1st bot

Does anybody have any information regarding technobots windscreen wiper motors i.e their current draw etc.

Very little mark. They can easily last for a full battle on 2.2amp/h batteries and that was at 24v.

Ive run two wiper motors off of 2x 2.1Ah Yuasa SLA batteries in series to give 24V for ten minutes before they started to slow down. They only got slightly warm.

Ok, I have a 24 Volt gold motor and an 8mm MOD1 gear. My only problem is..

*Places gear on spindle and flicks the gear.The gear rotates around the Axle.*

In the event of pushiong power, that aint gonna help. Any suggestions on a semi permanent fixture?

Are we talking about a flat(type PG) or with a boss(type G) gear? Because a type G is far easier to work with than a type PG. Also it would be handy to know the no. of teeth or the PCD.

All I knew off that Geoff, was the number of teeth. 18 of em if youre interested.

http://www.technobots.co.uk/en-gb/pg_26.htmlAll

i used grub screws on alphas golds. I used 2 M6s but M4s shoud be fine. Other option is to drill a hole through gear and shaft and put a pin through them both.

Like the quote!

As Alan says the best way is to drill it & pin it!

Ok i got some technobots ww motors today and i was just wondering if any one had any opinions on how to use the shafts on the motors as they are threaded.

anyone?

well ive got the same problem mark

Thing is is that the cogs im using from technobots just happen to have a hole of 5mm through the centre and the shaft, once filed down, on my motors looks as if it is roughly 5mm.

You could always attempt to smooth the thread to a smooth finish by putting an apoxy resin on it and then carefully smoothing it out. This should be strong enough as we used it in the hubs of the wheels for the lightweight robots, thunder and lightning.

Well i want to mount the wheels straight onto the right angle gear box shaft of the windscreen wiper motor. But the shaft is threaded and stubby. I was thinking maybe get a threaded tube then put a pin through that and the shaft or weld it. Im not too sure really. Ill have a mess about and see what i can come up with. Im sure somebody has succesfully done this before.

you could try and replace the shaft of the gearbox. I thought you were talking about the shft of the motor. Replacing the gearbox shaft is alot easier than trying to replace the motor shaft. This is probably easier than attempting to weld or pin a stubby shaft.

I replaced the motorshaft of the wipermotor I used on Project I and IIs steering, as the plastic gear came lose time and time again.
Oh well, I can do things like that fairly easy now.

So how would i go about replacing the shaft?

Do you have a lathe and mill?
You remove the original steel axle out of the plastic wormgear. Then you turn out the ragged hole to the dimension of the new axle. But be sure its in the centre of the gear.
The new axle has a large flat head, so you can bolt the gear onto that head.

If this to difficult, mail me and we will see how we can do that easier.

Im watching this thread with interest ;)

Why? Whatcha planning Stephen?

Anyway I am having difficulty getting 1 piece of my machine: the axle.

Stop laughing, Im serious. I have nothing round here to use for it. I need 2 * 12mm axles to finish collecting parts for a gearbox. Then I can start building. *hallelujah*


I (little mad old me) was planning on using 2 M12 roofing bolts and using the smooth part on those as an axle, but I cant manage to get the gears onto them without a thread..

Suggestions anyone?

Try m10 bolts. Some of them do not have a thread for the full length and the unthreaded parts are close enough to 12mm IIRC

go to a metal shop near you and ask them if they have any 12mm bar they will prob give you it if you dont need alot

technobots is where i got my 12mm bar when i needed some

around £5 plus postage

Well Ceri, Ive been saying since Newark (my first live event) that I wanted to build one but I didnt have the money to do it. Now that I have (thanks to employment) Im free to do so if I want to. :)

Ive still got a lot to learn though, and I want to be sure I can do it before starting. (and sort my free time out, heh)

(and Im watching the thread to see how a new builder makes progress with help from the community :))

Im needing some polycarbonate glue jjust to hold some or my polycarb together while im drilling and tapping holes.CAn anyone suggest a glue that would suit the job ? And what quantity would i need of it? And where can i get some
Ali

erm, al i can think of off my head would be Aryldite. That is a very strong glue, but takes a while to set. if you use that along with bolts i dont think you will be able to replace the panels very easily.

Hmm good point but i have 6 sheets of 6mm polycarb so i dont think it will be a problem ;)

Your best bet would be to try a sample of glues on seperate small sections of panels.

Go along to b and q or homebase and ask them if they have any glues specific for gluing plastics.

Araldite is good but you might also want to try loctite, doesnt get as good a stick but it sets a whole lot faster. Maybe even use a mixture of the two or other glues.

Their is an actual glue thats ment for polycarbonate, It is actually tiny amounts of polycarbonate in a liquid so the pieces are actually chemically bonded just as strongly as a premade piece. It is the equivelent of attaching two pieces of polythene (polyethene) together with ethene thus creating more polyethene where they are joined. The only problem is I dont know the name of teh glue.

ask John Reid
He knows about this sort of thing

Ian, what you are describing is called a solvent cement. For solvent welding polycarbonate (which is effectively what you are suggesting) methylene chloride is an efficient solvent though IIRC there are other chlorocarbons that will work. Dissolving some polycarbonate pieces in it would make a good cement. As you suggest there are commercial products for this, a bunch of solvent cements are marketed under the name Weld-on but you will have look further to find something more specific. It doesnt look optimal for something you just want to hold something in place temporarily as the bond is permanent. Also the solvents are farily severe so it should really be an outside only thing unless you have a fume-cuboard. For solvent welding with methylene chloride a hypodermic syringe is reccomended to use minimal amounts, some sanding may be required to remove the abrasion and chemically resistant protective film which may be found on some polycarbonate. Solvent joins do not reach full strength very quickly so for structural joins you would still need something to keep pieces in place (though that doesnt say much about its value as a temporary fixing)
Alistair I suggest you just stick with the measure twice, drill once rule or use some epoxy which will at least leave you able to take damaged pieces apart again without breaking more things.

Check pic on my profile this is how i attached my wheels to a ww motor. I used a small block of Nylon 6 with a hole slightly smaller than the hub, then bolted this on. i then drilled a hole through the side of the block and straight into the shaft. These i then taped out to take a bolt to hold them together. The 4 long bolts are to attatch the wheels to. The wheels never came of even after being hit by VORTEX.

Ok thanks. Not too sure if it will work because the mounts for the motor leave only the threaded bit of the motor which isnt bery much room.

mark I will get a pic tommorow of what I have done with hornet.

basically put an 8 tooth cog on and put a 2mm hole through with a pin holding it in place

My robot for the schools competition is coming along nicely and weve managed to attach wheels to the shafts. The competition date is june 22nd so we should be finished. And today £150 came for my proper featherweight so i can get started. Now all i need are so some good desgins- thinking linear actuator or LP flipper.

Anybody got any CADs of chains and sprockets?