+++TITANIUM+++

alasdair · Post by **alasdair** » Mon May 31, 2010 7:08 pm

Does anyone know where to buy ti cheap or does anyone have any that they can sell me?

thanks in advance!

joey_picus · Post by **joey_picus** » Mon May 31, 2010 7:55 pm

eBay's usually your best bet

it's a bit hit and miss as sometimes you can find good deals on there, other times there's nothing to be found - the only results I find for 'titanium sheet' that are really feasible atm are for 0.5mm thick 50mm square sheets, but keep checking back.

Sorry that that's not of much use, heh.

leo-rcc · Post by **leo-rcc** » Wed Jun 02, 2010 3:29 pm

http://www.titaniumjoe.com/

But you'd need someone in the US or Canada to buy it for you, unless it is more than 200 USD worth.

You could check with some US based roboteers if one of them is willing to buy a sheet for you.

peterwaller · Post by **peterwaller** » Sun Jun 06, 2010 9:52 pm

Here is a small piece 99mm x 296mm x 1mm on ebay.
http://cgi.ebay.co.uk/6-4-Titanium-shee ... 439fbb2c5a

widow_twanky · Post by **widow_twanky** » Sun Jun 06, 2010 10:32 pm

peterwaller wrote:Here is a small piece 99mm x 296mm x 1mm on ebay.
http://cgi.ebay.co.uk/6-4-Titanium-shee ... 439fbb2c5a

Bear in mind that you wont be abele to bend grade 5 ti. If you want to bend it then you'll need grade 1 or 2

peterwaller · Post by **peterwaller** » Mon Jun 07, 2010 8:47 am

Thats interesting and something I have been meaning to read up on. I have bought various bits of Titanium and have been suprised just how differently they behave. I have some 0.5mm 99% pure titanium from Slovakia which is very easy to bend and a bit on the soft side when you come up against a spinner. I also have some very much harder 1mm which I thought was described as grade 5 aerospace grade which has proved a challange to bend. If I bend it with around a sharp former you can feel it go sort of crystaline and crunchy and it breaks. If I bend it around about a 2-3mm radius it seems to bend OK if you have enough strength but this is normally for scoops and is only a matter of say 40 degree bend. I have some 0.12mm thick foil which is a much shinier titanium alloy and this bends well. I have also just got some 0.05mm 99% pure titanium which certainly bends with your fingers.
So when you say you can't bend grade 5 titanium do you mean that or is it just very difficult. It may be the stuff I have is not actually grade 5 it was a couple of years ago when I bought it on ebay and it is not labled in any way. Also does heating help and if so what sort of temperatures are we talking about.

razerdave · Post by **razerdave** » Mon Jun 07, 2010 5:34 pm

Grade 5 can be bent, its just an absolute sod to

I bought a sheet of grade 5 1mm thick ti from eBay, and it got used to make the flipper on Terrior, but that has a very gradual bend in it to fit the form of the robot, bending it to beyond 45 degrees would likely make it snap unless you can form it over a sizeable radius

widow_twanky · Post by **widow_twanky** » Mon Jun 07, 2010 9:14 pm

razerdave wrote:Grade 5 can be bent, its just an absolute sod to

I bought a sheet of grade 5 1mm thick ti from eBay, and it got used to make the flipper on Terrior, but that has a very gradual bend in it to fit the form of the robot, bending it to beyond 45 degrees would likely make it snap unless you can form it over a sizeable radius

If you're talking bending as in stick the bending dies in the vice and then get a straight and accurate bend in it you can forget it with grade 5. As Dave says you can 'form' it to a degree but not much more. That is however the same with most materials and the thinner the material and the wider the span the better you can form it.

Yes the grade 5 will go chrystaline and break if you over stress it on the bend

grade 5 i have is 1.2mm which you can't bend to any reasonable degree. Thor can bend 3mm ti

Grade 1 and 2 you can get an accurate bend in without any special measures making it much easier to work with and more likely to give positive results.

Ti is a funny material. I have been told frequently that welding ti leaves a very weak joint. That said Hydra's feet are welded ti and haven't even come close to being damaged.

As usual, if it works then fine but you will be ok if you use grade 1/2 for bendy ti.

I have some thinner ti in the shed (not for sale) which is bent in half. It's about 0.25-0.5mm and bent in half so I'll have a check what grade it is. It may well be that the thinner grade 5 stuff can bend.

Andy

widow_twanky · Post by **widow_twanky** » Mon Jun 07, 2010 9:22 pm

peterwaller wrote:Also does heating help and if so what sort of temperatures are we talking about.

Never tried it because i have always been told it hardens the material so never bothered.

Using cobalt drills is also a good idea

andy

nyditch · Post by **nyditch** » Tue Jun 08, 2010 2:07 am

I've done some serious Ti bending with heat. Guidelines for bending with heat:

- Create the bend wit ha large radius
- Heat the Ti until it gets only faintly red. Very bright red or orange is bad and will create a weak spot.
- Let it air cool. Quenching it makes it hard and brittle.

With a bench vise, pliers, and a blow torch it is fairly easy to do. Here's the piece I did, it was about 2mm thick, middle right in the picture.
http://smg.photobucket.com/albums/v215/ ... C_4792.jpg