[bobgerman]

How much heatsink is really required for a G320?...running 430 oz/in servos. What is the minimum requirement and when does it become an overkill?

I am inspired by cyclone's control work:
http://www.cnczone.com/gallery/showphoto.php/photo/1449
and will probably go that route (it just plain looks kool) but was wondering what it's really going to need.

[Kenwood714]

Cyclone's idea is a good one. My only objection is too much air inflow. You don't need that much fan unless you running the drives to full capacity all the time. It real depends on what you are cutting. If the drives where loaded to full current capacity they would disapate a fair amount of heat. I don't know what FETS they use in the bridge section of the drives, but modern FETS would have an average of .06 or so RDS. So at 20 amps they would disapate around 50 watts. But I doubt you will be running the drives at that load all the time. A healthy chunk of aluminum with one fan for three drives will work fine. I have three drives mounted on a old heat sink out of a home stereo receiver and is works great. I tend to lean away from all the fans unless you need them. If your cutting wood, you have to deal with your control box filling up with dust in a hurry.
Just my 2 cents.

[swarfmacdaddy]

You can never have too much cooling. Why skimp on a $10.00 fan and risk burning up your drive?

[widgitmaster]

Here is the design I choose to mount the Gecko to a Heatsink!
Two Clamps hold the Gecko's metal plate tightly to the Heatsink, with a dab of white heatsink compound between them!
I bought a hughe metal heatsink from an electronics surplus store, then cut it up on my Bridgeport mill!
All four Axis Gecko's are in a metal drawer, with two 60cfm 5" diameter cooling fans! (a bit noisy)

I tried to upload 4-images of the heatsinks, not sure if it worked!

Eric

[sol]

I too have 430 oz in servos with gecko 320s and just have the Geckos mounted on racks surrounded by air, no heat sink. They barely get warm even in multi hour runs at 60 IPM. The entire control box has a single cooling fan but nothing special is done for the drives.