Skaldiddog's "Progress"

[JohnRobHolmes]

Or you could just use bigger wires to the motors like I've been saying for months :lol:

 

[SkaldidDog]

Or you could just use bigger wires to the motors like I've been saying for months :lol:

I just put six packs of reasonable driving on my new setup. The finger meter tells me that heatsinks And skid were about 100° maybe 110 at the hottest. This is well below the 150 that the computers used to achieve sitting idol on the bench plugged in. I really like the hopped up wheel speed and the motors are a lot higher pitched now because they're spinning faster. Bryce noticed that one right away. If the capacitors are hitting 110° I'd be surprised. They used to get so hot that one of them melted the insulation on the signal wires. I am going to run your experiment on the bench. I'll compare your smashed versions versus my old smashed versions and then do some wire swapping in a controlled manner. I understand your point that larger guage motor wires may help but I don't see going down 4 guage points dropping the temperature 60 to 70° on the computers. I could be dead wrong. We'll see. I like this experimentation stuff. Thanks for being patient John."thumbsup"

 

[Highlucks]

I thought about that but I could never find an orientation that I felt would keep them out of harms way to my satisfaction. That's also a bit higher up than I want them. The TVP would pull heat but I think my sinks and skid will pull a bit more heat. We just woke up and you're about to head to bed I'm assuming. That always trips me out.

J

Yep, I think posted that around midnight.

Either way I am sure you will sort it to your liking as you always do"thumbsup"

 

[SDheavymetal]

That skid plate came out awesome. The heat sinks are very cool also. Are they made out of 7075? I thought so! Thanks for your help the other night.

I have always used big wires for speed controls and motors. I can't see micro deans handling a lot of AMP's either. My surround sound has big wires too. I also like solder with higher silver content.

 

[Wicked Monkey]

Love coming to this thread. Each time I do there is something spectacular going on. Nice work on the skid and the heat sinks Joel."thumbsup"

 

[SkaldidDog]

That skid plate came out awesome. The heat sinks are very cool also. Are they made out of 7075? I thought so! Thanks for your help the other night.

Thanks Matt. I had fun hanging out the other night too. Yes, 7075.

Love coming to this thread. Each time I do there is something spectacular going on. Nice work on the skid and the heat sinks Joel."thumbsup"

Gracias. More good stuff on the way.

 

[SkaldidDog]

The downside of 7075...

Yesterday PM I went crawling with the intention of seeing how hot I could get my ESCs to run. Pre run the skid, heat sinks and all parts of the ESCs (boards, caps etc) were 58-60F. After a long hard pack I checked them with my IR temp gun. Nothing was over 70F. My finger meter told me that was close but I was skeptical. JRH then informed me that shiny 7075 will throw off IR temp quantitation. He said I need to put scotch tape on the detection points. Point taken. Regardless, my ESCs use to be too hot to touch for a count of 4. Now they are just warm to the touch. More updates when I have the temp thing sorted out.

Some cool pics in the meantime. Man I love having my receiver up top. The convenience is awesome. I reinstalled my antenna to alleviate my line-of-site driving restriction in it's absence. My radio lacks the stock antenna.









J

 

[JeremyH]

Re: The downside of 7075...

...finger meter...

Sounds kinky.

 

[WAM]

I presume all the FETs are on just one side. When you were bench testing for temperature, did it seem like most all the heat was being generated on just that side?

 

[SkaldidDog]

Sounds kinky.

Just for you sweetie pie;-).

I presume all the FETs are on just one side. When you were bench testing for temperature, did it seem like most all the heat was being generated on just that side?

Correct FETS are on one side. I've done no bench testing yet but they are where the heat is coming from according to numerous sources. Capsused to get ripping hot too. That may have been soak heat, the same soak heat that made the edges of the boards 140F+ sitting still.

Hope this helps.

J

 

[ittybitty]

Joel...something else I'd be curious to see is the effect of a 4S battery with the same setup as 3S. In other words I think it'd be interesting to see how running an identical layout on 4S would pan out. From what I understand the 4S should allow the ESC's to run slightly cooler, as well as enhancing motor control...better low speed control and such.

Just a thought since it looks like you'll be doing another round of "fingering" things out...

 

[JohnRobHolmes]

4s would only reduce ESC heat if the motor wind was increased to keep wheelspeed the same. 4s would increase heat on the internal BEC, so without mitigation of that component it could actually increase system heat.

 

[stubs179]

This is intense! I have slowly been moving things around in my rig and at this point all my electronics are back in the chassis. The convenience far outweighs the minor weight gain in the chassis. I have been considering "unsmashing" and with your recent observations I think you've convinced me it's time?

 

[SkaldidDog]

Comments

Joel...something else I'd be curious to see is the effect of a 4S battery with the same setup as 3S. In other words I think it'd be interesting to see how running an identical layout on 4S would pan out. From what I understand the 4S should allow the ESC's to run slightly cooler, as well as enhancing motor control...better low speed control and such.

Just a thought since it looks like you'll be doing another round of "fingering" things out...

My experience with my go-fasts was gear down to manage heat when volting up. Looks like JRH below suggested just that albeit his gearing via the armatures. I'll stick with 3s for battery size and wheel speed sake. I'm happy where I am.

4s would only reduce ESC heat if the motor wind was increased to keep wheelspeed the same. 4s would increase heat on the internal BEC, so without mitigation of that component it could actually increase system heat.

Thanks JRH. Good to know.

This is intense! I have slowly been moving things around in my rig and at this point all my electronics are back in the chassis. The convenience far outweighs the minor weight gain in the chassis. I have been considering "unsmashing" and with your recent observations I think you've convinced me it's time?

Give it a try. I'll bring a can of -80F spray to my next comp and will shoot some guys ESC's post course with fixed throttle input. The motors will jump. When I built my axles I ensured my servo pressed into the front. Now instead of the servo going nuclear, the entire front of the rig (axles, tranny, knuckles etc) acts as a heat sink. I have way fewer servo motor problems than with my old rig. I do however have the same frequency of chewed up gears. That's just a crawl thing.

J

 

[JohnRobHolmes]

Be careful when you blast hot electronics with a cooling spray. The thermal shock can kill transistors and delaminate components. Bring it on slow and from afar at first. The #1 killer of waterproof escs is thermal shock when they hit water.

 

[SkaldidDog]

Be careful when you blast hot electronics with a cooling spray. The thermal shock can kill transistors and delaminate components. Bring it on slow and from afar at first. The #1 killer of waterproof escs is thermal shock when they hit water.

That would not have been pretty.

"Hey man watch this......ssssssssssssss....POP....ghost".

Thanks John.

J

 

[WAM]

Re: Comments

When I built my axles I ensured my servo pressed into the front. Now instead of the servo going nuclear, the entire front of the rig (axles, tranny, knuckles etc) acts as a heat sink. I have way fewer servo motor problems than with my old rig. J

Hmmm. I go thru lots of servos. I wonder if a piece of heavy copper foil between the bottom of the servo and servo plate, sticking out 1" on three sides would pull some heat out of there? Assuming I can find some copper foil.

 

[SkaldidDog]

Re: Comments

Hmmm. I go thru lots of servos. I wonder if a piece of heavy copper foil between the bottom of the servo and servo plate, sticking out 1" on three sides would pull some heat out of there? Assuming I can find some copper foil.

Not sure how much it'd help pulling heat from one side. My setup is still not optimal pulling heat from only three sides. If you don't try it you'll never know.

J

 

[WAM]

Re: Comments

Not sure how much it'd help pulling heat from one side. My setup is still not optimal pulling heat from only three sides. If you don't try it you'll never know.

J

Agreed. I already have some 22ga copper sheet on the way. The servo cases have built-in metal heat sinks exposed to air on three sides. But the bottom (on mine) is clamped down to CF, an insulator. It's heat from the insulated bottom I hope to extract. We'll see. Thanx for the inspiration.

 

[SkaldidDog]

Re: Comments

Agreed. I already have some 22ga copper sheet on the way. The servo cases have built-in metal heat sinks exposed to air on three sides. But the bottom (on mine) is clamped down to CF, an insulator. It's heat from the insulated bottom I hope to extract. We'll see. Thanx for the inspiration.

Sounds good. Lets see what pre and post mod temps look like.

Update: not that it really matters but my fat bitch rig currently weighs 4lb 10.32oz. No numbers on F/R weight distribution yet. I haven't forgotten Stubs."thumbsup"

J