Liftoff (FW) build diary

**Eventorizon** · 11th January 2014, 11:00

Is there anywhere else you can loose weight? It seems that your base is locked down for your design to work. You might be able to pocket out your HDPE bulkheads (I am assuming the machine is much like the one in the picture).

If Sketch up will let you, there is a tool in solidworks that allows you to view cross sections of the design, allowing you to move through and find large blobs of material that you may not need.

**Liftoff** · 11th January 2014, 11:23

Its very much similar yes to that (have a look here: http://www.fightingrobots.co.uk/thre...d-diary/page15 for pictures of the internals)...

My primary concern with the base, as I mentioned is its ability(or lack of) to take punishment from external forces rather than from forces from the ram etc. It ties all the parts together taking a major part of the load, so if the base material distorts and does not spring back, then that will be the end of it!

Ellis, titanium plate at 1.2mm will of course be ideal, but I cant find a piece 500x500 in grade 5 form...apart from that, God knows how much it'll cost me!

Alex, I could probably look elsewhere for weight reduction, but I have to be careful not to weaken the whole thing... The other parts that come to mind are the hdpe sides which are 20mm thick, I could maybe drill holes in them to half their weight (they weigh 0.5kg each)

**Ellis** · 11th January 2014, 11:44

Might be worth getting a quote from these guys on the offchance: http://www.firmetal.com/titanium-sheet.asp

I got one for a conceptual Tormenta 3's 4mm titanium armour (quite a lot of material) in grade 5, and it was surprisingly "cheap" compared to other sources.

**Liftoff** · 11th January 2014, 12:01

Interesting...do you have to get a whole sheet or they sell smaller pieces?

**Ellis** · 11th January 2014, 12:27

I got a quote for a specific size so yes, they'll get you a price for whatever size you want. I got a response to my email within 24 hours.

**Eventorizon** · 11th January 2014, 12:58

Going by this picture...

http://www.fightingrobots.co.uk/atta...0&d=1383419136

I would strategically thin out the HDPE outer armour as well as Swiss Cheesing (Yes that is a technical term ;-) )the internal wall of the aluminium box section. Inertia XL and NSW couldn't get more than 10mm into my 20mm armour on Conker 1.

People also have skimmed off their buffer tanks if they are desperate to save some weight. I have read that 1/6th of an inch is sensible in the Hanibalito 4 build diary.

**Liftoff** · 11th January 2014, 13:35

Thought about skimming the buffer, the walls are 3.4mm thick and was considering taking off 1.4mm off, but I'll leave that as a last option...
Don't know if its an overkill (probably it is from your comment Alex) the side armour is 20mm hdpe with 4mm gr5Ti bolted on, a precautionary measure after seeing LS4, NST, InertiaXL and all the spinning rest in action...
Maybe halving the 20mm hdpe to 10mm I'll still be safe

**Eventorizon** · 11th January 2014, 13:55

If you have 4mm of grade 5 Ti firmly bolted to the side I would drop the HDPE all together! LF3 had 3mm of ti on it and I dont think anything really got through. Little hitter has 3mm G5 on the front and 1.5mm on the sides. But theirs is sloped quite heavily.

You could keep maybe 6mm on the side to absorb some impacts and slow weapons before the reach the Ti but 4mm of grade 5 is more than most machines have.

**Liftoff** · 11th January 2014, 18:06

I would like to have something in between the Ti and the alu box section as that's where the tracks stay,will reduce to 10mm. Everything is sitting tight there so I cant risk anything getting distorted in there!

I have "re-sketchedup" Blastoff, a chopped off, starved version of the current build...and its now looking much smaller... yep reduced the hdpe sides from 20 to 10mm as well, that was a bit excessive,true...this means I have to place another order from direct plastics!

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