Sounds like something is not meshing

[burakol 462]

Hi,

I'm currently building my duaghters ReRe Terra Scorcher... I've finished putting up the parts for both front/rear diff cases, suspension arms, and dampers... I started doing the electronics and decided to test the brushless motor I'm using... to my surprise, it sounded something is off... i was not expecting it to sound loud... as if something is grinding inside... not sure is something is off or not meshing right... 

When I tested the motor, it was not driving anything under load... no wheels, no propeller shaft... just the rear half of the rear diff case with the axle... 

I took the motor off and measured the distance of the pinion in the motor shaft and it was within spec... re tested and still sounded the same... is this normal for the Terra Scorcher or should I open the case? 

The rear drive shafts are spinning freely and I dont feel any binding, slipping or anything unusual when I turn it manually... it does feel smooth so I'm not even sure if this is a mesh issue... 

Comparing it to my Manta Ray and Hot Shot, the Terra is noticeably running louder and that's without any wheels whatsoever... 

Am I being overly concerned over something I shouldn't be? 

Can someone post their Rere Terra and maybe let me hear how theirs sound like without any load/wheels lifted off ground? Thanks. 

[mud4fun 1696]

This has already been raised and discussed in detail in the re-re Terra Scorcher 2020 thread, look at the last page and work up. It seems there are moulding issues with the re-re gear set. We have identical issues with my daughter's new re-re Terra Scorcher too.

NOTE: You might not be able to test the new terra scorcher with wheels off ground because suspension droop at rear is too great for the UJ driveshafts and you will get serious vibration (as we did). We have swapped to dog bones at rear on ours as they can operate at greater angles. If you do test in the air then may be wise to compress rear suspension with your hand to reduce driveshaft angles.

NOTE2: We also binned the new alloy mount, bevel gears and kit pinion and have used vintage items and an aftermarket smaller steel  pinion. The old steel mount and pinion setting tool gives more accurate mesh on spur and vintage gears are much quieter.

[burakol 462]

3 hours ago, mud4fun said:

This has already been raised and discussed in detail in the re-re Terra Scorcher 2020 thread, look at the last page and work up. It seems there are moulding issues with the re-re gear set. We have identical issues with my daughter's new re-re Terra Scorcher too.

NOTE: You might not be able to test the new terra scorcher with wheels off ground because suspension droop at rear is too great for the UJ driveshafts and you will get serious vibration (as we did). We have swapped to dog bones at rear on ours as they can operate at greater angles. If you do test in the air then may be wise to compress rear suspension with your hand to reduce driveshaft angles.

NOTE2: We also binned the new alloy mount, bevel gears and kit pinion and have used vintage items and an aftermarket smaller steel  pinion. The old steel mount and pinion setting tool gives more accurate mesh on spur and vintage gears are much quieter.

Thans. Heading over to read the thread... sucks if this is the case... I wonder if there's any recourse to this straight from Tamiya?

[Superluminal 3750]

Im not sure if I dreamed this but hasnt it been suggested before that if you pack the diff with toothpaste and run it for a few minutes its just about abrasive enough to remove the burrs on the gear teeth and improve the mesh.

I may have made that all up but at least it will be still be noisy and smell minty fresh at the same time so possibly some improvement?

[burakol 462]

39 minutes ago, Superluminal said:

Im not sure if I dreamed this but hasnt it been suggested before that if you pack the diff with toothpaste and run it for a few minutes its just about abrasive enough to remove the burrs on the gear teeth and improve the mesh.

I may have made that all up but at least it will be still be noisy and smell minty fresh at the same time so possibly some improvement?

Interesting... but it does make sense... I did read over the thread and if this is the case on this particular ReRe kit, then I guess I have to do with it until the gears have been grounded down to where the gear becomes smoother... I'm not even particularly sure if the hobby shop I got this form will be of any help... I feel that once you buy the kit, there's really no guarantee whatsoever with the fit and finish... so long as it runs and does not crumble into pieces, we have to live up with it. Thank you!

[mud4fun 1696]

@burakol I added an update to that thread last night, not sure if you have seen it. My daughter's noisy gearbox and vibration issues all now fixed. It was not just the gears. 

[burakol 462]

@mud4fun Hi, I saw your update. Thank you for the info. Unfortunately I do not have any spares like you do and I don't want to spend extra at the moment. Hopefully after some time, the plastic will eventually smoothen out before anything drastic happens... 

[mud4fun 1696]

2 hours ago, burakol said:

@mud4fun Hi, I saw your update. Thank you for the info. Unfortunately I do not have any spares like you do and I don't want to spend extra at the moment. Hopefully after some time, the plastic will eventually smoothen out before anything drastic happens... 

Yes, my daughters was actually gradually quietening down to be honest but sadly taking a bit too long for my daughters patience to last LOL, I reckon given 20 hours of running it probably would have bedded itself in nicely. The buggy has been superb in every other way so this is the only thing we can really complain about. She has used it alot in the last month and no other issues have cropped up.

[MICHAELs TopForce17 586]

I contacted tamiya usa about this issue and today they replied with " Be sure the motor is mounted in the right position". So they were no help.

[TurnipJF 9192]

With a steady hand, a sharp scalpel and a magnifying glass, it is possible to carve off the mis-moulded bits from the gears, significantly reducing their noise. I did this when putting a new gearset in my Thundershot. It is still not exactly quiet, but far less noisy than it was before the carving.

[mud4fun 1696]

2 hours ago, MICHAELs TopForce17 said:

I contacted tamiya usa about this issue and today they replied with " Be sure the motor is mounted in the right position". So they were no help.

Are they idiots? The motor mounting plate can only fit one way!!!! 

Anyway, the gearbox was notchy and the driveshafts were binding even without the motor installed. It is clearly a combination of a poor decision to use UJ driveshafts that are not suitable for the driveshaft angles on a stock terra scorcher rear end, poor moulding on gears plus poor quality metal shafts that are not the correct size!!! (My daughter's were undersize by 2-3 thou meaning they rattled in the bearings). On top of all that the kit supplied bearings were unlubricated, I had to apply penetrating oil to sort them out. 

My daughter and I tested the UJ driveshafts, they are hopeless compared to the original design which operate smoothly a full 10 degrees more than the re-re ones and even they fall well short of dog bones.

My daughter has tested her Terra Scorcher tonight (after the entire back end was replaced with vintage thundershot parts including dog bones) and says it is alot quicker now as well as being quieter. The motor also runs cooler so runtime should be extended. 

[burakol 462]

2 hours ago, MICHAELs TopForce17 said:

I contacted tamiya usa about this issue and today they replied with " Be sure the motor is mounted in the right position". So they were no help.

Hmmm... Makes me think... I should probably send them an email to and start planting seed in case they would do something about it... maybe if they get enough email/complain they would provide a more directed response

[mud4fun 1696]

My take on this, admittedly very controversial, is that Tamiya don't care. They are targeting the re-releases at people that buy them to keep as NIB or as shelf queen's. Those sort of people want to say they have this or that car with UJ's all round or such and such a hop up etc but don't actually ever drive their cars so don't really understand what those hop ups are for or the effects on the car in actual use. And most certainly would not notice the insane vibrations from using poorly designed or inappropriate use of UJ's or care if the gears are badly moulded, the shafts are pants and the bearings are not fit for purpose because they never actually run them, certainly not hard enough to notice issues. UJ driveshafts are only really required on front where the driveshaft has to accommodate vertical movement of suspension AND steering movement. Dog bones are perfectly fine, or even superior on the rear.

This is similar to the long standing issue of people paying silly money  (and pushing up prices of parts) for the Avante while claiming the Avante2001 or even the Vanquish are inferior cars. The truth is that the Avante is completely naff as a basher or racer, the Avante2001 and Vanquish are far superior and in my opinion the Avante is the poor man's Avante2001/Egress/Vanquish not the other way around.   If Tamiya were truly interested in people that ran their cars they would have re-released the Avante2001 or Egress for more often than the inferior Avante but it is exact opposite - clearly driven by the shelf queen collectors not the people that use their cars.

Over the years I have given up trying to argue with people who buy cars to simply display on a shelf, sadly it affects those of us who wish to actually run our cars because Tamiya don't seem to care for people that want to use their cars. As shown by their abysmal spares situation. I'm gonna guess that most re-release Terra Scorchers end up as shelf queen's with at best the odd light run on some smooth clean tarmac. Same is probably true of all the regurgitated Avante versions and the new VQS. It is why I'm switching to Schumacher.  

 

EDIT: Sadly some of the biggest YouTube channels for Tamiya Cars seem to be all about shelf queen's and have near zero knowledge of actually running cars in anger. Some of the advise is truly laughable along with their reviews of new cars which seems to exclude any actual running, let alone long term use in racing or bashing and trying to find spare parts! Even my kids have got fed up and are now looking at other brands, after being told that they can't run their Tamiya cars because we can't find parts or afford parts for their cars. Tamiya are going down a narrowing and limited market. Such a shame. RC cars should be driven. If you want to look at a model on a shelf, buy a plastic model kit! Sorry just my opinion. YouTubers proclaiming how wonderful a model is because it is scratch free simply exemplify the problem, too many people buying to collect instead of using. None of my buggies is scratch free and all my buggies are used hard and are broken regularly...

 

[Ferruz 11702]

I recently started my 2020 TS build and, like everybody else, have encountered the same issue earlier on this week. The bevel gears were as lumpy as the lunar surface, especially in the area around the point attached to the tree.

6 hours ago, TurnipJF said:

With a steady hand, a sharp scalpel and a magnifying glass, it is possible to carve off the mis-moulded bits from the gears, significantly reducing their noise. I did this when putting a new gearset in my Thundershot. It is still not exactly quiet, but far less noisy than it was before the carving.

That is exactly what I've done, and am relieved it's been contemplated and done by somebody else. I hope my hand was steady enough as not only had I no magnifying glass, but I had already applied the cereamic grease which made it difficult to find the parts that needed to be shaved off (driven by the enthusiasm of the beginning, I forgot to check them before).

I hope I wasn't too bold with my exacto knife, though it seems that the intervention made a great improvement. This I judged by spinning the propeller joint: when before there was no way to turn it all around by hand without applying a certain force, now if does smoothly. Even after mounting the motor, I gently turned the prop joint with a screwdriver and the feeling is right, I perceive no more lumps or at least nothing so evident, although I haven't yet installed the gearbox joints so for now I can only hope for the other gears to be not as horrendous as the bevels.

I have the feeling I'm gonna have to reopen those gearboxes anyway 

[mud4fun 1696]

@Ferruz you may find, like us, that it wasn't just the bevels. We sorted them out and still had noise issues. My daughter noticed it specifically when backing off the throttle to enter a turn, the gearbox would make a horrible rattling sound verging on sounding like a backfiring engine (that rattling they make just before the bang). This was down to the rear UJ's causing violent vibrations through the drivetrain. Totally sorted by replacing with dogbones.

To be fair, her buggy rides too high at the moment for doing postal racing on tarmac so we are going to add spacers to the shocks and lower the car, this would probably have also solved the UJ issues by significantly reducing driveshaft angles. We may put the UJ's back in once we've lowered the car. They are nice quality and strong, sadly just limited on the angle they will tolerate.

I would also recommend double checking your bearings because ours were dry and needed lubricating. Everything turned smoothly by hand but the noise issues only became apparent under power and load.

 

[taffer 948]

Look on the bright side......after all my spares have been used I'll start buying all the unused shelf queen's for parts! 😂

[Hobbimaster 190]

I just finished my build of the Terra Scorcher. Before even powdering it up, I rotated the wheels by hand and it has very noticeable "tight spot" felt in the drive gears. I read that some on here just let the gears bed in, and that is what I plan to do. I have since ran it for a few minutes, and noticed this "tight spot" is almost gone. Its still a bit noisy, but I'm hoping that will disappear as the gears continue to seat themselves. Tamiya has now completely pulled the TS off of TamiyaUSA's web sight as if it never existed, which I find odd. At least the Fire Dragon will be back soon, so spare parts should not be an issue for the TS.

[burakol 462]

Well, I did send them an email... I don't expect them to give me a solution to this but at least they should be getting feedback from their customers... if they truly value their fan following, then the least they could do is acknowledge the dissatisfaction and apologize for it... I might eventually open and replace the innards and the rear shaft as suggested by @mud4fun fi and when something breaks, but for now, I might just let it be and hope that after some time, it will fix itself... 

I must admit though, that I didn't even bother/care about checking the actual condition of the plastic/gears like @Ferruz did so I didn't notice anything unusual... it was an oversight on my part and this build taught me to start doing it for my next builds... honestly, however, it is really disappointing that the quality of the product is subpar considering Tamiya is a pioneer for plastic kits and RC... 

[mud4fun 1696]

Yes @burakol the terra scorcher is the first brand new Tamiya RC kit we've bought in 20 years and it has been disappointing to have issues, especially moulding issues as Tamiya has such a good reputation in that regard.

The UJ issue that we had has not been reported by others which is odd, unless ours are different I'm not sure why that has not been noticed by others? The vibrations were severe and well below acceptable limits.  Maybe we noticed the noise and vibration issues more because my daughter is running a 19T Reedy spec motor in it which is 10mph quicker than stock?

I'm running a 13T Dyna Run super touring in my vintage thundershot, it is 25mph faster than stock and yet is almost silent and vibration free so in my opinion the re-re problems are down to poor quality manufacturing or quality control, not fundamental design flaws.

Thankfully all easily fixed but we should not have to do this to a brand new £180 kit!

[taffer 948]

Using no CVA spacers mean (especially the rear) the buggy droops (esp with a NiMH battery) so no issues. Holding off the ground and running it did highlight it's minor vibration issue, I wasn't going to use them at first but I was curious to see how long they will last .....we shall see

[mud4fun 1696]

13 minutes ago, taffer said:

Using no CVA spacers mean (especially the rear) the buggy droops (esp with a NiMH battery) so no issues. Holding off the ground and running it did highlight it's minor vibration issue, I wasn't going to use them at first but I was curious to see how long they will last .....we shall see

My daughter was using the larger spacers because she was running on tarmac with a heavy battery and found the buggy was bottoming out without the spacers. That may explain the extreme driveshaft angles/vibration issue BUT why supply UJ's that don't work for the kit supplied stock shocks? I believe the manual says to use X3 spacer as standard but my daughter needed X4. Surely you'd think the UJ's should work for all kit supplied shock spacers? Either that or they should have supplied different spring rates for different terrains - another Tamiya weak point. 

[taffer 948]

I suppose pressure to maintain the higher spec of the terra meant they had to supply something 'more' than a normal tshot.

The original Universal's are much better but have long since been discontinued.

I'm hoping the fire dragon rerere will just turn out to be a re-numbering exercise, rather than including the new motor mount etc.

I'll be surprised if the fire dragon is available to buy easily more than six months.

 

[burakol 462]

On another note, is the front body post really short on this kit? I feel that the post is not long enough and not clearing the front mounting hole enough for me to slide a body pin. Unless there is a fron/back side to the body mount part that I reversed? 

[mud4fun 1696]

1 hour ago, burakol said:

On another note, is the front body post really short on this kit? I feel that the post is not long enough and not clearing the front mounting hole enough for me to slide a body pin. Unless there is a fron/back side to the body mount part that I reversed? 

Not noticed any issues with the front post on my daughter's other than she insists on using the annoyingly fiddly little clip supplied by Tamiya. I run much larger and easier to fit fluorescent clips on all my buggies, far easier to slide in and easier to find when they fall off 

[mud4fun 1696]

@taffer, I have a good number of the original design UJ driveshafts, some brand new. You are correct, they operate smoothly at greater angles than the new design but new ones are stronger by the look and feel of them. 

We binned the new alloy mount and reverted to the vintage steel plate. That actually reduced noise too, not sure why, may be a thou or two out of alignment on the holes compared to the steel one which resulted in too tight a mesh on spur and more noise? Or the thick plate bolted to the plastic gearcase amplifying sound somehow?

At least we can easily set pinion height now using the setting tool on the steel plate.

Oh that reminds me, the offset stated in the manual when using the new alloy mount appears to be wrong, it resulted in the pinion not sitting fully across the width of the spur, easily recognised on removal where you can see clear wear lines over only 3/4 of the width of the spur. I got a Vernier out and measured the distance from the flat on the gearcase where the mounting plate sits to to spur, the original setting tool on the steel mounting plate results in engagement across the full width of spur teeth so one more benefit of using the vintage steel plate and setting tool.  (Lesson here Tamiya, don't fix what ain't broke!)