Norway!!!

[Dudster]

Hello.

Norway calling!

I have realized that old nitro Mad Forces are on the cheap and have recently acquired 4 more or less abused nitro Mad Forces.

I have sold off all the nitro bits and have torn the cars down in order to rebuild two of them with a custom long wheelbase chassis.

I have a 1:7 scale Kyosho Scorpion that performs wonderfully on a local beach. I love it's sheer size and I want to extend the two Mad Force's to the same wheelbase, ie stretch it from 316mm to 452mm as part of the rebuild.

The leftover Mad Force parts will be organized in parts bins to form an el cheapo spare parts inventory.

My problem seems to be with regards to shimming the diffs. I have discarded the straight cut gears and only kept the helical cut ones.
The instructions for the old Mad Force specifies that only the rear axle housing should be fitted with a 8x16x1mm washer for the shaft of the outgoing gear, but I find that the gear mesh between the 43th/13T gears are way too tight. What am I doing wrong?

 

[Tzicul]

Strange... I don't remember installing that shim on my MF! Especially only on the rear axle. It's been some time now since I don't need the instructions to correctly shim a diff, and I shimed A LOT. What happens if you don't install that shim? Too much play between the pinion and the crown? Maybe it's ok not to install it, but just add more or less of those thin shims near the crown, on the planetary output.
If you need any information about how I elongated my MF, or how I solved the cvd problem, please let me know. Mine is longer by 150mm, if I remember correctly

Sent from my Sony Xperia Z5

 

[Dudster]

I have downloaded all the owner's manuals for the Mad Force lineup I could find at Kyosho's support page and I see now that there is no washer at the outgoing gear's inner bearing if yoy use the straight cut crown gears. On later vehicles there is a washer on the bearing on the rear axle only. If you run the helical gears there are to be used washers on both the front and rear axles.
As for shims, there are shown no shims with straight cut gears on one vehicle, while others with straight cut gears shows shims on one side only while one vehicle shows shims on either side of the diff. For helical cut gears it's always shown shims on only side of the diff. Will upload images of all the manuals I have later.

Would love to see images of your stretched car. Was thinking to solder or braze extended driveshafts though, no budget for cvd's...

 

[Tzicul]

I have helical cut gears on both front and rear and I also installed the second set of satellites in the front diff. But I really can't remember if I have that thick spacer!
Here are a few pictures










After I finished thid build I also installed a Junfac rear driveshaft and Losi LST front CVD, both of them was rather cheap. Junfac was spot on and the CVD's needed a little tlc as they were a little too long Electric Losi XXL-2 AXLES (DRIVE SHAFTS LST2 front rear Super-Duty 2pc – Jennys RC LLC

 

[Tzicul]

PS The Junfac driveshaft has a 6mm input, while the output from the diff is 8mm. But you can figure it out if you have a turner friend

 

[Dudster]

Thanks a bunch!
I love the way you set up the centre driveshaft. As I have 4 Mad Forces, I have enough parts to do the same as I want to build up 2 extended Mad Forces. Super!

Having a hard time uploading jpg's to photobucket, it's just so slow...
I am still far away from starting my builds, as I am still cleaning and sorting parts from the 4 Mad Forces... The main thing is the axles and shimming, can't figure it out...

 

[Dudster]

Aaaaaargh!!!!

Just realized that I ruined 16 Mad Force shocks...

Soaked the end caps that holds the o-rings in WD40 and guess what? They swelled up!!! Any way to change the o-rings?

 

[Dudster]

30522B - Twin Force Spirit

 

[Tzicul]

No photos!
I believe those are what you need, I bought them some time ago
10Pairs 13 x 11 x 1mm Flexible Rubber O Ring Oil Seal Gasket Replacement | eBay

 

[Dudster]

Finally managed to obtain the patience to work with a very slow photobucket website... See all 26 pictures of the front and rear axles for 13 versions of the Mad Force platform.

Here is a link to the slideshow of the album as well:

http://s1248.photobucket.com/user/123Dudster/slideshow/Mad Force axles

Here is a link to the album:

Mad Force Axles by 123Dudster | Photobucket

 

[Dudster]

No photos!
I believe those are what you need, I bought them some time ago
10Pairs 13 x 11 x 1mm Flexible Rubber O Ring Oil Seal Gasket Replacement | eBay

Sorry, that is the wrong o-rings... The ones that swelled up are the orange ones, the ones that line up for the shock shaft. They are held in place from inside the shock cap by means of a metal circlip thingy, the kind that is pressed down where it locks into a groove with 6 small tabs. It's made of metal, but it won't come out easily. The shocks are the MA061 kind:

InfernosOnly Kyosho Inferno, Lazer, Ultima Parts and Kits Specialists

Here's a picture of one of my damaged shock cap o-rings:

 

[Dudster]

I found that the large diff gear (ring gear?) has been worn to a different degree. The same applies of course to the small gear (crown gear?) mating with the large gear. When I stripped down the 4 Mad Force's I tossed the gears in parts bins together with my stripped down Inferno gears. In retrospect I should have kept the paired gears together as they are worn in to the same degree relative to each other.

I noticed just how different the wear of the gears are. I moved the crown gears between the ring gears and it seems like I have a good mesh for two axles. Will play around with the other crown gears I have tomorrow and see if I can find the ones that mate perfect.

 

[Dudster]

Looking at the 26 images of various axle builds from Kyosho's manuals.

On some rear axles the washer on the crown gear shaft is placed between the gear and the inner bearing, while one others it's placed between the bearings while yet on others there are not washer at all!
Of course some versions of the Mad Force use straight cut gears while others use helical cut gears and this would very likely affect the need for a washer, but still, it seems like Kyosho also played around with different setups. I guess all axle housings are identical throughout the Mad Force line?

 

[Tzicul]

Sorry, that is the wrong o-rings

Ok, I see... those are the right ones for the shocks

https://www.amainhobbies.com/kyosho-p4-silicone-oring-orange-10-kyoorg04/p22389

 

[Tzicul]

Looking at the 26 images of various axle builds from Kyosho's manuals.

On some rear axles the washer on the crown gear shaft is placed between the gear and the inner bearing, while one others it's placed between the bearings while yet on others there are not washer at all!
Of course some versions of the Mad Force use straight cut gears while others use helical cut gears and this would very likely affect the need for a washer, but still, it seems like Kyosho also played around with different setups. I guess all axle housings are identical throughout the Mad Force line?

I am using for both front and rear helical cut pinion/ring as the original straight cut set have a prohibitive price, and this is IF you can find them Furthermore, I'm using four satellites in the front diff also. Not that is needed, but what the hell!
Whatever version of diff you have you only have to pay attention to a few things:
- The pinion has to stay as close as possible to the diff's case, so you can use the entire surfaces of the teeth - you have to shim the pinion according to this
- The diff has to stay as fixed as possible inside the diff's case - shim the output bearings according to this
- After all the shimming, you are suppose to rotate the pinion/diff as smoothe as possible. I even like to feel just a little bit of resistance when I turn them, it will came loose after a few runs.

 

[Dudster]

Ok, I see... those are the right ones for the shocks

https://www.amainhobbies.com/kyosho-p4-silicone-oring-orange-10-kyoorg04/p22389

Super, but have you or anybody managed to replace the o-rings on the MA061 shocks? How do you remove that circlip thingy?

 

[Dudster]

I am using for both front and rear helical cut pinion/ring as the original straight cut set have a prohibitive price, and this is IF you can find them Furthermore, I'm using four satellites in the front diff also. Not that is needed, but what the hell!
Whatever version of diff you have you only have to pay attention to a few things:
- The pinion has to stay as close as possible to the diff's case, so you can use the entire surfaces of the teeth - you have to shim the pinion according to this
- The diff has to stay as fixed as possible inside the diff's case - shim the output bearings according to this
- After all the shimming, you are suppose to rotate the pinion/diff as smoothe as possible. I even like to feel just a little bit of resistance when I turn them, it will came loose after a few runs.

Thanks for the tips. Really puzzled by this, will need to be methodical in order to find which of my crown gears mate with the matching ring gears.

 

[Tzicul]

Super, but have you or anybody managed to replace the o-rings on the MA061 shocks? How do you remove that circlip thingy?

If I remember correctly I used a thin flat screwdriver to pop out that metal clip. Not very sure, though, I did it a long time ago.

 

[Dudster]

Super, so it's possible to pry those suckers out then. Will take my time and be careful. 16 shocks, will be fun. Actualky, I did the same mistake to 16 Inferno shocks too, will check again if I can open them too.

Getting my hands on yet another Mad Force tomorrow. That brings my fleet up to 5 vintage Mad Force's.
Plan to keep one stock with the nitro engine, one will be stretched and converted to 4S brushless while one will be a 6 wheeler brushless with 4 or 6 wheel steering. I want ti build up a SC truck with a Inferno ST front end and a Mad Force rear end, possibly 4 linked. Already got 8 long throw HPI Savage shocks for that truck. Also working on extending two Inferno ST-US's to the same wheelbase as my 1:7 Scorpion buggy. And I'm also building up a old Inferno VE for indoor racing (I can't drive on a track worth s***, so I need a sturdy car that can take a beating) and I'm also prepping a Inferno TKI3 VE for indoor racing as well. I'm really on a fairly tight budget, but I'm amazed how cheaop old nitro vehicles are these days. My best catch was 100 USD for the TKI 3 buggy. Second best were 4 x ST-US trucks and one Inferno buggy for 150USD. Paid 40USD for one complete Mad Force and 30 for a Mad Force incomplete chassis with engine. 2 other Mad Force's were purchased for 75 USD each and a Inferno VE buggy, complete, were purchased for 50 USD. Seems like a lot of people tried their hand on RC and then left the hobby, only to let the gear collect dust. I love to wrench and since the Inferno and Mad Force platforms share so many parts, I 'm in no need to by spare parts in a long time.

 

[Tzicul]

Yeah, I know, everybody is going brushless - cleaner, no needle settings, no oil... bleah!! No freaking fun without some smoke. And not from a burnt ESC I can accept an electric if it's a crawler... or a Yeti XL

Sent from my Sony Xperia Z5