malice23

You know, I took my whole drivetrain apart last night and realized a few things. I thought my clutch was not set right but that wasnt at fault. The layshaft I thought was bent so I ordered a new clutch set just to see if it would fix the problem. It still moves in a wobbly way which would cause the pinion to strip the spur in an instant. I took the clutch apart again and saw that one of my pulleys melted...the outer one that holds the front belt. I ordered the center one-way being that it is aluminum to prevent the heat build up Im getting from the plastic ones. I hope this might help because maybe the pulley is at fault? I really dont know what the problem could be for the layshaft to be moving in a crooked manner. Any help is appreciated thanks!

ElectricGuy007

I have never seen a pulley look like that. Geez, you seered off all the teeth on it.[X(]
You must have too much power in your durga. Let me guess a Velion and 3s Lipo. Yep
that would cause that for sure. Better go to a 2s lipo. LOL

dimblum

It sounds like your bearings are at fault or the bearing slots on the chassis tub that holds the whole assembly in place. If the bearings are damaged or warped, then there is no way the bearings can keep the layshaft level.. Besides the bearings, you will also want to check the bearing slots for any plastic burrs or dirt that might have built up in the slots to make the layshaft mis-align.

Cheap bearings are -very bad- for the DB-01, especially if you plan to use a high-speed brushless motor. High quality bearings make a "huge" difference. I would not have thought so myself until I invested in some.. I was able to attain a noticeable improvement in acceleration and a slight improvement in top speed by changing nothing but my bearings.

Hope this helps.

dimblum

It sounds like your bearings are at fault or the bearing slots on the chassis tub that holds the whole assembly in place. If the bearings are damaged or warped, then there is no way the bearings can keep the layshaft level.. Besides the bearings, you will also want to check the bearing slots for any plastic burrs or dirt that might have built up in the slots to make the layshaft mis-align.

Cheap bearings are -very bad- for the DB-01, especially if you plan to use a high-speed brushless motor. High quality bearings make a "huge" difference. I would not have thought so myself until I invested in some.. I was able to attain a noticeable improvement in acceleration and a slight improvement in top speed by changing nothing but my bearings.

Hope this helps.

malice23

Nope...the bearings aret he best money can buy...boca ceramic bearings yellow seal...also I tried using the stock bearings and no difference...I think its the motor mount from 3racing...Im going to try swapping it for the stock mount or at least put the whole assemply on the stock mount and see if it spins straight...if thats the issue then its a faulty mount. It cant be a bent layshaft 2wice I just got and installed a new clutch set and my assembly is spot on so I dont see why it should be spinning like that.

dimblum

Your right, it's got to be the motor mount 100%. The stock mount is still great and should solve your problems.. The Tamiya one is excellent, but dang if it isn't -way- overpriced.. I bit the bullet and bought one a while ago since it improves the cooling a little.. I would not say it helps cooling that much, so it's kind of hard to substantiate the price unless you are going for bling.

Good luck with changing out the motor mount. I am sure you are right.

malice23

I know it is real expensive and the tamiya version is very over priced...I may use the kit one...whaever nasty material that is lol and see how it goes...first thing after work today Im going to go check and see how it rolls on the stock mount. Il let you know and its a real shame cuz Ive barely ever driven it. SOOOOOOO disapointed.

ElectricGuy007

People have said to me to avoid anything from 3racing, especially the shocks.
If you have to get an aluminum mount for your motor it might be better to get the tamiya one.
Strange that you didnt notice a difference no matter what type of bearing you used.
Dimblum dont snap at me but I use the Acer bearings in my 501x, I shaved
a couple seconds off my lap times so yes it barley improves it. The only
thing good about ceramic bearings is no oiling ever, just install them and leave them.

If I can beat my old B44 lap times with the 501x this year I'll be a happy camper.[>:]
Just got to learn to drive smooth.

I'll probably do the swap trick and run one car one week and the other the next.
Either that or run the cheaper car on the club circuit and the big boy car on trophy races.
There is 1 trophy race for sure that is around thanksgiving. IL State Shootout.

Tilux

Im not sure, got the shock today, would the included oil do it? It only say soft.

dimblum

Ha, no worries about the Acer bearings.. I was bashing the company's marketing strategy - not the people that use them.. For the most part I thought is was silly that Acer didn't openly provide tech specs for their products..

To be honest, I have been really interested to get feedback from someone that has used them.. Sounds like they are on-par with the Boca Bearings.. Does Acer use grease to seal their ceramic bearings [sealed for life - no need to ever clean or oil them]?

malice23

Dimblum...seems I found the problem upon futher inspection...The center diff cover has 2 grooves that hold the 2 bearings down...the mamba seems to have grinded one of those grooves to the point where they it didnt hold it down anymore...also the 3 racing motor mount was grinded down to the point where it wasnt even blue anymore...At this point I think the stock motor mount is the way to go as it looks strong and is pretty much the same weight. I ordered a center one way bearing because my stock pulley melted on to the shaft and the center one way is made of aluminum whcih is better for high powered motors. Cant wait to get this thing together again...What would cause the the diff groove to grind down though? Is that mamba too much motor for the durga? I swear that motor destroys every kit ive put it in to. I have also installed the atomic carbon towers and they are super tough...real thick and they look really high quality. Cant wait to get this thing going already. Im just pissed that my carbon reinforced diff cover is destroyed.

dimblum

Malice,

Thanks for the update.. One thing I can guarantee is that the Mamba is -not- too much motor for the Durga.. The Durga can easily take the fastest motors on the market without any problems.. I have been running a Novak Ballistic 6.5T brushless for some time now and it has not worn down my parts any more than a stock silver can motor would.

Normally the motor mount and diff cover grooves could not be worn down unless the bearings were to slip while the car is running.. The screws holding the diff cover would have to be pretty loose to allow that to happen and/or some oil may have gotten into the grooves causing slippage.. This is very unlikely..

A better explanation would be that there was already a flaw with the grooves on the motor mount (one was machined deeper than the other) forcing the layshaft to mount slightly off axis. This would cause excessive force against the inside rings on your bearings forcing them to slip and grind away at the mounts. If that layshaft was pushing at an angle while the grooves were trying to hold the bearings straight, then I could see all the problems occurring that you have described.


I think you will find everything to be in working order once it is rebuilt with the stock motor mount. Just to be on the safe side, you may want to rotate the bearings with your finger to make sure they were not torqued or warped in the process.. Also, you might want to check the shaft on your Mamba Max.. If that got bent, then the problems might repeat themselves.

Good luck. Please let me know how everything is working once it is rebuilt.

ElectricGuy007

After further inspection yes they have that grease in them. The Boca Bearings I'll try sometime too.
Like to get them for my B44, that a way both cars will have ceramic bearings. My whole plan
was to have a belt drive and shaft drive 4wd, to experiment with both platforms.
But it would be nice to have one with a different driving feel to it than the other one.
That's why I have one setup with a front one way and the other with a standard diff.
My 501x is very quiet compared to my B44, and that is partically due to being belt drive.

malice23

DIMBLUM...repairs have finished and the fun has begun lol. I finally finished installing new pulleys, the stock motor mount and the new center gear box cover and clutch set. I was even anal enough to go through all my diffs re-grease them and make sure they were all still in good shape. It is now 2:20 am (NYC) AND I ran 2 batteries through her to make sure all is well. I was also dying to drive it for weeks now since the incident with the 4 spur gears but it looks to be solved now. Previously I couldnt finish one battery due to the spur stripping but now everything looks good and its ready to go. I ordered the center one way and will install it when I get a chance...whats the advantage of running that part?

The Atomic Carbon shock towers are real strong and thick as hell. You were 100% right about them. Also the noticeable difference in handling was well worth the money spent. I also did the 35wt up front and the 30 wt in the rear like you recommended and Im running the stock tires for now. I was on pavement and boy do those tires grip on that surface and they still have life left in them. Must be really hard compound. I went full speed down the street to an intersection that I was standing at and popped a 90 degree turn and this thing did not even flinch! just skidded sideways slightly and took it like nothing! Mind you its a mamba 7700 so that is pretty incredible. Only thing that bothers me is that my motor is running kinda hot. I have vents cut out as well as a fan installed on the esc. I dont know what else to do for cooling. The heat sink on the bottom of the carbon chassis is doing its thing too I guess but its still running hot. The timing is set at its lowest setting and Im running the smaller pinion, 17t? I guess theres not much you can do the mambs probably just drains those batteries. Theyre all LIPO 7.4v 4000mah 20c batteries from Intellect. BUT...as long as Im not having those other weird issues I was having, a hot motor is a welcome "problem" lol.

All in all she works great and Im very satisfied, couldnt ask for more...now I gotta bring her to the track and kick some A-S-S.

crusadores

Hello malice23!

I am happy everything worked out well! May i ask what your average run times with the 4000mah LiPo are?
There is no plan to switch to LiPo anytime soon, but i would like to compare, so i can build a case pro or against
LiPo. Right now their "exploding" attitude is a deterrent ...


Hey dimblum,

Could you please comment on the following items:

JConcepts Bar Codes 2.2 Front Buggy Tires (Gold) (2) (JCI3017-05)
Pro-Line Bow Tie M3 2.2" Rear Buggy Tires (2) (PRO8186-02)
HPI 35mm Ultra 7 Rear Wheels (Black) (2) (HPI100625)
HPI 30mm Ultra 7 Front Wheels (Black) (2) (HPI100624)

... on the tobee hex conversion....

I may buy these from a guy who owns a HPI Brama. At the moment i am trying to test as many combinations of
wheel-tire, although the Bar Codes and (especially Bow Tie) seem to be the best for the trackwhere the next ELME
race is going to take place (hard packed with small patches of loose dirt and lots of hairpin corners)

Stef

Eman77

malice - what temps are you getting on the ESC/motor?

malice23

After I ran her I sat her down for a few mins and the esc read 112 degrees and the motor read 143 degrees. The esc has a fan so Obviously that would cool better.

malice23

My fellow Greek lol, how are you doing with all the fires? haha Unless You decide to drive your car through the fires the lipo wont blow up so dont worry. Ive been running lipos for a long time and I never had an issue with any of them. None blew up ever. Unless you have one of those old chargers that doesnt detect when a battery is fully charged, then u have to worry. But any of the new chargers, I have the duratrax ice charger, will do the job fine. They take quite a while longer to charge but the performance is well worth it. More power, waaaaay longer runtimes and when theyre done they just stop, none of that slow dying power b.s. like in NIMH packs when they are about to die. NIMH is outdated...come over to the darkside my firend.

Eman77

To be honest, seeing 140F after bashing wouldn't bother me. From what I recall, castle says something like under 180 F is fine (check their site to verify). Given how the Durga is laid out wrt cooling on that motor, I don' think there's much else you can do. It's not like you can cram a fan on top of that motor and have it fit, since the body sits right on top of it as it is.

Now, if I saw 140F on a 27T brushed motor, I might wonder what's up. But on a 7700 Mamba, I say it's ok as is. Your ESC temp sounds pretty nice too.

Do you have a heatsink on the motor? You can fit that, at least.

malice23

I run the carbon reinforced chassis which has a cutout at the bottom where the motor fits. You have to buy the aluminum plate that fits in the cut-out and the motor sits right on top of that plate and acts as a heat sink. On a side note...some guy was walking his dog that last night and I didnt see him crossing the street and i wizzed by him at warp speed and he was like "ok what was that?" and i showed him and hes like ok where do i get 1?! lol. So it looks like I got some1 into the db01. Afew pages back I have photos of my durga but without the vents. You gusy should check them out!

malice23

here u go guys, this is before I made the vent cut-outs and before I added the atmoic carbon shock towers. For some reason I cant view them full size but if you guys want bigger pics go to page 35 of the forum.

dimblum

This is great news! Really happy to hear that your Durga is back in shape

Ahh yes, a center-one-way.. I've done a few write-ups on them in the past to explain their function in detail (a front one-way works differently than a center one-way).. I think my write up is still in this forum thread somewhere. I'll do a search once this message is posted.

In the meantime, here is the short version on what the center-one-way will do: Your Durga will gain the benefits of both a 2WD and 4WD at the same time.. The one-way will allow your front tires to 'free spin' in a forward direction only (mostly when you are off the throttle). This will do two things - you will have better steering grip from the front (because the tire on the outside of a turn can now spin more than the inside tire) and it will help your car when landing a jump (less shock to the drive-train and smoother landings)..

The center-one-way still leaves your front diff fully operational, so the diff action will still be in play in case you run your Durga off-road

The Durga will only break with the 'rear tires' once the one-way is installed.. 2WD breaking seems to have a similar effect to 4WD breaking, so it should not be an inconvenience.


Yup, the stock tires use a stiff medium compound which is OK for the street.. Most of the grip is coming from the mini pins, which unfortunately can get worn down by pavement or tarmac pretty quick.. The stock tires were really meant for use on softer surfaces like grass or damp dirt. I found that the stock tires are not so good for hard packed dirt - the medium compound is too hard for that surface causing them to slip too easy.. Ultra soft tires are way better for hard packed dirt..

It sounds like you did all the right stuff to keep the Durga cool.. The only extra tips I can suggest are: 1. Add thermal grease (the kind used for computer heat sinks) between the motor mount and the heatsink plate. It will help to pull heat away from the motor mount faster and dissipate it from the plate. 2. Try to target better gearing for your motor using www.gearchart.com.. The Durga will accept aftermarket spur gears, so you should be able to find that gearing sweet spot to help your car run cooler.

Have fun at the track!!! Let me know how everything goes..

Dan

dimblum

The exploding Lipo information people talk about is mostly related to very cheaply made Lipo cells or from misuse of the battery. To this day I have never seen one go up in smoke - and everyone at out track uses Lipo batteries now..

The best explosion proof Lipo I know of is still manufactured by Team Orion. They are the only company that uses Kokam cells for their batteries.. It's a long story why these cells are better, but due to a special manufacturing process called a 'z-fold', the cells really can't explode (they will only smoke a little). Damaging a Kokam cell is like popping a bunch of fuses rather than setting off a roman candle.

I can confidently say I will never use a NiMH battery again.. The benefits of Lipo batteries are too numerous - the best being the fact that you can charge them as much as you want with -no- memory effect over time.. I still use the same Lipo I bought 8 months ago, and it works like it was brand new.


For the tires:

JConcepts Bar Codes 2.2 Front Buggy Tires (Gold) (2) (JCI3017-05) - Awesome tire designed for hard smooth indoor surfaces (Gold Compound). Avoid using them on loose dirt or soft dirt. JConcept tires are some of my favorite all around

Pro-Line Bow Tie M3 2.2'' Rear Buggy Tires (2) (PRO8186-02) - Good tire when the surface is a little loose or dusty. The M3 soft compound is great when the track is hard. I have not used these myself, but know other racers who have.

HPI 35mm Ultra 7 Rear Wheels (Black) (2) (HPI100625)
HPI 30mm Ultra 7 Front Wheels (Black) (2) (HPI100624) - I haven't seen these before you mentioned them, but I sure like the look of those wheels Made for their new Brama10B buggy.. I am guessing they use the same hex and pin configuration of every other buggy out there. If so, then I will probably buy myself a set.. Up until now I have been using the JConcepts Rulux wheels or the Losi XXX4 wheels.


For other 'go anywhere' tires, you may also want to try:
* JConcept Double-Dees - soft
* Panther Raptors - soft

These tires are especially great for hard packed dirt

Hope this helps

Dan

Tilux

Just to revive this wonderful post with some of my Durga! [sm=wink_smile.gif] Sorry if pic are is pixelish a bit!

Forgetful_Duck

Hey all, I'm new to the DB01 scene, Just got my kit and a pile up hop ups, I have a quesiton in regards to the flourine coated suspension balls (53709)
Do they matter a whole lot? Actualyl do much compared to the plastic ones from the kit? The only thing i can think of is the plastic ones grinding down over time with sand/dirt but wouldnt that be the same witht he metal flourine coated ones as well? Guess one will outlast the other, but until then, stick with stock plastic suspension arm ball mounts?