New hi-speed project

[Peter Zicha]

I agree a 100% with the complexity end of it
Luciano Once I get caught up on my boats I will get a little more serious with the buggy .....But hey for now

Dreaming is for free

[lutach]

Originally Posted by Peter Zicha

I agree a 100% with the complexity end of it
Luciano Once I get caught up on my boats I will get a little more serious with the buggy .....But hey for now

Dreaming is for free

Actually I'm going to start messing with it. I'll do some planning first on where all the components will go and after I sort it out, I'll start marking and fitting before I start drilling away. I know it will be a while before I finish it.

[BrianG]

A little more progress:

1) Glued a tapped plastic block to the bottom of the ESC and re-heatshrunk it to allow me to mount it.



2) One of the first things I noticed upon receiving the GTP is the the chassis is quite "flexy", even with the existing front and rear braces. This is presumably from the lack of kickups on the sides. So, I made a top plate out of 6061-T6 Al, and doubles as the ESC mount. VERY sturdy now! I also cut off the excess brake cam shaft so it sits flush with the top plate (gotta make sure nothing rubs on the power wires).



On a side note: I was a little concerned that the HV-110 wouldn't have a high enough current capability for this project, so I looked up the specs for the FDS5672 FETs. Turns out they are rated for 60v, 12A, and 0.01 ohms each (@ 25*C). There are 108 of them on this ESC. And seeing as how there are 36 of them on at any one time (18 on the + coil, 18 on the - coil), that brings the rating to 216A and 0.00055 ohms! Even derating the FETs for 75*C (167*F), they are still good for 130A. And that is continuous current. Peak is much higher depending on how long the burst lasts (ex: if the burst is 0.1s, the rating is 40A each). Seems a tad underrated compared to some of the other ESCs out there.

[Dagger Thrasher]

Looking good Brian! Should be a really sweet conversion. :) Sounds like Castle really did underrate the 110...a lot, lol. I guess they must've known that it's likely to be pushed hard in some crazy setups, so gave it more headroom than some of their other ESCs.

[Mod Man]

I got some insider info from Castle (they are one of my sponsors) regarding the HV110. Joe and Bernie both told me the HV110 should really be labeled HV140. They have run them in planes at 160 amps for 20 seconds without any problems. Personally, I have run mine on 12S at 127 amps and it barely heated up.

I am a HUGE fan of the HV110.

Matt

[BrianG]

When I contact Castle about my concerns, they said it should be fine but I would be using it out of spec - so basically "at your own risk". However, they did say they could make me a special version with an additional FET layer to make a "HV-160". That would be crazy at 288A @ 25*C and 0.00042 ohms. At 75*C, it would still be 172A continuous.

IMO, they could conservatively rate the 3-layer HV-110 for 120A, and a 4-layer version for 160A. And that's at almost 170*F! Man, they should just slap a brains board with car software on it and call it the HV-MMM!

[BP-Revo]

Originally Posted by BrianG

When I contact Castle about my concerns, they said it should be fine but I would be using it out of spec - so basically "at your own risk". However, they did say they could make me a special version with an additional FET layer to make a "HV-160". That would be crazy at 288A @ 25*C and 0.00042 ohms. At 75*C, it would still be 172A continuous.

IMO, they could conservatively rate the 3-layer HV-110 for 120A, and a 4-layer version for 160A. And that's at almost 170*F! Man, they should just slap a brains board with car software on it and call it the HV-MMM!

I wonder if thats possible...to put an MM brain board on otherwise an HV-110, maybe even double stack the HV-110 to make an HV-220.

150mph Truggy anyone?

[What's_nitro?]

Originally Posted by BrianG

Man, they should just slap a brains board with car software on it and call it the HV-MMM!

HmmmmMM.... I wonder where they (and/or we) could get a board with car software to use?

EDIT: BP-Revo you scallywag!

[BrianG]

Well, it would take a little work. I found that when I removed the heatshrink, that the brains board is just held on with a special connector (no soldering). So, it's just held on via heatshrink. Makes removal easy (the FET boards have this same connector, but also have soldered heavy power and motor bridges). Figuring out the pinout shouldn't be too hard either (GriffinRU, are you listening? ). There are a few other things to work out (like gate drive, using the Opto instead of a BEC, etc), but a worthwhile goal IMO...

[lutach]

I have some MOSFETs to run by Patrick and if he gives the OK, I'll buy them to put in my HV110 that I still have to send to them. My options for the MOSFETs looks like this: (75V, 45.8A cont. and 0.0133ohms), (60V, 30A cont. and 0.0092ohms)and (100V, 34A cont. and 0.023ohms). I might go with the 100V unit as they are in stock. I just have to see if Patrick can use them.

[BrianG]

I'll take option 2 (60v, 30A, 0.0092). Makes a solid 10-12 ESC with low rdson and high current. Higher voltage would be nice, but then we'll start needing electrican's licenses for the high voltages! What's the switching speed like on those options? The voltage drop X current during pulse ramp-up/down when switching on/off is a big culprit for heat, not only Rds on...

[lutach]

Originally Posted by BrianG

Well, it would take a little work. I found that when I removed the heatshrink, that the brains board is just held on with a special connector (no soldering). So, it's just held on via heatshrink. Makes removal easy (the FET boards have this same connector, but also have soldered heavy power and motor bridges). Figuring out the pinout shouldn't be too hard either (GriffinRU, are you listening? ). There are a few other things to work out (like gate drive, using the Opto instead of a BEC, etc), but a worthwhile goal IMO...

I've been trying or should I say begging for something like that to be done. Patrick has mentioned something about hardware not being compatible. I'm going to see if he can do something real simple to atleast have my HV110 working with forward/brake only, but be able to use a pistol radio.

[BrianG]

You can use a pistol radio with the existing setup - with a bit of tweaking. But I wouldn't want to use electrical brakes with voltages that high...

[What's_nitro?]

It wouldn't have to be an MM brainboard. The fet boards are passive, after all, so you could use a Quark brainboard and have the nice smooth power without the heat!

[lutach]

Originally Posted by BrianG

I'll take option 2 (60v, 30A, 0.0092). Makes a solid 10-12 ESC with low rdson and high current. Higher voltage would be nice, but then we'll start needing electrican's licenses for the high voltages! What's the switching speed like on those options? The voltage drop X current during pulse ramp-up/down when switching on/off is a big culprit for heat, not only Rds on...

I'm going through my datasheet database and I basically know the good stuff (volts, amps and rds). When looking at the datasheet, where can I find the switching speed? Man I hate just knowing how to sell this things, when it comes to anything else I stink at it .