Turning a CR01 into a monster truck

[OldSchoolRC1 1099]

Any amount of "V" helps, the further out you can get at the bottom, the better

[davidwj95 168]

I got the front end done today.  It took a bit of time as I was trying different spacers to get a bit more angle on the shocks.  It looks like it might make it a bit lower than standard but I have enough adjustment to raise it a bit if necessary.

[OldSchoolRC1 1099]

Looks great - nice work! 

[davidwj95 168]

I put it all together and was a bit disappointed to find that the torque twist hadn't improved much.  I took the rear shocks off again to clean them up as I'd bought them second hand.  I didn't realise until I'd stripped them that there were two different sets of springs so I rebuilt the rears using the stiffer set and 800 cst oil.  The torque twist has reduced loads now.  Next job is to do the fronts, I'll try with the stiff springs first to to see if i can get an 80s bouncy monster truck ride.

The wheels have adjustable offset.  I'd had them on the middle option at first but had to go to the wide setting to give a bit more clearance around the shocks.

[CRC505 233]

On 10/7/2023 at 4:57 AM, davidwj95 said:

我把它们放在一起，有点失望地发现扭矩扭曲没有太大改善。我再次取下后减震器清理它们，因为我买了二手的。直到我剥去它们，我才意识到有两组不同的弹簧，所以我使用更硬的弹簧组和 800 cst 油重建了后部。扭矩扭转现在减少了负载。下一个工作是做前线，我会先尝试使用刚性的弹簧，看看我是否可以乘坐 80 年代的弹力怪物卡车。

车轮具有可调节的偏移量。起初我把它们放在中间选项上，但不得不去宽设置，以便在冲击周围提供更多的间隙。

这看起来非常好！
 

[Dreams200VR4 8]

Right now, I am also in the middle of a project to customize the CR-01 (Rock Socker) into a monster truck.
I don't have the skills to paint the body properly, so I bought a cheap pre-painted body from Amazon and made the stickers myself on my computer.
This is an image of Blue Thunder from Monster Jam.
It incorporates Tamiya's reinforced propeller shaft, Eagle's friction damper, PMM's side plate and skid plate, and Kyosho 1/8 buggy big damper spring (the diameter is perfect).
The tires were difficult to install, but I installed them using a hexagonal wheel adapter for Clad Buster, a 20mm extension hub, and a Tamiya long joint cup.
It has a 25T pinion and brushless motor, but since it uses a NiMH battery, there were no problems during the indoor test run.
I'm still in the process of trial and error💦

[ThunderDragonCy 8721]

This was running at the track meet today. Was so cool and so nice to look at.

J Concepts wheels and tyres, stock Blackfoot body, rocker shock delete.

[davidwj95 168]

13 hours ago, ThunderDragonCy said:

This was running at the track meet today. Was so cool and so nice to look at.

J Concepts wheels and tyres, stock Blackfoot body, rocker shock delete.

Thanks for posting, another great day as usual at the tamiya junkies meet.   I always come back from these meets with a list of jobs I want to do on each car.  On the list for this car:

Reduce rear steering

Try sport tuned motor (currently has torque tuned)

Get lexan body for running.

[ThunderDragonCy 8721]

Just now, davidwj95 said:

Thanks for posting, another great day as usual at the tamiya junkies meet.   I always come back from these meets with a list of jobs I want to do on each car.  On the list for this car:

Reduce rear steering

Try sport tuned motor (currently has torque tuned)

Get lexan body for running.

Didn't mean to steal your thunder, but i just looked so cool I had to share it. Didn't realise you were on here. Whilst i sympathise with wanting a lexan runner body, it would be a shame. The blackfoot looked AMAZING out there

[davidwj95 168]

3 hours ago, ThunderDragonCy said:

Didn't mean to steal your thunder, but i just looked so cool I had to share it. Didn't realise you were on here. Whilst i sympathise with wanting a lexan runner body, it would be a shame. The blackfoot looked AMAZING out there

No problem at all, I'm glad you liked it.  I know what you mean about the body, the hard shells look so good.

[Badcrumble 4430]

Slowly getting there with my monster CR-01.

[NeonScorcher 78]

On 9/7/2021 at 11:51 AM, jonboy1 said:

thanks @Saito2  and @Badcrumble   

I was admiring some nice monster trucks and found myself thinking that I have a rather large hole in my collection where one should be, but I'm ashamed to say I'm not and never have been a fan of the Clod chassis. The it occurred to me that the overall chassis setup of the CR-01 isn't a million miles away from a MT so why not give it a go? The gearbox was what I figured would be the main issue, which I, along with Badcrumble, led me to swapping it out. So then I started looking at Axials, and I saw the SMT10, and figured that was probably the cheaper option, if not the most satisfying  

I guess along with the pinion you'd really need to find a replacement for the sun gear to get any decent improvements in gearing?

@jonboy1 I'm converting my CR-01 into a monstertruck, too. Do you maybe remember which gearbox you used? I found some from injora for the scx10 which might fit, but they have not so much less gear reduction than the original Tamiya one. Any help appreciated, tia.

Jan

[NeonScorcher 78]

Started the conversion with Axial rims and JConcepts tires, removed the springs and dampers and fitted some „pogo sticks“ I had lying around. They are about one centimeter too short, will replace them with the WR-02 aluminum shocks as soon as budget restocks. They are a great fit, I have them on another car. Not much suspension needed for the chassis anyway.
Also raised the body two holes for more monster vibe, now I’ll need some inner fenders to prevent looking through 😂. Rims are the wrong color, but green would have been worse. Probably going to paint them.

 

[JimBear 1268]

@NeonScorcher - WR-02 dampers? Oh, that's tiny stuff.

I see you kept the rails too. I was thinking of ditching the rails (the CR-01 feels so top heavy, but maybe that has to do with the cantilever setup). But yes, that gets me an idea ... I have to raid the kids' box of pogo sticks (DT-01) and see what's up. How did you attach the dampers on the lower end?

[NeonScorcher 78]

@JimBear the top isn’t too heavy, I use a shorty lipo. I first had the original shocks angled and fixed to the rails with standoffs. But that caused quite limited steering travel, and driving or jumping did hardly any compression to them, even with soft springs. Also it didn’t look very scale. So I got the 55mm not-even-friction-dampers left over from a MF01x and fixed those up. On the bottom I used the original position, only adding 3mm spacers. That way the shocks sit practically under the rails, looks quite scale to me. Just need 1cm more of travel, which the WR02 dampers delivery nicely while being even slimmer. 

 

[NeonScorcher 78]

Current status with painted rims. Not quite happy with the tire tread yet, it is too sharp, seems more like a mega mud truck than a stadium monster. 
Might try to sand it down - anyone tried that before?

[87lc2 2853]

I agree.  The Renegade is an awful looking tire, but nothing works better in racing.  I run the stock Axial SMT10 tires on my CR-01 and love how they look.

[JimBear 1268]

@87lc2 - have you kept everything stock (including the cantilever setup) on the chassis of your truck?

[87lc2 2853]

7 hours ago, JimBear said:

@87lc2 - have you kept everything stock (including the cantilever setup) on the chassis of your truck?

Yes, everything is completely stock on my truck.  Works great out on the trails with 4WS. 

[NeonScorcher 78]

@87lc2 Yes, the Axial tires look great, but are not available anywhere. I just got their rims, which fit perfectly, too. 
Maybe at some point there will be something similar available. We’ll have to wait and see. 

[87lc2 2853]

7 hours ago, NeonScorcher said:

@87lc2 Yes, the Axial tires look great, but are not available anywhere. I just got their rims, which fit perfectly, too. 
Maybe at some point there will be something similar available. We’ll have to wait and see. 

You can get them in the US pretty easily, but I see you're in Germany.

 

https://www.amazon.com/Axial-Racing-AX31344-Monster-Compound/dp/B073PFB4SS

 

[NeonScorcher 78]

Started to make some changes. First of all I wanted to fit a different transmission case to get lower FDR. So I ordered one of these.

It comes with a mod 0.8 9t pinion and looks like it could accommodate other sizes, too. Question was only, if smaller, larger, or both. So I wrote to injora customer service. They did reply to my question, but the answer was "we don't know". I told them this would be vital information sure to increase sales, but don't have high hopes they'll add the info.

So I ordered it anyway and got lucky. The 9t pinion is the smallest you can use, I was even able to test-fit a 17t (guess where that came from 😉). Otherwise nice full steel gears, ball bearings, aluminium housing. 

Next step is designing a new skid plate to use this. As I just have started CAD and 3D printing I want to try that.

BTW anyone have an idea what the two shims might be intended for? 

 

[NeonScorcher 78]

So this is what I came up with and did a few test prints of the side faces to get the mounting holes aligned.

Yes, the transmission will be on its side, motor on top. I'm aware that will lead to a higher cg but that way I can use the existing drive shafts. As the transmission housing is quite a bit narrower, too angled drive shafts would not engage properly. By taking the sideways angle out, this will work. And I plan to mount the battery lower to compensate.

[NeonScorcher 78]

And here's a quick look at the first test mount. I'm quite happy with it, the screws went in nicely, everything sits flush and makes a very compact unit.

Next I"ll be brainstorming battery mounting. Will update here but might be a while 

[JimBear 1268]

@NeonScorcher - looks good. Does the transmission/motor sit in about the same height as the original? The combination looks smaller, and maybe it weighs less, so that compensates for the higher CG?

What Injora transmission is it?