Thetopcat's build log

[thetopcat84]

3 reasons:

-1 stripped its gears
-The other had a superglue mishap in my first attempt at speed hacking
-I'm too tight fisted to throw something away that can still be used to botch something together

Actually works out ok, it still drives fine and is now narrower, so I don't mind tbh...

[haz]

with no pushing power

[thetopcat84]

Well, I got it all assembled on a chassis, but as you rightly pointed out, haz, it was rather lacking in drive... Will try a new over the weekend and see what I can come up with...

[Remote-Controlled Dave]

If your engineering is up to it, you can always mount the largest gear of the servo to the wheel and mesh it directly to the one of the motor. This'll give a single stage transmission with less parts to go wrong in terms of stripped gears. Or you could try and find some more sturdy gears to use.

[thetopcat84]

Well, this feels like threadro-mancy, but it is my build log after all! After such a long time, I have finally found myself with enough time and pocket-money from the missus to dedicate some time to this again!

Having dusted off all the stuff I'd kept from years ago, I've been through the inventory and fixed a lot of stuff, botched together a drive system again (this time with gear box intact) and found myself wanting more... the drive system is a bit unreliable to say the least, the speed hacked servos tend to give out quite easily with super glue coming unstuck or teeth going missing...

With that in mind, I'm going to put an order in for some new bits and pieces, but before doing so was hoping to pick some brains...

1) for keeping things cheap and cheerful for the time being, I assume I can recover the ESCs from the tower-pro SG90s and re-use them, but bypass the old potentiometer by simply wiring up the gap on board? Or would a couple of resistors be needed to keep it functioning?

2) Channel mixers, would I be right in thinking that a channel mixer would help me off tank steering and onto single stick steering? Leaving the other stick free for a weapon (eventually, walk before you can run, TC)

3) Is it absolutely necessary to stick capacitors onto geared brushed motors? From what I've read, apparently things can get sparky?

Assuming my ideas aren't too far from the mark, my plan is to build some entry-level bots (a wedge, a pusher and a flipper) in fairly quick succession to get me started, and beginning with the wedge, I'm thinking of a couple of cheapy geared motors (possibly some of ebays finest) on a couple of salvaged ESCs from the botched servos above and ideally shifted from tank-style to single stick to get into good driving habits longer-term.

I'm now going to read through a lot of stuff on here to see all the latest and greatest work you guys have been up to!

[joey_picus]

1) for keeping things cheap and cheerful for the time being, I assume I can recover the ESCs from the tower-pro SG90s and re-use them, but bypass the old potentiometer by simply wiring up the gap on board? Or would a couple of resistors be needed to keep it functioning?

You will need a couple of resistors (I've heard 2.2k quoted, but obviously it'll depend on the precise servo), *or* what you can do is keep the pot but just glue it in place to provide enough resistance to keep the motor still. I'd use hot glue so you're not locked into one position forever...

2) Channel mixers, would I be right in thinking that a channel mixer would help me off tank steering and onto single stick steering? Leaving the other stick free for a weapon (eventually, walk before you can run, TC)

You are correct in thinking that! (You can simulate single stick steering by having one servo/motor on aileron and one on elevator, and everything makes sense if you turn the transmitter 45 degrees, but I wouldn't reccommend it...) Depending on your transmitter you may be able to use a mixing function on that, and a lot of dual channel controllers now have mixing built in, so you don't necessarily have to do it with an in-robot mixer (which tend to be a little cheap and nasty in my experience).

3) Is it absolutely necessary to stick capacitors onto geared brushed motors? From what I've read, apparently things can get sparky?

It's not as necessary as it used to be - back in the 40mhz days, you sometimes had to do literally anything and everything to cut down on RF noise, but in the Spektrum era it's not as much of a concern. There's no reason not to, but then there's also no reason, erm, yes to, any more!

[thetopcat84]

Thanks, Joey!

Will have a look for more info on the ESCs then, for now your idea of keeping the pot is a good shout, but will probably look into what resistors are required to make things neater/lighter...

On the steering front, I was turning the Tx 45 degrees and felt not only silly, but also found it hard to drive in a straight line too! The Txs I have are cheapy EFlite MLP4DSMs, so no luxury of mixing... same goes for the couple of old Orange Rxs I'm using too... so for a few extra grams I'm prepared to chuck a mixer onboard...

[Rapidrory]

If you wanted a bit of an upgrade... http://robotwars101.org/forum/viewtopic.php?f=1&t=2187

[thetopcat84]

They look pretty damned good! How much are the full flea kits, Rory? I'm assuming the Lemon Rx is DSM2/X compatible?

Any multi-buy discount?

[Rapidrory]

The lemon RX is only DSM2 compatible; worth double checking these days as things are moving over to DSMX and the like which aren't backwards compatible.
I should probably also update the page as I don't do the fleaweight version any more; the new wheels I use can't be cut down easily.

No multi buy discount I'm afraid, but it is only £40 for the full kit which is about the same as it would cost to buy similar parts separately, just it's smaller and already put together.

Just to say, I've sold out of current stock, and have exams imminently so likely won't have any more till late May