Water Cooled Dillon 1200B Trimmer

[joelogic]

Background: I had my trimmer for about 2 years and trimmed around 40k pieces. Someone said they have trimmed 2 million pieces on theirs but I guess my luck isn't that good. Like anything electronic, my trimmer died. Dillon really came through with this one, their warranty on electronics is only one year but I sent mine in anyway. The tech said the brushes needed to be replaced and they did it free of charge. +1,000,000 for Dillon's No BS Warranty.

Why: I was trying to figure out why the brushes wore out and I reasoned it must be the heat. Someone posted that their trimmer gets to 140F after 30 minutes. HOT.

What: Enter some borrowed tech and I decided to try and water cool the trimmer motor. What I built so far is just to test a theory, so dont judge the build quality. If it works I will clean up the build and post the details. Copper tubing around the trimmer, a small radiator, and a submersible water pump. Function tests fine, no leaks. Heat test run tonight.

[foxtrotuniformlima]

Looks good.

I'd suggest a valve on the out flow side of the coil to regulate dwell time.

You want the water to have a fair amount of contact and depending on the flow rate of the pump it may not sat in the coil long enough to do the most good.

At work, we use a similar set up to cool stuff in the field and without the valve, it just does not work as well. Most of the time we use a normal water source like a hose bib and then let the water go to drain.

[Us3rName]

that looks to be one hell of a pump.

I think you might want a slower flow going through the radiator. Allowing more contact time for heat to exchange. Maybe dig around craigslist for a used aquarium chiller.

This concept will cool down the trimmer with no problems. The only thing I can figure that might be an issue is the volume of metal the trimmer contains. Thus, your cooling the whole assembly. Unless you can find a way to actually chill the assembly, I think heat will still eventually build up.

[rsrocket1]

Take a look at this article. It says that the coefficient of friction is lowest between 140F and 212F and rises quickly on either side (Figure 3). It also says friction and electrical erosion are the biggest factors in wearing out brushed motors.

Just sayin'

PS are you keeping that trimmer clean of brass dust? That could also be a contributor.

[PolishMike]

I think a little fan on the radiator couldn't hurt as well

[joelogic]

that looks to be one hell of a pump.

I think you might want a slower flow going through the radiator. Allowing more contact time for heat to exchange. Maybe dig around craigslist for a used aquarium chiller.

This concept will cool down the trimmer with no problems. The only thing I can figure that might be an issue is the volume of metal the trimmer contains. Thus, your cooling the whole assembly. Unless you can find a way to actually chill the assembly, I think heat will still eventually build up.

Stupid "Growers" have kept the price of chillers over $400. Maybe I will ice the bucket.

Take a look at this article. It says that the coefficient of friction is lowest between 140F and 212F and rises quickly on either side (Figure 3). It also says friction and electrical erosion are the biggest factors in wearing out brushed motors.

Just sayin'

PS are you keeping that trimmer clean of brass dust? That could also be a contributor.

You lost me at "Coefficient of Friction". 140F was after 30 mins of use, Dillon's recommeded use time. I run mine for an hour or so and I will check the temp after an hour of runtime. I am using a 5hp shop vac but dust can be hard to control.

I think a little fan on the radiator couldn't hurt as well

The fan is on order. I couldn't find a 120mm AC fan locally.

[rsrocket1]

You lost me at "Coefficient of Friction".

Friction = bad

temperature of brushes above 212F = more friction = bad
temperature of brushes below 140F = also more friction = bad

cooler does not always mean better

[joelogic]

I was exaggerating there but thanks for the recap. The amps/in2 was interesting. Now if I knew the size of the brush I could calculate expected life. I think my problem is load, trimming/sizing .223 into 300BLK trims quite a bit.

[PolishMike]

I was exaggerating there but thanks for the recap. The amps/in2 was interesting. Now if I knew the size of the brush I could calculate expected life. I think my problem is load, trimming/sizing .223 into 300BLK trims quite a bit.

When I do my 5.56->300BLK i use a cutter chuck in my drill press with a vice jig. Cuts it instantly.

I then throw it in a RCBS power trimmer to square the case and cut to final length.

It does add an extra step but I can punch out a ton of brass that way and heat isn't an issue.

[Us3rName]

Check out aquarium chillers.

I have one for my salt water aquariums. Can chill down to the point where it'll ice up the lines...

[Patrick Aherne]

How about just setting up a fan to blow air past the motor?

[joelogic]

When I do my 5.56->300BLK i use a cutter chuck in my drill press with a vice jig. Cuts it instantly.

I then throw it in a RCBS power trimmer to square the case and cut to final length.

It does add an extra step but I can punch out a ton of brass that way and heat isn't an issue.

Well you size, cut, final trim, right? Thats two extra steps.

Check out aquarium chillers.

I have one for my salt water aquariums. Can chill down to the point where it'll ice up the lines...

A $300 chiller is too expensive for this project.

[Sub95]

the big cooper tube is to big, use the smallest cooper tube you can get, you get more wraps (surface area) of it and will slow the flow of water down put a valve on it to control the temp of the motor, heat sink would be another roll of copper in a tube of cold water and maybe some ice. or just make a heat sink for the top of the trimmer.

The brushes are under the big black cap near the top, one on both sides, just use a flat blade screw driver to unscrew the caps.

biggest problem is not letting the motor cool down after triming it will eat the brushes up. take a temp of the outside case after running with no load say 5 mins then start trimming for 30mins take another temp, most people just turn them off after they are done trimming.

I have found that sometimes the brush springs are to stiff and the brushes will wear out to fast.

[TMC]

Another cooling solution would be a closed loop system with another coil in a bucket of ice water or your system and submerse the radiator in ice water.

[rsrocket1]

I was exaggerating there but thanks for the recap. The amps/in2 was interesting. Now if I knew the size of the brush I could calculate expected life. I think my problem is load, trimming/sizing .223 into 300BLK trims quite a bit.

I hope you aren't joking here too.

So you're grinding down nearly 0.4" of brass on each case? No wonder the motor is burning out!

I believe the trimmers are expected to run at fairly high speeds with very little load.