XB-600 "Shunt Mod" instructions

I got my "new" controller in the mail today. It looks like it has been on a shelf for 10 years or used as the case and plugs were dirty.
It took me about 20 minutes to wire it up to test, rewire to install, and then another 20 minutes to screw everything back together. Now that it is running I don't think I will do the shunt mod again since I only have 2 overpasses to conquer on my commute. I am considering the 60-72v mod for more top end but on the other hand...

I drove a co-workers Tank 150cc yesterday. I got that thing up to a speedo reading of 55mph with no problem. I might just get a 150-250cc scooter instead of modding my xb-600 or buying an xm-3000/3500. I have 3 people tha twant to buy my xb-600 so I would have a nice down payment on a gas scooter. Decisions...decisions...

LOL! Tell your wife not to worry. Although my wife says the same things. LOL. I have to work the next 7 days, but when I get a day off I'll be replacing the FETs in my controller. Look for pics here. Until then, have fun at 60v!

FETs replaced! What a pain!! Here's the new link..
http://visforvoltage.org/forum/4275-72v-35mph-xtreme-xb-600-video-link-here#comment-24560
-Warren

I don't know about all that. I just want to see what is possible "on the cheap". So far, I've spent about $1150 on my ride(including 2 new batteries) and almost caught up to the xm3000. $1150= 35MPH.... $2499= 43MPH....HMMMMM. I like the first option.:) When I get all the parts in and see what the rad2go will do with a chain drive the xb 600 might get changed again. Who knows? I'm satisfied with it....for now.
-Warren

I agree, even if it does go kaput, it's nothing that a ADC motor and controller with a chain and sprocket can't fix. :)

I will probably sound like a noob asking this, but what exactly does the "shunt mod" do?
What are the pros and cons of doing it? I have purchased a spare controller and I was
just wondering what I'm getting out of it. I will be sure to post results on mods, as I'll
be attempting them on my lower-end xb500. I just hope that it works out the same as it did
for everyone else's 600's. If not I will definitely get a 600.

The shunt mod reduces resistance across the shunt(s). In effect a shunt somewhat controls the flow of amps through the controller(from the batteries to the motor). Lowering it's resistance allows the motor to draw more amps for hill climbing and acceleration. If you don't go up any hills and you're happy with the acceleration of your bike you don't need to do the shunt mod. :)

Hyperob,
I just got my controller and will be attempting this mod tomorrow, hopefully. I was wondering if you could be more detailed with your previous problem with the fuse/holder melt problem. Also, as I'm not really big on these such details, in case I want to change my fuse and/or fuse box like you did, how will I know which fuses to ask the people at the store for?
Thanks a bunch! Anyone else's 2-cents are very welcome too as I am a noob at this.

Use same AH for extra batt. and 8 or 6 gauge wire for the connection.

Ok, here is another Shunt story;

I have had my XB-600 for about three weeks now, and I wanted to have a bit more umph to go up the minor hills I have between home and work. It would make it, only dropping to about 15-17 mph, but it would be so nice if it didn't seem to slow down so much. I didn't want to risk my current controller, in case I blew it up, so I ordered a second controller for $65 including shipping. It arrived today, first class, and only took about two days to get here. On opening the box, the controller looked like it might have been pulled out of another bike, that is it was kind of beat up, and several of the screws already had stripped heads. S, being cautious, I decided to test it before modifying it. It is over 100 degrees here in Austin, so into the family room comes the bike.

CIMG6348.jpg (34.42 KB)

Note: I switched off the power and removed the main fuse for all of these operations, but I left the batteries connected.

I removed the seat and front part of the back end enclosure, I hooked up the new (new?) controller and it seemed to work fine. Next step was to open the controller to make the mod. That was a bit of a challenge because several of the screws already had stripped heads. I used a pair of long nose pliers to grab the heads and twist them loose. After removing the screws, the cover came off the controller relatively easily, AFTER if bent open the end covers and HIT the end of the sliding top with a RUBBER hammer to convince it of the need to slide.

CIMG6349.jpg (40.84 KB)

Now we can see the unmodified shunt jumpers. Nice looking board, there appears to be a date at the upper right (not in picture) of 20051121 (Nov 21, 2005).

CIMG6350.jpg (42.77 KB)

Next is the modified shunt, notice that I did not remove the board from the case, I thought it would be too much trouble, and would increase the risk of damaging something. Not only did I not remove the controller, I left it connected to the bike. Only the key switch was off, and the fuse was removed. As you can see, I just used a piece of about 16 gauge speaker wire, somewhere around 2-3 inches long, and simply soldered the ends to the top of the board where the existing shunts were soldered. I used an old Weller temperature controlled soldering gun that was designed for electronic repair, it heats quickly, and puts out around 100 watts on demand if needed. I worked as an electronic tech for a long time, so I know not to use too much heat, but to use enough to get a good bond with the existing shunts.

CIMG6351.jpg (35.05 KB)

Next step was to retest, by simply putting the fuse back in, and turning on the key. Sure enough it runs. Notice that everything is just laid out there, and I haven't even removed the old controller yet. I wanted to make sure that this was going to work first. The next step was the really miserable part, which is getting the controller together again and sealed. I would much rather have not had to do that. I just don't like to get messy. Oh, be sure to turn off the key and remove the fuse during reassembly and mounting of the controller. I dug around and found some small screws in a junk box, and some silicone rubber sealer to assist with the messy job, and I think it is sealed as well as it was before. Next, It was time to remove the old controller, which was something of a challenge, since one of the mounting screws is under the wires coming out of the controller, and in addition it is hard to get a tool on the lock nuts on the back of the bracket. I managed to do it, but I didn't want to put the new controller back in the same place, as I think I might be taking it out again for more work one of these days. The solution I cam up with was to use some medium ty-wraps to hook the controller to the side of the frame, inside the left part of the rear fairing. There turns out to be plenty of room, and any future work will be much easier since I will only have to cut two ty-wraps to get the controller out.

Finally it all goes back together and out I go for a test ride. Sure enough it now goes up the hills at around 20 mph, and doesn't seem to bog down as easily. Top speed is the same, since either the motor, or the electronics are set for a maximum RPM. It would be nice to change that, but that will have to be for another day.

The only bad news today, is that when we were about to take it out for a test drive, my wife noticed that the front tire had a bug bulge in it. I deflated the tire, and checked the rim (it's ok). It looks like the tire just has a bulge. Either I hit something that damaged it, or it was defective. In any case it looks like I need a new front tire.

The battery will probably run down quicker, but since I live only a mile from work, that won't be a problem.

Happy Scooting,

Tom

I thought wire didn't provide enough resistance for the shunt mod... Any comments from others?

On that same note, has anyone come up with a shunt mode switch? I would like to have a scooter that would have two modes:
1) max of 20MPH (unmodified)
2) higher top end (shunt mode)

I thought wire didn't provide enough resistance for the shunt mod... Any comments from others?

On that same note, has anyone come up with a shunt mode switch? I would like to have a scooter that would have two modes:
1) max of 20MPH (unmodified)
2) higher top end (shunt mode)

About the resistance of the shunt, my goal was simply to make it go down. I suppose there is some risk that under heavy load it might blow the main fuse since my shunt could be allowing too much current to flow. I suspect however that in this stock 48 volt system that it doesn't really increase the current that much. If I were to go to higher voltage, with more batteries, I am sure it could be a different question, but at least for now mine (and others) seem to be working as expected with a modest increase in pulling power.

Note that there was NO INCREASE in top speed. For that, you need apparently more voltage I guess, or a higher controller pulse rate. I say I guess, because it is not clear to me why increasing the voltage increases the speed since the XB-600 uses an AC (Alternating Current) motor whose speed is controlled by the controller, and I don't know why the controller would automatically give a higher pulse rate to the motor just because it was running on a higher voltage. As an engineer I would call that a flaw in the controller's design, if it was effected by the supply voltage.

Just my thoughts, which seem to contradict the experience of several people on this forum.

Tom

My humble belief is that it really would take lots of more components to run an ac on top of a bike. DC motors are the common rule.The controller is complicated enough as it is.

zomg forum people! I did the "shunt mod" on my xb-500. Now i can make it up the freaking hill without peddaling! NO more pedals for me! By the way, xb500 controller is much different than xb600 and only comes with one loop. Mine has two now. I ordered my fifth battery today and will be posting any updates.

I guess "shunt mod" works on the xb500 as well and we have proof of that now! I'm hoping the xb500 can take the 60V mod!

-cheers

My humble belief is that it really would take lots of more components to run an ac on top of a bike. DC motors are the common rule.The controller is complicated enough as it is.

Brainy,

Well, the XB-600 motor has three fairly large wires, and four skinny wires going to it, so I am pretty sure, especially since the controller has 12 FETs in it that the motor is AC.

The three heavier wires are labeled "phase line", and the four skinny wires are labeled "signal" on the XB-600 schematic. In addition to the FETs, the controller has several integrated circuits in it. It is quite a sophisticated piece of electronics, especially since it only costs $65 US Dollars.

Tom

The hub motors are DC and the 3 wires are phase lines. The other 4 or 5 skinny wires are for the hall sensors. To get more speed you will have to increase voltage which increases RPMs of the hub. AC propulsion is waaaaay to expensive for x-treme to be using it on these bikes. LOL http://www.youtube.com/watch?v=cl7V5iHOYbQ See for yourself...

Hello everyone,
Something horrible happened! I finished my "shunt mod" and I was able to ride for a while this afternoon after having finished it, even up some relatively steep hills. I was going at about 10-13 mph, which is better then...not going at all. BUT ALAS! Tonight I was about to go for a ride, and I turn the key and the lights go on and I sit down and what?... Nothing! Nothing happened when I turned the throttle... :(
So my first guesses were, either motor or controller? Since the one i modded was a spared and I had time, I quickly switched controllers hoping for it to having been that... but it was not! Different controller gave the same result. I sniffed around my scooter for any smells of burns, but nothing. BUT... after doing the shunt mod, when I was connecting some wires - I believe it was the red wire that goes to the battery pack, there was a spark. This was before I rode the scooter this afternoon, when everything seemed fine... :( Also, when i switched the controllers tonight, before plugging the cables for the new controller back in, I unplugged the main black cable from the battery pack( the one that comes from the wall) thinking it would be safer, then after having all wires connected from controller to circuit, I plugged the main black cable and there was another spark. Any help will be appreciated. Thanks everyone

Hello everyone,
Something horrible happened! I finished my "shunt mod" and I was able to ride for a while this afternoon after having finished it, even up some relatively steep hills. I was going at about 10-13 mph, which is better then...not going at all. BUT ALAS! Tonight I was about to go for a ride, and I turn the key and the lights go on and I sit down and what?... Nothing! Nothing happened when I turned the throttle... :(
So my first guesses were, either motor or controller? Since the one i modded was a spared and I had time, I quickly switched controllers hoping for it to having been that... but it was not! Different controller gave the same result. I sniffed around my scooter for any smells of burns, but nothing. BUT... after doing the shunt mod, when I was connecting some wires - I believe it was the red wire that goes to the battery pack, there was a spark. This was before I rode the scooter this afternoon, when everything seemed fine... :( Also, when i switched the controllers tonight, before plugging the cables for the new controller back in, I unplugged the main black cable from the battery pack( the one that comes from the wall) thinking it would be safer, then after having all wires connected from controller to circuit, I plugged the main black cable and there was another spark. Any help will be appreciated. Thanks everyone

Have you checked the fuses, one of them could be blown. The spark you see when connecting the power is normal I think, and is sue to applying power to the capacitors in the controller after it has been powered down for a while.

The hub motors are DC and the 3 wires are phase lines. The other 4 or 5 skinny wires are for the hall sensors. To get more speed you will have to increase voltage which increases RPMs of the hub. AC propulsion is waaaaay to expensive for x-treme to be using it on these bikes. LOL http://www.youtube.com/watch?v=cl7V5iHOYbQ See for yourself...

zerogas,

I guess I need to do some research on the subject before I can understand. I will look around the forum and the web and see if I can find more information.

Tom

Check all fuses and plug in connectors(sometimes the terminals pull out of the connectors). You've blown a fuse or got a short(loose connector or broken wire) Also, use a coathanger for the shunt. Wire reduces resistance too much.

I used a coat hanger. I checked the fuse last night and it looked normal, but the red cable connection which goes from controller to the fuse box looked toasted. I'll be checking the connections then.

The hub motors are DC and the 3 wires are phase lines.

Zerogas,

You are absolutely right, these scooters are driven by DC motors, pulsed DC, but DC.

Ain't technology wonderful,

Tom

Hello all,

I know this is comming late in the thread, and some will do the mod before reading this warning.

PLEASE remove the battey pack first and then turn the ignition on to discharge the capacitors in the controller. Yes you will see your battery meter start to rise and then fall off to 0.

An ounce of prevention is worth a pound of cure!

Happy scooting
JamesS

haha thanks for the warning!!! that sounds like a painful discovery

Hello all,

I know this is comming late in the thread, and some will do the mod before reading this warning.

PLEASE remove the battey pack first and then turn the ignition on to discharge the capacitors in the controller. Yes you will see your battery meter start to rise and then fall off to 0.

An ounce of prevention is worth a pound of cure!

Happy scooting
JamesS

That sounds like a good idea, perhaps hyperrob could update his original post to include this suggestion.

Tom