MOSFET mod for BCGs
 

Here is a look at the way to change the high resistance transistors in your BGC to low resistancs high current MOSFETs.
This mod boosts the current going to the motor and turns a standard BCG or MS into a rocket.
Once modded it will pop wheelies after rolling in reverse, and screams accross carpet like its on floorboards.
It now loves high revving motors, the higher the better, and can still pull wheelies with a 3.8 motor and the highest gear set.
Power is improved massively and because its not carrying the weight of an extra cell it takes corners at full speed without flipping or spinning out, its like a different beast altogether.
A 1.2V FET modded car with a 3.8 and high gears will leave any dual cell for dead, both off the line and especially around turns.
The beauty of this mod is that YOU CAN CHARGE THIS HIGH PERFORMANCE BEAST ON AN ORDINARY CONTROLLER CHARGER !!
Here's how it all looks




2 of the MOSFETS are mounted underneith the circuit board
http://www.prahranpianos.com/bit_g/m...om_fets_in.jpg



The other 2 are on the top in the same places as 2 of the removed transistors, then both pairs are wired together to form a new H-bridge that drives the motor. Thats them at the bottom near the V+ and F terminals.
http://www.prahranpianos.com/bit_g/m..._fly_leads.jpg



Once its finished there is no external differences and you can charge on a standard charger
http://www.prahranpianos.com/bit_g/m...l_finished.jpg

Here is the original thread on Ausmicro.
MOSFET mod link

What you think?
:) uA

micro_Amps lives @ AUSMICRO.com
 

Way to link! Great job on that car!

FET mods for your BCG car
 

Just wondering guys (and gals),
What would you say if I was to offer to do a MOSFET mod for people.....
you send me your bare chassis, I do the FET mod to it, and send it straight back to you in the same packaging,
would any of you be interested ???
Its a tricky mod requiring precise and steady soldering but worth the effort in sizeable power gain and speed gain too if you are using high speed motors.
Say for US$20 including return postage. (I am assuming US$5 for return postage, so the mod is done for US$15 incl. the MOSFETs)

What do you think, is it worth it ?
(If you are not sure what I'm talking about, scroll up to the first post above, and checkout the link.

:) uA

No thanks.
 

$20 is going to get me 20 MOSFETS, shipped, from Digikey. Good for FIVE cars!

(And my dad can do all the soldering for me for free!) :D

Thats great BillyP.
My question is really directed at those who dont have the knowledge of electronics, or the experience to be able to put this mod together, but would still like to have a FET modded car.
I'm not in it to try and make heaps, just cover my costs and provide access to a different mod that can make these cars even more fun, thats all.
If your dad can put this together, thats great, sit him down and get him into it, because you are going to enjoy the result.
All the best with it.
:) uA

I'm interested...
 

I guess you mean $20AU? That's supposedly $13.15USD according to this page. That's really a good price, considering I'd hate to screw up my booster chassis with the tiny soldering. I know you've got the skillz b/c I've seen your other work. I've never shipped stuff to AU before, but I'd be willing to find out how for such a sweet mod. How would we pay you? PM me please; I'm in.

Yeah, I would send you my cars if I didn't have all the stuff I need to solder. It's not easy, so I would recommend everybody to send you their cars. It's the best thing you can do for your car (imho).

Hey actofgod,
in an earlier post I did say US$20 for the mod inc return post. I put this price because of the extra postage etc, sorry if that wasnt clear enough.
Payment could be done with a US$20 note in the package with the chassis, or you could pay me into my paypal account, they would be my two preferred options. I can easily get the cash transferred to AU$ here.
Work would be of a high and reliable standard, I have been a technician for a long time.
All modded cars would be tested before return to their owner. I have all the different controllers, (6 freqs. and 4B) so testing is not a problem. I prefer at this stage to stay with genuine Tomy chassis, BitChargs and Microsizers.
Standard airmail should do to get it here. You send it to me in a padded bag, I mod it, test it, and put it in the same bag and send it straight back to you, minus the 20.

It sure is worth the effort.

All the best.
:) uA

$20USD is still a pretty good deal IMO. I was mixing up my forums.. this one says PM's are disabled, but you can e-mail me. Go to "user cp" at top, then "edit buddy list". Add my username, and then I'll appear in your buddy list in your usercp. Click my name, then choose "e-mail actofgod". Sorry about the hassle, but I get enough spam as it is :) Send me your shipping and paypal addresses, and I'll send you my 350z.

I'm interested. I'll be sending you an email soon.;)

BGC FET mod
 

Ok, I have fresh stocks of the MOSFETS I use for this mod and I am currently doing the mod for people that want to lift their BCG or MS to the next level. US$20 per chassis is what I charge, including return postage.

If you want me to do this FET mod for you, email or PM me and we can organise things. (Email is: bitstuff@dodo.com.au) I will need your bare chassis. It will be modded, tested, and returned to you, along with confirmation emails on receipt and departure.
Payment can be via cash or Paypal, as stated in an earlier post.

actofgod, you have an email.
sezzis10, lets get things happening.

You should see what it does to a dual cell. Hehehe its good stuff.

:) uA

Can someone plz tell me where to get the mosfets?
I kind of want to try the mod myself;)

Yeh I got them from Conrad electronics in Germany
:) uA

you got a link?
Anywhere in Canada/U.S.?:confused:

what kinda speed increasment are we talking about here?

What mosfet do you use? IRLM2505?

Yeh Daisycutter, that sounds about right. I'd have to check the packet, it is at work and I am at home now.

Babykiller, the speed increase is significant because there is so much more power going to the motor. It loves high speed motors now, even with the highest gear sets.
:) uA

with all this extra power going to the motor, what is runtime like? i am interested also.

The runtime is about the same as normal, because before the mod, some power was being used up by the transistors on the way to the motor. Now, almost none is used by the FETS, and the extra is used by the motor. It seems to run for about the same amount of time.
The biggest difference I see with runtime is the choice of motor.
3.8s drink power and 1.0s dont, same as before. But the 3.8 is heaps more fun.
:) uA

if i send it to you with $20 will you also resolder a loose steering wire? it was broken at the pcb

Yeh no problem vtheo, lets do the rest on email tho hey.
bitstuff@dodo.com.au
:) uA

Can't wait for my new MS Pro to get here from Tinyrc... I'm going to send it straight away to get this mod done. Thanks again Micro for being willing to do this mod for a reasonable price (going all the way to Australia and all). If it's as good as you say, this may become the new mod of choice. For all those who haven't decided about doing this mod, maybe some of us who get it done can post some performance reviews.

No problems actofgod, thanks for the kind words, I'm happy to help.
I think performance reviews are the best way to judge any mod.
Some people that have electronics knowledge of FETS or know the performance of this mod from elsewhere on the net, have jumped at having this mod done. Others that have no prior knowledge are waiting to see if its any good, and thats a good attitude to have too. I have tried not to 'hype it up' too much, preferring to tell it how it is but theres only so much people will believe from one person.
I will be interested to see what you (in particular) have to say when you receive it , I am sure you wont be dissapointed at all.
I will look forward to reading all the comments of people that experience this mod for the first time.
It should make very interesting reading.
:) uA

I got my 27Mhz S2000 Compact Char-G (Official TOMY Aussie version of the Bit Char-G) back from Micro the other day and I can only say one thing. WOOOOOW! This mod rocks! I can't say that enough. At first I put back in a 2.2 that came stock with the car when I bought it. The 2.2 with the FET mod takes off faster than my 40Mhz Compact with a perfection 3.8. I then put the perfection 3.8 in the FET modded car and I gotta say that it leaves my clone dual batt with a 2.6 for dead!

My FET modded car has the following after market mods:

FET Mod.
3.8 perfection motor
Bit Racer Soft front and rear tyres.
Crip cap (in the car) mod and longer antenna.

I run this car on polished floorboards so the soft tyres were the go. Taking a corner keeps the car on the ground. On carpet the car requires hard tyres for the front end or it will flip ( this even happened with the 2.2 stock motor!!!)

The general handling of the car is much better than ANY internal daul batt (the external daul batt mod is a waste of time, you can do wheelies and nothing else) mod due to the lighter weight and no stuffing around with raising the car's centre of gravity. (which is what dual batt mods do)

I gotta say that if you can get this mod done DO IT. Micro had my car back within 2 days, in great packaging and all the original parts. (The transistors that were replaced are useful for a techo like me, Micro gave me the option which is great.)

I will be getting all my cars modded to suit. I will also take some video showing the results of this mod, watch this space!

Excellent job micro, Kudos!

For all you techies out there (BillyP) you still might want to consider getting Micro to do the job for you. I believe he has the specialist SMD tools for this application of soldering surface mount components. I've got many different projects on the go and I have killed a fair few SMD components by over heating them, breaking etc,etc, 'cause I didn't have the right tools.

ph2t.

hey how much would you want to do a bit pcb to a zz?

BK, what do you mean....."a bit pcb to a zz"
:) uA

pcb transfer from a bit to a zz

i'll swap a pcp for 5 dollars. but i'd need the two pcbs and the chassis. you'll pay shipping.

Sounds like it can be done BK, you even have someone offering to do it for you.

I have transferred pcs between cars with no problems. I've never done a ZZ, but if all the functions are the same, then probably yes.

:) uA

Well, I guess I will have to send off my car to you micro_Amps. I attemped the mod myself, but I will send an untouched board. I got the whole thing all together, and only had to solder the wires that go around to the other side. When I was moving the wires into place, one of the **** tabs on the mosfet broke off! I did however manage the two cell version mod! I can manage the swap out of the transistors, it's the **** mosfets that ya gotta glue to the other side that were giving me all the trouble. I have not put the two cell board in a car yet, but the motor actually jumps when I hit the throttle it, has so much torque. I may attempt the single cell version again, but I think if you are an experienced smd tech, then the results would be better than what I could do. Too bad there is not a one for one swap for a single cell like the dual cell swap.

Oh, and those mosfets are available in the states, from Newark Electronics in case you would like to know (someguy).

Yeh sure thing bdebde, send me an email and we can get the ball rolling. It is a tricky fiddly mod but I've been working in SMD for a while now so it isnt that much trouble.
You are right about the torque tho. It kicks big time, especially the dual cell. I am currently working on a 3.6v (internal) FET modded booster, should be fun.
I had my dual cell FET booster on my speed checker, running bit racer gears and a 4.0 motor and it was running at 20.8Km/h (thats about 13.4mph in your money) which is absolutely SCREEAAMING for a bit. Torque was a bit low but it builds up to an amazing straight line speed when its on the floor.
I just wonder how the 3.6v will go. I am hoping to run the same gears and have better acceleration.

bdebde email me on bitstuff@dodo.com.au and we can get things happening. Well done on the FET swap mod too, its not easy.

:) uA

I tried the mosfet modified pcb!!! I used a four wheel drive chassis (2 back halves glued together) with no steering, 3 cells, 2 red zip zap motors and kit racer gears. This thing just FRIES the tires!!! And boy is it fast, gonna have to speed check this baby! I will have to try this in a dual cell with steering and faster motor. I can't wait to see what a single cell modded one will do!

something tells me that as the word gets out, this thread is going to get interesting.
Way to go bdebde
:) uA

would this mod work for dual cell cars?

OH YES!! and the soldering job is even easier, no wires to run around to the other side of the board. I did that one myself! It is just a matter of removing 4 transistors and replacing with fets. The mod for the single cell proved to be somewhat harder for me. You have to glue 2 fets on the oppisite side of the board and run wires to the other fets. I am giving up on that one for now, and sending one off to micro_Amps for the single cell mosfet mod.

i have a switch in my car (see super accord in the gallery), so i go 1 or 2 batteries. So would i be able to run 2 cells under the single cell mosfet setup? because i usaully run my car at one battery and 2 to race.

I am not sure, maybe micro_Amps can answer that. I would think so though.

Yep, you sure can. The FETs I am using are good for up over 12v and can run more current than you will ever need.
A single/twin cell with a FET mod would be excellent. Nice and powerful on 1.2v and absolutely insane on 2.4v.
What a great combination.

:) uA

The MOSFET mod in action
 

Well as promised here's some video of the FET Mod in action.

The three cars pictured below have the following:

Silver Compact Char-G S2000, stock TOMY 2.2 motor.
Blue Compact Char-G Skyline GT-R, Perfection 3.0 motor.
Yellow MicroSizer Mistu Lancer,Perfection 3.8 motor. (FET Mod)

http://www.prahranpianos.com/bit_g/lights/fet_test.jpg

And see the video of how they all take off from a stop HERE .

You can now see for yourself the power of the FET Mod.

Cheers,

ph2t.

that is crazy acceleration!