Carl's platform Reloaded

[prodigy]

I think I might steal that as well

Great solution Carl

[sirnoname]

Same Problem with the pedals here.
But I think it is the small lower part of the gas pedal.

[Carl]

Thanks for the kind comments everybody. MotionDave,I agree, the gas pedal design is very odd indeed. I might swap it out or modify it before inverting the pedals.

[motiondave]

No i never bothered with fan speed control . I just used a fast fan only.

[Carl]

Well despite the lack of posts I have been a busy boy these past couple of months. I am where I want or think I want to be mechanically and now need to install the electrics. All the alloy chequer plate has been cut by hand using a jig-saw... well two jig saws actually as the first died half way through. I have the vibration white finger to show for my effort. I will post some cad drawings at the end with all my dims.

[Carl]

I inverted my pedals and mounted them on a rexroth goal post frame. I showed this view to illustrate the reinforcement flat bar I formed out of stainless steel. They are rock solid and give great feedback. I had to remove the spacer blocks to get them to the right height.

I mounted my steering column on a linear track to make it adjustable between me and the boy. Spreading the mount across two bearing slides gives it great ridgidity.

I fitted some gas struts to give the motors a little boost and provide damping. I chose to anchor them at the motor linkage point but this might change.

[Carl]

I need to sort out a PSU or 2 PSU's to drive my 12v12's. Question is do I buy one psu or two? I have seen some very cheap psu's on fleabay designed for driving led lights. Has anybody ever tried one of these? http://www.ebay.com/itm/High-Quality-12V-30A-360W-Switch-Power-Supply-Driver-For-LED-Lights-Strips-/150790646680?pt=LH_DefaultDomain_0&hash=item231bd2ab98 Advice would be very welcome. Thanks

[Carl]

I have fitted a bottomed out rod which is too long purely to give lockout on the platform whilst Im developing the build. What you may notice in this pic is that I had fixed a rotary magnet onto the shaft of my pots. I had tried to use a magnetic clutch directly driven from the other side of the wiper motor which I drilled and affixed a new positioning shaft but the shaft extension kept failing under test. I decided to scrap that idea and make a linkage as Floriske did.

[crs2012]

Greetings Carl,

Great project so far! Just wanted to throw you my 2 cents from personal experience with my setup...

I need to sort out a PSU or 2 PSU's to drive my 12v12's. Question is do I buy one psu or two? I have seen some very cheap psu's on fleabay designed for driving led lights. Has anybody ever tried one of these? http://www.ebay.com/itm/High-Quality-12V-30A-360W-Switch-Power-Supply-Driver-For-LED-Lights-Strips-/150790646680?pt=LH_DefaultDomain_0&hash=item231bd2ab98 Advice would be very welcome. Thanks

That PSU may not be adequate for a single PSU setup to run 2 jrk boards at once. 12v x 30A = 360 W, Not knowing what your motors will
draw under load, it's hard to really answer your query with a definite answer. But this math can be used as a guide.

I run 2 boards with 1 power supply myself, but I'm only moving a seat and H-shifter attached , and it's mounted with a U-Joint directly underneath. So,
there is very little load added to the motors from anyone sitting, and not much more added during motion.
It took me a good while to get the PID set correctly before it would be stable enough to handle various size/weight people on it without having the
PSU cut off due to AMP spikes out of range. Mainly from the fast direction changes.

So the amp spike draw for both motors are no where near what your setup will experience having to move the entire platform under load. The only
sure way to know what kind of PSU setup you require would be to test your motors under load with a car battery and AMP meter. I believe
the amp draw is doubled during immediate change of motor direction giving the massive spikes under load. Quick and easy to
test. Once you know what AMP draw you have for how much weight, just double it up for 2 motors, and get a PSU with 20% more power than what your
total MAX would be. Which I think would be cheaper than 2 separate power supplies. Unless your power requirement is something outrages due to spikes,
in which case, an inline car battery may be an alternate option. I've seen that solution used by many different wiper mover projects as well.

This is my simplified version of the math. Anyone with more technical expertise is welcome to explain it with more detail.
Hope this bit of info is of some use to you...

[Carl]

Thanks CRS.

I measured my motors at around 11a peak under no additional load but working hard in the changes of direction. If I double this and add 20% Im still way below what I had in mind. I was planning on running them at about 30a each. If I buy 2 separate psu's Im thinking at least 30a each, if its one supply Im thinking 60a plus. I have the weight balanced neutral on the gas springs from pivot to pedal but the inertial forces will need the beans current wise when shifting the platform from side to side. Think Im just gonna have to take a chance with the 30a psu's... the Mrs would kill me if I attempted to bring a car battery into the living room. Also, my 12v12's wouldn't like any more than 30a even with the heatsink and cooler enclosure.

Did you fit any caps or diodes into your card dc supply wiring circuit to manage back emf or is it nothing to be worried about?

How much did them scn5's cost... hope to upgrade to them at some point.