Modest E-Slayer

[mulepic]

I've seen a few questions about the cost so I thought I'd post mine. I did join the Tower Hobbies club which saved a bunch.

slayer 379
havoc 10.5 150
futaba 3pm 179
battery 65
charger 25 (it's a cheepo I've had for years but works)
total $798
tower discounts -$130 (at least this it's probably more like $150)
sold motor -$125
[*]final total $543 [/*]
I thought this was a pretty good price for a 4wd truck that performs awesome.

[mulepic]

I have a little update. I installed the sway bar and I concluded the rear one didn't make much of a difference so I'm running the front only. I'm running the sliver one at the softest setting. I just didn't like how it ran with it any firmer and it didn't prevent it from rolling over anymore than the softest setting. The other major update was the motor. I upgraded my esc to the novak hv and I put a ballistic 5.5t in there. I retarded the timing and got my top speed just over 32mph and my runtime was a little over 20 mins. The motor didn't get very hot at all considering how hot the pavement was. Here's all the stats:

-novak ballistic 5.5T
-2s lipo 4000mah
-narrow gear set
-2nd gear locked
-10T pinion
-40T spur
-running weight 7lbs 2oz (The bigger esc and sway bar added a couple oz's)
-outside temp 95F
-ground temp 145F
-Total run time was 20 mins
-ESC temp never above 150
-Battery temp never above 105
-Motor temp never above 130
-Top speed 32mph

I'm going to install the esc fan and rerun this test after the sun goes down so that the ground is cooler. I'm hoping everything will run cooler and maybe I'll get longer runtimes. I'm fairly impressed that this hot motor isn't running so hot and my top speed is pretty good.

[mulepic]

This test the ground was cooler at 100F and I ran WOT pretty much the whole time and added the esc fan. My run time increased to 23 minutes and my temps came down.

-novak ballistic 5.5T
-2s lipo 4000mah
-narrow gear set
-2nd gear locked
-10T pinion
-40T spur
-running weight 7lbs 2oz (The bigger esc and sway bar added a couple oz's)
-outside temp 95F
-ground temp 100F
-Total run time was 23 mins
-ESC temp never above 108
-Battery temp never above 105
-Motor temp never above 115
-Top speed 32mph

Here's a picture of it all together.


I'm thinking about moving up to the 12T or 15T pinion just to see how fast it will go but the 10T is just awesome with the instant torque. It's a lot of fun to drive.

Next I'll be putting on the carbon fiber chassis and looking for a way to lower the motor and battery to lower the center of gravity.

[mulepic]

I installed the vantage carbon fiber chassis today and lost some weight and I'm finally under 7lbs



I hope to get close to 6.5lbs when it's all said and done.

The stock chassis weighs 8.25lbs and the carbon fiber chassis weighs 4.5lbs so it's decent weight savings.

Here's a picture of the chassis installed:


I have not driven it yet because I don't have a good way to mount the battery. I don't know much about carbon fiber so anyone with some info please chime in. With the aluminum chassis I simply set the 2s lipo on the aluminum arm that stuck out. I have fear that the carbon fiber isn't as strong and it will break. Does anyone have any experience with carbon fiber they can share regarding it's strength etc? Thanks for you help.

[jammi]

I dont hold back with mine and as yet have not seen any probs with the chassis there are a few chips on the bottom atm but other then that its fine I have the blue groove battery tray and it is connected via two hex and bolts and has also been fine

[mulepic]

I was just looking at your pictures of the battery tray. Does the arm that extends out under the battery support any weight? It sort of looks like there is a space above it and under the battery tray.

[jammi]

na it doesnt support the tray its about 3-4mm away

[TXSuperman2005]

Looks great Mule glad to see you getting the weight down, the 1/10th motor should be great on there now.

[mulepic]

I made some progress on reducing the weight. I made my own motor mount which removed 3 ounces and I made aluminum push rods which reduced another ounce.
Here's the motor mount. It lowered the height of it considerably.

So here is my new weight:

I have nylon shock bodies and a smaller esc on the way that hopefully get me to 6.5lbs.

[mulepic]

For kicks and grins I decided to do a couple speed runs w/ the 12 and 15t pinions. From above, I normally run the 10T w/ a top speed of 31-32mph b/c I'm a bit conservative and I like to keep the motor in the 120F range. Anyway the 12T put the slayer at 36mph and the 15T put it at 43mph. We ran the 15T for about 10 mins w/ no heat issues but it was in the 140'sF range.

[mulepic]

I just noticed my mistake above:
"The stock chassis weighs 8.25lbs and the carbon fiber chassis weighs 4.5lbs so it's decent weight savings.
"
lbs should be ounces.

My latest updates include a smaller ESC and swapping out the aluminum shock bodies for the nylon ones. The aluminum bodies weigh 6 grams and the nylon ones weigh 3 grams. So while it's half the weight it only totals a reduction in 1/2 ounce. I'm finally in the 6.5lbs range. I'll add a picture when I'm done w/ the shocks. At this point the truck is very light and now the shock springs seem too stiff. I'd also like to have the truck sit lower but not shorten the push rods to accomplish it. Does anyone have any ideas?

[mulepic]

Mission accomplished, the e-slayer is 6.5lbs; significantly lighter than stock.


But now I have the center diff and rear brake kit coming so I'm going to have to find some ounces to make up for it. When I was looking for weight to shed I shortened my power wires and lost 3/8 of an ounce. I was surprised they were that heavy. So I may look to the motor wires for more weight.

[Stockslasher]

I like the new motor mount. I can see a billit aluminum version coming from one of the majors someday. This must drop your CG too!

Like the build Mole and may copy with pride soon.

[mulepic]

For kicks and grins I purchased a smaller battery. I figured if I ever raced this thing I would want it to be as light as possible and it only needs to survive for 5mins. I needed a battery that would put out 63 amps (420w/6.4v=61.8amps) continuous as to not over heat it. This battery: http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXWRB5 is 25c so 25*3.3=82.5amps

When I installed the battery naturally I had to weigh the car again and it's down to 6lbs 5.25 ounces! I was surprised that I actually got 20 mins of bashing out of this battery but take that w/ a grain of salt b/c I stopped frequently to check the voltage and the temparature. Nonetheless it should have plenty of capacity to get through a race. Also the temperature never got above 100 (outside temp was 96) and the motor and esc ran cool as well.

[jammi]

you could save alot more weight by getting rid of the brake and servo etc, have you tried the carbon brake disc most porb only save you 5 grams but then again.

[mulepic]

I agree loosing the mechanical break would save a lot of weight but then my motor would overheat trying to slow the thing down. I really feel it's the mechanical break that is allowing me to use a 540 motor in such a heavy car.

[rc-cpr]

I agree loosing the mechanical break would save a lot of weight but then my motor would overheat trying to slow the thing down. I really feel it's the mechanical break that is allowing me to use a 540 motor in such a heavy car.

Agreed - my MMM ESC runs incredibly cool because I'm still using the mechanical brakes.

[mulepic]

Maybe it's just me, but I think everything looks better with larger tires.


This was a simple mod to get the Axial Rock Lizards on the Proline beadlocks. And they are actually staying on the tire for my initial street testing of 30+mph and some heavy dirt/rock terrain.

[mulepic]

Here's a little update. The modest slayer became not so modest. I installed a tekin rx8 w/ the tekin 2000kv motor. I had to gear it way up to 25T/40T(pinion/spur) and add another battery; now 4s. All the extra weight put a pound on the car; back to 7.5lbs and it showed.

I don't want to ruffle any feathers but I know conventional thinking says the slayer is too heavy for a 540 sized motor but I have to disagree. I only ran the tekin for a few minutes just to see how fast it would go. It was so unstable with the extra weight that it took me several attempts before I could open up the throttle all the way. The handling absolutely, hands down sucked. And I'm pretty sure it wasn't even as fast as my final 540 setup above. So I will be returning the e-slayer back to my last setup described above b/c I could power slide the thing and drive it very aggressively without flipping it. With the larger motor I barely got it out of the garage before it flipped over. I think it flipped over as soon as I put the battery in

Now, I do have a bunch of extra parts and I'll be piecing together an e-revo and I do think the wider stance will provide for a much better platform for a motor of this size and the added weight. But, my conclusion is that the slayer is too narrow to weigh more than 6.5lbs and be a fun car to drive. Just my opinion, I know other have had different success and everyone should do what is right for them.

[MudFlaps]

Sorry about digging up the thread but I have to give you credit for inspiring me to convert a slayer this way. Especially now with the surge of 4wd electric SC. I plan on using the Hot Racing motor mount with the Velineon system on 2s ( possibly 3 )

Thanks again for all the info.

[mulepic]

No problem I actually drove the car yesterday b/c it's a blast to jump, etc. I'm not familiar w/ the hot racing motor mount but I know when I made a simple mount out of angle aluminum I shed some weight (as stated earlier) and removed cost. The key is getting weight down to the 6lbs range. Have fun.

[MudFlaps]

Good to hear it is still running strong. I am considering the Hot Racing mount because it is made for 540 motors but I am concerned with the COG. It does put the motor towards the middle of the chassis though. Toss up between that and the RC-Monster mount.

Are you still using the Vantage chassis?

[mulepic]

The vantage chassis is a good option if you can find it for cheap, it does save some weight. I got mine off of ebay. I'm currently using the chassis in a summit build.

[MudFlaps]

Cool...I was curious about it's durability

[mulepic]

I'm starting this build back up with the new slayer pro wider suspension arms and longer chassis.

The goal is still to make it as light as possible. The suspension arms are on the way so I got started on the chassis. I took the longer blue chassis and made swiss cheese out of it w/ the drill press. I reduced its weight from 9 to 6 ounces. I would like to get another vantage chassis b/c I guestimate it to be only 5 ounces. But I'll do that once I have it all together and the SC proves to be a good performer.

As of now I left out the mechanical brake. I haven't gotten a sense if the heat is an issue or not. The outside temperature is cooler these days so it's hard to compare w/ my build during the summer months.

Currently I'm running the old slayer arms/body w/ the new chassis and my weight is at 6.5lbs. When I get the new arms on I'll post some pictures. With the larger footprint I think this thing can really be competitive if I can get the weight down to 6.25-6.5lbs. I've also lowered the front 1/4". BTW, from the review I read the 5907 RTR weight is 7.75lbs so reducing the weight by 1.5lbs should certainly improve its handling.

Stay tuned for details.

[mulepic1]

I just found the new forum website and had to create a new user name.

Anyway, I installed the new wider suspension arms and this thing rocks. Even w/ my earlier light weight build I could easily make the slayer barrel roll. Now w/ the new arms it just power slides and does a 360. I'm actually surprised how much more stable it is than before. A new body should be showing up today. Once I have it on I'll take some pictures.

The new arms added 3/4 ounce of weight and my current RTR weight w/o the body is 5 lbs 12 ounces. I expect w/ the body it will be 6.5 lbs. My top speed w/ the 5.5T novak 540 ballistic is 32MPH. I'm currently running the standard gear set in the tranny. I need to install the narrow gear set and I should get more runtime out of the battery and probably still hit 30mph.

THIS THING IS SWEET!

[SilentWolv]

Had a hard time getting back into the forum myself, but hitting the "contact" twice at the bottom of the page, the guys helped me out.

Nice to hear the wider footprint is awesome, as I hoped it would be. Post up some pics when you get the body, and the final weight.

I got my Slayer Pro 4X4 last week, and went from 8lbs to 5.5lbs when I took all the nitro carp off! hehe
I've ordered the e-revo mounts to see if I can make a "traxxas" parts conversion fit first, later I may make my own mounts.

[mulepic]

I just purchased the vantage carbon fiber chassis which should take me down an ounce. The body showed up and my rtr weight is 6 lbs 5 ounces. But I'm debating using a 550 motor or the current 540 w/ a 14mm rotor. I'm considering racing this thing now that it seems worthy. The track said I would race w/ the 1/10 4x4 SC open class if there is not enough 1/8 SC's. I think this thing would have more of an advantage in the 1/8th class b/c of it's low weight. But in the 1/10 class it has a wider footprint.

[mulepic]

I installed the vantage chassis this morning. I've not even driven it yet but I thought I get some pictures out there.



In the background you can see the blue chassis I drilled



I'm still working out the details for the battery mount. I like it under the chassis b/c it's much lower but doesn't bottom out. As it sits w/ that 3.3A 2s lipo, the RTR weight is 6lbs 3 ounces.

[SilentWolv]

The chassis looks awesome, and 6lbs 3oz is incredible!! Yeah, the battery placement needs more work. Is there a way to keep the nerf bars on to support the side of the body?

[mulepic]

I'm just about done w/ the battery placement. I can easily put on the nerf bar on the motor side, I'll look into adding it to the other side. It's probably good to have these as a defensive measure, but I don't think they reach out to the body. I'll take another picture when I'm done.

I'm debating whether to add the center diff. I can't seem to get any info on how this works out w/o mechanical brakes. It seems like it would bias the back which wouldn't be so bad for an SC. Yet the center diff will probably reduce the understeer or push 4x4's exhibit.

[SilentWolv]

Check out the TWO conversions Divey1130 over in the other thread did into an E-Revo. The motor is up higher with the second plastic chassis, but the twin 2S packs on either side are lower, (like you liked), so the net CoG is prolly the same. Personally I like the rigidity of the alum chassis, but it looks like a clean build. Check out the 1st conversion with the aluminum chassis, looks great... http://traxxas.com/forums/showthread...o-Erevo-Builds ..

I ebay'd the E-revo motor mount, but the E-Revo and Slayer Pro transmissions are not the same, so the E-Slayer conversion is not gonna be that easy. I think the smaller Revo transmission is single speed? So my choices are to buy the E-revo transmission, or to get the Tecno conversion kit... http://www3.towerhobbies.com/cgi-bin...2785&search=Go .. I do like the way the Tecno battery tray bolts on, so I'll prolly get both, just use another motor mount.

The nerf bars are about 1/4" from the body sides. I put the velcro soft side on the bars to eliminate any rattle, and my 4X4 Slash feels pretty solid for trading paint. (defensive like you said <G>)

I'll eventually want to put the center diff in my Slayer Pro. If the transmission is locked down, you wont need a mechanical brake, and the Slayer only has one brake anyway, so theres no brake bias. As the weight transfers forward, the front brakes harder, a bad thing. Again in my Slash 4X4, the center diff allows the front and rear to stay "hooked up" in the corners as well as in the straights. A trick I use in racing it is to initiate the turn-in slightly before I put the brakes on, and the truck continues to rotate nicely. Here's a vid. I'm "Paul" in the second qualifying position driving the black Traxxas 4X4. I like this vid because its one of the few times I beat my son-in-law Brad driving the white/green Hyper 10..... http://www.youtube.com/watch?v=yM2t6tTzljg ..

Anyway, let us know how your lighter e-Slayer drives. You still thinking about racing it? Should do well in either class.

[mulepic]

Thanks for the info. I do prefer the nitro chassis. I learned the erevo plastic chassis weighs the same as the blue aluminum one. But I don't think you could drill out the plastic one to save weight and still have decent strength. I did learn last night from a very smart engineer that I can drill out the carbon fiber chassis w/o too much conern about the strength. I won't use as big as holes as I used on the aluminum and I'll probably go about it more conservatively. I hope to shed an ounce off the chassis and get it in the 4 ounce territory.

I cleaned up my battery mount. I'm pretty happy with it. If I was using this as a basher I wouldn't mount it like this. I would mount it up higher like I had in the past. I'm not fond of the battery in the picture b/c it has those plug-in battery leads. I'm hoping to find a way to solder wires in those holes w/o melting the case. I also don't like the battery b/c it's so heavy. It's a 5000 mah and weighs over 10 ounces. The 3300 mah I hope to race with is only 6.5 ounces or if I need more I have a 4000 that is 8 ounces. I had to create a rubber bumper for the front of the battery to be able to access the plug-in leads. I need to figure out how to get those out of the battery.



You can see the nerf bar on the far side mounted w/ existing chassis holes. The one on the battery side is going to take a little more thought. But I do want to keep them on.

Center Diff:
From what I've read having the center diff and using the motor to brake will cause the rear to be biased and depending on how thick the diff fluid will determine how much if any braking will go to the front. I think this will suite my driving style and it sounds like it would work for you as well (if I understand your turn-&-brake technique correctly). BTW the slayer does have a rear brake you just have to buy it separately http://www3.towerhobbies.com/cgi-bin...&I=LXMHR2&P=ML. But you do bring up a good point, if I have to go w/ mechanical brakes I could just use the rear to get the same feel as the motor brake setup.

[mulepic]

I drilled out the chassis and removed 3/4 ounces from it. I also drilled out the cantilevers and got another 1/4 ounce out of it. I just received the composite shock boddies and will install those shortly. Here's what it looks like in race form. The RTR weight w/ a 5A 2S lipo is right at 6 lbs 8 ounces.



I took it to the track last night. This was my first time driving an RC on the track. My concerns going in were my driving ability and the slayer. I thought the slayer was too big for the track and it would handle like junk. I was also concerned my nerves would get the best of me and I'd be upsetting the regulars. Well here it is after 3 hours at the track:



It's wearing AKA Enduros, super soft, b/c that's what the track pro said to use. In total they added 2 ounces of weight compared to the stock tires but these tires were amazing.

I'll give the details of my setup in another post. But I cannot tell you how happy I am with the performance and durability of this thing. It handled amazingly well. It had great steering, I could slide it into a turn or I could slow up and take a sharp turn w/o pushing. It had great rear end grip. Very seldom did the rear end get out from underneath it and spin out. Jumping was awesome, I could tell I had much more control over my jumps than some of the other SC's out there. Towards the end I was flying the tripple w/ some consistency. AND TRACTION ROLLING IS A THING OF THE PAST!!! Only a couple times I got the slayer on two wheels but I could manage to bring it back. As for durability the Slayer gets an A+, the only issue I had was with my custom motor mount. It just couldn't handle the abuse of nose diving into last jump of the tripple or casing other jumps. I know how to fix it though. But nothing on the slayer gave me issues, NOTHING.

In the end my driving was not an issue b/c the slayer is so easy to drive. It's extremely smooth and responds to throttle and steering input well. As for it's size, it's definitely bigger than those tiny SC10's and HPI's but it didn't look out of place. Again, I'll give more details in a later post. Once again, this wider/longer Slayer rock, nice job Traxxas!!!!

[SilentWolv]

Not a big fan of the swiss cheese, but the conversion to an E-Slayer looks pretty good. I'm excited to hear it handled and jumps nicely. I'm sure the tight turns are due to the center diff. My Slash 4X4 is about 6 lbs on the bathroom scale, so yours is slightly heavier for the 10th scale 4X4 class, and slightly underpowered, (but lighter) for the 4S 8th scale buggies. I would think the SC 4WD class would be a better fit and the longer wider wheelbase a definite advantage. Sounds like it handled so good, a 3S might be in order.

Makes me want to hurry up get my E-Slayer together. I bought the tekno Slayer conversion package for it, s'posed to arrive next week.

[mulepic]

I don't like drilling the chassis either but when you're scraping for fractions of an ounces, it was worth it. And after last night I feel confident it'll still be strong.

My logic around my weight obsession is actually quite trivial. I watched cars on the track that seemed to just float over bumps and glide around turns. Then I got a duratrax 1/18 SC and built a track in the back yard. I noticed it too floated over bumps and glided around the turns. I figured it had to do w/ the distribution or ratio of weight of the car. So I use a basic furmula of Area/rtrWeight = stabilityFactor. Area=WheelBase X TrackWidth. Of course I understand the height of the COG and suspension tunning makes a difference but all those equal the greater the stabilityFactor the better it will handle. I calculated the stability factor of the dtx and it was 27.5. I actualy have two dtx sc's and one is lighter and is near 30. BTW, 2wd SC's are around 30. I then calculated the stabilityFactor of the old slayer w/ and w/o my weight loss mods and it was between 19-22. And of course the way the revo/slayer setup is the COG is even higher. So this confirmed (in my mind anyway) why the slayer was so tippy. I actually tried to sell my slayer once w/ no luck.

When the new wider/longer slayer pro came out I recalculated the stabilityFactor and figured I could get it over 25 and maybe to 28. This was my motivation to keep it and do the slayer pro conversion. The current stabilityFactor is 26 and as I said above it handles awesome. It handles darn close to my dtx SC. So now you know why I'm finding every last ounce to shed. I think I can get it to 6lbs w/ some creativity. Heck the body itself weighs 8 ounces and the new tires added 2 ounces. I'll be looking for lighter bodies and tires in the near future. Next post I'll talk about my suspension and motor setup.

[privatesposato4]

hey, wanted to ask,

Are you limiting (or being limited by) your battery power with your setup? Because i too have an e slayer but ive got a novak 5.5t and hv pro esc and use a 3s lipo on it and the thing goes very fast for the weight.

But i really do like this build. Being able to run this tubby on a 1/10 motor system (i presume) is sure on heck of a feat.
And lastly what springs are you running? Im wondering what configuration will keep my inside rear tire from lifting in a turn.

thanks

[mulepic]

Finally got some time here to post my setup.

Front suspension:
Toe out 1 degree
camber negative 2
roll center lower
caster 2 clips front 2 clips back
ride height 7/8"
bump steer mild
no sway bar
springs pink/white
40wt AE oil
no variable damping
drilled piston holes w/ #53 drill bit

Rear Suspension
No toe in or out
camber is 0 degrees
roll center lower
pushrod location is inner
ride height 1.125"
reactive toe angle is mild
springs blue/white
40wt AE oil
no variable damping
drilled piston holes w/ #53 drill bit

Motor
Motor 5.5t 540 novak ballistic
12mm rotor
40T spur
10t pinion
narrow gear set locked in 2nd gear
center diff 100k oil

but things got interesting when i chewed up the 40t spur and I only had a 36T w/ me. W/ the 36T i couldn't get my 10T pinion to reach so I had to run a 12t. This was far too much gearing for the motor/esc b/c my temps sky rocketed and couldn't run very long. So I had to change out the rotor to a 14mm to essentially make it like a 8.5T (guessing). This actually worked pretty well. In all cases I knew after the first lap I had too much speed and turned my throttle endpoint down to 80-90%.

When I got home I calculated my top speed to be 30mph which provided me w/ a wealth of information. From this I decided to change to an 8.5T w/ the 12mm rotor and the 36T spur and 12T pinion. Now w/ 100% throttle endpoint I'm running 30mph. B/c this setup is not nearly as hot as the 5.5t the esc runs much cooler and I can run a smaller 3300mah battery and still get 12mins of run time.

[mulepic]

Here's a little update on the diet plan. The truck lost nearly 2oz today. I switched the shock bodies over to composite bodies which weigh 3 grams vs. the 6 grams of th stock ones. This removed 3/8 oz for the 4 shocks. I shaved the vertical pieces of the front and rear bumper, this remove 1/2 oz. Then I discovered my heavy duty servo weighed 2 oz and the traxxas 2070 digital servo only weighs 1.25 oz so that remove 3/4 of an ounce. The 2070 is 125 oz in. which is plenty for this soon to be 6lbs truck. I'm closing in on my 6.0lbs rtr weight. If it wasn't for those heavy tires I'd be there. I'm also looking into a lighter body, but I can't seem to find anyone to weigh theirs for me. The body I have is 8oz but I think the jaconcepts manta body for the slash is 6oz and I can make it work.

[mulepic]

I just removed a little more weight by rebuilding my links and drilling some 'flight stability' holes in the body I'll take pictures later. Essentially I have shed 4 ounces since I took it to the track. I have the following items on the way that I hope are lighter: jconcepts manta body for the Slash, Traxxas S1 tires and foam, aluminum hollow ball set, aluminum rocker arm posts, and titanium pivot balls (I wanted the lighter aluminum ones but I got these at a great price). I'm hoping these additions remove 2 ounces. Then my goal will have been met.

I also picked up a Novak GTB ESC and a HV4.5t 550 motor. I got it used for a pretty decent price (I'm not too sure I'll by used again). This will be the combo I use when I run it on larger 1/8 scale tracks. It will be geared for 40mph.

I will essentially have 2 trucks in one. For smaller, 1/10 tracks I will run the 540 ballistic/tekin RS w/ a top speed of 30mph and an RTR weight of 6.0lbs w/ a 4A 2s lipo. For larger 1/8 tracks I will run the 550 HV/GTB w/ a top speed of 40mph and an RTR weight of 6.5lbs w/ a 5A 2s lipo.