Df03 Diff Tightening

[BUNGCHIDDI]

Lads - how tight is tight...this is a tad subjective - any help is appreciated.

I tightened and it felt fairly tight..so the manual states not too tight so i backed off...then the small screw just came loose...so im, thinking i was way to loose - my version of tight is probably not very..?

Any clues..?

[BUNGCHIDDI]

also...im in work at the moment so excuse my memory but can i just unscrew the that back plastic gearbox plate behind the rear bumper and pull the diff right out without striping the whole buggy down..?

[terry.sc]

You need to tighten the diff enough that you can't turn the gear while holding the two diff outdrives, to make sure it doesn't slip. How to hold the diff outdrives is shown in the manual and it's this section:

It can be a bit tricky, but I find putting a large flat screwdriver in each slot you can then hold them in one hand while trying to turn the gear. If you can turn the gear at all you need to tighten the diff a bit more and try again.

The diff access hatch is there so it's easy to pop the diff out for rebuilds.

[TA-Mark]

You don't need to remove the diff centre to adjust the hex screw. Just pop the shock off and the upper link at the knuckle (slipper clutch side). Remove the dogbone/CVD driveshaft from the outdrive and remove the dust pads from the outdrive. You can now adjust it in the gearbox. Enough of the hex screw thread needs to come out of the nut on the other side for the nylon in the nut to lock it in place to stop it undoing again.

It certainly won't hurt to remove it and give it a complete check over and regrease.

[BUNGCHIDDI]

cheers lads.....am gonna have your heads done in with this df03...!

[BUNGCHIDDI]

OK CHECKED IT OUT - everything was spot on...couldnt spin the gear when clamping both drive shaft ends...handy being able to pop it out the back like that.

Anyway my Pinions arrived also so i ran the recommended 23T (was running kit 26T) and moved to the larger 85T Spur (was running the 78T)...and the buggy didnt perform well at all..??

The top end speed was slower...accelaration looked pretty much the same as 26/78T. Im confused now, dont know what i was expecting from the DF03 but my old HS2 was/is a better, faster drive - which is strange given the 20 gaps between them.

Also when i took the battery out (1900mAh) is was HOT...i mean pretty HOT...maybe thats because it cant breath in the DF03 compared with the HS2's open battery compartment...almost like it was having to work hard. The motor was hot too...hotter than ive felt it in the HS2 - maybe again because its snugged up in the DF03.

So - i took the pinion off to see how the buggy rolls to see if there was anything hindering the motion...but it rolled perfectly...just as well as my HS2 (which currently has no motor in it)...so now im really confused, so the DF03 has the same no friction roll as the HS2...but when i run it ..its not as fast and the battery heats up alot. The top end speed is defo down from the 26/78T set up...alomost boring to drive...but the 26/78T setup had no punch from start...?

Maybe i was just exepecting to much...i think i was hoping to install my HS2's electrics and have a slighly faster, responsive buggy...it hasnt happened. Anyone else seen this...?

Any feedback would be really appreciated..

[TA-Mark]

23/85 is the sort of gearing you use when you fit a 5700Kv brushless. With this gearing it should very quickly accelerate to full speed (which is quite slow) and feel like it is trying to go faster but the motor just won't rev any higher. With the standard gearing it should seem as though the motor never fully revs out. (This is all while driving and the motor under load... not held in the air and spin up the wheels).

23T or 25T pinion with the 82T spur. 82T spur comes with the slipper clutch set or with the DF-03 MS kit.

How tight is your pinion/spur gear mesh? Did you use a piece of paper to set the gap? Too tight will load everything right up, heating up the motor and battery.

1900mAh pack will run hot with any high amp draw motor, especially brushless. Brushless will kill a Ni-Cd pack in a short time.

For your comparison:

Standard 26/78 is a 9.17:1 FDR (final drive ratio)

23/85 is an 11.29:1 FDR

23/82 is a 10.89:1 FDR

and 25/82 is a 10.02:1 FDR

You should be able to see how 26/78 is too tall, 23/85 too short, and the other 2 are in the middle. It is possible that you have damaged the motor or pack by running it very overgeared and causing it to get very hot (Kills cells and melts the balancing resin in the motor).

[BUNGCHIDDI]

fantastic - hopefully not..!

I dont think my pinion to spur was too tight...but then again im no expert, how do u test with paper...?

I just loosened the motor and moved it over untill the gears meshed..?

My 1900maH pack never ran than hot in my HS2...which i had been running since jan.

I ran the df03 for ~10mins at the 26/78T...first trial after build, then i ran it for ~10mins on the 23/85T......dont remember the pack being hot after the first run of 26/78T - if this is enough to damage both battery and motor then im hosed.

Id like to check the mesh...whats the procedure..i mush have missed that part during the build..?

[TA-Mark]

Single thickness of paper, put it between the pinion and spur, slide the motor up so it bites the paper into the teeth of the gears, tighten the motor screws, wind the paper out by rotating the spur.

When set like this you should now be able to see a small gap between the teeth and should be able to hold the pinion still with one hand and rock the spur very slightly (the amount of the gap) with the other hand.

If you watch this .gif you will see that only 1 side of each tooth touches and there is a gap on the backside. The paper sets this gap distance.

Any tighter than this will drag on the previous tooth and wear the shoulder off the tooth and load up the motor.

[BUNGCHIDDI]

where do u get these diagrams..lol

Explained it well tho - ill give this a whirl......in your opinion...would u expect the DF03 to be slighly quicker or at least the same as a Hotshot with the same electrics..?

Forgot to say the DF03 did sound louder with the new gears..?...but ther is just no freewheel when you push it (with motor in place) compared to the HS2..i could push this an it travelled a bit..the DF03 gets a push then stops pretty dead....i started thinking my motor was dead or restricted...like if i hold it up in my hand and throttle it forward the wheels spin then just die when i stop it...whereas the HS would have had a certain amount of afterspin doing the same test.

Given the fact that i rolled both chasis with no motor and they are the same then its the motor is beat now or your gear mesh theory....suppose i could stick the corally back in the HS2 to see if it freewheels..this would rue out motor a a source of restriction.

Cheers mark.

[BUNGCHIDDI]

by the way...forgot to ask....again...can the rear suspension by hardened up any - even at small jumps its hitting the ground.

[TA-Mark]

Wind the pre tension down to about 20mm from the top (or use spacers on the black CVA dampers). Use 2 hole white piston with #500 wt oil, gold spring in the alloy dampers (1 hole black piston with #500 wt oil in black CVAs). Move the damper to the inner most hole on the lower arm and outer most hole on the tower (stand the damper up straighter to make it harder and offer more ride height). Take note of where the dogbones sit in the outdrive cups when modifying ride height. Too much and the dogbones fall out as the dogbone is not parallel to the lower arm. The rear of a DF03 is slightly heavier than the front and needs a harder spring/damper tune.

In standard trim, both with a 540 silvercan and TEU101BK ESC, I would expect the vintage to be slightly faster as it's FDR is taller. The HS2 would not be able to use the same motors as the newer chassis due to gearing combination restrictions. Ideally they should be geared to go the same speed with the same motor and battery.

What you describe is either a jammed bearing in the motor or too tight gear mesh. If the motor spins freely in you fingers when out of the vehicle it's not the motor.

[WW-nut]

TA-Mark,

I'm amazed on how technical it is to set up a car - and the amount of knowledge you and other forum contributers have regarding setting up cars - there's definitely an art to it. Using a piece of paper to set up the gap between the pinion and spur Guess you must have been racing r/c's for a long time. I assume gone are the days people winning races with fresh out of the box cars.

Anyway, back to the thread........

Nige

[BUNGCHIDDI]

Agree totally WW-Nut....am bleedin their brains dry - very handy tho. No one near me knows or owns a car so Id have no one to ask.

This forum with its many members is a must for someone like me - just getting back to the hobby, the amount of info ive gained in a short space of time.....

Ill strighten up the dampers mark cheers - ill pull the motor out at lunch time and see how it spins.

[TA-Mark]

TA-Mark,

I'm amazed on how technical it is to set up a car - and the amount of knowledge you and other forum contributers have regarding setting up cars - there's definitely an art to it. Using a piece of paper to set up the gap between the pinion and spur Guess you must have been racing r/c's for a long time. I assume gone are the days people winning races with fresh out of the box cars.

Anyway, back to the thread........

Nige

Helps when you have done this to 1:1 cars since you could first see over the dash to drive one (age 12 I bought my first car), and you are a qualified motor mechanic for 1:1's (retired since my accident). Good memory for all the figures you need to remember helps too. READ EVERYTHING! lol Heading off to a race meet with other drivers is a very steep learning curve as there is so much they can teach a beginner.

I probably drive my RCs the most from anyone here on this forum. Run 8 packs today and 7 yesterday, nearly all track practice. I'm quite upset if I don't get to atleast squeeze 1 pack off a day. I even drive the F-350 to get the mail from the Post Office... eccentric I know... LOL!

Winning races is not so much who has the faster car. When the class is evenly matched it all comes down to suspension/gearing tune and driver ability. A good driver with a poor car will win against a poor driver with the best car you can buy most times.

[Brett74]

Mark, just a quickie! i keep breaking a and b parts where the lower arms attch. any ideas? thanks

[TA-Mark]

Mark, just a quickie! i keep breaking a and b parts where the lower arms attch. any ideas? thanks

GPM #DF3008: Alloy Front Gear Box Lower Mount With Screws (from asiatees.com). 2 of the screws are too long and need 1mm filed from them in this set. Stops the hinges breaking off the front gearbox mount. This will move the stresses of a crash to the tub however, breaking the tub where it mounts to the front diff. I'm quite impressed with the quality of all the DF-03 GPM parts I have. Only things I did not get are the lower arms and damper towers (Oh... I don't have body mounts either, velcro full length of the tub at the sides to hold the body on).

The other way is to slow down a bit and stop crashing (sorry couldn't resist that). LMAO

[Brett74]

GPM #DF3008: Alloy Front Gear Box Lower Mount With Screws (from asiatees.com). 2 of the screws are too long and need 1mm filed from them in this set. Stops the hinges breaking off the front gearbox mount. This will move the stresses of a crash to the tub however, breaking the tub where it mounts to the front diff. I'm quite impressed with the quality of all the DF-03 GPM parts I have. Only things I did not get are the lower arms and damper towers (Oh... I don't have body mounts either, velcro full length of the tub at the sides to hold the body on).

The other way is to slow down a bit and stop crashing (sorry couldn't resist that). LMAO

LMOA!!!!!! Cheers!!!

[4towing]

GPM #DF3008: Alloy Front Gear Box Lower Mount With Screws (from asiatees.com). 2 of the screws are too long and need 1mm filed from them in this set. Stops the hinges breaking off the front gearbox mount. This will move the stresses of a crash to the tub however, breaking the tub where it mounts to the front diff.

I can support this theory. Having upgraded to Alloy front gearbox lower mount following break of the plastic one, my son's friend's lack of control caused this...........

Fortunately a spare chassis was quickly sourced from Time Tunnel, and I had the satisfaction of completing a quick rebuild.

[terry.sc]

The other way is to slow down a bit and stop crashing (sorry couldn't resist that). LMAO

Best bit of advice that, the best way to stop breaking your car is to improve your driving so you stop hitting things.

As 4towing has found out it's better to leave a plastic wishbone mount on there so in a very hard impact you break the mount. Upgrade to an alloy one and you break a chassis instead.

[BUNGCHIDDI]

Just a quick one to say i found the problem....when i removed the shell i found a fairly large grove worn inn the 4wd shaft....must have wedged the battery clip on to it when i put the shell on after the gear change...hadnt noticed it the last time...also did the paper gear mesh set-up..

This explains the temps in motor battery...when resolved the temps never got that high again.

Jobs a goodin...shes running like the old HS2...if not better. - in my opinion theres too much stuff wedged into the RHS of the DF03....id like to locate the ESC opn the other side so the 4wd transfer shaft is not in the way of anything plugable.

I thinks its time for me to get a new battery and charger,.....im using my 20 year old acoms trickle charger...and the green light never comes on when charging my 1900mAh pack....so i dont think ive ever ran it fully charged....plus its taking ~24 hours to charge up..!!

double the capacity with an hours charging time would be a dream.

[HereBeMonsters]

Just a quick one to say i found the problem....when i removed the shell i found a fairly large grove worn inn the 4wd shaft....must have wedged the battery clip on to it when i put the shell on after the gear change...

This keeps happening to me too. Almost wore through a battery wire with the centre driveshaft. Don't know what can be done about it, as that's the only place for the connector to go...

[TA-Mark]

This keeps happening to me too. Almost wore through a battery wire with the centre driveshaft. Don't know what can be done about it, as that's the only place for the connector to go...

Have a look at my chassis pictures. What I do is coil about 2/3 of the wire inside the battery bay (it's a tight squeeze) and come out the hole under the driveshaft. There is no where it can rub then. Coming over the top of the driveshaft with a motor/battery wire is asking for it to get damaged as the body pinches it down.

[BUNGCHIDDI]

excuse my ignorance ....but whats those blue bars hangin out over the motor on the far side there...also you have done what i was getting...putting some of the gear on the other side (your RX) this gives more room around the battery contacts...my rHS is busy with wires, RX & ESC.....might just do what youve done.

[TA-Mark]

The blue bars on the motor plate is the heatsink bar set. I actually have them on backwards so they are out where air can pass over them.

This layout fits everything on the one side if your RX is too large to fit infront of the servo:

The battery wire still exits the battery compartment in the same location.