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ruebiracer

Building Wrenchdogs midmotor Dyna Storm

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3 minutes ago, Collin said:

:wub:

I was waiting so much for this photos, great that you finished the wing, finally. Also thanks for your comments posted in your showroom.

Now from the distance, I think the whole conversion still keeps the spirit of the Dyna Storm. It feels like it was made by Tamiya. I would love to have used Tamiya style aluminum poles between the upper and chassis deck instead of the premade one for use on drones, but that details would have blowen up costs too much.

But I have to admit, the rear of the orignal Dyna looks fantastic, the organic shape with the motor guard and the gear cover. The Mid Motor is a bit choped off, but no wonder, no motor there LOL.

 

Thank you so much Tom, for enabling me to build this beauty! Regarding the choped off rear look, even that is totally Tamiya 90´s and reminding me of the rear of my Top Force Evo very much!:wub: Got to love both Dynas! But you really put so much design love in it, it looks totally Tamiya. And sorry, that it took the whole winter for the final steps. Now only the 5 on the wing sides is missing, have to cut them out of the big sticker avoiding the black framing.

And as soon as it gets warmer, I will take the next ride in the garden to run it in, but with care.:lol:

And I just noticed that on the rere the old spike tires are on as with the original. As these are not available anymore, I will keep them for the shelf and dig out some square spiked ones for the moment. If the cooling of the cheap ESC gets critical on warmer days, I´ll maybe add a fan under the body. But first let´s see, how it performs without...

:)

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Cooling is indeed a good point. Now the airscoop at the left side is really tiny. My LRP Indy 600 switched off after 10 minutes of full on, which is pretty much okay I think. No I have the GM V12 which is much more modern electronic and I think it will work even better.
 

 

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Well, this nice little beauty is giving me a hard time running it in!:rolleyes:

Yesterday it were the batteries fooling me, so today I finished the body fixing with the kit supplied tape and a little foam for the battery brace.

Then out in the garden of my wife´s dad, but unfortunately still high winter grass. I used the square spikes of my other Dyna together with the ribbed front tires to not get a rollover problem with the shiny new body. 

Well, at least that worked! Made some nice jumps downhill, no harm to the car. Really good absorbing now with the 2 hole pistons in rear, and adjusted ground clearance. But launching still made some strange sounds sometimes. So I digged out my boxwrench and wanted to tigthen the slipper clutch further!

The nut and spring were already quite hot, couldn´t touch it longer with my finger. Totally clear , I thought, due to high grass and the brushless power.:lol:

No, that did not help! Again, I thought about a build problem in the Multi disc clutch system. So I went to the road, and there was no problem at all. Car felt great even with the offroad tires! Relatively small turning circle with the not very grippy old rib spikes in front, but you really had to turn quite small and go early on the gas, to do a powerslide! But no 360, always controllable, even offpower turn in in 180° turn! :)

Loved it! It did roll noticeably in a tight turn, but very parallel f/r! Tom did a good job sorting the springs out, I tend to say! It tracked straight, soaked up bumps on the road nicely. And that with nearly no clutch effect for smoothening power delivery.

So I went back in the house and searched my high grip problem again: Clutch checked and compared to my original one, torque testing with hand and brutal force: It works fine, I´m quite sure now! Heat problem was finally identified after checking the quick closure cap for the adjusting nut: This was mountable, but comes in contact with the spring, which caused just enough friction to heat the parts up, but not bind too much to be obvious!

In parallel, I digged out the ball diff again, to check for heat traces or wear circles on the pressure discs: Sweet, looking new, I thought. Building everything together, and get out in the evening again! 

Guess what: I´m still missing some traction up the hill and out of the corner! :ph34r:

Then I did some rookie maneuvres, like going backwards and fully launching forward suddenly: There were again the whining sound and clearly loss of drive. Tires grip, but torque is lost. :wacko: 

Feel like a Newbie, after all this years.:lol:

Really not keen to tear down everything again, hand testing the diff pressure was o.k. acc. to manual check, tigtened it so much, that I really could not turn the gear with my hand. Plus the fact, that the DS diff is not a weak design, never had a problem with my Original Dyna Storm.

Last suspect for today is the tires. I didn´t glue them yet, so maybe these are turning on the wheels!?  Still cannot believe it, to be honest, but some quick drops of glue is for sure quicker than tearing everything apart again...

Keep you posted, otherwise it´s already great.

Engine cool as can be, Esc just slightly warm after my misuse tests.;)

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That sounds like my last outing with the Boomerang, hardly one undisturbed run...

The tires can slip quite fast on the wheels, even though they are tough to get on. From my experience, I would not suspect the Dyna differential at first.

The slipper clutch acts pretty fast in my Blaster and had to be tightened much more than the manual suggests (running on sand), which makes me pretty sure it is not good for high traction. But I am curious what @Collin has to say to this topic.

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Gras is the surface I avoid most. It kills everything, (more or less) in compare to other surfaces.

@ruebiracer How did the clutch discs look like when you disassemble the MDC? If the fiber discs are glossy (after getting too hot) you need to sand them down. I would check all discs with 600 grid sandpaper (wet) for being flat. Are you shure you assembeled everything correct? One I pulled the whole MDC off the shaft and back on, thought I can place everything correctly without opening the clutch, no, it was not an one metal disc was not sitting nicely on the flattened part of the shaft.

The MDC fades a bit when getting on temperature, its simply what it does. Also Its good to know the difference between diff screaming and MDC screaming. Its a different noise. Also for setting up the clutch (MDC & slipper), I stop the car in front of an obstacle (on the surface I want to set the clutch for) and give some gas. If tires dont turn, and motor is spinning, the clutch is too soft. Tighten the clutch nut, and go again. Just very short, dont burn the clutch. Once the clutch is transfering power to the wheels (car want to push the obstacle) you found the sweet spot to start working. Now its only a tiny bit loosening or tightening the nut to set it correctly, but you are most likely where you want to be.

Does it help?

 

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Thank you guys for the good advice!:)

I hope to have some test time this evening again. Tires are glued now. Clutch is lightly closed for the start (hand test). Yesterday I checked the assembly the third time, since I built the car acc. to the manual. Everything seems fine. Discs are hardly used, maybe a little too smooth, so @Collin could be on to something with the roughness.

But for the start, I´ll try it with the glued tires, and see what will happen. From my experience with the MDC, it has always been bulletproof to me with a 13x2 wind motor maximum I used in my Dyna Storm. Just cannot believe, that it´s not possible to fully lock it. But next tests will tell!

If there will be still a torque loss, I will tear everything down again and make some photos for TC. Could maybe be helpful to someone else in the future.

Quick change could also be just swap the clutch of my second Dyna on the Mid and also compare the behaviour.

Anyway, thanks already for your help, really appreciate it!:)

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Matthias, bevor you havend glued tires :D you should not do anything else around the drivetrain.

Sand down the discs gently, just a few times up and down, clean it, dry it, mount it, run it. Twist it, bop it, turn it, ... and so on... :blink: :lol:

 

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And if you need fresh carbon discs, give me a shout, I still have your envelope here...

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6 minutes ago, Collin said:

Matthias, bevor you havend glued tires :D you should not do anything else around the drivetrain.

Sand down the discs gently, just a few times up and down, clean it, dry it, mount it, run it. Twist it, bop it, turn it, ... and so on... :blink: :lol:

 

**** true! Never did it before with these kind of tires from Tamiya, but it is possible, that they turn on the wheels. Just a question of torque. The same hill got me last year with the knowledge, that even on my Brushless Monster beetle the tires slipped on the nice Aluminum wheels and limited my uphill speed.:lol:

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2 minutes ago, Collin said:

And if you need fresh carbon discs, give me a shout, I still have your envelope here...

If the tires don´t do the trick, next guess is the clutch internals. If I don´t come any further with the std. discs, I know you have the nice carbon discs...;)

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Btw. got some very cool Top Secret Tamiya papers.... :ph34r:  this is how they thought about using the MDC with different order of discs.

TRF211X_MDC.bmp

 

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5 hours ago, Collin said:

Btw. got some very cool Top Secret Tamiya papers.... :ph34r:  this is how they thought about using the MDC with different order of discs.

TRF211X_MDC.bmp

 

Wow, ths is very cool Tom! Just don´t understand the adjustment extent from the picture. But I guess it´s the preload of the spring. And right side is sanded!

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On Dry-Clutches you have hard and soft discs. (C)arbon and (S)teel in our case. Depending on how you put them in (for example configuration B:  C-S-C-C-S-S-C) you have different friction between the discs. Pretty clever : )

 

It has nothing to do with the preload, becaus you still use the same package of discs.

 

Edit: But to be honest, I have to find out what they meant with small/mediulm/large. Maybe there where differnent aluminum spring discs which change preload indeed.

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Just got out for a quick run before sunset: ;)

At first the lawn mower was here, so conditions were more consistent. The glued tires were on, and off it went. It´s a beast! Definitely some of the topspeed was lost in the tires:ph34r:. Buuut: I still have the strange noise during kick down. But it´s fast nevertheless, also in acceleration. Uphill is also big fun now. Minute after minute I stopped to increase the preload a bit, to see if it helped. I´tend to say, the noise was shorter, but still there! I don´t really know the difference between diff noise and clutch yet, to be honest. Just have my doubt, that the diff would be so loud with all the grease in?:wacko:

 I didn´t find circular traces on the diff plates during the last 2 tear downs, that would indicate excessive slipping. Buuuuuut, I used no ball diff grease during the build. Instead I chose Tamiya AW grease. I have very good experience with it in my Sand Scorcher ball diff (Tamiya Version 1). It gives a little more locking effect on the beach and I never had the problems that other users reported on the V1 diff so far. But it leaves the bad taste, that it could be not good for the DS... Maybe it works o.k. to a certain torque, and is then slipping without creating wear, Lol. (Anti wear grease):lol:

From my feeling and hope, I could better live with the thought, that the very smooth looking clutch discs and washers could create such a noise, if they were not broken in correctly last year, as @Collin suspects. (Too much heat in the beginning, glass surface)

Anyway, we come closer to the problem, tires are out at least! I don´t want to take everything apart now without a plan, as I really want to know the defintive root cause now. So next run will be with the complete clutch or at least internals from my second Dyna Storm. If the noise is already gone then, the hottest trace is the MDC and not the diff for me...

Keep you updated!;)

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Sounds good already!

Diff screams higher frequency in my opinion. But to be shure, you can really tighten the MDC to see which noise becomes lounder. You will not ruin the diff immediatly (even if some people say so). I have to admit, I tighten the diff a bit more after a short run and I am probably more on the tight side of life (then others). After a few runs on the track I could not spot any excessiv wear.

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7 minutes ago, Collin said:

Sounds good already!

Diff screams higher frequency in my opinion. But to be shure, you can really tighten the MDC to see which noise becomes lounder. You will not ruin the diff immediatly (even if some people say so). I have to admit, I tighten the diff a bit more after a short run and I am probably more on the tight side of life (then others). After a few runs on the track I could not spot any excessiv wear.

I think next week latest I know all kind of noises in this drivetrain, if it continues this way!:lol:

But thanks again for good tips Tom! The sheet is awesome Tamiya secret info! They just should have made differnt drawings for the extent, then it would be more clear. I also think some ball diffs need a liitle settling in. Last year I already did that after the first run, as it was too loose (anxious me). But it has a lot more pressure discs than my other Tamiya diffs, so I was not brave enough it seems.

But the driving: I already can say that uphill on gas it keeps the nose better down compared to my rear motor Dyna, as you would expect from the motor not hanging out in the back of the car. It was real fun already despite the tranny problems. (Which are totally not part of your conversion). 

I love this thing already!:wub:

One point down for my set of MCI Dyna Storm decals already: I think I ordered with the protective coat. (the Blue/red Dyna Storm original set) on 2 decals in front, which come in contact with the slightly wet grass, the coat is peeling already like a snake skin. I removed it completely on one, still looks good under the coat. But seems that this optional coat is not a good idea for a runner...

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Another thing I checked yesterday again: I was running 28T pinion /120T spur giving 8,57:1 gearing with the cheap Speed Passion Sportsman 13,5t (closed can type). TBLE02S ESC, so zero boost. Motor is **** cool all the time, even on the high grass / uphill torture. So ratio wise, with Brushless you can go even longer from the gearing, I´m pretty sure. No fan needed for the motor. Just for the ESC on hot days probably.

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Exactly my thought about MCI decals, the coat is so much for the bin.

I studied the manual where the clutch sheet comes from, no word about other shims delivered from Tamiya. But every M4 shim will do it. Maybe one of the former drivers know about. But if you ask me, its more then enough to re-arrange the clutch discs if necessary.

About drivin difference between Dyna and Mid. The orignal Dyna runs really good as it is. The advantage of the Mid Motor is just the weight ballance. I am curious how different rear suspension mounts (3°/4° antisquat) will change the handeling.

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Always forget to not use "bad " words on TC. Good luck the software always comes to my rescue!:P

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2 minutes ago, Collin said:

Exactly my thought about MCI decals, the coat is so much for the bin.

I studied the manual where the clutch sheet comes from, no word about other shims delivered from Tamiya. But every M4 shim will do it. Maybe one of the former drivers know about. But if you ask me, its more then enough to re-arrange the clutch discs if necessary.

About drivin difference between Dyna and Mid. The orignal Dyna runs really good as it is. The advantage of the Mid Motor is just the weight ballance. I am curious how different rear suspension mounts (3°/4° antisquat) will change the handeling.

Antisquat is for sure some tuning potential for a RWD car.

Yes, I think they mean the preload. Maybe they measured geometry as indicator, and extent is what is the shaft coming out of the adjusting nut or sth.. Another washer is not really needed, when you can adjust the preload with a spring...

But they only sand the bigger FRP discs, not the metal shims, right? Probably that would end up in big wear, if you would sand the metal shims with #300 grit sandpaper.

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The metal discs are very hard, you can not  sand them down so easy. Yes, its the FRP discs you work on. I do just a qick sanding on the steel discs to clean them and see how flat they are.

You are right with the preload. I think the drawing (small/medium/large) means how much of the nut is tightened on the shaft and how much thread is shown free.
Butits still funny, how they offer you different settings.

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14 minutes ago, Collin said:

The metal discs are very hard, you can sand them down so easy. Yes, its the FRP discs you work on. I do just a qick sanding on the steel discs to clean them and see how flat they are.

You are right with the preload. I think the drawing (small/medium/large) means how much of the nut is tightened on the shaft and how much thread is shown free.
Butits still funny, how they offer you different settings.

For sure something we have to try out Tom! :wub: It´s really clever. The number of contacts inside the press force do not change, but the friction values change by sorting metal to metal instead of metal to FRP in all the parts...

And with conductivity, I guess they refer to the thermal conductivity, so heat transfer changes/slows down a bit with sanded plates. Would make sense, as the the roughened material has less contact points to the metal shim...

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Just edit above, the steel discs are NOT easy to sand down. :D

About the various MDC settings, I am wondering if I EVER would notice a big difference. I think the right tires and suspension setup will do muche more difference.

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Hi everyone, today was another test run, now with the clutch internals of my second Dyna. So this clutch was run in over the years, and clearly wearing on the complete disc surface already. This resulted already in no noise with light pressure and good acceleration, although a little clutch "phase" was noticeable. I run 2 minutes, and then decided to go reverse and launch full throttle whilst rolling back. There was a little whining sound again, but quite short. I repeated some uphill accelerations from standstill, and there was always a little noise. So I tightened the clutch some more, to get more "lock". Then it became clear, that the noise was worse / longer lasting. Guess what, It is Diff noise. To verify it, I llosened the clutch clearly to get less "drive", and it the car was quiet. With the looser clutch, I couldn´t get above the torque limit of the differential.:P

In principle, I could run it that way now. I just tightened the diff screw half a turn more until I felt what must be full lock, and backed off 90° again, before securing everything with the lock screw. I´d say on 90% of the surfaces it will be now problem anyway, just on the very high grip situations, and when using nearly no MDC effect. Maybe there is also some gain in diff torque by using real ball diffferential grease. But actually I don´t like the Tamiya ball diff grease, as it can get "gritty" with heat and time, letting the diff feel very notchy. At the moment, it runs smooth, with a good locking effect, though I misused it as second clutch.

I think I will drive my original Dyna Storm first on the same ground with the same tires, to see how it performs here vompared to the Mid...

 

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