HK 180 amp ESC banjo mod

[RocketM1419]

Hi everyone,

Been lurking for a while but thought I would make my first post a build post. I am building an Insane RC FE30 and have been looking through all the posts here about it. It will be built initially with a AQ UL-1 motor. I decided to go ahead and put the HK 180 amp ESC in as I plan to power it up. After reading the posts from Tony "properchopper" regarding the issues of space in the FE30 when using the HK ESC I decided to do the modification he recommends.

The HK ESC has its water ports on the sides of the unit perpendicular to the normal mounting position. This causes an issue with using 2 batteries on the sides in the narrow bay of the FE30. After looking at the modification I thought it might be useful for anyone using the HK 180 amp ESC.

Here is a picture of the tools needed and the heat sink (removed from the ESC)

Todd Knight

[RocketM1419]

HK 180 amp ESC banjo mod

One of the problems with this modification is that the water ports are epoxied into the heat sink. They are very thin and will tear if you try to back them out with a pair of pliers. To solve this I used a piece of 1/8" brass rod. It matches the internal size of the barb and it allows you to clamp onto the port without crushing and tearing it. Here is a picture with the rod inserted to make it clearer.

Todd Knight

[RocketM1419]

Now for the fun part as anything involving fire is fun. I clamped the vice grips onto the fitting to be removed then used a set of pliers to hold onto the heat sink. I used a piece of Nomex (I am also a high power rocket guy). I do recommend being careful here as you will be using the torch. Use a wet rag or something that will not burn in the short time flame is applied.

I held the torch (at lowest setting and still burn) on the fitting for about 10 seconds. That is when I saw the epoxy around the fitting start to burn a little. You have a little time so don't get in a hurry. Shut off the torch then slowly remove the fitting counter clockwise. They come out easily.

Just be careful and take your time. The heat sink will retain heat as well as the rod and end of the vice grips. Allow everything to cool down before moving on the next fitting. Here are a couple of pictures. Sorry could not operate torch and camera at same time.

Todd Knight

[RocketM1419]

HK 180 amp ESC banjo mod

Next is the mundane part, cleaning out the holes. You could use a tap to clean them out our use a plastic dental pick (I use the gun cleaning picks). Just be careful as the threads in there are not the best. There is a lot epoxy left over so make sure they are clean.

Here is a better picture of what the holes look like after removing the fittings

Todd Knight

[RocketM1419]

HK 180 amp ESC banjo mod

The next step is to install the banjo fittings. I used the 90 degree high flow fittings from Kintec. They include a rubber o-ring and a small nut that I did not use. This was to keep everything as low profile as I could. There are 2 parts, the fitting that threads into the heat sink and the nipple that threads into the fitting.

*VERY IMPORTANT* Layout the ESC as it going to go into the boat and note how the new fittings have to be installed. I did not do this and had to repeat the process as I had 2 of the banjos going the wrong way.

The threads in the heat sink are very loose so do not tighten the new banjos in to tight.

I decided to use 5 minute epoxy to mount the new fittings in place and to make them water tight in the process. I use the epoxy like I would loctite, use a small stick to apply it to the threads. I screwed the fittings, without the nipples in place, until they bottomed out. I then backed them out until they were in the proper position and allowed the glue to set up. I did 2 at a time as the epoxy sets quickly.

On the side that has the input from rudder and the output to the motor I set the banjos to face the rear of the boat to allow clean routing (this is where I made the mistake on 1st try, had them facing front of boat).

The other side has the nipples facing each other. DO NOT INSTALL ONE OF THE NIPPLES AT THIS TIME.

On the side with the fittings facing each other cut a piece of tubing the proper length. Insert the loose nipple into one end then insert the other end of the tubing into the nipple attached to the heat sink. Bend the end of tubing with the loose nipple into the fitting on the heat sink then thread into the fitting carefully (a little oil helps to let the tubing turn when you start tightening in the next step). Be careful as it is a tight fit and you don't want booger up the threads. You have to do it this way as there is not enough room to get the tubing on with both nipples on the fittings. Tighten the nipple into the fitting slowly so as to not tear the silicone tubing.

The first picture shows the input and output fittings in place. The second picture shows the other side with the crossover tubing. You can see how small the space is between the nipples and why you have to put this side together as described above.

After everything is done remount the heat sink and it is ready to go. Any questions let me know. Thanks to Tony "properchopper" for the tidy solution.

Todd Knight

[srislash]

Nice job on the demo Todd.Quite useful.Going to need to do this to the Miss Bud.Thanks.

[mstek]

nice job!! Thank!

Max