BasicMicro - Forums

This question may have an obvious answer, but I've seen only top side images of Robo Claw (I just ordered mine) and I see no nice way to mount it to the robot chassis. What are your suggestions? Are there mounting holes in the bottom of the heatsink?

There aren't holes in the heatsink, like what you're probably thinking. At least not that i can remember, it's been a year since i built my rover and i've been gone the whole time.
But you can use the holes that mount the claw to the heatsink, with some longer screws.

Large images.
http://blog.basicmicro.com/wp-content/u ... step-9.jpg
http://blog.basicmicro.com/wp-content/u ... tep-10.jpg
I did make suggestions to have screw holes on the corners of the heatsink sticking out, but seems new roboclaws are out, and the mounting holes are nowhere to be seen.

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Universal Robot Controller

We thought about adding secondary mounting holes but size is an issue with some of our customers so making it bigger to have mounting tabs wasn't going to work. You can replace the screws holding the heat sink with longer ones. AYou need to be carefull not to get any metal shavings under the board when you do this. Also do not drill out the holes on the PCB to make them bigger(yes we've had that one before) and if you pull the board off the heat sink you may need to put new heat sink past on. If the contact is pour to the heatsink you can fry your board without the heat sink ever getting warm and the thermal cutout can't act fast enough to save it in that case.

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Basic Micro - Robotic Technology Evolved

My RoboClaw conveniently fit vertically between two decks of my aluminum 4" dia Table Top 'bot.

Alan KM6VV

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Maybe offer heatsink upgrade packages, with little packs of thermal paste.

Also make sure you use ceramic thermal paste (white stuff) not the silver stuff. Newer ceramic paste is better anyways, and far cheaper.

I did just think of 1 other option but it's not an easy on/off deal. Thermal tape.
I had some left over thermal tape from the PC Memory modules, i purchased 3rd party heat spreaders for, and it came with thermal tape. Keep in mind this stuff holds strong and doesn't come off easily or cleanly.
Using longer screws is the best bet,and is what i did.

Maybe BMicro can offer extended screw sets with little washers and nuts.

1 more note, don't use a washer or anything between the heatsink and chassis/frame of your bot. If anything use a tiny bit of thermal paste, it'll cause some of the heat to spread to the bot, and actually use the frame itself as an additional heat spreader. Giving the frame is metal.
Even after 5mins of full speed (about 4.5A) on my roboclaw 2x5, the heatsink and bot frame is barely warm to the touch.

http://blog.basicmicro.com/wp-content/u ... step-2.jpg
The shiny silver square, is where i removed the powder coat and mounted a high amp voltage regulator in a previous bot build. The whole frame was the heatsink for that regulator.

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Basic Micro Blog
Universal Robot Controller