Model Boat Mayhem
Technical, Techniques, Hints, and Tips => The "Black Arts!" ( Electrics & Electronics ) => Topic started by: subs1 on June 18, 2012, 04:06:56 am
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Hi all . I thought I posted this yesterday , but it's not showing so I will redo.
I am building a DUKW and being the cheap person I am , I would like to know it there is a simple way ( or electronic ) to switch between using one speed controller ( Mtronic ) to operate the land drive and then use microswitches or electronic gee-jaw to change from that drive to a different motor ( using the same speed controller ) driving the prop motor ? The land drive motor draws 10-12 amps loaded . I hope I have made that clear enough ?
Thanks . malcolm NZ
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The are electronic change over switches you can use. Flick the control arm to one side and it locks a changeover circuit which switches a heavy relay. This should be enough for your motors and save an R/X into the bargain.
ken
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There maybe a problem if one , both or either speed controller is using BEC - you might loose control or burn up your receiver.
I would have though the easiest/safest way was to have the prop speed controller on a separate channel...
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There was a chap on here last year who did a kit that does just what you want
Switched steering to rudder and speed controllers via another channel... you do need a seperate reciver battery and 2 drive batteries tho
I was looking into to doing a deans DUKW, but never managed to find the running gear I wanted cheap enough (Tamiya tractor truck)
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Could it be done using a double pole, double throw relay with a 5v coil which could be switched from the Tx? bit of a rough drawing show what I mean
(http://s13.postimage.org/wl9ixlzo3/Drawing.jpg) (http://postimage.org/image/wl9ixlzo3/)
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There was a chap on here last year who did a kit that does just what you want
I suspect that was Pete Keirle ('PMK') who sadly died earlier this year. I don't have the code for the PIC he used.
Ref the question, why not have both motors connected in parallel to the same ESC and thus engaged at the same time? The road wheels won't present any load when the craft is on the water and the prop won't be under any forces when on the road. It also makes switching over very easy (i.e. you don't have to) and the transition from water to land and vice verse should be very smooth.
No need to make things complicated. Just make sure you have a decent speed controller of at least 20A - I can recommend one if you're in any doubt 8)
DM
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Could it be done using a double pole, double throw relay with a 5v coil which could be switched from the Tx? bit of a rough drawing show what I mean
(http://s13.postimage.org/wl9ixlzo3/Drawing.jpg) (http://postimage.org/image/wl9ixlzo3/)
Yes it can be done that way, but by the time you have bought the materials (including a switcher to operate the relay to do the job) you may as well buy a £20 speed controller.....
Russ
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I suspect that was Pete Keirle ('PMK') who sadly died earlier this year. I don't have the code for the PIC he used.
Ref the question, why not have both motors connected in parallel to the same ESC and thus engaged at the same time? The road wheels won't present any load when the craft is on the water and the prop won't be under any forces when on the road. It also makes switching over very easy (i.e. you don't have to) and the transition from water to land and vice verse should be very smooth.
No need to make things complicated. Just make sure you have a decent speed controller of at least 20A - I can recommend one if you're in any doubt 8)
DM
Thats the chap!
I never realised he had passed away :( such a shame.... a really nice chap!
With regards to the PIC code.. could his code be read back from the chip so that someone could continue to make them?
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With regards to the PIC code.. could his code be read back from the chip so that someone could continue to make them?
Nope - 'fraid not; it's encrypted. As Pete himself might have said, 'I might be a thick, two-bit yokel but I ain't stupid'!
Dave M
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Fair enough.
I think Ill hold on to my unbuilt one and sell it on Ebay in a few years lol
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Thanks guys for the input . And no , I'm not using BEC as I prefer a separate RX battery pack .
regards , Malcolm NZ