Relative power of different drive trains in comparison to each other

[mark_m]

Starting with an off-the-shelf screw is a great idea. I think an M16 cap head would just about do it, or a '16mm' (M12) shoulder bolt. The head wouldn't be as large as the Dewut one, but it should still sufficient to engage with the 'nubs'. Lets chat offline.

[typhoon_driver]

"nubs"? Do you mean shaft splines? If so, for any kind of reliable drive, you need to have a spline on the shaft to engage the gearbox. A fudged solution will work for only so long.

[mark_m]

dewut

The output carrier has both 'nubs' and an internal spline:
http://www.etotheipiplusone.net/pics...dw/dewut25.jpg
The 'nubs' originally interacted with an anti-backdrive' system:
http://www.etotheipiplusone.net/pics...dw/dewut24.jpg
But Charles used them to drive the output shaft:
http://www.etotheipiplusone.net/pics...dw/dewut29.jpg

An M16 screw head is large enough to have cut outs machined into it to engage with the nubs, but would have a little less engagement.

[daveimi]

How would 4x 12V drills compare to say 2x Makita's or Dewalts? Beginning to think the easiest way to more power would simply be 4WD drill pusher.

[overkill]

Generic drill motors are rated about 100W peak power while 18V Dewalt motors have 1100W peak power. To get the Dewalts pushing efficiently, you will need some very wide & grippy wheels.

[knightrous]

To get the Dewalts pushing efficiently, you will need some very wide & grippy wheels.

I found wide wheels to be an issue with my Dewalts. Running 4"x2" colsons have too much surface area for the weight of robot and just allowed excessive wheel spin. I'm currently looking at stepping down to 1" wide wheels to up the weight per mm on the tread. Probably not an issue if the robot was a LW however.

[overkill]

I never heard that before, thought you were happy with those wheels. Do you think a softer tread would have worked better?

[knightrous]

I love the wheels, but I just do not have the weight to utilise the available potential. Annoying Box Rush's fight against Plastic Fantastic showed it evidently as PF's drill motors with two 100x20mm Anderson wheels was able to stale mate ABR with Dewalts and four 4"x2" Colsons when in a pushing match (ABR just had wheel spin at anything over 1/4 throttle).

[MikeNCR]

To add a bit to the Dewalt/Wut discussion, I've been using the older style Dewalts in my 30's for quite a long time. (Moros, Nyx, and Spanky) The DeWut seems to be a really good replacement for the older Dewalt and the bots that are running them seem to move pretty well.

Here's a few matches from Motorama with bots running DeWuts-
https://www.youtube.com/watch?v=UYFMMGfviO8 (MegatRON, 2wd overhead saw)
https://www.youtube.com/watch?v=8J9fuvAswQI (MegatRON, 2wd overhead saw)
https://www.youtube.com/watch?v=hjSkzD26W4E (MegatRON, 2wd overhead saw)
https://www.youtube.com/watch?v=ODVCgQCR0vI
(Nyx is mine, green and black, Blitz was running 4 DeWuts, probably mid gear with these wheels: http://robotcombat.com/products/0-YAK3.html )
https://www.youtube.com/results?sear...locker+Advance (Clocker uses 2 DeWuts for drive, 1 for the weapon)

I'm personally a big fan of the Colsons, to the point that I'm actually doing a small production batch of hubs for a 1/2" keyed shaft that will fit the 1.5" wide Colsons (which is what Nyx uses and Nyx2 will use) They'll fit 2" wide as well, but there will be a gap on one side as the hubs fit flush with the 1.5" wide wheels.

[overkill]

Aaron: do you turn the Colson's surface flat? I find that skimming the wheel on my lathe exposes slightly softer plastic which gives a bit better grip. Its not a huge difference but worth doing IMHO. I agree the 1" wheels are the right way to go. Along those lines, can your forthcoming BotBitz wheels get a softer tread than the Colsons?

[knightrous]

Aaron: do you turn the Colson's surface flat? I find that skimming the wheel on my lathe exposes slightly softer plastic which gives a bit better grip. Its not a huge difference but worth doing IMHO. I agree the 1" wheels are the right way to go. Along those lines, can your forthcoming BotBitz wheels get a softer tread than the Colsons?

I don't turn the wheels down, but I do drive the robots on rough concrete to wear that initial few layers off, which also allows the wheels to wear to suit the robots particular stance. The forthcoming BotBitz wheels are going to be 50A compound, which is the same as the blue Banebots wheels (Which I personally liked), which is a bit softer then the Colsons which are ~60A.

[bitternboy]

Would I be mistaken in thinking the motors in these were similar in power to the dewalts from robot marketplace?
http://www.ebay.co.uk/itm/PARTS-ONLY...item5d50828d1e

[craig_colliass]

I think I have said this before somewhere,

"It's not the power of the transmission it's the power you can transfer to the arena surface".

There are lots of very powerful transmissions in the featherweight arena I have been up against, and I have pushed all of them around with E-Knock AKA Tron. and that runs on 4 drill motors 12v, powered with one 3s 2200mAh battery. wheels standard blue type with bike tyres screwed to them!

The only way to get even better traction is to use some sort of ground effect to increase the attractive force between the friction surfaces!

I would go for 4 drill motors. like E-Knock
have a floating blade on the front. like E-Knock
make it invertible. like E-Knock
and have some fun like ME-EEEE.

[bitternboy]

Thanks for the advice, it's good to know 4 cheap drills on 12v would do fine. None the less, I'm aware that even though you can't put down all the available power with more powerful motors, it does make a difference and certainly won't make it worse

Nick mentioned earlier that he thought a pair of DeWalts on 18v would create a good pushy bot and I was wondering if I'd found a way around paying $200 and postage from America.

[shakesc]

I've ran Spur and Spur II
Spur had 4 drill motors with 100mm x 25mm wheels with a grippy mountain bike tyre screwed on
Spur II had 4 Gimsons with 100mm x 20mm wheels with a grippy mountain bike tyre screwed on

I would say Spur II was the better drive. The loading on the Gimsons though killed motors easily.

I have a couple of DeWuts as well and they are certainly very nice