Durga Rear Diff Slip - Help

[VinceVegaUK 0]

Hi,

I have read up a few post's about getting the diffs right on the DB01 (durga) and so I took care in building mine (with slipper clutch). I haven’t even run it properly yet (just a gentle roll around the living room) and I can feel the rear diff slipping. I’m going to open it back up later today but before I built the diffs i did all the usual checks and held the diff on each side and tried to pull round the centre etc.. and all seamed in working order. If I hold both front wheels I can roll both rears without the spur moving surly this is not right. The slipper is not moving but neither is the spur and the rolling rubbing sound is clearly coming from the rear diff. If I spin one rear wheel the other doesn’t spin quite right. I popped of the wheel to get to the diff screw and its tight (maybe too tight) :-s

Any advise, could I have done something wrong, put something in the wrong way to cause this.

Any help would be much appreciated.

Many thanks

VV

[BUNGCHIDDI 0]

Im no expert when it comes to slipper clutches and i havnt seen one...only new to this too....but i think the diff is the same in the df03 as the db01..i have a df03.

Mines was slipping too and when i opened it i done the grip test too and it seemed fine but when i ran it it was slipping. I then opened up again and glued the matal plates to the outdrives using superglue...it says to use tamiya cemet on the manual. I missed this when i was building it.....also i have read on Ople.com that if you dont glue them they can strip the plastic edge off the outdrive...!

Dont know if you have done this or not....what do u mean when u said the other weheel does spin quite right. Ive always felt that the tightening of the diff is a little subjective...my tight and your tight may not be the same thing.

Are the ball bearings seated OK....is it defo the diff thats slipping...you dont have a slipping pinion or anything..?...u can open the gearbox back cover and roll the buggy backwards to visibly see if its slipping...u can on the df03 anyway should be the same on the db01...roll it backwards and the gearing is forced to the front of the gearbox cover so it stays in place and u can watch as you push it by hand..

P.

[VinceVegaUK 0]

I glued it with some Unibond repair extreame, its rubber based so should work ok, the front one is fine. when i turn one back wheel the other only moves sometimes, like its half working. If i hold the front wheels roll both rear wheels i just hear it slip and the spur, pinion, slipper and belt doesn't move. Im openinng it up in a few minutes so will see what is wrong. I did put the spring and screw in the wrong way the 1st time i put it together, then i swapped it around so maybe i missed something then :-s.

As you said, i dont want to go melting my diff with 5.5 brushless in it :-p

[VinceVegaUK 0]

Looks like its fixed, need to test it propper when i have a painted shell to give it its first run but the diff doesnt slip. A big panic over nothing, i just re built the diff and all seams good, i didnt note if i had it in wrong i just took it to bits and started again.

I just didnt want to ruin my 30th birthday gift :-p before i even got it off the starting grid.

Can't wait for my custom painted shell, then off to Southport i go :-)

[Ian_P 0]

hi everyone

got a db-01 on the way and have seen a few threads like this one about the rear diff. What glue should i be using to ensure the diff plates(?) are held down firmly, some things seemed to suggest super glue? if not what exactly is "rubber cement" can anyone suggest some brands / places to buy?

Also, reading up on the build seems to be a few complaints about the difficulty of getting screws into the chassis in the first place. Is the hex head set an absolute must? if so, anyone know of a good place in the uk to pick one up?

Finally - i haven't ordered the slipper clutch just yet as i like to run things first and then get to appreciate the difference the hop-ups make. Is this a really bad idea? I'm only going to be running warm-ish brushed motors for now, so is it ok to skip the slipper for now?

[VinceVegaUK 0]

hi everyone

got a db-01 on the way and have seen a few threads like this one about the rear diff. What glue should i be using to ensure the diff plates(?) are held down firmly, some things seemed to suggest super glue? if not what exactly is "rubber cement" can anyone suggest some brands / places to buy?

Also, reading up on the build seems to be a few complaints about the difficulty of getting screws into the chassis in the first place. Is the hex head set an absolute must? if so, anyone know of a good place in the uk to pick one up?

Finally - i haven't ordered the slipper clutch just yet as i like to run things first and then get to appreciate the difference the hop-ups make. Is this a really bad idea? I'm only going to be running warm-ish brushed motors for now, so is it ok to skip the slipper for now?

I used Unibond Extreme all purpose glue (B&Q), Its better to use a Vulcanizing Rubber Glue/cement (as per instruction) than Super Glue. Super Glue is too brittle and also doesn't like heat or grease over time it will lose its stick or crack. Rubber cement is more flexible and gives a better longer lasting hold. You can run fine without a slipper but it does save the drive train if you do. Brushless offers more Torque so you would need it for that more so. The reason a slipper helps is that being a buggy you tend to have only a few or even one wheel in contact with the ground as you bounce and jump over rough terrain, if your on the throttle you can put excess stress through the drive train, over time it will just wear quicker.

I did use the titanium hex set but got it for £20 from a friend, even then i nearly stripped them using tempered steal hex screws. Once there in however you have created a thread and they go in and out a lot easier. I used a small drop of ceramic grease on the tip of each screw as i put it in. If you use the stock screws just make sure you have a good fitting screw head and a good hand grip so you don't let the head slip off the screw and you will be fine.

Im running it with a 5.5 EzRun burshless set with slipper and front universal shafts which i would recommend. I use Vellrip for my HopUps he offers a good price and ships from Singapore within the week.

Have fun and post if you need any more help

Later

VV

[Ian_P 0]

I used Unibond Extreme all purpose glue (B&Q), Its better to use a Vulcanizing Rubber Glue/cement (as per instruction) than Super Glue. Super Glue is too brittle and also doesn't like heat or grease over time it will lose its stick or crack. Rubber cement is more flexible and gives a better longer lasting hold. You can run fine without a slipper but it does save the drive train if you do. Brushless offers more Torque so you would need it for that more so. The reason a slipper helps is that being a buggy you tend to have only a few or even one wheel in contact with the ground as you bounce and jump over rough terrain, if your on the throttle you can put excess stress through the drive train, over time it will just wear quicker.

I did use the titanium hex set but got it for £20 from a friend, even then i nearly stripped them using tempered steal hex screws. Once there in however you have created a thread and they go in and out a lot easier. I used a small drop of ceramic grease on the tip of each screw as i put it in. If you use the stock screws just make sure you have a good fitting screw head and a good hand grip so you don't let the head slip off the screw and you will be fine.

Im running it with a 5.5 EzRun burshless set with slipper and front universal shafts which i would recommend. I use Vellrip for my HopUps he offers a good price and ships from Singapore within the week.

Have fun and post if you need any more help

Later

VV

Thanks for the advice, gave it a go with the standard screws and a good driver was fine - guess i'd just read too many horror stories. Screws didn't half get warm going in though

[VinceVegaUK 0]

Thanks for the advice, gave it a go with the standard screws and a good driver was fine - guess i'd just read too many horror stories. Screws didn't half get warm going in though

Glad to help, hope you have fun, i haven't given mine a good run yet i'm waiting on a friend to paint my shell, should get it on thursday :-)

What did you glue the Diff plates on with?

[Ian_P 0]

Glad to help, hope you have fun, i haven't given mine a good run yet i'm waiting on a friend to paint my shell, should get it on thursday :-)

What did you glue the Diff plates on with?

Not got round to that yet - couldn't find the glue you mentioned this weekend or anything similar for that matter, but ordered some online so should be here tomorrow.

[dimblum 1]

It's best to replace the DB-01 diff joint assembly with the 501X aluminum diff joints (or the 3Racing aluminum diff joints - less expensive). It eliminates all the concern about the diff rings coming loose since they are not glued when you use the aluminum joints.

I have been club racing a Durga with the 501X diff joints for about a year.. They are excellent.

[94eg! 834]

501X & 3-racing diff joints are steel...

Kit setup can/will be fine if built with proper glue...

[VinceVegaUK 0]

501X & 3-racing diff joints are steel...

Kit setup can/will be fine if built with proper glue...

Just to add I have now ran the car twice at high speed across grass, and also ran in a 4 heat 1 final race meet at bury and the diffs work perfectly. I needed to tighten them again after the first test run on grass. I carefully tightened them till they where fully tight (don’t force it though) and then made one full rotation back. You should be able to feel the diff rolling but both wheels should run in opposite detections and not cause the spur to move (a little movement is ok usually when you rotate the wheels back an forth quickly) if you freely spin the wheels it should roll around about 2/3 the way until the diff friction stops it. If you rotate one wheel and the other doesn’t move the diff is too lose, if you rotate the wheel and the other moves in the same direction the diff is too tight. Once bedded in they should stay as they are for quite some time. I would highly recommend not using super glue but use Unibond Extreme all purpose glue or similar but make sure its safe on plastic. If your unsure test a little on a spare piece and make sure its doesn't melt or deform the plastic.

Thanks

VV

[94eg! 834]

...if you rotate the wheel and the other moves in the same direction the diff is too tight....

With brushless motors it's not this simple. The motors have almost no internal cogging, so you get zero resistance from the pinion. No matter how you set the diff, both tires will spin in the same direction.

There are other ways to check for proper diff tighteness, but it mostly comes down to experience. Don't be affraid to ruin your car. Everything is replacable...

[stu22 12]

Setting a diff is more a matter of personal preference, it's not an exact science. I did notice that Tamiya put nothing in the assembly manual when I put my DB01 together which did suprise me. As a starting point I would suggest backing off half a turn from fully compressed and experiment with a quarter turn in each direction until you find what you like. Personally I run my rear diff tighter than most and use a one way up front.

[94eg! 834]

Tamiya instructs you to tighten the diff until you can no longer slip the pulley by hand with both out-drives locked. It's clearly described in step 3 of the DB01 instructions. This is a very effective way to find your diffs minimum tension setting. Also keep in mind that a new diff will require some readjustment after a few break-in runs.

Tightening the diff fully to start is not the best idea cause it causes the spring to loose quite a bit tension. It is only meant to be fully compressed for a moment (just before install). A good starting point would be to run the rear diff as loose as you can without the pulley slipping. Then run the front one just a little tighter.

[VinceVegaUK 0]

With brushless motors it's not this simple. The motors have almost no internal cogging, so you get zero resistance from the pinion. No matter how you set the diff, both tires will spin in the same direction.

There are other ways to check for proper diff tighteness, but it mostly comes down to experience. Don't be affraid to ruin your car. Everything is replacable...

You are right but you can hold the spur or slipper nut to stop this!

As mentioned the instructions tell you to tighten the diff then hold the two diff cups (using a ruler or hex key in the diff slots) and try and rotate the pulley by hand, this will set its first point but after a run or too it will loosen, I also clamp both front wheels with my inner elbow and rotate the rears (and vice versa), if it slips its still too lose, there is more leverage this way so do it firmly but not too hard. There is a minimum set point and from there you can tighten the diff more and more to a point, obviously don't over tighten it. the diff spring should work fine even if you do tighten it fully and then back off, its a sping! it will spring back just like the slipper clutch spring. it may become less springy if done too often but these parts are readily available.

In tightening the diff you can adjust the way the car handles. A tighter front diff gives you less turn in but more drive out of a corner, a tighter rear diff gives you more turn in but usually more over steer when entering and exiting a corner. To put this to the extreme a locked type of front diff can be set up using a spool or front one way.

As you probably know the diff controls the rotation of the drive and wheels so if the inside wheel can rotate slower than the outside you get less slip and more turn in, if the inside wheel is restricted and can only rotate slightly slower or at the same speed as the outside wheel you get more slip and less turn in but more power can be put though the wheels giving you better corner and straight line speed until you brake traction by putting on too much juice.

Diff set up is preference in one way but also needs to be at a point where it is always working to stop any damage. As you mentioned though, don't stress too much new diff parts can always be replaced its all a learning process and part of the hobby and diffs do wear/break as they are under a alot of stress.

Good luck

Later

VV

lol, just read the post back and realised i have learned a lot since building my durga and rebuilding my TA05 diffs