That wouldn't work for 2 reasons:
1) the plate is too thin to get a good top into
2) the ends of the bolts have to lie flush with the plate. Go to far and rip apart the gearbox, not far enough and you would have the strength. You could counter sink them from the other side, but as I said there wasn't enough to tap as it is.
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Get Some!!!

Secretary of the Queensland Robotics Sports Club inc.

Yeah, there is always a weak link somewhere! If you replaced the pins with screws you would have to turn down the thread to get a smooth bearing surface, plus the head wouldn't fit on the intermediate plate (any idea what it's proper name is?) An M4 size would do it and enlarging the hole in the gear to allow a thicker pin would be good too. Anyone got a micro lathe?

I think half the problem is that the soft steel the plates are made of allows the pin to deform the plate and pull out sideways - the screw would fix that nicely. the next weak link after that would be the gear teeth.
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Australian 2015 Featherweight champion
UK 2016 Gladiator champion

Hello all,

Scrap still isnt moving yet as i have been busy with stuff.

What i need is a simple wiring diagram for microswitch drives for forward and reverese for each motor.

Chris could probably do it best of jeff as they ahve used it often and such. Al i need is a diageram and ill have scrap tuning in a hour or 2 so could someone email me a diagram r post one here please.

Thanks.
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Andrew Welch, Team Unconventional Robotics

IIRC jakes robot revenge of 386 used the gearboxes that had billet ali housings, they had proper bearings and a reworked output shaft, although the pins snapped when they where installed in Plan A.

a lot of people in america have reworkeed the HF drills in that manner. i know that team cosmos reworked dewalt gearboxes out of ali to fit some mini evs for neutrino and a pair of speed 400s with the same gearboxes for dandelion (www.happyrobots.com).

there is one upgrade called the mini walt that is basically a dewalt 18v transmission with a mini ev jammed into it. not a good combo and not worth the money is what i was told by most of the US fellers.

as for chris barons solution IIRC the gearboxes where those humungous NEMA gearboxes out of solid iron or something of that nature.

i think the best option is to look for a better drive.. the XU1 gearbox is essentially a disaster packed into a little plastic housing. given you can only realistically go a 120mm wheel with no tread on them at best.

to get some results from them you would need all new gears and pin carriers.

i was considering having CNC botparts make up a new output shaft out of tool steel.

quote:

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the XU1 gearbox is essentially a disaster packed into a little plastic housing

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The motor shaft pinion used on the mini ev in the cordless impact guns available from supercheap is a small pinion that steps down from the shaft.
I am using one to swing the hammer in Fragmentor.

As you all are trying to sort out motor / gearbox issues to be ready for the event, and I haven't look in to the motor gearbox improvements yet.

I thought I would give every one a little wiring hint.

Motor noise reduction.
To help reduce electrical noise from the motors solder a 0.1 uF capacitor across the terminals of each motor.

Wiring.
All the wires are in pairs. Twist the pairs together, with about 1 twist per inch (25mm). this will also help reduce electrical noise.

Reciever.
Try and keep the receiver as far way from the motors and power source (Including the main power cables) as posible.
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It's all about the destruction.

Ok, here's a different tip that I thought I'd better post after I realised I had to say that Hellbringer (the origonal and the best) won't be turning up to the annihilator. This came about when I sat down with the w/w motors I got off Chris and had a good look at them while watching CSI. They only came with one nylock-nut so thats the first thing I looked at as I would need something to hold the other wheel on, when I realised what thread was on the shaft. So my tip is about threads.
I'm guessing most of you were like I was about 6 months ago in thinking that there are only 2 types of threads used on these sort of things, Imperial and Metric. Well that is Wrong. I know of 4 main types, 5 lesser types and I'm deffently sure there are more less commenly used threads. The 4 main thypes that we'll all face are Metric, BSW, UNC and UNF. Here's a little ramble about them.

Metric - Deisigned by the International Strandard Organisation from the standard German thread it was made as the a thread that'll be used around the world, as with all metric thingy's. Pretty easy to understand, out side dia is in millimeters and the pitch is measured as a distance between the tips of the grooves in millimeters. The angle of the slopes of the tips is 60 degrees. There is more, but this'll do for now. You can by nuts and bolts made with metric threads from Bunnings

BSW (British Standard Whitworth) - The standard pommy thread. Still in common use because the pom's built things to last and you can't spend millions of dollers (or pounds) just to change the threads in an 100 year old peice of equipment and still need the taps and dies to make spares (plus pommy engineers always stick with the same idea, I know, I worked with one). Because its an old thread its imperial, so the outside diameter is measured in inches (damn fractions), the pitch is measured in how many tips there are in an inch (T.P.I or Tips Per Inch) and the tread sides are 55 degrees. This is what the imperial nut and bolts from Bunnings are made with.

UNC (Unified National Corse) - The first yankee thread made the same time as the Metric theard, during the big wars when different factorys all need the same tooling to make the same tanks and planes, instead of different factorys having there own individual threads like before. And because it was made the same time as the metric thread it just help's prove how insular (good word there Philip) the yanks are. You won't find these threads in bunnings, but don't panic. Its is almost identical to the BSW thread except for the slope being 60 degrees instead of the pommy's 55 degrees (the shape of the tread is actually identical to the metric thread). If you had a UNC bolt, a BSW nut will fit on 99% of the time, but its not recomended as the nut would loosen over time.

UNF (Unified National Fine) - Guess what, these threads are on the XU1 drill style gearbox and as it turns out, on my w/w motors too. And as you can guess by the name, basically the same as the UNC thread, but finer. Where an 3/8 UNC bolt has 16 T.P.I or tips per inch a 3/8 UNF has 24 T.P.I. Basically giving you more theard over a given distance, but the tips are smaller. Useful in high speed machinerary like drills and w/w motor shafts. You won't buys these from bunnings, but can get them cheap from fastening shops.

There are other threads like Metric fine, British standard pipe thread, acme threads, ect.... But I haven't used these yet.

I could tell striaght away the nylock nut on the w/w motor was imperial because the nylon was white, were metric nylock nuts have blue nylon. And I could see the tread did not compare well against the BSW nut I had even before testing it. So I remebered what car the w/w motors came from, which Chris said was a Toyota, which is Japanese and the Japanese have be using American standards since they lost WW2, so UNF. I havn't got the time to go to a fastening shop to spend a doller on 2 nuts so Hellbringer is out.
I hope the bloke at the shop didn't tell Chris he had to custom make those nuts and then put the price up.

Did you know they don't teach ANY of this at uni.
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Get Some!!!

Secretary of the Queensland Robotics Sports Club inc.

Most bolts / nuts can be got from someone like 'The Bolt Bloke' Metric, UNC, UNF, or BSW

If it is a special eg, revierse thread, 1mm bolt, 0.5mm bolt, etc (And yes I have used a 0.5 bolt. not in a Bot)

Keables in melbourne should be able to help.

I have bought many a wierd bolt of them.

I have not found any other bolt supplier in Australia that has a range any where as good.

They also deliever intersate.

suppier details:-

Keables Pty Ltd
185 A'Beckett St Melbourne VIC 3000
ph: (03) 9321 6400 Bolts & Nuts
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It's all about the destruction.

A bit more on drill motor improvements:

I disassembled the output shaft and bearing of an XU1 drill (has anyone else tried that?). It turns out the ballbearing under the circlip is just a thrust bearing that would be needed on a drill but is barely used in our drive systems. The important bearing is a steel sleeve behind this. It takes all the sideways load from the wheel and in my drill at least, it had almost no lubrication on it. The steel was rather soft as well.

The other end of this sleeve is hard up against back of the gear carrier, so Spockie's idea of button screws would not work (As the Kkeerroos mentioned). The pins on the XU1 barely go half way thru the plate so it would be a HUGE improvement to drill the holes out a little and press in new pins almost all the way, then fasten them with a tiny TIG weld or brazing.
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Australian 2015 Featherweight champion
UK 2016 Gladiator champion

So there is someone out there that is game enough to pull the gearbox completely apart.

I am currently putting a document together that every one is welcome to have a copy off once completed, which will show in detail how to dismantle and reassemble an XU1 gearbox assembly.
I also plan on putting some comment on how it can be improved or modified.

It will be a complete guide for the XU1.

Nick the pins are press fitted and can be removed using a Pin punch. Then all that is needed is some new pins and tap them in place.
I would not recommend welding the pins in place as that can cause other problems with the main drive shaft, due to uneven heat.
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It's all about the destruction.

Hello, yes I have taken the drive shaft out before and found you can simply put it in a vice and press the pins all the way in, no need to drill the holes any larger. It leaves them a bit short, I havn`t tried replacing them with longer ones but they seem to be ok. Only thing is, if the pins don`t pop out, the poor little centre cog gets it`s teeth ripped off. A gearbox gotta know it`s limitations I guess

P.S. Thanks for the lesson Kkeerroo, I was aware of the threads but didn`t know the details, Cheers!
Jeff.

After all this talk about upgrading drill motors, Robot Combat have brought out a great-looking planetary grearbox & motor combo (I'm sure many of you have seen it already. Its $165 Us, but that is still cheaper than a fully set up Dewalt combo and you get all-steel gears in an easy to mount aluminium gearbox. Check out http://www.parts4robots.com/
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Australian 2015 Featherweight champion
UK 2016 Gladiator champion

So when do your gearboxes arrive . Just kidding.
So who's going to be the first to test those gearboxes here?
The only problem I see is that their twice as heavy has the drill gearbox.
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Get Some!!!

Secretary of the Queensland Robotics Sports Club inc.

I am itching to get some, even though my broken Thingaps should be working soon (its only been 8 months since I bought them )

As I see it, the weight is up but the extra strength should mean that each motor can drive two wheels, just like most US builders do with Dewalts. That means that the extra weight is offset by having less motors.

I would be thinking of using no more than 3" wheels in that situation to save the gears from death by backlash. Guess we will find out after the next pay packet
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Australian 2015 Featherweight champion
UK 2016 Gladiator champion