Titanium grade? thickness?

hi all

what grade and thickness should i look at for feather weight body armour? it has to obviosly not bend and be easily used for a lifter arm. also the previso armour 3mm aluminium suffered bably from big impacts (intentional of course), so with this armour i dont want the same problem

any help/

thanks alex

Depends on what capabilities on working the stuff you have.
Can you weld it? If yes, you want grade 2 or 3.
If no, you are limited to bolting or rivetting it to a chassis/frame. Then the higher grades are fun.

Weigth for weight, titanium is twice as heavy as ali, and 2/3ths the weight of steel/hardox.
That gives you, if you just replace the ali, without change in weight, 1.5mm Ti.

yeh i think i can get it weleded, but would 1.5mm be strong enogh? or were you just give an example?

alex

The raptor Nebelwerfer used 1.2mm Ti as armor over 5mm HDPE. The Finnish raptor Projudju ripped the Ti appart as if it was butter.

I just gave a comparisation of what you would do by just replacing the ali.
So 1.5mm in a feather is ok-ish as long you dont go against spinners.

i was thinking, if the weight allows 3 or 4mm, will this stand up to spinners (if i ever face any)

alex

Should do but then it depends on the spinner and on the circumstances of the hit. These things are always guess work.

4mm Ti is 15mm HDPE in weight. I know what I would use.

HDPE is a lot cheaper, easier to work with and strangely enough, more resilient to dents.

and if you have a friendly dutch roboteer available, repairable :)

Gary, Im Flemish.

But yes, with the right tools, HDPE is a nice material. It can be worked like wood, with the advantage of being weldable, bendable and virtualy unbreakable. Disadvantage, in some cases, is the fact it has a memory. It always will try to bend into the original shape.
This gave us nice surprises in the past. Like a wheel from TAN that went from crooked to straight after a few hours.

woops sorry mario :)

And lets not forget wood. 30 mm of oak or mahogany will stand up to any feather spinner Ive yet encountered.

absolutely. Wood is very underrated in robotwars.

is titanium easy to drill? to secure the pannels to the frame i thought about using bolts, but the way i want to do it wont let me put a nut on, and i tap the holes and do it that way? the frame is stainless steel box section

thanks alex

Rivnuts rule the world !!!

I have about 500 of them in Obsidian to prove it. :)

i done 126 today.....wot fun !!!

yeh but i need to remove the pannels

then u just drill them out and re do them after

thats wt my dad does on beauty

Alexander, drilling Ti isnt a great deal on the lower grades. Then in almost acts as stainless, but for best results, cool abundandly. On higher grades, use better grade drills, cool abundantly.

To mount it, use rivnuts, or weld in nuts in the box section.

Rivnuts are not blind rivets, they are threaded so you can bolt the panels on.

just done some caculations on the weight side of things, the total armour should weigh 3.542kg 3mm thick

can someone explain what these rivnuts to me? i know and have used rivets and found myself going through alot of them

just wanted a yes or no answer to one of my above questions, can i tap (i think im using the right pharse)/ make a thread in box section?

thanks alex

Hi Alex

See below....
http://www.fjr1300.info/howto/rivnut-tool.htmlhttp://www.fjr1300.info/howto/rivnut-tool.html

Fork N Torque will use about 200 to mount armour

Cheers Froggy

You could tap in a thick walled box section. A guideline for treads depths.
In steel and Titanium bolt size. M4 is perfectly possible in a 4mm thick plate (or box section wall).

In ali and other soft alloys,boltsize *2. An M4 needs 8mm of flesh.

Bronze and simular boltsize *1.5

thanks for that tony, so from what i can gather i would put these into the box section? and am i right in think i use a bolt to secure the whole thing together?

alex

hi alex

All ya gotta do is drill a 10mm hole in one side (outside) of box section...insert rivnut then if ya have the special tool just close the jaws...if ya dont have tool follow instructions on addy given.....i also give each one a couple of tack welds to really make sure it dont come loose !!

Cheers Froggy

had a meeting today with a local metal fabrication company, about sponsorship very interested but said they dont use ti much but have loads of stanless steel still good right?

also going to help with welding cutting....

very happy now, alex

just done some calculations couple of kgs over with 3mm stainless steel, does someone know the density of stainless steel?

thanks alex

search on google. It wont be far off mild steel/hardox

http://www.matweb.com/tools/weight-calculator.asphttp://www.matweb.com/tools/weight-calculator.asp

Stainless steel is as heavy as hardox. Take 8kg dm³ as guideline. Normal steel is a bit lighter with 7.8kg dm³