RC10Talk - The Net's Largest Vintage R/C Community

I wish you luck. It just floors me that some guys who've exceeded 100+ mph speed runs are just standing there in the middle of the road while they launch their land missiles directly at themselves...I hope you're not one of those guys!

Wow

I bow down to the master of speed! I have a Mamba Max with a 7700kv motor in my B44 on 2s and it is already STUPID fast. Couldn't imagine going faster with this crazy setup!!

Coelacanth wrote:I wish you luck. It just floors me that some guys who've exceeded 100+ mph speed runs are just standing there in the middle of the road while they launch their land missiles directly at themselves...I hope you're not one of those guys!

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I have seen that last video "127! 127!" Lol

I have also seen the one where the dude chops his ankle with a street car doing over 100. Totaled car, and trip to the ER. I am definitely NOT the type to do this with anyone nearby. All of my runs I am behind my solid brick 2'x4' mailbox. I also stop when anything comes around (neighbors, cars, kids, etc...). Very good point for you to make.

RC104ever wrote:Wow

I bow down to the master of speed! I have a Mamba Max with a 7700kv motor in my B44 on 2s and it is already STUPID fast. Couldn't imagine going faster with this crazy setup!!

Haha thanks dude! But no bowing necessary


More to come.

you can easily see these types of voltage swings in a power delivery system, it's likely nothing to worry about. When you remove power from an ac/dc motor, it will freewheel and generate emf or voltage, and can be much greater than the source voltage, especially if the voltage is turned off abruptly. You can't remove current from an inductor (motor winding) instantaneously. so the voltage will go up as the current drops to maintain the same power.

as for the total ripple, it looks to me to be about 10-15%, which again, its not unlikely given the little resistance you will have in solder connections, connectors, and circuit traces. it all adds up. it sounds to me like the software measures max excursions, so it you were to look at it as a histogram, you would see tiny narrow spikes here and there as you load and unload the system.

Thanks. As long as the ripples don't explode my project then I'll deal with the 10%.




The new top shafts are not heat treated or hardened in any way. Sucks, I purchased 4 top shafts on my last trip to AE in lake forest for a lot of conversions. Guess I can't be trying to lock out the slipper by tightening the spring down like the old V.1 style disk/spring. Come to find out they are all cast shafts.

I can remember many years ago trying to drive the wrong roll pin into the GT's top shaft. It took a lot of buggering to finally bend that shaft (in a vice no less).

Well, the new shaft I just installed bent at the threads trying to tighten down the v.2 spring. Could not believe it, grabbed my needle nose pliers and sure enough, yanked those threads clean off. Still amazed...I know a bit about metal, this is not a hardened shaft. It came apart like a cold tootsie roll.

How did you manage that? I've never heard of this before. Top shafts being milled wrong, sure that's common, but I've never seen one break. Maybe you can find another way to effectively remove the slipper.

Maybe use the old style where the slipper was only on one side, tap the furthest in slipper piece so that the holes match the gear, and bolt the gear directly to the inside slipper disk. Or rough up the metal on the gear side of the inner slipper halve, and gear on the inside side, and JB weld them together? This way the bolt only needs to be reasonably tight.

Or somehow keep the two slipper halves, remove the slip material, and weld, bolt, JB weld, the two metal halves together? The slipper metal is anodized, so the coating has to be removed before you do any welding. Since I have a Tig machine, this is what I'd try. You wouldn't even need any filler rod, just lightly tig the outer edges together.

I may just re thread the shaft for a larger nut and do like your saying and just delete the slipper. I am pausing completely until my new pinion/spurs come.

It bent so easily, I really thought I was fighting the nylock.

I have been following this thread, and I think you're nuts! (in a good way) Tightening the slipper down 'til it is locked with that much power sounds risky to everything downstream in the drive train to me, but maybe you need one of these?

http://www.exotekracing.com/b5-b4-t4-sc10-direct-spur-mount/

Not to hijack but while on the topic of speed runs ans short course this is my street sweeper. 6s power good for about 2hp.

^that is perrrdy when the slipper gets locked out i may be contacting you about your wheelie bar

harvey wrote:I have been following this thread, and I think you're nuts! (in a good way) Tightening the slipper down 'til it is locked with that much power sounds risky to everything downstream in the drive train to me, but maybe you need one of these?

http://www.exotekracing.com/b5-b4-t4-sc10-direct-spur-mount/

even WOT the stock GT2 trans has held up well to 4s. But yes thank you. Now I NEED that too

Gears just showed up

18/66 40mph
24/54 70mph
35/47.....?

Houston we have a problem. 4 runs.

80.2 MPH
128.8 degrees
42,008 RPM max
130.0 Amp max
84% throttle achieved
2.0V max ripple

I am approaching a LOT of thresholds. Almost lost her at 80. 84% throttle achieved. 42k RPMs. That scriptasylums calculator this whole time....

Shocks, blown, all 4. Now what? They can't handle the vibrations. We can rebuild he says! But I should look into big bore...?

Tires, no good. New, but 20 some odd passes later and they aren't happy. It appears the tires are beginning to lose their rigidity and balloon. I might need some kind of 4.2" solid tire? Belted radial?

Other then almost losing it as I squeezed, she did ok.

Pre mounted foam tires is what I found works best so far. Should stop the vibrations.

I'm surprised the tires even hold up to 80mph. Make sure you balance them.

Anyone have any objections to HPI Phaltlines? I have read they do not balloon at over 80.
Or has anyone ever seen a foam tire over 4"?