Go Back  R/C Tech Forums > General Forums > Electric On-Road
Yokomo MR-4TC SD >

Yokomo MR-4TC SD

Community
Wiki Posts
Search
Like Tree12Likes

Yokomo MR-4TC SD

Thread Tools
 
Search this Thread
 
Old 08-18-2004, 10:28 PM
  #9451  
Tech Champion
iTrader: (31)
 
JayBee's Avatar
 
Join Date: Mar 2004
Location: 12TH-MAN COUNTRY
Posts: 6,819
Trader Rating: 31 (100%+)
Talking

what the hell, one more....

- jaybee

Last edited by JayBee; 09-12-2008 at 09:27 PM.
JayBee is offline  
Old 08-18-2004, 11:49 PM
  #9452  
Tech Adept
 
Join Date: Jan 2003
Location: Auckland, New Zealand
Posts: 116
Default Re: Unrelated curious anomaly number two.....

Originally posted by Mabuchi540
I know the shotkey diode has to go across the + and - terminals of the motor but as the 540 doesn't have these marked is it ok to just solder the diode further back and across the positive and negative esc wires?
The 540's here in NZ have a square on the can inline with the positive tab. You gotta run your car sometime, all that stuff about your rattling drivetrain will all change when you finally run the car on the ground. What gearing did you end up with on the CGM as a starting point BTW? People are just going lower and lower these days. My brother ended up on 4.40 on a tight track at Hamilton last weekend. And where you gonna be racing?
Trevor is offline  
Old 08-19-2004, 12:03 AM
  #9453  
Tech Master
 
Join Date: May 2004
Location: New Zealand
Posts: 1,204
Default Re: Re: Unrelated curious anomaly number two.....

Originally posted by Trevor
The 540's here in NZ have a square on the can inline with the positive tab. You gotta run your car sometime, all that stuff about your rattling drivetrain will all change when you finally run the car on the ground. What gearing did you end up with on the CGM as a starting point BTW? People are just going lower and lower these days. My brother ended up on 4.40 on a tight track at Hamilton last weekend. And where you gonna be racing?

Tah, will have a look for that on the motor (I assume it applies to Johnson 540's)?

As for gearing I was thinking of starting with 4.7. As for where I'll most likely end up racing...in Palmerston North when they get a track going.

Last edited by Mabuchi540; 08-19-2004 at 12:17 AM.
Mabuchi540 is offline  
Old 08-19-2004, 12:49 AM
  #9454  
Tech Master
 
johnbull's Avatar
 
Join Date: Aug 2001
Location: Malta. G.C.
Posts: 1,762
Default

Hi friends. Greetings from Malta.

MABUCHI.

I have read all your tales of woe. To be perfectly honest a number of them are real trivialities. You really don't need to bother with them and take them so seriouslyor you'll end up with heart trouble like me.

I think that at some time or another in the last 12 years playing with RC cars I have had dealings and fiddled with probably every makeof car in existance. Tamiyas, Losi, HPI, X Ray, AE, Schumacher, Hyper, Serpent, Corally, Barracuda, Yokomo, M1 Express, Kyosho. The list is endless. I can assure you that the Yoke SD is no less or no more susceptible to build problems than any of the above.

My present CGM is actually one of the quietest running cars I have ever built. If you want a noisy one try a Barracuda - sounds like a bag of nails. For screw fits try Tamiya - overtighten once and you need new cases. I could go on for ever.

So my advice, as an old man is simply take them all as challenges and go out and enjoy racing it instead of worrying about trivialities.

JAY BEE.

Much as your bodyshells are very nice, I don't think Futureal will be too impressed with the space you are taking up. The same applies for your signature.

If we want RCTECH to survive we have to be reasonable and cooperative. I'm only telling you this because I know Shane has asked people before to keep their signatures brief.

In closing I have to say that my CGM has been my best car to date. It is smooth, easy to work on, and handles well and consistantly, and is very competitive.

Perhaps it's greatest single asset though is the fact that it so easy to work on.

Please take this contribution in the spirit that it is written.

Good luck.
johnbull is offline  
Old 08-19-2004, 01:28 AM
  #9455  
tornado
Guest
 
Posts: n/a
Default

John

I know you have the one of the quietest SD around here....so I need help from the master and also that is why I'm asking why my car makes that stupid annoying sharp pitch sound....sounds like the gear is very tight...but...I have a very free rolling car...gear meshing is ok.....I've changed the spur, pinion, diff bevel gears but that annoying sharp pitch noise just gets to my nerve. I've owned, ran and sold off a Barracuda R2 and I know how it sounds like (sounds like a chain saw) but my CGM is making that annoying noise which is not similar to the R2.

Is there anything I've done wrong ? Or is it the material of the spur and pinion. I'm using Xenon spur and Kawada pinion....both made by the same manufacturer. Just got Kimborough spurs and Robinson Racing Spurs to try tomolo while still seeking someone to shed some light at the end of the dark tunnel.

Its the learning curve mate.

Thanks

Bryan
 
Old 08-19-2004, 02:10 AM
  #9456  
Tech Champion
iTrader: (31)
 
JayBee's Avatar
 
Join Date: Mar 2004
Location: 12TH-MAN COUNTRY
Posts: 6,819
Trader Rating: 31 (100%+)
Talking

Originally posted by johnbull

JAY BEE.

Much as your bodyshells are very nice, I don't think Futureal will be too impressed with the space you are taking up. The same applies for your signature.

If we want RCTECH to survive we have to be reasonable and cooperative. I'm only telling you this because I know Shane has asked people before to keep their signatures brief.


Please take this contribution in the spirit that it is written.

Good luck. [/B]
I can't tell what 'spirit' that's in but if you saw my sig before, I don't think you would've let that fall out of your mouth. I will cut back on the space though. You're a good look-out for the moderators too, there's probably a boatload of threads you could patrol to make sure everyone's being reasonable and cooperative.
I apologize for that.... I just couldn't fight it

OH YEAH, thanks 4 the compliment...

- jAyBeE

Last edited by JayBee; 08-19-2004 at 02:17 AM.
JayBee is offline  
Old 08-19-2004, 03:54 AM
  #9457  
Tech Elite
iTrader: (14)
 
Lonestar's Avatar
 
Join Date: Oct 2001
Location: Switzerland
Posts: 3,039
Trader Rating: 14 (100%+)
Default Re: Speaking of spur gears......

Originally posted by Mabuchi540
Yokomo problem 2568.......

The spur gear adaptor is causing the spur gear itself to wobble.

Screwing the spur to the adaptor as evenly as possible (and using various brands of spur) it spins without wobble...BUT.... as soon as I screw down the grub screw onto the input shaft (even stopping as soon as I feel any resistance of the screw on the shaft) the spur wobbles.

This I figured is due to the shaft being a lose fit through the adaptor and when the screw (as mentioned above) barely touches the shaft it is causing the adaptor to run untrue.

Any ideas how to stop this happening as I have two adaptors and it does it with both of them?

For the sort of money in NZ I had to pay for this thing it's turning out to be the least well constructed kit (accuracy of part fit wise) I've ever had the misfortune to buy.

Sorry to be so much harsher that JohnBull (who's a wise man as opposed to me being a young impetuous hot shot), but I'm beginning to seriously think that you have a problem, not the car... You are the noisiest around here, systematically complaining about everything (now that Horatio has his graphite parts ). You've worked on assembling this car for what, three weeks now? It still hasn't hit the track... Go race it now instead of fiddling with everything. Practice will give you way more speed than shimming CVD's with rubber. Thank you.

However... I'm still willing to help... so here ya go:

locked diffs with factory shimming: check that the bearings are fully seated (pushed) on the input gear. This is a VERY common assembly problem (not a manufacturing problem). You probably made another mistake, not Yokomo.

Rubber on CVD pins to compensate play: your transmission will bind in some circumstances. Plus it kills its freeness. Keep using them if you hate seeing more than 1/100th of an inch of play in your CVD's, but it's useless.

Wobbling spur: yes it wobbles SLIGHTLY... like on all cars. Don't bother with it, just run it, and be thankful you don't run a Evo3 (which eats up spurs), an Xray (on which the spur holder is not thick enough) or a TC3 (on which changing a spur is a MAJOR pain in the rear).

Screws that unscrew themselves in cold weather: I think this says it all....

Now quit giving the car a bad rep and seeing problems where there aren't, it's not perfect (none is) but it's way above average as far as quality's concerned, believe me, and I've been playing with little cars since 1986.... And remember that your nice, supertight, immaculate car WILL be in much lesser shape as soon as you run a few battery packs and hit a few walls. It will start being sloppy, make strange noise and be less accurate. Welcome to the RC Car world.

Paul
Lonestar is offline  
Old 08-19-2004, 04:00 AM
  #9458  
Tech Master
 
Join Date: May 2004
Location: New Zealand
Posts: 1,204
Talking Re: Re: Speaking of spur gears......

Beat you by a year, I've been playing with little cars since 1985. :P This is just my first on-road car.
Mabuchi540 is offline  
Old 08-19-2004, 04:18 AM
  #9459  
Tech Elite
iTrader: (14)
 
Lonestar's Avatar
 
Join Date: Oct 2001
Location: Switzerland
Posts: 3,039
Trader Rating: 14 (100%+)
Default

back to business...

tried all my stuff yesterday.

It actually was a terrible afternoon... I had to fight radio glitches for the first three hours... I finally removed my superduper KO Fet servo, et voila, no more glitches... so much for that 0.06s/9.5kg.cm baby...

When my radio problems got solved, I could finally work on driving and setup. It seems that the graphite parts actually made the car way harder to drive (which makes sense). I had to go down in spring rate considerably, now that the chassis and suspension parts don't flex anymore.

The lightnened input shafts DO actually seem to improve acceleration... but it might very well be psychological. But, hey, blue is faster, like we all know

Finally, since we're talking about quite trannies... mine has never been quiter. And I think there's no miracle: all parts but pinion, spur, drive axles and rear bones were changed. The graphite gears seem considerably quiter, but a lot of improvement seems to come from the new front bones... the older ones were very used and distorted around the barrel pin (Ti is softer than steel...). The easiest is to check diff and input gears, as soon as there's an imperfect tooth in one of them, it soon spreads to the other and then finally to all sections of both.

Still gotta work on car setup

Later,
Paul
Lonestar is offline  
Old 08-19-2004, 05:26 AM
  #9460  
Tech Elite
 
Horatio's Avatar
 
Join Date: Sep 2003
Location: Wales, UK
Posts: 3,970
Default

I've always been very happy with my transmission - no problems whatsoever. It was slightly tight when first assembled, but the gears need to bed-in. A few runs and the tranny was both super smooth and quiet. Remove the inner seals from the ballraces and replace the grease with oil, especially if you run stock motors. I highly recommend the blade mod on all the driveshafts too - it's much quieter and removes alot of slop.

I suspect that when this guy actually starts racing his car, the entertainment on this forum will really begin - crikey - and you thought I was bad!!!!

Just warn him now to get all the graphite parts!
Horatio is offline  
Old 08-19-2004, 06:56 AM
  #9461  
Tech Master
 
johnbull's Avatar
 
Join Date: Aug 2001
Location: Malta. G.C.
Posts: 1,762
Default

Hi friends. Greetings from Malta.

I'm glad none of you took what I suggested earlier too badly and both took it in the right spirit. Thank you.

TORNADO.

I have never liked the material of those spurs. Spurs of a material that seems brittle in appearance always seem much noisier. I use RW spurs or Corally spurs but I have used Robinson too with good results.

One more possibility is the pinions one uses. I bought some very expensive titanium pinions a while ago. I put one on the car - fine. At the shop the next day I fitted another pinion but thought nothing of it and went down to the track. The car sounded terrible. Embarrasing noise. I thought it was a motor bearing because it got worse with revs. I ended up changing all the cars bearings and still it did it. I eventually traced it down to one of those expensive pinions. It's gears were not perfectly straight cut but slightly helical. It wasn't doing much good to my spur gears either.

Another possibility here and I learnt this one from a customer CGM. This guy habitually gives the car the most almighty head on bashes. After each one the car developes a real loud noise in the rear diff.

Twice I traced it to an input shaft that is moving back into the diff. With the head on impact the chassis flexes, pushing the propshaft which in turn pushes the input shaft. I told him this couldn't happen if the cross pin was fitted, which on both occasions it was not. Hopefully he'll make sure the pin is always fitted in future.

But this one is an extreme one and I'm sure it's not the case with yours.

Regards
johnbull is offline  
Old 08-19-2004, 07:30 AM
  #9462  
Tech Elite
iTrader: (14)
 
Lonestar's Avatar
 
Join Date: Oct 2001
Location: Switzerland
Posts: 3,039
Trader Rating: 14 (100%+)
Default

Originally posted by johnbull
I told him this couldn't happen if the cross pin was fitted, which on both occasions it was not. Hopefully he'll make sure the pin is always fitted in future.


May I add that I also use Corally spurs and am 100% happy with them? Actually I've been using the same 78 spur for almost a whole season now... and not a single chewed up tooth. I also use Robinson lightened pinions (which seem to be Aluminum).

I was really amazed how quite the car was yesterday, although much less under braking than acceleration... I guess I should use blades on the rear bones too! I know this has been asked already, but has anybody got the part number for Corally blades?

Thanks!
Pau
Lonestar is offline  
Old 08-19-2004, 08:49 AM
  #9463  
Tech Regular
 
Join Date: Jul 2004
Location: Hinckley, England
Posts: 448
Default

Originally posted by Lonestar


May I add that I also use Corally spurs and am 100% happy with them? Actually I've been using the same 78 spur for almost a whole season now... and not a single chewed up tooth. I also use Robinson lightened pinions (which seem to be Aluminum).

I was really amazed how quite the car was yesterday, although much less under braking than acceleration... I guess I should use blades on the rear bones too! I know this has been asked already, but has anybody got the part number for Corally blades?

Thanks!
Pau
what are these corally blades and where do they go? on the end of the driveshafts over the pin that goes through it?
agower is offline  
Old 08-19-2004, 04:36 PM
  #9464  
Tech Elite
 
Horatio's Avatar
 
Join Date: Sep 2003
Location: Wales, UK
Posts: 3,970
Default

Corally or RC Lab blades are used on the dog bone end that goes into the diff out put cup. They are c shaped and fit snugly over the pin. The diff out put cup's slots then need to be filed so that they are a clearance fit with the blades. The slots have to be straight and precisely filed or dremmeled, but it's not hard to do. Also the diff bolt will need to be trimmed to prevent fouling with the end of the blades as the suspension operates during hard cornering.

I think all the details, including part no's and web addresses etc, are way back on page 218(ish) of this very thread.

Regards

Horatio
Horatio is offline  
Old 08-19-2004, 04:39 PM
  #9465  
Tech Elite
 
Horatio's Avatar
 
Join Date: Sep 2003
Location: Wales, UK
Posts: 3,970
Default

Here's a pic to refresh peoples memory:
Attached Thumbnails Yokomo MR-4TC SD-bladesindiff.jpg  
Horatio is offline  


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.