw
Satanix and BonX say: Who needs 4 or 6 wheels? ;)Quote:
Originally Posted by Eventorizon
Storm 2 would be more effective as a rambot if it had spikes on the top to stop it's opponent going over the top and puttin all the energy into it's opponent (well, not all, but the theory's still good).
I am using the same 1000rpm gearbox/motor combos from ebay as everyone else. I am not sure of a single machine besides Gonzales that doesn't. The 6WD will give it the advantage there as everyone uses the same motors.
Flatulence.Quote:
I am not sure of a single machine besides Gonzales that doesn't.
Although I will be upgrading it to those whenever I get time.
chop suey will run 800rpm motors
Inversion (Harry DT's beetle uses MFA motors), Son of Basketcase (but he got something similar, but a lot slower), Fracture (Copal motors), Shane's former FBS (standard 12mm Antweight motors). Think that covers the ones that don't use them.
What size are the wheels?
chop suey has 78mm wheels I guess (70mm hdpe with bike thread around it)
On folding titanium. I stand by my point that heating Ti above a mechanical advantage point isn't beneficial to the properties.