I picked up a MERV a few months ago while on holiday in the US, 1 because it looked so cool and 2 because it was a cheap way to get back into the hobby.
After that I thought that I should race it at the local RC track which is a 1/10th scale track that I used to race at years ago. Seeing as the full scale Revo was really good on the track I thought this would be really good too. So basically i'm trying to build and tune this mini e-revo so that it will perform on the track as good as I hope.
I'm making the thread so i can keep track of everything and hopefully I will get some feedback and help some others out to that might plan on doing this. I know the MERV isn't the best choice for a track car but I like the challenge!
I'm starting the thread a bit late as a lot of the mods I have already performed, but I took pictures along the way so I will post most of the steps up as I go.
- 1/10th scale
- Hard Clay that gets dusty pretty quickly
- Can crack if it has been raining during the week, leading to pot holes in the corners
- quite a number and mixture of jumps, turns and a big straight
MERV: (up to the point before I started recording what I was doing with it)
- Stock electronics
- Dual Stock servos
- RPM a-arms all around
- RPM axel carriers all around
- Traxxas aluminium turn buckles and push rods
- Traxxas 3S lipos
- Redback 2S lipos
- Aluminium Steering post
- Aluminium Servo Saver
- Shimmed rear diff (front still needs to be done)
- Black springs in the rear, Tan springs in the front
- 90wt shock oil all around
- Stock wheels and tyres
- Traxxas response pro tyres on stock wheels
There are probably some other things I have missed to.
Initial Handling on the Track
Before i changed the springs and shock oil from standard this thing handled like a pig! It would just bounce over every bump it could find I 70% of the time it would flip and roll and the end of the straight. Once changing to the new springs and shock oil it settled it down A LOT. Is was a different truck. And after the first night the stock shocks were pouring out with oil so they need to be replaced with something that is going to hold the oil in.
The response Pro tyres seemed ok, I didn't bother trying the talons, but they still seemed to lack a bit of grip once the dust started to build.
I only had the 3S lipos at the time so I ran with those and as expected they were just too much for the track. I ended up picking up some 2S 1300mAh packs to run in parallel and they seemed much more appropriate for the size of the track. I could actually hit full throttle down the straight without wheelieing!
Oh yeah and I stripped the rear diff after the first 2 races. That has now been replaced and shimmed.
So after the first night of racing there were a few pointers to take away that needed improving:
- bounces and rolls wayyy to much. Need to settle down the suspension. (was mostly fixed with the springs and shock oil)
- Tyres are lacking grip once it gets dusty
- The truck seems too light for all the bumps and jumps
I have heaps more to post over the next couple of days when I have time, I have done a lot more since the first race test.
I always say a thread is useless without pictures so here are some of how it started and how it sits now.
I had all of this purchased before I had even purchased the truck!
Well more to come soon.
Last edited by Dadx2mj; 12-11-2012 at 12:51 PM. Reason: Language
They are a handful on a track can't compare with a 1/10 scale but you will get there! Nice setup so far watch the dual servos they have a way of fighting each other .one strong servo is probably better. If you had some wider offset runs like the hpi 2160 and proline tires like caliber that would help out
I'm in the process of building a race setup as well after building a mini 8ight that was running with a couple full sized Losi 8-E at the local track. Minis are more fun when you beat up on 1/10th & 1/8th scales. I think the MERV will be an even better platform when it comes to Minis.
Are you still running stock ESC/Motor? Were you running the 3S parallel as well?
I havent had any problems with the dual but i'm sure I will soon enough.
I have some Jconcepts relux and the traxxas dish wheels which are both offset, How offset ate the hpi?
Next step was the Jconcepts Relux Wheels and Goose bumps:
2x Jconcepts Relux #3333B
2x Jconcepts Goose Bumps Rear Buggy Tires #3018-02
These looked like they have heaps of grip and after watching an Ultimaterc video this was one of their recommendations. Plus the Relux wheels were only $5 for 2! So i cleaned out the place I ordered them from..
The night I got to try them on the track was after it had rained and cracked all of the clay. Every corner has arge cracks in the clay and made the tires pretty unusable since the edges would just grab the cracks and flip at high speed. So I switched back to the Response Pros and these handled much better. I do think that if the surface wasn't cracked and back to how it usually is then the Goose Bumps would have performed much better. They definitely gripped more!
Plus the wider stance of the relux wheels helped with the stability.
You can see the different in the offset here:
Goose Bumps on Relux:
The majority of the 4x4 buggies were running on Suburbs, Bro codes or something similar So they will be my next option. Any other recommendations on tyres that will hold onto a clay track that develops a lot of dust?
I was after a new body since I knew the stock one wouldn't last too much longer and my local hobby store had a F150 Raptor body on the shelf that looked pretty cool so I picked it up without doing any research.
Pro-line F150 Raptor Body #3360-00
First impressions are that it looks pretty cool but after cutting it out and test fitting it I wasn't too impressed. Its like they didn't even test fit it from factory on an out of the box revo. You can see the fitment in the post above. With stock wheels it rubs on the back and you can't turn the front wheels without it catching. It also hits the front push rods when fully compressed.
I decided that I would go with a red and black theme for the truck and was going to use Tamiya Paint for the colour.
Tamiya Part Numbers:
Metallic Red #PS-15
The silver was only used for backing the metallic red to give it a heavier metallic look and stop some of the light seeping through.
Final Before Stickers:
And the finished product:
I think it turned out alright for my first time painting an RC body. It was only simple.
I will see how the body goes, although I can only run it with the offset wheels.
Next my steel hollow balls, rocker bearings, steering bearings and HR shocks arrived!! Hooray no more leaking shocks!
Steel hollow balls
Traxxas #: TRA7028X
These are definitely worth it. It removes a bit of slop but most of all makes things smoother. Easy to install, its just a matter of popping the old ones out and pushing the new ones in.
No pics as they don't look much different to stock, just a little shinier.
Rocker and Steering bearings
From the Toyz
Rocker bearings #TOYZ 98
Steering Bearings #TOYZ 202
Again they improved the smoothness of the steering and the suspension. More so the suspension.
Again no pics as they don't look that much different and I forgot to take pictures as I was installing them. Any questions about the install just ask..
HR Shock Bodies
These shock bodies are a great upgrade. I went with these over the traxxas ones since the traxxas looked like it still had the push on end cap where as the HR use a screw on one making it less likely for it to pop off and lose all your oil.
HR Shocks with Red Caps #VXS15502
A good guide is here: (I couldn't find the link, maybe someone else has it? I think it was 50togo that posted it up.. I could be wrong though. I will find the link and update my post.)
Old vs. New:
Disassembled the old shocks and cleaned them all up with some WD40:
I went with the Blue-Black-Blue combo. I thought the black was a little tighter but ended up going the other way since that was what I had read on these forums. I also had no Green Slime to put on the o-rings so i just used a small amount of thick marine grease to keep the oil from leaking out. It's held up so far!
The near final product:
Filled them up with some 90wt shock oil and re-installed them on the truck:
The shocks are silky smooth, and together with the rocker bearings and steel hollow balls they feel much better than stock.
More to come.
Awesome Merv! How did you mask the body so well? I just started painting my raptor body and the black streaked through.
All it took was patience and some good quality tape. It took longer to mask it than it did to paint. I used a narrow automotive pin stripes tape that is plastic and not like the regular masking tape. It's flexible which made it easier to go around bends and corners.
I got a couple of spots that bled through slightly but that was likely me not making sure it was down enough.
If the black is your first colour then just use a sharp blade to scratch off the paint before doing the next colour. It worked well for me and didn't leave any visible marks.
That MERV is sweet! Good job so far!
MERV, Broken Alias.
Love the build so far, but isn't it a race rig? Why the raptor body and not a slipstream or j concepts illusion? Plus you need to get a hold of the Ofna 1/12th scale wing to finish it off. Fits the Merv much better size wise and is much more durable than stock.
I was looking at the jconcepts body, and still am. The only reason I picked up the raptor one was because it was on the wall at the hobby store I was in at the time, and it's not often you find that here in Aus. It costs just as much to ship one here as what the body costs if I have to buy from elsewhere.. The raptor is only going to be used on road, not the track.
How much bigger are the ofna wings? Much more functionality or just looks?
I think the automotive tape was the trick because I spent a lot of time masking the body too, but home painters tape does not bend very well. Thanks for the tips
No worries. It is very similar to the windows mask material that comes with the body, except this stuff is thicker, more flexible and on a roll obviously.
I had a nice package show up the other day! I needed to order some shims for the diffs and shipping alone on a $2 item was going to be $8. So i thought I might as well order some other stuff while im there. Purchased some traxxas White dish wheels and some Proline Road Rage tyres.
Proline Road Rage #1102-00
Traxxas white dish #7171
Instead of shredding the stock tyres on the road all the time I wanted to get something that would last and be a bit gripper. I also wanted to strap these tyres as wel as i'm not a big ran of ballooning.
They were skinnier than I expected as well.
The offset on the traxxas dish wheels seems to be about the same as the rulux wheels which is good.
I cleaned them all up with some hot soapy water to remove anything that was left over from the moulding process and started strapping them up. I used reinforced tape which was of decent quality so that it would stick well and hold the wheels in. Started by cutting it to length and width and then wrapping it tightly around the tyres. Left about 1cm of overlap so the tape can stick to itself.Came out like this:
All 4 done and ready to glue!
I get the tyre mounted in place then lift up one section and put a decent amount of glue in, squeeze it around to get all parts of the tyre. You just need to know how much to use and it works perfect! Ive done 3 sets of tyres this way so far.
If anyone is interested in seeing the difference the offset and the narrower tyre makes you can see if here by following the join in the tiles:
There its all done!
If you have any questions just ask me.
Well i did some ordering today.
To add to the list:
- Hitec 5085MG
- Ofna 1/12th rear wing in black
- Some more rulux wheels
- a set of Jconcepts Bro Codes rear buggy tyres
I wouldn't mind the hitec servo being waterproof so ill look into doing that. If I do i will post up a how to guide in here for others to see.
Looks like fun times ahead!
Great looking MERV froggie! Mine is very similar to yours.
If you haven't already, you may want to look into a center differential. Makes track driving much more enjoyable, in my opinion.
Did you notice any increase in performance after installing the HR shocks? I keep reading about people having to use 1k diff fluid (yikes!) in their shocks for it to actually dampen jumps. Going from 40 wt (stock) to 70 wt resulted in dismal results.
Only if Exotek continued making their Big Bore shocks..
Havn't posted for a while due to being busy with christmas and a few other things. Excited that I have another addition to the rc collection! I though I should get something that is built for the track so I can be competitive as well.
Here it is!
I have finished building it and just waiting for the painter to finish the body then down to the track when they open again. Can't wait!
As for the MERV, my Bro Codes arrived as well as the Hitec 5085mg.
I have tried my best to waterproof or at least make the hitec water resistant which you can see below. The servo arm required a bit of modification, I just purchased a full size Team Losi servo horn to suit the hitec spline and had to cut it down to fit then reset my trims. I also wanted to switch back to the stock servo saver as aposed to the Aluminium Integy one. It was terrible! I had to sand the integy one when I got it so that it was smooth (still wasn't perfect). It always got stuck and just felt bad in general. I would not recommend it to anyone.
Alright onto the waterproofing..
Hitec 5085MG Digital Metal Geared Servo.
Team Losi Servo Horn to suit Hitec Spline (cut down)
Remove the 4 screws holding the case together:
Apply the marine grease to all exposed electrical connections. Don't add to much as you don't really want the case fully packed with it:
There are 3 main areas that required the grease, you can see 2 in the picture. The other was deeper inside which is the position sensor i'm guessing?
I applied some on the main gear set as well to help with keeping water out. I also installed a small o-ring between the servo horn and the casing.
I applied a small amount of silicone on the case joins before re assembling it, don't lather it on, be very sparing especially on the side of the casing with the gears. You don't want any silicone getting on the gears and setting hard. After re-assembling it all, apply a small bit of silicone around all the case joins, the screw inlets and the cable outlet. This is about the best I could 'waterproof' it without dipping the whole servo in plasti-dip.
It's not very pretty but i'm more after the practicality of it. I say waterproofing loosely since i'm not gonna go and dunk it just to test it, but theoretically it should be pretty waterproof/resistant.
Here is the integry aluminium servo saver, stuck as per usual. It never worked very well. After putting the stock one back in it felt MUCH better.
I decided to grab some Bro Codes from Jconcepts as it seemed a lot of the 4wd buggies were running Bar Codes, Suburbs or similar on the track. I mounted them to some Relux Rims too.
Jconcepts Bro Codes rear Buggy Tyres #3066-02
Jconcepts Relux Wheels #3333B
I'm still yet to try them out as the track is closed.
Since I purchased the DX4S radio for the new B44.2 buggy, I thought I may as well use that radio with the MERV as well which will give me a few more tuning options and only having to take 1 remote to the track. The install was easy to do as it just required removing of the old receiver and placing the new one in. The SR3100 is smaller than the traxxas system so it went in very easily.
More to come.
I decided to try and velcro the body instead of using body clips which can be a pain. All I can say is i wish I did this earlier! Took a whole of 2 minutes to complete and makes things much easier. The velcro has enough strength to hold the body on securely and can be removed and put on in seconds.
I just cut the velcro to size and placed in on the battery doors first, then with the rough side attached to the fuzzy side I removed the backing and placed the body on carefully so that I knew it would line up. Pushed the body on and done! Easy!
I havent really taken the MERV for any speed runs (with speed recording) so i found an app for android that had a GPS speed reader and recorded the max speed. I wrapped my phone up and stuffed it under the body and set out for a few runs. The runs were done with the larger pinion and 2x traxxas 3S packs run in parallel. I also dropped with suspension quite a bit as you can see below and run on the road rage tyres with traxxas dish rims.
The first few runs it maxed out at 78km/h but I was running out of room. So i went up the road a bit more and tried again (after it cooled down). This time it topped out at 90km/h !! I was pretty pleased with the result.
Thats all the updates for now. Sorry for all the pictures and such a long post! I'm still waiting on the 1/12th Ofna wing to arrive so i'll post again after that has come, or after I have tracked this thing again.
One final picture off all of the RC's together!
Good build! Nice speed
I would make a longer link between the horn and servo saver with two.end links and a long bolt cut for a stud
Last edited by 50togo; 12-29-2012 at 01:44 AM.
Supposed to be TRXrubber-TRXspacer-HRrubber in the bottom cap isnt it?
'cus if it isnt, i built mine wrong today haha d'oh!
Last edited by Cameron; 12-29-2012 at 01:50 AM.
(RAH)² (AH)³ + [ROMA (1+MA)] + (GA)² + (OOH)(LA)²
I had read about doing that before but it didn't seem like a problem once I had it all in there and going. It seams nice a quick with good torque too.
Any real reason as on to make it longer? Apart from being able to adjust it? I have a lot of adjustment on the DX4S now.
I used all rubber as it seemed to give a tighter seal. I have had 1 race night and various bash sessions along with street runs and still no sign of leaking so I guess it's working lol!
it helps equalize the throw in both directions. If you haven't played with the end points on the radio and you turn the wheels both ways you will go one way further. Ideally you want the steering arms perpendicular to the center line when it is centered out with 0 trim.
(RAH)² (AH)³ + [ROMA (1+MA)] + (GA)² + (OOH)(LA)²
Yeah thought that was it, just wasn't sure if there was another reason. It was near on centre anyway and with only slight adjustments on the radio it was centred. Also used the radio to set the end points as well so they are even and reaching the max they can. The end points are set at 80% and 70% (have to take into account the offset) I get full and even reach in both directions.
Yeah with EPA you can usually overcome it.
But if you dont have that available to you, the only way you will have equal throw is the perpendicular steering linkage.
(RAH)² (AH)³ + [ROMA (1+MA)] + (GA)² + (OOH)(LA)²
Yep. Thankfully I don't have to worry about that. The hitec is a great upgrade, even over synced dual servos. I would recommend it to anyway straight out of the box.
i went with the non digital hitec 85. i may end up swapping out for the 8085.
(RAH)² (AH)³ + [ROMA (1+MA)] + (GA)² + (OOH)(LA)²
Run Trx seal- spacer -trx seal then one hr seal and squeeze the cap on!
You still need a longer link without it you will have less turning radius turning one side than the other
Last edited by 50togo; 12-29-2012 at 02:23 AM.
Any particular reason you wouldn't recommend TRX, HR, TRX all seals?
I haven't had any issues and they don't seam to be too restrictive with motion.
I used 3 seals and haven't had a problem and some run 2 traxxas seals and are fine
Ok, I'll stick with my 3 seals as I still have no leaks. As for the turning radius, the servo isn't maxing out in any direction and the end points have been set so they reach max throw. Visual inspection shows they are both reaching the same point too. But yes I understand why you have added in the adjustable link.
What servo horn did you use?
My 1/12th scale ofna wing arrived today. It's significantly bigger than standard which is good. Seems to be a nice size. I'll put the install pictures up tomorrow.
90wt shock oil around is way to much IMHO. I race on a offroad dirt / clay track designed for 1/10 scales with my MERV.
35 wt shock oil in front with black springs. 30wt shock oil in the rear with tan springs. J-Concepts Goosebumps w / Rulex wheels. Set at -2 Camber. 1 Hitech HS-85 MG Servo with Ofna 10732 Alum- Servo Horn. 50t Spur with 23t pinion. And RPM A-arms.
This bad boy can keep up with the 1/10 scale buggies.
2 1/18 Mini Desert Truck & Buggy
I initially had the standard weight with black and tan springs, which is 30 I think, and it was way too bouncy for the track I was on. Little bumps would send the truck flying. The night I tried the goosebumps was when the clay was cracking up in the corners from the rain so they were gripping in the cracks too much and tracking rolling. I will try them again tomorrow though.
But there is no way I'll be going back to a lighter oil any time soon for the track I run on.
What sort of surface do you run on?
Finally I am getting around to update this thread.
Not a lot has happened since last time but here goes.
Ofna 1/12th Wing
Onfa 1/12th scale wing Black #: 40906
Picked it up from Phil's Hobby Shop off eBay for $8.49 plus postage
Straight away without even comparing them you can see the size difference. This thing is BIG compared to stock. It comes without holes in it so you need to align them and drill before you can mount it.
Compared to stock:
Here is where i punched a mark to drill the holes:
The traxxas mounting style is slightly different to Ofna, traxxas actually have lugs that locate the wing. These lugs are on the wing mount itself. I would advise you to remove these to allow the wing to sit flat. If you do remove them however, it will not be so easy to re-mount the stock one. Although new wing mounts are pretty cheap.
I just used the standard wing screws along with a washer on each mount in order to give it a bit more mounting strength and stability. If you don't use any washers I can't see it lasting too long in a crash.
Here it is mounted up:
Looks much more functional than the stock.
Now to performance. On the track I noticed the difference straight away. Over jumps it would correct itself so much faster and land much straighter than stock. I was surprised at how much of a difference it made. Apart from jumps, it created a lot of downforce at higher speeds while taking the back straight. It stabilised the revo from twitchy side movements and planted the rear much better. You could visually see the rear end being pushed down quite hard. If I can get a picture of it in action this friday I will. Overall it was a great improvement in the trucks stability and for $8.49 you really can't go wrong. The whole process took no longer than 10 minutes.
With the Ofna wing and the Jconcepts Bar Codes on Rulux wheels this thing handles much better. I also switched the springs around to have the black at the front and tan at he back. It greatly improved the cornering of the truck and felt a bit more planted through the turns. The rear end has also never kicked up coming off a jump now which I often had to be careful of before. I played with the camber and toe a bit too. Added some inward toe in the rear (not sure exactly on degrees) and a small amount of toe out in the front. Also reduced the camber of the rear to about 1.5 degrees, fronts about 1 degree. All of these changes made improvements to how it handled out there, although its still a hand full, just not as much!
These shocks still don't absorb any impacts very well so something needs to be done in that area. I'm also toying with the idea of adding some weight inside the battery compartments to weight the vehicle down and lower its CG. The 2S packs I run are only 1300mAh each so they are quite small, waiting for some other 2200mAh ones to come in stock at the moment which should add some weight once I get them.
I run the big wing on both of my mervs. Much tougher too takes more abuse
Yeah they are a great, cheap upgrade.
Here are a couple of recent pictures of the MERV along with the B44.2:
I want to try and get some action shots of it this friday at the track, so keep an eye out!
Looking good, lots of good information in here!