Align ESC mod page

[Finless]

Call Align RC USA.
Web site is http://www.alignrcusa.com

Bob

[Gary JP4]

This is a great mod. There was a very good discussion on RR under Bob's mod thead and since it was lost, and this is kind of a recreation, hear is a link (froogle search) on arctic silver's "arctic alumina" that was in the thread. This is the way I found it.

http://froogle.google.com/froogle?q=arctic+silver+arctic+alumina&hl=en&lr=&sa=X&oi=froogle&ct=title

I did the mod a while back. I used the Arctic Silver "Arctic Alumina". The heat sink and everything else on the ESC runs evenly warm now. The heat sink was barely above ambient temperature before with the heat shrink under it.

A did a mod to put a heat sink on the sim's of an FP 4 in 1 before and made my own heat sink adhesive. A thread to a computer link (stuff for hopped up video accelerators) was also on the RR’s lost stuff explaining how to make it and a test report. Edit: Here is the link: http://www.overclockers.com/tips683/. The test was devised to check thermal transfer and showed that the homemade stuff worked just about as good as Artic Alumina. It was one part 5-minute epoxy to 1 part thermal paste by weight I think. I used a non-silicone paste for that. Heat transfer was good and it held well. But, I waited for the Arctic Silver Epoxy for the T-Rex ESC.

[WillJames]

I have been using the arctic silver for years on CPU's and it is very good. Interesting idea to mix it with epoxy!!

[cudaboy_71]

regular epoxy is an insulator...seems kinda like defeating the purpose. i'd just go for the arctic silver epoxy made for the job. it's only $8.

[Finless]

Yep Cuda.... Got to agree with this one!


But.... BlakeMcBrayer will ship you for CHEAP the stuff I used which is even better stuff IMHO.....

BVob

[Skiddz]

I have been using the arctic silver for years on CPU's and it is very good. Interesting idea to mix it with epoxy!!

Dear gawd don't do that!! Artic Silver makes a 2 part thermal epoxy. It can be had at Fry's Electronics or any other computer store for about $8. I've used it to glue heatsinks to all kinds of oddball projects I've run up over the years. It works very well.

[BlakeMcBrayer]

The Artic Silver is good stuff, but it doesn't have as high of a thermal transfer rate as what Finless uses and I ship in my kit. But to each is own, use what you like, as long as it will transfer heat and not insulate it.

My kit is only $7.50 for the epoxy and INCLUDES the needed heat shrink along with shipping.

[GimbalFan]

I did the mod using Blake's kit. After 9 minutes of FFF and mild 3D the heatsink is barely warm to the touch. I'd say his kit is a great bargain.

[cudaboy_71]

actually if you were getting good thermal transfer you'd want the sink to be getting hot...meaning its taking heat away from the mosfets, right?

just picking nits i suppose...but if you're going to judge results, judge the right ones.

...anyway i'm sure anything you do at all is better than what align provides ;)

[GimbalFan]

if you were getting good thermal transfer you'd want the sink to be getting hot

With the thermal connection that you get with the mod the mosfets couldn't possibly be getting hot without the heatsink also getting hot. I believe the lack of heat reveals that the mod is permitting the heatsink to do exactly what it's supposed to do, rather than being just a cosmetic accessory that actually allows temps to go up.

There's lots of Rex SE's where I fly, most without the mod. The heatsinks on those also don't get very warm (mostly because they're insulated from the mosfets) but the backsides of the ESCs sure do. Some even show a slight bubbling of the shrinkwrap at the sides.

[BlakeMcBrayer]

For those whom might be intrested, while picking up more heat shrink stocks today, I added yellow as a color I'll be keeping on hand for the kits.

:twisted:

[Finless]

Good man Blake! Thanks for supporting people wanting to do the mod with CHEAP materials......

Bob

[Wingless]

The Artic Silver is good stuff, but it doesn't have as high of a thermal transfer rate as what Finless uses and I ship in my kit. But to each is own, use what you like, as long as it will transfer heat and not insulate it.

My kit is only $7.50 for the epoxy and INCLUDES the needed heat shrink along with shipping.


Blake,

What is the size of the shrink wrap when unshrink? Just curious because i got spare heat shrink from my work (about 1-1/2 inch when flat).

[Wingless]

The Artic Silver is good stuff, but it doesn't have as high of a thermal transfer rate as what Finless uses and I ship in my kit. But to each is own, use what you like, as long as it will transfer heat and not insulate it.

My kit is only $7.50 for the epoxy and INCLUDES the needed heat shrink along with shipping.


Blake,

What is the size of the shrink wrap when unshrink? Just curious because i got spare heat shrink from my work (about 1-1/2 inch when flat).

[BlakeMcBrayer]

Wingless,

Yes it's 1.5" when flat. It sounds like what you have at work is PERFECT for the job!

[Wingman 65]

Thanks Bob, very useful mod. Don't know what Align was thinking, probably trying to cut corners to speed up production.

[ZwergNase]

Has anyone tried the easier way to just attach the heatsink to the metal plate without removing the tape between the mosfets and the plate ? Because, if it only eventually turned off during flight in hot days, it may be enough to just do it the easy way.

[cudaboy_71]

the trouble is i beleive the tape to the mosfets is just as inefficient as the sink to shrinkwrap. Align screwed up twice. To realize any benefit from one you've got to do the other.

[BlakeMcBrayer]

I agree with cudaboy_71 on this one. It might help some, but not enough to make it worth the trouble when for a little more effort it can be done right, the first time you do it.

[Gary JP4]

Maybe I should have said don’t try this at home. I just wanted to get all the lost information back that we could for somebody reading this for the first time. I thought the discussion lost at RR was very good and some of those ideas might be useful in a pinch or on other applications. I was working through problems when I first found the RR thread. It was a great discussion and the first mod I did to the T-Rex. I am sure the thermal epoxy used is the best and I didn’t suggest using regular epoxy alone which is plastic and a heat insulator. I don’t know how it would compare to heat shrink or air. I just pointed out some viable and tested options. Here is the link for making your own thermal epoxy http://www.overclockers.com/tips683/

In the "lost thread" there was one guy in Australia who couldn't find and thermal epoxy and used thermal paste alone. He got the heat sink to stay in place using the heat shrink. I believe the paste has an even higher thermal transfer than the thermal epoxy. I think the thermal epoxy is a compromise in thermal transfer to achieve adhesion. The non-electrically conductive properties also probably required a compromise in thermal conduction ability compared to those that are electrical conductors. Using thermal adhesive is good for practical reasons in this case and it has some type of epoxy in it, which is a heat insulator and probable reduces its heat transfer ability (a compromise). If you want to go after more subtle things you probably should remove the anodize from the base of the heat sink. It decreases heat transfer by conduction (bad for the glue line) and increases heat transfer by convection (good for the cooling fins) and possibly radiation (especially in black) so I am told. Now they use other colors that are prettier and work almost as well. Also the flatter the surface and the less thermal whatever you use the better. Both the stock heat sink and the one I used were not flat due to the extrusion process. And, yes I flattened the base of the heat sink thus removing the anodize, used a better heat sink with lighter bigger fins, touched off the top of the sims with a mill file (they had some high spots on them), used Arctic Alumina thermal epoxy, and clamped as tight as I thought I could get away with given the delicate parts using a soft clamp. I like those soft clamps in the directions. I also used a piece of soft aluminum to shim for the space where the heat tape had gone instead of bending the joggle into the EMF plate to step up over the switching transistors. That way my longer heat sink could go the full length of the EMF plate and over the switching transistors.

I don’t think that any of these things are significant compared to having heat shrink between the heat sink and sim’s. Seeing now how well it works some of this was overkill but it can’t hurt. If I did it again I would probably get the older thermal epoxy used here from BlakeMcBrayer and use the stock sink as it is adequate and looks better. After the mod I ran it then touched the board on both sides with out the heat shrink on and nothing gets hot.

This is a great mod and those are excellent directions! Seems ridiculous that we have to do this. Thanks Bob and thanks BlakeMcBrayer for making the materials available. That is a lot of work.

[Finless]

Hehehe Gary... good stuff and thanks for bringing back some of the lost discussion!

Back when we were over clocking Celron 300's and making them 450mhz processors I use to LAP the heat sink, use the best thermal trasanfer compound you could get etc... YES doing all of the above does help thermal transfer!!!! But as you say for this application just the fact of getting the heat sink on the MOSFETS is good enough IMHO......

Thanks again,
Bob

[GimbalFan]

I'm still a mostly mild flyer. The heaviest load I can 'safely' put on the 35G ESC is full throttle FFF, which because of the high airflow over the components is not the best way to test the thermal mod, but I've intentionally flown for max loading in the hot sun here recently on a 105° day for a full pack, and when I landed the ESC's heatsink was barely warm to the touch.

Considering that the airflow during hard stationary 3D is still pretty good due to the rotor wash, I think this ESC mod pretty much solves all the temp issues it may have had.

[BlakeMcBrayer]

GimbalFan,

Thanks for the update on your mod.

How about everyone else? I have been sending out lots of the epoxy kits, but no one seems to be posting the results?

[skew]

Blake, Mine has been doing great also. I haven't put a temp gauge on it but its way cooler than the motor and battery. I'll get a reading today :)

[Seeker]

I've been too busy flying to do the mod on my 25 ESC. :D