Cool. We have a huge stack of dead drills in the workshop at the moment so I'll raid them for MOSFET's and resistors, see what I can find.
Cheers for the advise, this is very Bitza!
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Cool. We have a huge stack of dead drills in the workshop at the moment so I'll raid them for MOSFET's and resistors, see what I can find.
Cheers for the advise, this is very Bitza!
Up to you... depends on the rating of the fets or power transistors.
You could just hook up the servo wires to one of these instead of the fets or power transistors.
http://www.jaycarelectronics.co.uk/prod ... ?ID=SY4086
..you'll need to find / buy the resistors as the drills don't have them.Quote:
Cool. We have a huge stack of dead drills in the workshop at the moment so I'll raid them for MOSFET's and resistors, see what I can find.
That was my original plan when I mentioned hacking a servo, just hooking it up to an existing relay.
If I can't find MOSFET's powerful enough then I'll do that
I've got loads of different rated resistors laying around, I'm sure I can make up what I need.
You should browse the web more .... I found those pages years ago.Quote:
Good find!
Here's another 2 dug from the depth of my favourites that might interest you.
http://www.rctankcombat.com/articles/speed-control/
This second one is a copy of the page that once resided here .. http://www.x-eng.co.uk
http://www.teamonslaught.fsnet.co.uk/Rotraktor.htm
That page is great. It puts into words and diagrams most of my disjointed musings.
Don't worry I do browse the web. I just know there are some neat and very robo combat specific solutions that I would only learn from here.
Most of the time it's what I was already thinking only in a more viable/logical form!
Thinking about getting a Spektrum DX5E for new Bitza. Any reservations?
Also does it come with the type of mixing we all use to drive robots. I don't know what it's called, but it's advertised as having Delta Wing mixing, what ever that is.........
Thanks,
Delta wing is an Ele and Ail mix.
BUT ...I think the DX5 has a reduced output when using the transmitters Delta wing mix....
IE.. Your bot might only go at 1/2 speed.
Go for the dx6i and I'll send you the YouTube link on how to get full throws but remind me as it's at home on the computer
I don't think that the mixing has redused throw, ie half speed.
I use it for my planes and I think it has the same amount of movement as normal.
You could always buy a dx5e and get a mixer as well if this is the problem or....
Buy a ESC with a built in mixer eg Sabertooth, SyRen, Scorpian.
You could go for the DX6i which is very nice but the dx5e is still very good.
I use a planet T5 with a sabertooth, which has built in mixing. This is almost the same as the spektrum but the planet, unlike the spektrum, doesn't have a failsafe.
Thanks for the offer of help but we are getting a DX5E because we can get one cheap.......
Don't really want to start buying additional mixers and none of our ESC's have built in mixing....
What ESC's do you use?
Electronize in Bitza and I'm putting Mtronics in my Beetle.
for the price between the dx5e and dx6i it's best to get a mixer they're only £10
So is Delta mixing the sort we use to get tank steer on one stick?
There must be a way round the half power problem......
I think delta steering is on one stick eg forward, back, left, right.
Well we won (eBay) the DX5E Tx, so i'll let you know how we get on with it!
do u have any photos of the inside of bitza?
You can check the photo bucket page, but I don't think so....
The lighting is pretty crap in the workshop in winter so all internal shots came out like muddy blobs.
I'll try and get some of Bitza next time i'm in the work shop and other Bitza 2 when we start building.
[quote=PJ-27]The lighting is pretty crap in the workshop in winter so all internal shots came out like muddy blobs.quote]
Thats were miniture lamps come in handy
What is the best way to bend Titanium?
I've managed to come into some Grade 5 (Ti6A) Ti (don't worry it's an off cut, so still Bitza esque...) that I want to use on my Beetle, but I'm concerned it will crack if I bend it without heat?
It's 2mm thick, and I need to do a 90degree bend along a 40mm section (possible longer sections if I can afford the weight).
I've got some Cobalt drill bits to machine it, but not too sure the best way to cut it? Angle Grinder?
Thanks!
my sponsors do all my ti stuff i think grade 5 will bend with ti if it bends it will if its designed not to then it will crack
easiest way to cut is on a guillotine but ive used angle grinder before
to bend it my sponsors use a piece of equipment to do it you can get exact angles best way id say
alex
Cheers for the advise.
Will it bend, that is the question?
What is the best way to attach a pulley to a motor shaft?
Just bought a brushless for my Beetle, it has a shaft diameter of just over 3mm and is completely smooth. The timing pulley just has a pilot hole.
The motor is an outrunner, and Ewan advised bolting onto the casing (since that also rotates) but I could do with some more detail.
Any suggestions?
Thanks,
PJ
drill the pulley out to 3mm. Drill and tap a grub screw hole to intersect this hole. File a very small flat onto the motor shaft. Mount using the non rotating face of the motor, slide the pulley on and tighten the grub.
Id say do what gary suggests.. If you dont have any drills and taps small enough for a grub screw, get some high grade loctite, and loctite the pulley onto the shaft... I did this for the gears in 360's first stage disc drive and it worked fine... thats putting much more tourque through the pulley then you will be able to generate... It just makes removing the pulley a pain.
I wouldnt suggest mounting it of the rear of the motor if you can help it- its asking a lot of the bearings in the front plate of the motor over that sort of distance.
As for the ti- try it... the term grade 5 is pretty open.... put it in a vice, try bend it over with a hammer, if it cracks, try heating it :)... you will need to get it cherry red until the point that the surface of the titanium looks like its gone flakey before you will be able to bend it easy.... Wear some welding gogles if you've got some while heating it.
Don't use cobalt drills on titanium. They're best used on hardox and steel. Use regular HSS drill bits on titanium with plenty of lubricant/coolant
No to Cobalt? They went through a dream! Although I did use a lot of lubricant.
It's TA6, which I believe is the British name for Grade 4 (Not Grade 5 which is Ti-6A... you can see my confusion...). The Verniers come up at 1.6mm, so I'm hoping it'll bend without heating. But I'll test it on an un-needed bit first.
Unfortunately I don't think we have taps that small, but I'll check. If not then I'll try the Loctite idea.
Thanks guys.
even if it's an M3 tap going through it should be fine (sets usually go down to around the M2 mark). Or you would probably be able to pick up a cheap tap on ebay.
I should have quantified the drill bit statement. On sheet, cobalt drills will be fine, however when it comes to thicker sections you're best using HSS bits (a wee tip for the future there). I can't remember the exact reasoning but it was advice from a very reliable source on the subject of machining titanium.
If my memory serves me right, grade 4 should be bendable to a certain point. Grade 5 and upwards are the ones that are more likely to snap although don't quote me on that one!
Cheers for the advise.
Apparently we do have some small taps, so I'll see what I can find.
Also Grade 4 does bend without heat. Dan just turned up with it all done!
What would people recommend for a super light plastic?
I'm over the weight on my Beetle and yet to cover some parts.
I was thinking 1mm Lexan.
or 1mm POLYCARBONATE?
1mm carbon fibre :) i use it on featherweights.
Lexan is just a brand name for PolyCarb, didn't want to write the whole name, but here I am....
Can you bend Carbon Fibre?
I need to make a box shape, figured Lexan would be easy.
You can't bend carbon fibre in its bought sheet form, but you can buy matting and mould that to the required shape. Josh Valman does mine.
how bout 1mm makralon :lol:
HDPE seems to work well on any type of robot, from AW to HW
And it deflects blows quite nicely :D
I'm currently overweight though, I just need an excuse of a cover really. I think HPDE (as much as I like it) will be too heavy.
You got access to a laminating machine at all? If so, just run one of the laminating pouches through it and you'll get the flexible plasticy sheet out as a result. It will be far from impenetrable but if it's just an excuse of a cover you need, it could be suitable. Pretty cheap too if someone else has already bought the laminating pouches 8)
Good idea!
My Mum may have one.......
1mm (or thinner) Lexan is pretty cheap and light, so I may give that a whirl.
Just use some tin foil, it's really super thin aluminium for some metal armour!