SVT builds CFX with parts from RPP, OMG!

[svt923]

Hello friends.

It is April, the weather is getting warmer (for me at least, I didn't make the poor choice to live where it is cold 9 months a year) and the Azaleas are in bloom. It is time for a tradition unlike any other.

Another SVT build thread but with acronyms abound!

Yay!

Yes, the Masters is on too but its golf. I think you can manage to follow along with me in between Tiger's drives missing the fairway and Sergio putting another ball in the water on 15. That's right, golf commentary is just one of the many things you can expect on this journey from a box of parts to a functioning model vehicle. If I get behind, maybe I'll roll out my 3 round 2018 NFL mock draft. Who will the Titans pick at #57? Find out if I don't feel like painting my body!

Now, you may be thinking "SVT, don't you have a Honcho build to finish?" The answer is yes I do however as the old saying goes "never do today what you can put off til tomorrow when you have a new truck delivered." You may also be thinking "what the hell are you talking about?": don't worry dear reader, I do this a lot. Who cares if I get off track all the time? You're in the CFX section, you clearly have nothing better to do so roll with it.

Back to tiny trucks.

I love short wheelbase trucks, there is just something awesomely absurd about them. Many times I have come close to ordering a CC01 but something has always stopped me. When MST rolled out the CMX, I loved the idea. It was like a Tamiya on the outside but a tiny SCX10 on the inside, everything I ever wanted. Still never bought one because I probably ended up buying other stuff, don't really know but that sounds like me. Then the CFX came out and it was even cooler. Then Amain put them on clearance. Then they lowered the price again. Then they lowered the price yet again. Then I decided "cheap build time!"

The goal of this build is low cost fun. It will be simple, cheap, and possibly look good. The aftermarket parts will be kept to a minimum, the electronics will be rather low end, and it will (hopefully) get driven quite a bit.

In exchange for the paltry sum of $138.99, the good folks of Amain sent me this box:

It was a nice box; 6 sided, color graphics, a lid, all the stops. It felt pretty light, I wouldn't blame Amain for sticking a couple old staplers and some bubble wrap in it for the price I paid. A pinion and set of bearings for the axles was also picked up for the build.

Sealed for my protection.

Now I am in great danger, too late to turn back now.

Hey, kinda looks like a truck kit but the staplers could still be at the bottom.

Nope, just a bunch of bags of parts.

MST thoughtfully included this advertisement for the CFX inside the box.

I really needed an ad to expound upon the great features of a truck that I literally just bought. Maybe MST thinks I will be so impressed, I'll go out and get another on upon reading the included box material.

Leafing through the instructions I came across this gem:

What the hell does that mean? I need a Chinese to English translated through Google Translator to English translator.

Look at these cute, little tires.

Sure the compound is awful but they are adorable. The tread reminds me of the many terrible Chinese mud terrains you can get anywhere that sells tires for $50/piece. They probably perform just like the real thing.

OMG!!!! These cute, wittle chassis rails.

I just want to hug them.

After I moved past the "everything small is adorable" phase, it was time for building.

The transmission was up first.

Even partially assembled, you can tell the planetary trans has a ton of reduction. Don't go overboard with the grease here.

The motor plate is some nice, thick aluminum. Surprisingly beefy for a kit this cheap.

Cheap truck, cheap motor.

An old Integy 35T was dug out of the box-o-motors. The comm has been cut and the brushes were replaced not too long ago so this probably better than a new Integy motor. A 18T mod .06 pinion from RRP gives the truck an overall ratio of about 46:1. Should be good enough on 3S.

Transfer case: nice and small.

The input shaft has quite a bit of in and out play, not a fan of that.

At this point, we arrive at our first significant aftermarket part.

A very nice 3D printed CMS bracket I picked up from Shapeways. While I much prefer a CMS system that allows the servo to swing in the same arc as the knuckles, the CFX doesn't have much suspension travel so I'm not too worried about bumpsteer or servo throw.

Chassis and transmission all bolted up. The rear shock towers were set for a 252mm wheelbase because of reasons to be revealed.

A closeup of the CMS bracket installed.

I know I should have installed the servo but that would have required digging out a radio and receiver, finding something to power the servo and receiver, centering the trim, finding an appropriate servo horn, finding screws to attach the servo to the mount, and so forth but it was late and I like sleep more than tiny trucks on weeknights.

Tune in next time when I build tiny axles, bleed tiny shocks, make tiny links, and paint a tiny body. I'll also install not tiny electronics because this truck will be driven. I will not, however, be gluing tiny tires, tire gluing is for chumps.

You can get back to the Masters now, Tony Finau is starting his second round about now. The dude popped a dislocated ankle back in with his bare hands on Wednesday and went out and shot a -4 on Thursday. Golfers are so bad ass.

 

[calcagno45]

Screw the masters, entertain me.


I waited too long, thinking the price would drop another $5. This kit isn’t listed on Amain any longer...

 

[JohnnyAnguish]

I couldn’t resist, either. I’ll be doing a build soon. I like my CC-01 on hiking trails, so this should do nicely. Looking forward to sing what you do with it.

 

[StomperCrawler]

Sub'd. I had wanted to get one from Amain when I saw them on sale, but my piggybank is empty. Time to live vicariously. Maybe by the time peeps have built theirs, they'll be ready to resell one to me and my pig will be porky again.

 

[soze]

I waited too long and missed out. Sub'ed to your build.

 

[OSRC]

I'm kinda glad that mine didn't sell. Second one I built, and second one I would have sold without running it. That's just silliness! Taking it out tomorrow for some play time! Time to get the little guy dirty.

 

[MAGNUMB]

I couldn’t resist, either. I’ll be doing a build soon. I like my CC-01 on hiking trails, so this should do nicely. Looking forward to sing what you do with it.

Works great for trail running with the shorter wheelbase. The open diff option also works really well.

 

[StomperCrawler]

Does it come stock with a weak plastic locker in the diff?

 

[2mtech]

You're going to want to lose the stock shocks if you're putting any kind of body weight on. One trip to Eno River took out two on my JK build. The King 70mm shocks worked great!

 

[svt923]

Screw the masters, entertain me.


I waited too long, thinking the price would drop another $5. This kit isn’t listed on Amain any longer...

But think of the Azaleas and the green jackets and $2 pimento cheese sandwiches and rolling out the corpse of Gary Player for the ceremonial first tee shot!

You're right, I don't really care either.

I couldn’t resist, either. I’ll be doing a build soon. I like my CC-01 on hiking trails, so this should do nicely. Looking forward to sing what you do with it.

I look forward to your build.

We can have a cheap CFX build off. I'm really good at not following through on things so you can have the trophy now.

Sub'd. I had wanted to get one from Amain when I saw them on sale, but my piggybank is empty. Time to live vicariously. Maybe by the time peeps have built theirs, they'll be ready to resell one to me and my pig will be porky again.

I was going to remind you that only one kidney is needed but this truck isn't quite kidney-sellin' good. Better just follow along.

I waited too long and missed out. Sub'ed to your build.

The RTR CMX is only $177. I mean, you won't get to be part of the super cool CFX club but it is still a pretty good deal.

I'm kinda glad that mine didn't sell. Second one I built, and second one I would have sold without running it. That's just silliness! Taking it out tomorrow for some play time! Time to get the little guy dirty.

This one seems like it is worth keeping around as long as parts are available.

Works great for trail running with the shorter wheelbase. The open diff option also works really well.

Open diff: minimum performance FTW!

Does it come stock with a weak plastic locker in the diff?

It comes with a plastic locker, don't know if it is weak. I haven't heard of the lockers failing so I'm going to roll with it.

Now that all you animals have settled down, are we ready for some more totally exciting CFX building!

Moving on to the next section of the manual, we get to links.

There they are in all their plastic glory. Pretty lame right?

It's a $150 kit, get over it cupcake.

For plastic links, they are pretty feel pretty good: not too much flex and threading in the setscrews gives the reassuring resistance of quality plastic. Axial plastic links these are not. This setup is not quite per the manual specs but I think it will meet my to be revealed purpose.

Oh, and if you are pressing pivot balls in the rod ends with a pair of pliers, stop being a savage and buy a proper tool. One of the complaints I have read about the CMX/CFX is the plastic pivot balls are junk. That may be the case but a pivot ball that has been mangled by ham-fisted plier usage is definitely junk.

See what it looks like when you don't try to pound the pivot balls in with a rock like a neanderthal?

Now we get to the part where MST gets all weird on us. For those of you that have build MST trucks before, you can take a break to go watch one of those stupid Youtube videos where some guy says Redcat tires are better than Prolines because they went up a carpet ramp better or whatever RC related garbage people think is interesting. If you enjoy those videos, just stay on Youtube and don't come back. Although if you enjoy those videos, the quantity of reading required up to this point has likely exceeded your capabilities and you gave up.

Anyway, weird MST stuff:

1. The ring gear and half the diff housing are cast as 1 piece
2. The CVDs have no center barrel that helps the joint pivot.
3. The CVDs are pinned inside the diff assembly. They don't slide in and out like pretty much every other solid axle truck made.
4. There is a plastic locker inside the diff cup. Since the CVDs are driven off pins instead of flat spots on the shaft, the plastic should hold up to appropriate levels of power rather well. No, guy who is definitely thinking about it right now, you can't run your Puller Pro XL on 4S in this truck.

That about covers it. I forgot to take pictures of the locker before I bolted everything up, sorry. Maybe you will get lucky when its time for the rear (try that line on your wife later).

Locker and axle assembly dropped into the axle housing. Just like a tiny SCX10 made by foreigners who struggle to understand our ways.

The kit comes with bronze bushings but those weren't acceptable in the early 90s and they definitely aren't acceptable now. I bought a CMX bearing set from Jim's Bearings since the CFX only needs axle bearings and the axles between the 2 trucks are the same. The CMX bearing set is cheaper than the complete CFX set and I'm a smart guy.

After sliding on the most convoluted set of c-hubs ever and installing the axle stub (again, weird MST stuff), we get back to more standard building steps. I really do love the inclusion of Phillips head kingpins. Nothing is better than using 1.5 & 2mm hex wrenches for the whole build then stopping and having to hunt down a Phillips screwdriver to install 4 screws before going back to the hex wrenches.

Getting there.

Steering links were added. The manual calls for a 5mm gap in the steering link rod ends but there are 5mm spacers included in the parts trees for the pivot balls so I threw one on there. Much less dumb looking.

The draglink has to attach to the opposite side for the CMS mount. This was incredibly long and involved so I won't bore you with details.

Are you entertained yet Mr. Calcagno45?

Tune in for some more cheap amusement and personalized attention that you can only get in a SVT build thread.

 

[svt923]

So, you know that thing where when you're an adult and you need to do stuff to get ready for the next day? Yeah, I did none of that last night so I can continue building a tiny truck.

I regret nothing.

It was time to work on the rear end so I skipped the manual and consulted an expert on rear ends:

Sir Mix-a-lot, may I call you Sir? What are your thoughts on this assembly?

"I like big butts and I cannot lie"

Well said.

Here are some pictures of the parts I skipped over when doing the front:

The pinion is held on by a M2 screw, threadlock is your friend here.

Plastic locker, definitely different.

How do you eliminate roational slop in the rear axles? Make them one big piece clearly. I would have went with better manufacturing tolerances but sure, why not?

Rear locker installed on the axle.

Everyone better remember what an assembled axle looks like because we are moving on.

Sir, what kind of suspension setup should I be using?

"You get sprung!"

Ah, coils are the way to go.

MST hits a big homerun here.

A full set of soft, medium, and firm springs are in the box. I have Axial kits that cost over twice as much that only included a single useful pair of springs. Nitpickers might complain the springs don't actually have spring rates other than "soft", "medium", and "firm" but those people are stupid. Right Sir?

"You other brothers can't deny"

See?

Look. Do you see it is possible to make a small shock piston that doesn't have it's holes blocked by the e-clip? Take note other companies.

Cool, bleeder caps!

Wait, fake bleeder caps, incredibly lame.

Here is the lower seal assembly:

It consists of 2 o-rings and that is it. I much prefer the designs that have some kind of shaft guide between the o-rings to prevent deflection. I threw some Green Slime on the seals and didn't worry about it too much.

Time to fill the shocks so I go into the kit bag for a bottle of:

#10 mineral oil? What the hell is that? Google found me a list of 30 things mineral oil is good for: not a single one of them was filling RC shocks. And why is it #10? Is that 10 weight? 10 CST? Their 10th mineral oil formula? So this absolutely isn't going in my shocks but at least I now know I can use mineral oil for removing gum from hair.

I had a good, old bottle of Axial 30wt shock oil laying around. It has a listed viscosity and it is made of silicone like all shock oil from this millennium. Besides, if it is good enough for me to not use but still keep, it must be good enough for this build.

Through the magic of the internet: completed shocks!

And it was time to start bolting on shocks.

Deal with my washed out pictures, I was in a hurry this morning to bring this quality content to all 3 of you.

Completed rear end with shocks all mounted up.

Sir, thoughts?

"She's gotta pack much back"

Indeed.

The front got shocks too.

You even start to get an idea about the CMS geometry at this point.

Some tweaking will be necessary but I'm getting there. Sir, any setup tips for 3 link/CMS suspensions?

"My anaconda don't want none"

I said setup tips, not if you want to.... nevermind.

Electronics are ready to be installed. Relatively cheap stuff for a cheap truck. The Hobbywing 1080 came from RPP so my title is no longer a lie but a glorious triumph in the overuse of acronyms. The Power HD servo and rebranded Radiolink receiver were dug out of the bin of spare electronics. An Axial aluminum servo horn appears to be a good size to maintain CMS geometry.

I may regret this but Sir, do you have any parting words?

Better than I thought. Now hop in your Benz and go back to doing whatever it is you do these days. Dial 1-900-Mix-A-Lot if you need him people.

Its Friday, we have all checked out.

 

[2mtech]

LMAO at this post, thanks for that! :lmao:

Mineral oil is good for removing ear wax...not sure how that translates to RC shocks.

Oh, and there's 4 of us

 

[Ninomaniac]

This was quite entertaining. "thumbsup"
Your audience of 5 awaits more!

 

[svt923]

LMAO at this post, thanks for that! :lmao:

Mineral oil is good for removing ear wax...not sure how that translates to RC shocks.

Oh, and there's 4 of us

This was quite entertaining. "thumbsup"
Your audience of 5 awaits more!

Updated audience count and alternative use for mineral oil have been noted for future posts. "thumbsup"

 

[JatoTheRipper]

I wish I had seen the CFX kit for that cheap! I have an RTR CMX on the way. I do want the front motor though, but as OSRC the CMX might actually perform better with it's lower COG. I can always buy the front motor kit, but that would be half of the price for what I paid for the RTR. :lmao:

I hope AMain's fire sale doesn't mean they're discontinued.

 

[OSRC]

Might. Get yours ready to go and we'll see!

I skipped the mineral oil too. Just like my wife's dinners - if I have to ask what it is, Pass.

Debated drilling out the shock tops and adding some setscrews to make bleeders, but then nothing particular happened. I'm sure I got distracted by something shiny nearby.

 

[soze]

I wish I had seen the CFX kit for that cheap! I have an RTR CMX on the way. I do want the front motor though, but as OSRC the CMX might actually perform better with it's lower COG. I can always buy the front motor kit, but that would be half of the price for what I paid for the RTR. :lmao:

I hope AMain's fire sale doesn't mean they're discontinued.

I'm in the same boat. I was actually eyeing the CFX bronco kit, and was waiting to see if it'd drop more, but waited too long. In the end, like you said, the CMX will probably perform better anyway, and I'm perfectly fine with it as I have my CFX-W for forward mount motor.

I hope these aren't discontinued... or at least something new takes it's place from MST.

Let's get to the important point with these....Tamiya bodies! Oh those Tamiya bodies! So many options...

 

[calcagno45]

Steering links were added. The manual calls for a 5mm gap in the steering link rod ends but there are 5mm spacers included in the parts trees for the pivot balls so I threw one on there. Much less dumb looking.

No extra 5mm spacer to put in the drag link to close that ugly gap as well?

Are you entertained yet Mr. Calcagno45?

Why yes, I'm now entertained. "thumbsup"

Cool, bleeder caps!

Wait, fake bleeder caps, incredibly lame.

Could you drill holes and make them functional caps?



This little truck in interesting. Not a fan of that diff pinion design, I like the included springs, shocks look good, interesting true "solid axle", and now I have ragrets that I didn't pick up a kit...

 

[svt923]

I wish I had seen the CFX kit for that cheap! I have an RTR CMX on the way. I do want the front motor though, but as OSRC the CMX might actually perform better with it's lower COG. I can always buy the front motor kit, but that would be half of the price for what I paid for the RTR. :lmao:

I hope AMain's fire sale doesn't mean they're discontinued.

Front motor 4 life yo!

I really don't think these trucks are at risk of getting discontinued any time soon. The MST monster truck wasn't released that long ago and it shares the axles with the CMX/CFX.

Might. Get yours ready to go and we'll see!

I skipped the mineral oil too. Just like my wife's dinners - if I have to ask what it is, Pass.

Debated drilling out the shock tops and adding some setscrews to make bleeders, but then nothing particular happened. I'm sure I got distracted by something shiny nearby.

I had the same thought on the shock caps but I would have needed to go find my drill and bits then find some setscrews and I gave up before leaving my chair. We can split credit for creating the shock cap mod without actually doing it though.

I'm in the same boat. I was actually eyeing the CFX bronco kit, and was waiting to see if it'd drop more, but waited too long. In the end, like you said, the CMX will probably perform better anyway, and I'm perfectly fine with it as I have my CFX-W for forward mount motor.

I hope these aren't discontinued... or at least something new takes it's place from MST.

Let's get to the important point with these....Tamiya bodies! Oh those Tamiya bodies! So many options...

The blowout at Amain has to be more about them not carrying the MST trucks anymore (they seem to be getting more of their drift cars in though). MST released the C10 version of the CMX in December and AsiaTees, RC Mart, and Ebay will keep us in parts for a long time.

No extra 5mm spacer to put in the drag link to close that ugly gap as well?

Why yes, I'm now entertained. "thumbsup"

Could you drill holes and make them functional caps?

This little truck in interesting. Not a fan of that diff pinion design, I like the included springs, shocks look good, interesting true "solid axle", and now I have ragrets that I didn't pick up a kit...

Lots of ground to cover here:

1. The draglink calls for a 4mm gap and I didn't bother to cut down a spacer. Also, the original draglink has been repurposed as the panhard bar because the offset rod ends help clear the axle housing. Still don't know what the final length with be at this point.

2. I'm glad, I'll try to inject more references to one-hit 90s rappers in this thread to keep up the entertainment value.

3. Maybe I'll get to performing the OS-VT shock cap mod eventually.

4. The truck is strange and quirky but generally solid so far. Probably wouldn't like it as much for $100 more. The RTR CMX in FJ Cruiser trim is the lone remaining MST truck at Amain for $185.

5. I got the over/under on that dude's combined DUI convictions plus number of teeth at 12. Taking all bets.

 

[2mtech]

You'll find a few extra spacers in your kit, I used one of those for both the CMX and CFX drag links.

I can say having run both a CMX 267mm kit with a Lexan body and the native centrally mounted motor and a CFX stretched to 300mm with a hard body on trails and moderate rock crawling the CFX shone brighter, but then I'm running 1.55 tires on the CMX so it's not a fair comparison.

YMMV.