Elektri-Clutch in a 1/8 Buggy

[jhautz]

I have been playing with a new setup for my Xray XB8 buggy using the Elektri-Clucth from the Tekno Revo conversion kit. A few pictures below of what I have so far.

I am using the M2C 3 shoe aluminum clutch setup that I turned the flywheel down to the same diameter as the clutch bell so I could get to the motor screws to tighten them. (please forgive the 2 different motor mount screws. Its just was was handy on the workbench at the moment. I'll fix it before I actually run it.) The dif has been flipped from the normal setup so the clutch bell can run next to the center diff housing. I used some spacers under the center dif mounts so the spur would clear the chassis. The other challenge is the motor clearing the brake disk and calipers. I am using a 48T spur so I get a couple extra MM of clearance and I still cant get less than a 18T clutch bell and still clear the disk. (see the picture below showing the disk/motor clearance) That means I will need a really low KV motor to gear it for track speeds of only around 35mph. I had a 1940/7 that I am going to change to star configuration and run it as a 1940/12 (1300kv approx).

I still need to come up with a servo mount for the mechanical brake, but I think I have a couple ideas on how to do it. (Thanks for the advice Mike)

Here are some pictures posted of the setup as it is right now. I'm still playiong with it and will probably make some adjustents still before it ready to run, but i thought I would post this up and see if anyone had any input on other ways to possibly set this up. I'm trying to keep it simple for now. I just want to see if the clutch helps make it easier to drive on the track. I always seem to have thm most trouble comming out of turns and hitting the throttle to hard and spinning out or just loosing traction. I'm hoping this will make it a little more forgiving. That and it just seems like an interesting idea I wanted to play with.

Let me know what you think so far.

Thats beautiful!

If I were to race, I think I would def have a clutch, but bashing no

Looks awesome!

[DrKnow65]

Scrap the rear disc, most of the braking is all front end anyway. Besides the heavy gear oil you have to run in the center diff (for the big motor to not just unload the front tires) should transfer plenty of brake force too IMHO.

What kind of RPM does it take to engauge the clutch?

[jhautz]

I actully think that I would like to have it setup with a little stronger rear brakes than front. Front only would make it tough to turn in. You would lock up the front tires and then it wouldnt turn at all. I'm not really running much stiffer diff fluid than a nitro runs anyway. I'm only running 7K in the center. I run 5k in my nitro.

Not sure what rpm the clutch engages yet. I have it setup with the standard 1.0mm springs right now. I'm going to start there, but it allows the use of lighter or harder clutch springs to get the feel you want. Not sure If I'll be able to tell the difference on a brushless motor or not, but it does allow some tuning. The stock revo clutch doesnt really allow any tuning thats why I decided to try the M2C. Its just a slightly smaller version of a standard 1/8 3 shoe clutch designed to work with the Traxxas clutch bells in revos with high power (for nitro) motors.

[hemi123]

that looks sweet i like the idea not sure how good a clutch will be for eletric. by the way i like the rear brakes to lock up a little befor the front it does help with steering. let use know how that clutch works out for you.

[lincpimp]

Slick idea jhautz! I have a tekno converted revo and I do like their clutch setup. I am running a L can size aveox motor with a quark air master 80 on 5s lipo. I fell that the combo of the clutch and the 2 speed is allowing me to run a smaller motor than a direct drive setup would allow. Plus my equipment does stay cool! I am actually thinking of building another revo with my spares and trying out direct drive to see how that will compare to the clutch!

[jhautz]

That comparison is actually what I'm trying to do. I have a nitro XB8, a conventional direct drive brushless XB8 and now I am working on the brushless elektri-clutch version of the brushless xb8 with mechanical brakes.

This elektri-clutch version is hopefully the "best of both worlds" Brushless power and speed and convienience, with the nitro low end control and adjustable brake bias. I will be adding a little maintenence with the clutch but nothing comes for free.

I'm looking forward to taking all 3 to the track at the same time and see which allows me the fastest times. I already know which one it wont be

the reality is my driving is the limiting factor on all 3, but the easier it is to drive, the better I can do.

I'am to do exactly the same thing with my RC8. But to the place to use the RCM RC8 motor mount, i've use the RCM revo motor mount. Like that, i can leave the center diff on the stock direction. I've put spacer under the center diff mount (you can see it on the pics, it's red Traxxas spacer for the P2 aluminium pushrod), this spacer is need to allow the clutchbell to clear the rear brake calipers. I've use the Tekno elektri clutch adapter with the 26mm flywheel. I've mount the clutch shoes on the leading way to engage sooner.
The clutchbell is Robinson Racing extra hardened 18T (but i can easily mount a 16T. Due to the 4.3 diff ratio on the RC8, this is the only way i've found to can run revo hardened clutchbell. Because on a stadart 3.333 diff ratio, the only 12-14T clutchbell available was not recomand to run against a hardened buggy spur gear.
The only thing i've to do is to mount my brake sevo with Kingheadz servo post.
My motor is a Neu 1515, 1Y/F with an MGM 16018 + flightpower EVO25, 5000mAh, 4s.

[jhautz]

Looks good David!! Glad to see I'm not the only one thinking this way.

I'm interested in the kingsheads servo posts? Got a liknk to what youa re planning to use? It may be a smple solution compared to the plan I had.

All sounds good. Totally agree on the brake bias - it's one of the only advantages the Nitro has over us. Bias lets you add another tuning aid in your driving.

Keep it up...

DM

[teknorc]

Originally Posted by jhautz

...I am using a 48T spur so I get a couple extra MM of clearance and I still cant get less than a 18T clutch bell and still clear the disk....

Hi,

With a low kv motor and an 18t clutch bell, it will be hard to tune the clutch as you would normally. You may need to remove 1 or 2 springs for it to engage at low RPM and still grab without slipping. The clutches need a nitro RPM range to function correctly. You shouldn't have any trouble getting it to work, but you will need to set it up a little differently.

That said, I really like what you've done with it. Turning the diff around and using the RCM mount will eliminate flex issues so your metal to metal contact should be trouble free. Definitely keep us posted (you too David :).

[jhautz]

Originally Posted by teknorc

Hi,

With a low kv motor and an 18t clutch bell, it will be hard to tune the clutch as you would normally. You may need to remove 1 or 2 springs for it to engage at low RPM and still grab without slipping. The clutches need a nitro RPM range to function correctly. You shouldn't have any trouble getting it to work, but you will need to set it up a little differently.

That said, I really like what you've done with it. Turning the diff around and using the RCM mount will eliminate flex issues so your metal to metal contact should be trouble free. Definitely keep us posted (you too David :).

I think it will be OK. I'll probably just run the .9 or .95 springs if it doesnt grab the way I want with the 1.0 springs. I will be running a 1306kv motor, but it will be running on 5s so it will still get up to 24-25K rpm. It should be fine I hope. If I do run into that as my barrier to making it all work. I can always find a motor with a little higher KV. I have some in the 1500-1600kv range too. I'll for sure keep this updated as I make progress.

Originally Posted by Matthew_Armeni

In this picture i looks like your clutch bell is too far away from your flywheel, not all of the clutch shoe will be in contact with the bell. You should install a shim behind the flywheel and collet to move it forward, I had to do this on my Revo conversion. Looks really good, I like the RCM mount idea, I may try that on my 8ight because its diff is already facing that way.

Good eye... Yea your right about that. I just put it together for fit up and testing the layout. When I put it together I saw that it needed some adjustment, but I didnt feel like messing with the springs again so I just left it for now. Those clutch springs are a PITA. I'll fix it before running it. It will be a few weeks before I get much time to play with this again and finish it up with the hollidays coming up. I will have people in from out of town and then be traveling for a few weeks fr work. I'll be lucky if I get to it again by late January.

[jhautz]

Little update. I think I have the brake servo sorted out. It still needs to have some of the linkages shortened to neaten it all up and I am still missing some screws and using less than ideal screws in other areas just because it was what I had at the momnet, but I just assembled it to test the fit up and see if the mini servo was going to be powerful enough. I'll clean it all up later with the proper fasteners and correct length linages and all.

The goal was to come up with something that would be a compact setup that would take as little valuable chassis space as possible and add as little weight as possible. Again... Thanks for the suggestions Mike!!

It can hold the tires locked up when I drag it across the carpet so that should be enough to lock up the tires on any dirt surface. Something I really like about it is, the whole assembly will lift right off for maintenance of the diff just by removing the screws that take the diff top plate off. It all just stays together as one unit. It also gives me easy access to the thumb screws for adjusting brake bias. It should be just as easy to dial in the brakes as it is on a conventional nitro setup.

I made a carbon fiber servo plate that mounts to the center diff top plate and mounted the mini servo into it. I then made a lever to attach the the linkages to and used it to reverse the pull direction so I could pull the brake cams in their natural direction. I'm also using the lever arm to generate a little more effective torque by mounting the servo linkage to the farthest out hole on the lever and mounting the brake linkages to a hole a little closer in to the pivot point. I used .125 in. CF plate and it all seems very sturdy. I guess I won't really know until I land a few jumps and crash a few times, but I think it will be robust enough to withstand the abuse. At least I hop it will.

Anyway here are a few pictures. Its tough to explain and the pictures will do a much better job.

[starscream]

The HS5245 has the perfect size/weight/power for bashing but for racing, I've been using the HS81MG for a few years now. Its all about leverage
I am also ONLY using rear brakes. You still get some front braking power from the center diff but not much (depends on how heavy the diff fluid is)

I also picked up a Electrik-Clutch adapter. What type of clutch shoes and springs are you using?

I plan to run without the clutch springs so that the shoes will engage sooner.

[jhautz]

Thanks for the comments guys.

Kits are for the pros like Mike or Tekno to deal with. I think Mike is working on his own (probably much better) Elektri-Clutch setup in a 1/8 buggy to see how it works. If it does work well, I'm sure there will come a time when sombody makes kits, just like the direct drive setups now. But at this point I havent even seen a 1/8 with a fully functional clutch setup in it yet, so who knows if there is even a benefit to it yet. This may all be just a big elaborate waste of time.

Originally Posted by starscream

The HS5245 has the perfect size/weight/power for bashing but for racing, I've been using the HS81MG for a few years now. Its all about leverage
I am also ONLY using rear brakes. You still get some front braking power from the center diff but not much (depends on how heavy the diff fluid is)

I also picked up a Electrik-Clutch adapter. What type of clutch shoes and springs are you using?

I plan to run without the clutch springs so that the shoes will engage sooner.

HS81MG Wow thats a small servo for stopping a 1/8!!! Pretty impresive! You are right though, its all about leverage. I think the HS5245 is small enough for me for now though.

I'm using the M2C 3 shoe Revo clutch setup with the .9 springs and Med. shoes. I bought this kit http://www.m2cracing.com/product.sc?...&productId=175 and turned the flywheel down to the same diameter as the clutch bell because It was in the way and I couldnt make it fit anywhere.