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billysnarf
2012.01.18, 09:45 AM
OK well I am a bit frustrated at this point. I got the buggy (Lazer) last week along with some batts. Totally stock I ran about 5-6 packs through it. Loved every second. BUT then my rear diff broke. Upon inspection it was the 3 spider gears basically shredded.
So I ordered a new gear diff, which I got yesterday. I decided to put a little black grease into the diff this time (did the same thing to the front). Also I greased the slipper mechanism a bit. Anyways half way through the second pack last night, the rear diff gave up AGAIN. Took it apart and sure enough the 3 spider gears are shredded again. Now I am running this buggy stock on an 18x7 concrete track that I set up on my patio.. There were two 3-4 inch ramps also.. I was abusing not this car in any way, just trying to make consistent laps as a racer does... my point is i need to know what is causing these rear diff issues (im not bashing the hell out of this car)- just smooth driving.
Any thoughts? I am new to the mini z platform but not to r/c in any way..
Maybe I just need to suck it up and pick up an expensive ball diff? But wouldnt I really need 2 diffs?.. I mean I have no idea how the car would drive with a gear diff up front and a ball in the rear.? maybe it would be fine..Any help is very appreciated. Sorry for the long ramble. Thanks - Rob

Rune
2012.01.18, 10:24 AM
Strange.
We have been running 6 cars for a few weeks now, with 33 - 39 turn motors and stock diffs.
The only thing broken is a stub axle and a couple of driveshafts.

The same diffs are in the MA10, and I know a lot of people had issues with these diffs there, and we are surpriced that they hold up so well in the buggys.

Could it be that the chassis itself has a mold defect? Maybe the diff sits misaligned, or even that a bearing is locked?

Ball diff rear, and gear diff front works fine. No problem at all.

nicov
2012.01.18, 10:37 AM
+1

You may have a locked/defective bearing on the rear, or your rear drive train may not be balanced, so the diff is always acting, and finally shredded.
You should hear the diff screaming ?

For now, you could simply run with a locked rear diff - gluing your damaged diff for instance ?

billysnarf
2012.01.18, 11:25 AM
Thank you for the quick replies. FOR NOW I will glue the broken rear diff just so I can still drive the car. Will be interesting to see how it feels. BUT I am also shopping for a ball diff or two. Has anyone used the Atomic diffs? Shipping is cheap from reflex racing because they are close to me. Atomic ball diff TAR is 30.00. Cheaper than the Kyosho with shipping. I am concerned that you may get what you pay for.? Should I just go with a Kyosho ball diff instead of trying to save some money? The Kyosho is 20.00 more.
I have to find a solution because the gear diff is obviously not working out for me. I will take a very close look at the bearings after work today. There is obviously an issue somewhere that is causing the gear diff in the rear to fail.. A ball diff may just be a band-aid for the existing problem.

kryten
2012.01.18, 11:40 AM
We have about 8 buggys at our club and not had this issue either. I did shim my stock diffs tho.
There's nothing wrong with the atomic ball diffs at all. :) They are a good low cost option.

billysnarf
2012.01.18, 11:58 AM
Thx Kryten. Since this my first experience with a Mini z ball diff can you tell me what grease to use.. Generally with my 1/10 cars I use a clear lube on the diff balls/ rings and a black grease on the thrust part. Does this apply to these diffs as well. OR can I just use the Kyosho ball diff grease on everything?

Also you mentioned shims.. I will look into this possibility as well. I am assuming upon installing either ball diff I may need to use some shims. Do you know the size of these, so that I may order some? I would order my ball diff from Tiny but they are all sold out.

Thanks again for the help. - Rob

kryten
2012.01.18, 12:46 PM
Personally i oil the bearing like i would any other,and use the tiniest amount on the diff balls too. I find grease too thick,but i'm sure others use it.
The diff shims are 6x8. :) You should get some in with your diff.

billysnarf
2012.01.18, 12:50 PM
Thank you Sir.

billysnarf
2012.01.23, 09:54 AM
Well I am having another problem that maybe somebody can help me with. I somehow managed to break the main chassis at the front end.. If you take the front end of car off you see the two points where the front potion of the chassis attaches to the rest. It is here where it broke. Not sure if it was in a collision or when I was working on the front diff.. Anyways Kyosho lists the main chassis part as MB001..BUT this part ALSO comes with RC Unit 2.4GHz ASF/ICS PCB & Servo Unit Set and is listed at 169.99!! So I may end up with a 169.99 chassis! Crazy. Do you think I can buy this and sell the PCB and servo unit set?
Should I somehow contact Kyosho and see if they can just send me the Chassis? I have never dealt with Kyosho before. Should I call Kyosho America or elsewhere? I just need a main chassis! Thanks, sorry for the ramble, - Rob

kryten
2012.01.23, 10:06 AM
Calling them,or your nearest kyosho dealer can't hurt. You never know they may be able to sell you just the chassis piece you need.

billysnarf
2012.01.23, 12:31 PM
Just an FYI - I talked with Kyosho America this morning. They are releasing a new part # MB001-1 next month that will be the main chassis ONLY, not paired with the electronics. Good new for those who need a new chassis. In the mean time, i will attempt some sort of fix to get by.

nicov
2012.02.09, 04:46 AM
Hi Billysnarf,
same problem here - broken the buggy in 2 pieces :(
That's what happens when you start hitting the track seriously I guess...
I just ordered MB001-1 and MB003 parts for replacement.
The main chassis is now shipping from japan :o
So I should get the parts sometime next week.
Hope you'll fix yours as well !

billysnarf
2012.02.09, 10:03 AM
Nicov -sorry to hear, but i know how you feel. First of all I would like to know where you ordered the main chassis part from. As I could still use that part. For now though (I have 2 buggies) I think I have temporarily fixed my buggy that has broken. If you take the "front clip" off the car you see the front of the chassis connects the middle in 3 places. Two on each outside edge (either of these is where it breaks first) and one one connection in the middle. My buggy was broken on the outside and in the middle. One of the sides was still intact, therefore the whole chassis was not completely broken into two separate parts.. Hard to explain sorry. I took a piece of plastic and cut it into a square and mounted it to the bottom of the car using 4 screws. This piece acts as a brace that holds the front clip potion of the chassis to the rest. The car now works perfectly and the fix seems very strong. If I was not at work I would show pics.. ANYWAYS- I still would like a new chassis to fix it the right way.
Glad to hear you have the new part coming.

Tzei
2012.03.01, 01:04 AM
I have had Mini-Z Buggy now few months and Im disappointed to the chassis quality. Chassis is so weak that just minor crash to the wall and chassis is broken behind front tires. What should I do? Cannot find and upgrade part to solve this problem. Im tired to buy new chassis every week. First chassis I bought was with electronics and was damn expensive... If someone has solved this problem please help. Some pics maybe?

oXYnary
2012.03.01, 03:04 AM
I have had Mini-Z Buggy now few months and Im disappointed to the chassis quality. Chassis is so weak that just minor crash to the wall and chassis is broken behind front tires. What should I do? Cannot find and upgrade part to solve this problem. Im tired to buy new chassis every week. First chassis I bought was with electronics and was damn expensive... If someone has solved this problem please help. Some pics maybe?

What motor are you using? A mod? I have taken a few good hits to the front end without destroying it.

Are you using the wide front bumper from the optima? I found going to that helped lower front end damage.

Tzei
2012.03.01, 06:25 AM
I use just original stock motor. And my son drives buggy inside our house so you cannot avoid mild crashes to the wall but nothing bigger, just minor hit to the wall and chassis is broken again and this was not first time... :(

And yes... I use wider front bumper and it might help a little bit but not enough.

http://aijaa.com/003359677929

You can see picture

http://aijaa.com/003359677929

I don't know how to post picture better...

billysnarf
2012.03.01, 02:25 PM
YES. I agree, the chassis (for lack of better words) - sucks. I have broken 2. The wide bumper helps a little. Here is how I fixed one of them.. I used an extra battery cover and dremeled it.. Then 4 screws.. Had to drill 2 new holes behind the steering rack.. The car I fixed is on the right..

This fix has been excellent. no problems since.

gctkaz
2012.03.02, 08:58 PM
YES. I agree, the chassis (for lack of better words) - sucks. I have broken 2. The wide bumper helps a little. Here is how I fixed one of them.. I used an extra battery cover and dremeled it.. Then 4 screws.. Had to drill 2 new holes behind the steering rack.. The car I fixed is on the right..

This fix has been excellent. no problems since.
Thanks for your inspiration, today I also broke off my front end at the exact same spot while driving it around my house and crashed into a wall.

I could not find any suitable glue, but I braced it using a spare 2WD RM T-plate. It would probably be better to use the shorter MM T-plate, but I don't have any MM parts on hand. The silver screws I used were long-ish, so I kind of just prayed they would not interfere with anything, but both steering and drive seem to be fine. The black screws are the ones which attach the T-plate to the stock plastic 2WD motor mount, they have the same thread as the original counter-sunk screws and are a nice length for this brace.

Even though my upper cover got cracked on one side as well, this seems super strong now and I'm even hoping it will reduce the problem of the steering link popping off.

Even a brand-new unmodified chassis has a lot of upward flex in the front end, if you have the materials available, I would even suggest doing this to an unbroken chassis as it feels much stronger.

slobben
2012.04.23, 10:57 AM
Both my buddy and myself had the same problem with broken chassis on our buggies, and fixed it as suggested in this thread. We used the MZW205 (MR-015/02) Carbon Rear Suspension Plate Set, with the short screw included. So far it works like a charm, so thanks for the help!
It was less work than changing the whole chassis, and the chassis also looks and feels stronger than the original setup after this modification.

yamar6
2012.04.28, 11:12 PM
man thank god i read all the post before i spent over 300.00 on this buggy.What was kyosho thinking i love kyosho but my friends hobby store had losi truggy and both kyosho buggies i picked the losi truggy with the 2.4 brushless sytem and for a couple days beating it up outside with no problems.Hope kyosho up dates it because i would love to have one but for that much money come on.

slobben
2012.05.03, 04:51 PM
Actually managed to break the front top too...the plastic part with the kyosho logo covering steering. Fixed it with another modified carbon fiber brace, making a new screwmount and reusing the front right screwmount (together with the body-mount). Makes it even more solid. Even though its not pretty its hidden under the body.
On another note Ive upgraded to the atomic graphite shock stay set, solving another annoying issue with the buggy: The rear bodymount.
When you crash, the body has a tendency to fly off, especially if the rear mount is already weakened on the lexan end. The shock stay set comes with a better mount, problem solved. Together with their shock conversion kit it makes a great difference in handling and stability. Now I guess the wheel bases/dog bones will take more beating than the chassis-elements on landing jumps, will be interesting to see how well they take it.

Bodom
2013.02.25, 05:13 PM
I've had my buggy for a year. No serious driving or abuse. Home usage and two outdoor tests. I use old X Speed V motor from my MA-010.
A month ago I realized that it drives well on a smooth surface like hardwood floor or granite blocks floor (which are the usual playgrounds for it), but when it hits some terrain with more grip like carpet or my bed - the acceleration is slow and the motor revs up, but the transmission is slipping.
I've already managed to broke my chassis at the front some months ago of course :)
But now the damage was unexpected to me :eek:
It turned out that the slippery clutch has lost two of it's arms:
http://i447.photobucket.com/albums/qq194/Bodom_photos/Mini-Z%20Buggy/DSC_2837_zps52c85a59.jpg
This is glue with which I tried to fix it temporary.

And both front and rear diffs. slip :eek: and the reason is this:
http://i447.photobucket.com/albums/qq194/Bodom_photos/Mini-Z%20Buggy/DSC_2826_zps1389499f.jpg
http://i447.photobucket.com/albums/qq194/Bodom_photos/Mini-Z%20Buggy/DSC_2831_zps6fc62366.jpg

The other outdrive looks fine though:
http://i447.photobucket.com/albums/qq194/Bodom_photos/Mini-Z%20Buggy/DSC_2836_zps5039fdd7.jpg

My theory is that this happened because the outdrives are allowed to come out a little and thus having less surface to hold on to the outdrive's gear... :rolleyes:

I don't think I've put my buggy trough some serious driving.. And overall it disappoints me :)

Pierro
2013.03.02, 06:25 AM
Hi!

The three arms slipper comes from the factory it's absolutely normal.
You can reduce the number of arms if you want more slip or buy a full five arm version and set it up to your liking.

About the outdrives, there is a simple tric to avoid this once replace. Put a small o-ring, spring or rubber piece in the outdrive cup then put the dogbone on it. Ensure this isn't causing binding in the suspension and this will help you keeping the outdrive well-seated in the diff.

If you check the manual and the exploded view, you can spot those small o-rings on the rear side.

Bodom
2013.03.02, 05:40 PM
Hi!

The three arms slipper comes from the factory it's absolutely normal.
You can reduce the number of arms if you want more slip or buy a full five arm version and set it up to your liking.

About the outdrives, there is a simple tric to avoid this once replace. Put a small o-ring, spring or rubber piece in the outdrive cup then put the dogbone on it. Ensure this isn't causing binding in the suspension and this will help you keeping the outdrive well-seated in the diff.

If you check the manual and the exploded view, you can spot those small o-rings on the rear side.

Thanks for the reply.
The slippery clutch had five arms when it was new. I am sure about that :)
I know that I can set the slipping by removing arms.
As for the diffs - I have one small o-ring at one side of the rear diff. It is that way from the factory and maybe I've somehow managed to lost the other o-ring before I knew it was there. Your suggestion seems reasonable and I will find something appropriate to put in the outdrive cups. Thanks :cool:

Rune
2013.03.02, 06:37 PM
All the buggy's at our track came with 3 arms on the clutch out of the box.
5 arms gives almost no slipper effect at all. 3 arms works good on the hottest motors. 5 will most probably let something else give before the slipper.

Most racers here are using Kyosho ball diffs and ATM, PN and Kyosho cvd's or ATM alu dog bones. With these upgrades, coupled with the PN alu center shaft and pinions give a near bullet proof drivetrain.

briankstan
2014.03.26, 10:47 AM
has anyone tried the GF Main Chassis. (Kyosho number #MBW007).

this might be the ticket to the front end chassis issue (Kyosho #MBW033)

Description: Stiffer chassis for more performance. High response chassis for Mini-Z Buggy.

http://mini-zracer.com/forums/attachment.php?attachmentid=34174&stc=1&d=1395844821

They also have a under guard that spans the area on the bottom so it would act as an additional brace. (Kyosho #MBW033)

http://mini-zracer.com/forums/attachment.php?attachmentid=34175&stc=1&d=1395844821

KWT
2014.03.26, 09:19 PM
I have the GF Main Chassis and my son has already broken it in the front. he was just jumping the buggy off a card board ramp.

Pierro
2014.03.29, 06:39 AM
Hi!

I do use the new underguard with my buggy now. I never broke a chassis but someone at my club did. This underguard is a real nice addition if you have already switched to an aluminium tie rod. Cause the original plastic keeps popping out if you take a hit on the wheels and this underguard is screwed onto the chassis as opposed to the normal clip, so you'll have to unscrew it every time your tie-rod will pop out.

With this underguard and the alloy tie rod, I now have much faith in my front end and can race it more hard without worrying about the chassis issue.

gctkaz
2014.04.02, 11:49 AM
Pierro, you say you have more faith but did you actually test it from taking a few hits?

I would love to run my Buggy on track but having to retrieve the car to pop the tie rod back in every 5 laps is tiresome. If you can say with certainty that alloy tie rod + underguard effectively prevents the tie rod from popping out, then I will go make a purchase!

briankstan
2014.04.02, 12:57 PM
Pierro, you say you have more faith but did you actually test it from taking a few hits?

I would love to run my Buggy on track but having to retrieve the car to pop the tie rod back in every 5 laps is tiresome. If you can say with certainty that alloy tie rod + underguard effectively prevents the tie rod from popping out, then I will go make a purchase!

I have been running the aluminum tie rod on mine and haven't had it pop out since installing it. I did have the plastic one pop out a few times. I haven't switched to the under guard yet, but I have it and will be installing it. I have a pretty good main jump on my setup with the buggy traveling 30+ inches in the air and about 4ft or more in distance.

you can see it in my video here. https://www.youtube.com/watch?v=nVcGdyIauds

One of our guys did crack the chassis but was still working great with the under guard in place. He did end up changing the chassis but more for piece of mind than anything.

these little buggies are lots of fun. :D

Rune
2014.04.03, 07:55 AM
Alu tie-rod and some thick tape to limit absolute travel does the trick in regards of the bars popping of.

Pierro
2014.04.05, 08:06 PM
Pierro, you say you have more faith but did you actually test it from taking a few hits?

I would love to run my Buggy on track but having to retrieve the car to pop the tie rod back in every 5 laps is tiresome. If you can say with certainty that alloy tie rod + underguard effectively prevents the tie rod from popping out, then I will go make a purchase!

Hi!

Yes, I used my buggy on RCP track. Original set-up, if you take a hit, you get popped out. With the aluminium options, the front train is bullet proof. I didn't get any bar pop-out since the change. And I already got two race days with my buggy.

The underguard doesn't affect the direction problem, it solves the chassis weak point. But I wouldn't go for the underguard without the aluminium tie-rod because of the extra screws to remove to get the tie-rod back in place after it popped.

gctkaz
2014.06.17, 12:42 AM
Thanks Pierro,

With some reluctance I finally ordered the under guard and alloy tie rod set with some Paypal funds I had available. I must say I am quite impressed, the front end is much stiffer and I just had a bash with it around the house - something I had not done in a long time due to fear of breaking the chassis or top cover again.

I also got a set of foam inserts for the stock rubber tires which are now spares, because I got the Kyosho sponge tires - Unbelievable traction, I can drive this on dusty hardwood floors now and still have plenty of control, this has become an ideal basher with the upgrades. I haven't had this much fun with the Buggy in more than a year.

briankstan
2014.06.17, 10:22 AM
I have the Aluminum tie rod and the under guard and I haven't popped the tie rod off since installing it. I've taken some good front end shots and all is good. I did have the stock setup pop out quite a bit before changing it.

hope that give you more confidence in the change. :D