This tutorial will show you how to Stack a set of 4562 FETs onto your XMOD Generation 1 Electronics Package. The process is fairly in-depth and requires advanced soldering skills and a lot of patience. This is a tedious process and if you don't take your time you could damage FETs or fry your electronics package. This process is the same for Mini-Zs and most any car that uses 4562 FETs in the "H-Bridge" configuration.
Step 1
Using the flat nosed pliers, straighten the 4 Prongs on both sides of the FET. This can be done by simply holding the pliers at a 45 degree angle to the FET and squeezing the prongs until straight. Be careful not to put pressure against the FET itself as it will break the prongs out of the silicon and ruin the FET. (remember, you fry it you buy it) Do this to both sides of the FET.
Step 2
On the left is the FET with the straightened prongs, on the right is an unmodified one.
Repeat this process with a second FET. You will now have two straightened FETs and 2 unmodified.
Step 3
Take 1 straightened FET and one unmodified FET. Place the straightened FET directly on top of the unmodified FET.
Note: It is extremely important to make sure that the input side of the straightened FET is matched up to the input side of the unmodified FET. Failure to do so will result in the instantaneous frying of the FETs upon completion of the installation. You can determine the input side of the FET by looking at the writing on the face of the FET. There is a small circle marking the number 1 prong of the input side. In the picture I have highlighted this circle with a Red Mark.
Step 4
Now take the FETs that you just stacked on top of each other and secure them together with your pair of Hemostats.
Step 5
It is important to make sure that the alignment on the FETs is perfect (both front to back & side to side.)
Step 6
Take the pair of flat nosed pliers and squeeze the prongs from the straightened FET against the unmodified FET.
Step 7
This is what it should look like.
Step 8
You need them very steady while you solder the prongs. So while the FETs are still being secured by the Hemostats, place hold them in place with the Helping Hands to prep for this next step.
Step 9
Here’s where it gets hard. You are going to take your .032 solder and soldering iron and solder all 4 of the prongs on the input side. Start your solder from the bottom of each prong and work upwards. This ensures that you don’t have any solder hanging off of the bottom of the prongs which will prevent proper mating with the MainBoard FET contact pads.
Step 10
The output side of the FETs are a little bit easier. Since the voltage is common on all output prongs, all you have to do is run a bead of solder across the entire group of prongs with your .062 solder.
Now do the same to the other 2 FETs. This will yield you two sets of Stacked FETs.
Step 11
You are now going to secure your Electronics Package into your Helping Hands. You have a Helping Hands right? If not you will need a very steady friend, preferably someone without Attention Deficit Hyperactivity Disorder.
Step 12
Take some solder braid and soak up the solder on the input side of one of your FETs. You do this by laying the solder braid onto whatever solder you want to remove and press the solder gun to the braid. After a couple of seconds you will see the solder wick up into the braid.
TIP: Be careful to pull the braid away at the same instant you remove the iron. If you let the braid cool and pull it away, you can tear the pads away from the board.
Step 13
Now do the same procedure to the output side of the FET.
Once finished the FET should come off easily.
Step 14
Now do the same thing to the other FET. Leave the remaining solder on the MainBoard FET pads. This will bond with the new solder later.
Step 15
This will be the proper FET orientation. Pay close attention to this, unless you are looking for some fireworks.
Step 16
Take one of your FET stacks and set it where you have just removed the factory FET. You need to put the input side of the FET on the side of the board that has the 4 individual solder points. Now take your Solder Gun and press it to the bottom of one of the prongs. In less than a second you will see the solder on the FET start to melt. As soon as this happens remove the Solder Gun. Some of the solder will flow onto the board and will hold the FET in place.
Do this with all four of the prongs on the input side. You want to make sure that you’ve got a good connection between the FET and the board.
Step 17
On the output side of the FET, melt the solder so that it begins to flow onto the board. You will want to have something pressing down on the FET stack as you do this (to keep the FETs from separating). I use a hobby knife.
Step 18
Once the solder has melted onto the board you will want to make sure that all 4 prongs from both of the FETs (8 total) are joined with solder.
Repeat the process with the second FET stack.
Step 19
All that’s left is to inspect the FET stacks to make sure that you aren’t shorting any of the input prongs together.
Step 20
This is how the output side should look.
Make sure that the solder on the 2 output Stacks aren’t joined together as this would be a direct short.
Testing
We test our Stacked FET EPs 3 times before we ship them. Once while it is still stock before we do any work to it, once after we make it Pro Ready, and then finally after we put the Stacked FETS on it. By testing we mean the EP is tested for steering accuracy, for how much load it can handle, and for range (generally 50-60 feet). I suggest you do the same prior to putting the EP back into your car as it will only add to the frustration if you put it into your car and then test it only to find out there was some complication. Remember, if you don’t think you can do this yourself we will be more than happy to do it for you. You can either buy a pre-built Stacked FET Electronics Package or send us your EP and have us Stack the FETs on it for you.