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steelo

Ugh...I give up!

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Well, I think I've just about had it with my Neo Scorcher. I am having serious issues with gears stripping and have realized that unless I buy a new chassis, it's just about shot. I am a bit disappointed in Tamiya on this car because of the poor design of the motor mount and gear cover. It seems the only thing preventing the spur gear from flexing/moving under load is the flimsy motor cover that fits over the ball bearings. The problem is, once you strip the screw mounts on the cover, there is virtually nothing preventing movement of the spur gear. Also, the plastic motor mount seems to have warped somehow so when I fully tighten the screws on the bottom of the chassis, it sounds terrible like it's not meshing correctly.

I apparently have taken the motor/gear cover off so many times to replace stripped gears that the screws no longer hold. I know I could probably buy an aluminum motor mount for $10-15 and a new chassis for about the same, but I am now so turned off by this car that I don't want to mess with it. :rolleyes:

I know I have posted about my gear issues before and I have checked the directions probably about 30 times to make sure I assembled everything correctly and used the correct screws....

Anyone interested in a parts car? LOL

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You can easily repair the stripped threads using superglue. Might be worth a try before giving up completely.

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I'm wondering now if a metal screw insert (or even a nut) would fix the problem. I would drill a larger hole in the pastic to fit the insert and superglue it in so the top of the insert is flush with the plastic. Then I would be able to use machine screws to mount the cover and hopefully not have to worry about stripping plastic parts.

Do you think something like that would work? I know it would have to be quite small...I may try this as a last resort if I can fine some.

I was so frustrated last night with the car, I almost threw it in the trash. I have already pulled the motor/esc/servo out of it...

I feel awful because it was a bday gift from my wife.... :(

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Hmm. Inserts may solve the issue of the stripped threads, but if I understand your situation correctly, they are a consequence of repeated spur gear replacements, rather than the cause, so you'll still have the spur gear issues to contend with.

Considering how many issues you are having with the car, compared to how few myself and others are having with ours, I still can't help thinking there is something uniquely wrong with yours, like possibly a warped main chassis moulding or some other one-off oddity along those lines. Perhaps a new car is in order. Maybe something simpler like a DT-03. They are both bomb-proof and pretty capable from what I have read.

If I hadn't already spent my hobby budget for the coming month, I would be sorely tempted to make an offer for your TT-02B. I'd really like to see firsthand what is up with it, and if I can find a solution...

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Good point....and it could just be the idiot builder...aka, me =)

I'm hoping that the problem of the stripped gears is related to the cover not being fitted correctly...to the naked eye, everything appears to be straight and true.

I know I keep saying this, but I really think the issue with the spur gear stripping has to do with the gear cover not being as "tight" and snug as it needs to be. It appears to be the only thing that holds the ball bearings and shaft assembly in place. The fact that the screw mounting locations for the cover are all stripped means tons of wiggle room for the shaft because it's not sitting snugly around the ball bearing in front. If the ball bearing has any play, the spur gear will wiggle as well and under power will strip in no time.

The motor mount "works" and doesn't allow any movement as long as I don't torque the screws too tightly. I can immediately tell if the motor isn't aligned because it will sound awful.

That is my guess from looking at it....

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Howdy All! 1st post!

Steelo, I feel your pain. Stripped screws suck. The good news is, I have been a heavy handed moron for years and I have a possible band-aid for the stripped screw. Obviously you will be eventually ordering a new tub (#51532, thank goodness its only $7 @ TamiyaUSA), but you might be able to get away with using lock washers on the Spur cover screws. I have used them many times in "metal screw to plastic" applications, and I've had about 90% success. You can get a handful of them @ the hardware store for less than a buck, so there is not much to loose.

Now on to the problem at hand, the gear shredding.

I just got a Dual Ridge for my 40th B-day last Friday. I also ordered several hop-ups from Asiatees. I got impatient and decided to assemble the kit so I could address several "slop" points (of which there are many) on the car before she ever hits the tarmac. One thing I noticed in the drive-train was the side-to-side diff slop(especially in the rear diff). I measured about .4mm of side slop in the rear. If your Scorcher is like mine then, in the right conditions, the rear prop shaft end could "pop" or skip under high torque conditions. Months ago, while I was researching the TT-02B, I came across a TT-02 tips and tricks article. The guy had all but eliminated the diff slop using 8mm x .1mm shims behind the diff bearings. He also said it was important to replace the stock motor mount, especially if your upgrade the motor.

Now, I can't tell you that "hey, here is your solution for sure" as I haven't even really run my car yet(other then a quick 50ft out and 50ft back to test it). But I can tell you that I have been practically obsessing over getting this car for a few months now and it would be a shame to loose a fellow TT-02B owner before we've had a chance to become pals.

Sorry to ramble on, I hope this helps. Or at least gives you a little outside perspective. Good luck!

Mike

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Hey Mike, thanks for all of the great input! The car is a blast to drive, I'm just frustrated with screws stripping after assembling/disassembling more than 2 times. It would be great if Tamiya (or an off brand) offered an aluminum tub. That would eliminate a lot of the stripping issues (and reduce flexing)

I think I'm going to try to find some screw inserts tomorrow (not sure if my local hardware store would carry them) and see if I can get that to work. I think that's 90% of my problem right there. If that doesn't work, I'll pay the $20 for a new chassis and aluminum motor mount.

The shims sound like a really good idea, I do hear the rear differential skipping from time to time under full throttle. That will be my next plan.

Well, again thank you for the help guys, I think I'm going to take my time reassembling the car and address all of the slop. I now have a little hope this car is salvageable!

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I have another idea!!(Thank you, beer!)

If you can't find inserts small enough, get a length of threaded rod (same width and pitch as the screw of course) and several nuts and washers. Cut the rod to length for each stripped screw port, leaving a lot of extra sticking up for the nuts and washers. Put a drop of super glue on each rod before installing and just thread the rod about a half turn further than the length of the original screw. Then use nuts and lock washers to secure the spur cover down.

Just giving you a fall back plan. :)

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In a tt01 build I've tighten screws down too much and they poked through and interfered with the gearing, I'm sure its not the problem youre having but an idiots point of view sometimes lightens the mood....made an awful noise too like there was a grinder at work, left a dirty great channel in the spur...

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I haven't got a TT-02, but have had problems with the self tappers stripping threads before. My solution has been to drill the holes deeper with a 2.5mm drill bit, then cut a M3x0.5 thread into the holes and use much longer screws. No inserts required and no further issues with stripped threads. When I built my last DF-02, I used 3mmx12 self tappers instead of 3mm x 10 self tappers the instructions recommend and have not stripped the gearcover mount holes yet. HTH

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I attempted to follow the advice of Dynamite D but guess what...yet another stripped spur gear after 5 minutes of running it! His idea worked beautifully for fixing the stripped screw issues but obviously the car has other problems. I think the chassis must either be warped where parts aren't meshing together or there is some kind of defect in motor mount.

Ugh....I'm DONE with this car and will be looking for another 4wd. Tamiya is a great company, I love my M05 and Sand Scorcher but they aren't good bashers...

Any suggestions on a durable, cheap 4wd car? I had a 2wd Duratrax Evader with a 13T motor that absolutely flew and had to issues. Are the Arrma kits any good?

I may just wait until the Kyosho Optima is re-released =) Anyways, thank you everyone for your suggestions...everyone is so friendly on here!

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Does it absolutely have to be a 4WD?

There are several solid and trouble free 2WD Tamiyas out there that you might consider, such as the DT-01, DT-02, DT-03, DT-03T and WT-01, that are great for bashing and are less likely to give trouble than a similarly-specced 4WD.

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WR-01 if you want 4WD bulletproof but as XV says the DT's and WT's are strong contenders. I have a couple of both and have not killed them yet

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Ah, forgot to mention I'm wanting a buggy....The Wr-01's are really cool but they look like they are monster trucks

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Well, if it is a bulletproof basher you are after, have you considered the Mad Bull? It isn't 4WD, but its big tyres and high ground clearance coupled with wide stance and low centre of gravity mean that it can go most places that a 4WD could, and it is almost absurdly tough. Plus with its modified Grasshopper II shell, it has the looks of a buggy.

Much of the chassis is made of a rubbery plastic that shrugs off impacts that would demolish a stiffer vehicle, the 0.8 module pinion and spur have big, chunky teeth that won't strip even with hugely powerful motors, and the simplicity of the overall design means there is very little that can go wrong. If it is worry-free all-terrain bashing you want, this might be the one for you.

Coming a close second in terms of ruggedness is the WT-01. My nephew has one, and despite years of hard use in all conditions, the only mechanical failure it has ever suffered was the servo saver popping off due to a loose screw. Like the Mad Bull, big tyres and plenty of clearance give it great all-terrain ability, and if you find you do want a 4WD after all, you can easily convert a WT-01 to a 4WD twin-motor WR-01 by adding a second gearbox up front. And if the monster truck look doesn't do it for you, how about a monster touring car or monster rally car? Pretty much any shell can be persuaded to fit.

And then there are the DT-02 and DT-03 buggies, sharing the same 0.8 module pinions as the Mad Bull, making for an extremely reliable gearbox. The rest of the buggy is quite tough too - not Mad Bull or WT-01 tough, but certainly able to take a few knocks. They may not have the all-terrain abilities of the Mad Bull or WT-01 either, but handle better and are faster on less extreme terrain.

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I do like the Neo Fighter (DT-03) and Sand Viper (DT-02) buggies....I almost got the NF instead of the Neo Scorcher but wanted 4wd at the time...

What's the difference between the DT-02 and 03? I assume the 03 is newer and probably a more modern design, it also looks like the shock towers on the DT-03 are reinfoced by a cross bar. Not sure why the DT-02 is more expensive on towerhobbies...

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The Neo Fighter will certainly be less prone to gearbox issues than the Neo Scorcher, especially if you add a genuine Tamiya 0.8 module steel pinion at the outset. It can be modded into quite a capable racer too should that be your thing.

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It also appears to come with the TBLE-02 brushless ESC....I think we have a winner =)

Now the all important question...will I be able to keep up with my buddies Neo Scorcher...haha

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I have both the dt-02 and the dt-03 and they are sound 2WD buggies. There are also plenty of cheap hop ups available from HK. The dt-03 is cheaper to buy than the older dt-02 's and use the same gear box.

I run a 20 turn brushed motor with 2s lipos. The only thing to watch out for when using fast motors is the motor temperature. The motor is almost entirely enclosed in the gearbox but a heat sink fixes the problem or just cut away part of the gear box housing.

Steve.

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It also appears to come with the TBLE-02 brushless ESC....I think we have a winner =)

Now the all important question...will I be able to keep up with my buddies Neo Scorcher...haha

Pick a track where the emphasis is more on speed rather than handling, and yes, you'll certainly be in there with a chance! :)

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It also appears to come with the TBLE-02 brushless ESC....I think we have a winner =)

Now the all important question...will I be able to keep up with my buddies Neo Scorcher...haha

2WD will be quicker than 4WD with the same motor fitted. It will also be more maneuverable but less grip being 2WD.

Go for DT-03 Neo Fighter Buggy you won't be dissapointed.

Steve.

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We just race around a big flat dirt area that used to be a baseball field.

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Steelo,

My son has a DT-02. It was a great build and overall seems pretty rugged. Definitely more rugged than his sisters TT-02B IMHO. He bent a few teeth on the spur by landing jumps under power one time. The lack of a slipper puts more pressure on the gearing. The DT-03 uses the same gearbox as well so it's a weak spot for both cars. This shouldn't be an issue for you since you said you're running in "a big flat dirt area." Personally, I prefer a bathtub frame over a space frame, so a DT-02 would get my nod over the DT-03. Nobbi1977 recently did a great build-it on the DT-03 and there are lots of DT-02 build threads here as well. You might want to check them out before deciding which chassis to adopt.

The Mad Bull seems to be everyone's go-to when bullet proof is a requirement. Keep in mind that the Mad Fighter is the same basic buggy without the balloon tires. ;) I don't think there are nearly as many hop-up parts available for them as the DT-02/03 cars though. That might be a consideration.

I would also suggest building a new car as per the manual and for sure sticking with the stock motor and gearbox setup until you have a few dozen battery packs through it. Think of it as breaking in the car and learning it before making major changes, especially power upgrades. Things tend to break faster when there's more power involved. The exception to this is of course: ball bearings, steel pinion, and oil dampers. Just my 2 cents. ;)

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