New Robots

peterwaller · Post by **peterwaller** » Fri Jun 24, 2005 7:41 am

Actually I was joking I am playing with a vacuum pump trying to produce a little down force to stop my spinners from flying out of the arena. As expected there is no problem in sticking to the floor tha trick is being able to move at the same time. I wish I had paid more attention to vacuums design at the last WS. This is my second attempt at downforce some time ago I tried an fullbody spinner with a propeller but it was usless. It finally destroyed itself while set up on the kitchen scales as I attempted to measure what small amount of down force there was.

Remote-Controlled Dave · Fri Jun 24, 2005 4:04 pm

Can you still paint the disc as a pizza so everyone is happy?

And I dunno, I mite be wrong Pete, but if you suck one of your spinners down, instead of flying off at a hit, wont the forces be transferred into the bot, meaning it takes more of the impact?

peterwaller · Post by **peterwaller** » Sat Jun 25, 2005 4:30 pm

I expect the robot will have to absorb more of the impact but hopfully the design the can withstand it.

What I want to avoid is going out of the arena. Initial tests show I can get many pounds of downforce but cannot then move. The compromise is to balance downforce against movement using a sliding seal covered in polythene or PTFE. I dobt it will be finished by AWS17 but I will try and bring along what I have got working.

Raizor · Post by **Raizor** » Sat Jun 25, 2005 6:08 pm

From experience and from the chemical properties Ptfe (Poly-Tetra-Fluro-Ethene) is more slippery than Polythene (poly-ethene). However Poly-ethene might work better as too much slippage may be a bad thing.

olivers · Post by **olivers** » Mon Jun 27, 2005 6:57 am

You have to be carefull with PTFE, the fumes if burnt are very toxic.

Craig_Anto3 · Post by **Craig_Anto3** » Mon Jun 27, 2005 5:46 pm

on the subject of new robots, got something coming throu like a little biohazard called Ix (icks) and not really new but finished at last XP1HP got the wheels stayin on now still far far too quick but its driveable now its gonna replace Anto from now on so will drop the name XP1HP and go with Anto

pics of the finished XP are as rare as rocking horse sh*t so dont ask

Rhys · Post by **Rhys** » Mon Jun 27, 2005 8:13 pm

Also finished 2 of my ants today ready for AWS17. The New Duff is slower, heavier and more flimsy. Still flips well and goes quickly though, so I'm hopeful.

Also have finished the new TNT, which is now 4wd. Stupidly quick, and plenty of grip, but tricky to drive, and shredding its tyres. And as per usual, they both look dog-ugly.

Now to start on the 3rd one, my vertical spinner

Should be done for AWS17.

peterwaller · Post by **peterwaller** » Wed Jun 29, 2005 11:31 am

I dont see how you can have to much slippage zero friction would be nice. At the moment when the unit is fully sucked down the ant wont move. I selected ptfe for its low coefficient of friction but I only have 1mm sheet which is too stiff to seal and that extremely thin plummers tape which is easily damaged. The polythene gives a good seal and strong enough but still has too much friction. I have tried thrust bearings and ptfe supports to stop the unit crushing down on the seal too much and that does seem to be a little better. I think now I need to settle for less downforce maybe reucing the size of the sucktion area thus reducing the length of the seal. I have started making a sucker that is only 25mm dia and this appears to give a reaonable amount of suck. It was able to support the unit the pump and a 10" adjustable spanner when sucked on to the underside of a polycarb sheet.

peterwaller · Post by **peterwaller** » Wed Jun 29, 2005 11:32 am

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peterwaller · Post by **peterwaller** » Wed Jun 29, 2005 11:33 am

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