unnamed drum spinner

[Max]

The drum is just a piece of 2mm thick stainless steel tube with ends welded up and axels put on. The 'teeth' are made by cuttings arks out of a larger tube which are then bolted on.
To save weight I could invest in some lipos and some of the Ali is getting cut away for the wheels and to make space for the drum. If worst comes to worst I could drill large holes in some of the bits of hdpe which are just there for support and don't act as armour. Finally I could downgrade to 2mm Ali baseplate and lid (would help with ground clearance) or see if i can find some cheap titanium. Or I could get a brushless motor to power it

[jonny]

looking great!

[Max]

some more pics!
[attachment=1:1jym2jk5]robot_stage_2_001.JPG[/attachment:1jym2jk5]
[attachment=0:1jym2jk5]robot_stage_2_004.JPG[/attachment:1jym2jk5]
i've now finished making the motor mounts and i've melted in some nuts to use to bolt on the bearings. unfortunaty i've put the nuts in the wrong place so now it is more cramped and i'll have to replace the two bit of hdpe at the front with either 3mm ali or 2mm steel (prefferably) depending on weight. apart from that everything is going well
and don't worry about it all looking wonky thats just my photo taking skills

[Max]

Hi, I am going to buy timing pulleys from tecnobots, what gear ratio should I get for a 1.2 kg drum from a speed 900?

[Max]

Also, is the name invictus taken?

[Max]

What do most people use to power their battle switches?

[ewan]

Battle switches are usually powered by the 5/6V line that comes from the receiver - if you've got another speed controller with a BC in the machine (or even a separate Battery Eliminator Circuit) then this will regulate the main power voltage (24V you seem to be using?) to the 5 or 6V needed for the controller boards, including battle switch, so no seperate battery is required.

As for belt reduction with a Speed 900, is it this model http://www.cornwallmodelboats.co.uk/aca ... _6373.html ? and is it 24V you're running at?

[Max]

Yes I am using that motor at 24v ,
Sorry I meant what battery do people use to control a larger relay from the battle switch?
Also I have just wired up everything in my robot and set the travel adjusts on my dx6i spectrum transmitter to 10% so I could check the adjusts were working but what I found was that when I tried to reverse the motor it used only 10% of the power but when I made it go forwards it used all the power and no limiting took place? It was the same with left and right (left 10% power right all the power) what have I done wrong?

[ewan]

I'd go for around 2.5-3 to 1 ratio (e.g. one of these http://www.technobotsonline.com/timing-pulley-12t.html plus one of these http://www.technobotsonline.com/timing-pulley-30t.html), you're basically trying to find a sweet spot between torque for spin-up and continued motion during impact (especially with smaller drum teeth) and energy stored through inertia, I reckon that'd be about right given 12000+rpm motor speed.

For a larger relay (e.g. http://www.jaycarelectronics.co.uk/prod ... BCATID=754 ) you can use either the RC/BEC power or main battery power for the control side - many relays are rated for a range of switching voltages (3-32V in the linked example) so will operate on either. I'd use the BEC circuit if possible to avoid main power shorts.

Not sure about the transmitter, took me ages to refine my settings myself though so just look through the manual/rc forums and I'm sure you'l crack it.

[Max]

I've solved the transmitter issues (you had to push the channel stick in the direction you want to adjust the travel on)
I've ordered a 40 tooth pulley and a 20 tooth pulley and will see how it goes, if I have problems spinning it up I will change the 20 tooth to something small and then tension the belt with another pulley.
At the moment I have the battle switch running off two double a batteries, how do I use the bec from a sabertooth?