Throwing away $100 on morbid curiosity build

[DeoreDX]

I have a ton of spare junk electronics just taking up room. Stuff isn't nice enough to really use in any builds but it all works so I hate to just throw it away. I decided to browse through ebay to find an interesting roller/slider to build up. I wasn't necessarily looking for a crawler just something that piqued my interest. I eventually came across this listing for a mysterious crawler chassis called "CAL RC SC01"

https://www.ebay.com/itm/293436553828

I found the listing interesting but not really in a good way. It's obviously a crawler chassis and interesting that it looks like it's 100% metal with no polymers except for the battery straps. The metal components don't look to be designed for any type of scale aesthetic but instead designed to be manufactured/machined as easily/cheaply as possibly from bar stock. The bumpers look like plain stock with a couple of chamfers machined in.



Here is my favorite part of the design. Notice how the transmission housing sticks below the bottom of the skid plate giving you a nice sharp edge and fastener head to hang up on every rock and root you go over



So I google the company "Cal RC" and the model SC01 and it seems like it's a vaporware company. Zero evidence on any of the english speaking forums of anyone actually owning one. There are some hilariously bad videos by the company on youtube. They are cringworthy enough that I hesitate even posting them. The videos consist of people unwrapping Cal RC metal parts banging them together to hear the metallic clinking of the parts and the guys exclaiming "All Aluminum!". There are some driving videos of the chassis wearing bodies that are hilariously generic looking and that obviously don't fit the wheelbase. Once I played this video with the A-Team theme music I literally LOL'd and decided I had to have one just to satisfy my morbid curiosity on how it looks in person.

https://www.youtube.com/watch?v=WxMQJMA7GiE

Their channel if you want to subscribe.
https://www.youtube.com/channel/UCTN...iYPzVVg/videos

I made an offer for $95 that was accepted this morning. Now I have to decide what to do with it. Do I take the time to cut out and prep and paint a nice new scale body for it? Do I use a body I like or stick with the generic asthetic like a TRX4 generic truck body? I have an old neon green Deadbolt body I could maybe throw on there. Those seem like boring options maybe someone has a better idea. Wheelbase looks short too maybe 11.4" Dingo length? I do see myself at least dumping the trans and mounting plate and fabbing my own and throwing in an old AX10 transmission. Definitly dump those horrible bumpers. Guess I need to figure out the wheelbase first before I start trying to figure out what body to run.

I'm curious how much this thing weighs with all the metal parts I bet this thing weighs a ton.

[DeoreDX]

This is interesting. This article says the SC01 was designed by "The former owner of HPI, Tatsuro Watanabe". Noticed my paypal was to a Wantanabe LLC.

[JatoTheRipper]

Originally Posted by DeoreDX

This is interesting. This article says the SC01 was designed by "The former owner of HPI, Tatsuro Watanabe". Noticed my paypal was to a Wantanabe LLC.

If that's the case, no wonder HPI is dying.

This chassis has some elements that make me think the designer was drunk at the time.

I'm curious to see what you make with it.

[Jim85IROC]

I think it's really cool, and aside from the couple curious design, ahem, "Decisions", it looks pretty good. Definitely worth $100.

I searched ebay, and apparently there are no more listings for it, so you may have gotten THE prototype.

[DeoreDX]

Originally Posted by Jim85IROC

I think it's really cool, and aside from the couple curious design, ahem, "Decisions", it looks pretty good. Definitely worth $100.

I searched ebay, and apparently there are no more listings for it, so you may have gotten THE prototype.

If you do a search for completed items it looks like several has sold. Don't know if I got the last one or if he just lists one a week.

[dezfan]

Doesn’t really look any worse than the Injora clone I and others have tried out.

That local is the one Soze frequents(the name escapes me at the moment), but maybe a PM to Soze and see if he might have seen one of these or have some insight just by being a local?

[DeoreDX]

Something I noticed after I bought it. I wonder what spur gear it will use. The mount looks like it has 4 bolts while my axial stuff bolts with 3. Though the old 80t I have has a bunch of other hole patterns some of the aftermarket steel gears look like they are 3 bolt.

[Bob_in az]

Originally Posted by dezfan

That local is the one Soze frequents(the name escapes me at the moment), but maybe a PM to Soze and see if he might have seen one of these or have some insight just by being a local?

Corona Del Mar!

[soze]

Yeah this seller is local to this area. Never met the guy, but he's always got a bunch of HPI and Hot Bodies (HB Racing) items for sale on eBay.

I bought several Hot Bodies D413 buggies from this seller when he had them listed for ridiculously low prices.

[DeoreDX]

So I dug through the parts box.

No brainer parts:
-DuraTrax Deep Woods 1.9's and some old scratched up Axial beadlocks
-DS3218 20kg chinaservo
-Flysky receiver.

Now ESC and Motor becomes more of a difficult decision. I don't really have anything suitable for crawling. Most of the ESC/Motors would be more suited for a 1/10 buggy or SCT.

Brushed:
XL-5 and some orange and blue Hobby King X Car 45A brushed ESC. I have no idea where the Hobby King ESC came from but it looks brand new. I know the XL-5 doesn't have a drag brake I'm guessing this old HK ESC doesn't either.

Only Brushed motors I have are some cheap sealed can motors with no labels and an Axial 27T. Would at least get me moving.

Brushless:
Turnigy Trackstar ESC and 3100kv motor (Sensorless). Not really suited for a crawler. No programming card and I have no idea if I can set it up with a drag brake.

Hobbywing EZ-Run WP SC-8 Sensorless. I have the programming card and this one can go to 100% drag brake. The 4300kv EZ Run that's pairs with the ESC is definitely out of the question. Could try it with the 3100kv track star.
Still either motor is sensorless and way too much RPM so not really my first choice, or second choice.

Hobby King X-Car 45A Brushless sensored ESC. Another item I have no idea where it came from but looks brand new and I have a programming card for it. I don't have a brushless sensored motor though. Drag brake maxes at 25%. I'd probably but a cheap low kv motor to try it if it had more drag brake. Doubt this ESC will ever see the light of day.

I'll probably just throw one of the brushed ESC's and a no label motor on it to see how it does. I've been wanting to try a 1080 so I'll probably order a 1080 and one of the Crawlmaster motors once I get a feel for the weight of the crawler and decide how much power I need. I also need to figure out if I can fit a 550 on it. I have an Axial 80t 48p spur gear that has a lot of different hole patterns in it. Hopefully one of those will bolt up to the 4 bolt pattern on the transmission mount. Probably going to be over geared until I find out the bolt pattern and get better gearing.

[Rock solid]

I picked up one of these with the same intent as you. I was actually surprised at the quality of the machine. The chassis is half decent, the axles are robust but are geared very high 2:1 in fact. The trans is about worthless though. Surprisingly it uses universal shafts straight out of a scx10.2. my suggestion is use the axles but swap out the tranny for something with more gearing to make up for the high diff ratio.

[DeoreDX]

Originally Posted by Rock solid

I picked up one of these with the same intent as you. I was actually surprised at the quality of the machine. The chassis is half decent, the axles are robust but are geared very high 2:1 in fact. The trans is about worthless though. Surprisingly it uses universal shafts straight out of a scx10.2. my suggestion is use the axles but swap out the tranny for something with more gearing to make up for the high diff ratio.

2:1 that seems really high. I was already fearing the spur/pinion I have being too high that will just make it worse. I wonder if axial bevel gears would fit.

[Rock solid]

No unfortunately I don't think axial diff gears would work, the axles use a unique locker that is offset from the diff it allows the same size shafts but offsets the entire diff to one side.. which is actually kinda cool. You could set the stock transmission up as a transfer case unit and use another transmission up front linked with a short drive shaft. That would offset the lack of gear reduction plus give you the forward weight bias. I ended up using just the front axle on a build with a stock scx10 axle in the rear.. it gave me a nice over drive. All in all the price is actually pretty good but unfortunately it's not ideal as a stock crawler if your handy though it can be pretty cool.

[Rock solid]

This is the build I did using the front axle. I put an rc4wd r2 transmission in the center with a capra cage and custom skid.

[themountain]

The axles look interesting! For the price being I think its decent.

[DeoreDX]

First impressions are very good actually. Everything has a very high quality feel to it. Good even anodizing. Smooth well finished parts. The chassis is incredibly stuff. Grabbing it by either end and trying to twist it gives absolutely zero torsion. It's an extremely rigid chassis.

The suspension is set up way too stiff. There is zero droop when you set it down. Doesn't feel like there is enough damping. What you see here is the limits of the flex before the rear wheel lifts off the ground. While the chassis is very rigid the link setup is very sloppy. You can hold the frame and jiggle the front and rear axles side to side somewhere around 3/16". I've never held a crawler with that much jiggle in the axle. Does that come down to poor pink geometry? Low quality link/ball ends?




Looks like a 540 is the max I could fit in there without surgery in the electronics mounting plate. Not sure I want to hack up the pretty anodized aluminum mounting plate




I can only get two bolts into the stock Axial 80t spur. It uses a smaller mounting circle than the 3 holes it used when mated up to an Axial transmission. Anyone have a clue what spur gears I should try that might fit? I could at least jump up to a 87t Axial but I'm still stuck with only getting 2 of 4 holes lined up.



It feels nicely made and of high quality but the more you touch it and play with it you quickly figure out it wasn't very well designed and a lot of the parts aren't well thought out. Take the battery straps for example. They are completely unusable as the dimensions of the straps are such that unless you stack 2 batteries on top of each other, the velcro is too long so you can't actually get any of the velcro to "stick". One strap is right in line with the shock tower so you couldn't use it even if the velcro wasn't too long.

I wasn't able to use a pinion smaller than a 16 with the 80t spur so right now it feels way overgeared. With the stuff suspension I'm thinking it will take a lot of weight to get the suspension to flex so I'm thinking a hard body of some type now. I measured the wheelbase around 310mm. As you see it here it's 5.6lbs so far with no body.

[DeoreDX]

I think I decided what I want to do with this thing. I'm going to make this into more of a bashing trail truck, something my son will use on the trail as he tends to get bored with straight crawlers. I'm thinking 12-15mph top speed. I'd like to do a simple truggy build. Looking at pre-built back half cages and it looks like I can get a Proline, Honcho, or Injora. My son liked the Cherokee Injora Truggy but I'm not sure I cared for the way it looks. I'm leaning towards a Proline setup. I'm going to have to totally re-do the layout to try to truggy it. The big back battery setup will have to go. If I tried to put it in the front I can only fit a 1500mah cell. A 2200mah and larger are too big. 1500mah would suck on a trail truck. Maybe sideways behind the motor would work.

[DeoreDX]

Disaster.

Went with a cheap 1750kv motor I found on Amazon. Got all the electronics installed and dressed in the front electronics try. My son too it for a spin outside in the neighborhood with his friends. Apparently some girl was riding on a bike in the neighborhood and ran it over. Snapped the rear link/shock mount off the rear axle.



Two slivers of material less than a mm thick is all that holds the links on and that was the failure point. Of course being vaporware there are no spare parts to be had so I had to fabricate my own fix. The bracket was 4.2mm thick and I looked around for a thick piece of aluminum. Then I remembered the big aluminum bumpers that I pulled off the crawler.




Little time on the band saw, a few hits with a file, and a little drill pressing and she is back in action. The replacement is just a slight bit thicker to make it a little stronger. The drill bit wandered in my a hair so the mount is at a slight instead of strait. I've not yet decided if that annoys me enough to re-do the mount.



The Kimbrough spur gear works. I added the two missing mounting holes and I'm running 12/87 gearing now. Not sure it's worth it trying to go bigger on the spur, the biggest they offer being 96t. I'm at 7.25:1 right now with my spur/pinion combo. Not sure 7.5 or 7.66:1 or all the way up to the 96 for 8:1 is really going to be very noticeable gear reduction. I'm about 36:1 total through the drive train right now. 96t if it would even fit would give me 40:1. Is that much change in gearing even noticable? on 2s it crawls OK and I have a ton of wheel speed. I don't have any big 3s packs but I might give it a go on one of my small 3s packs to see what it's like. It not has matching Deeps Woods on all 4 wheels. Still need to decide on a body. My body purchase was pushed back because I ended up buying a SCX24 instead of a body when the son and I went into the hobby shop over the weekend

[DeoreDX]

I went with the cheap Injora Cherokee truggy body. Got it last week and spent the last couple of days painting it. Since I didn't care much for the whole thing I thought it would be a good opportunity to test out weathering techniques. Never tried to weather a body so this was treading new ground for me.

Krylon fusion orange. I used the salt method on the side and hood stripes to hopefully make them look like cracked faded and chipped vinyl. This was done in flat black and I dusted back over it with my base color to make it look faded.



I did a wash with a forest green, desert tan, and flat black to grime up the cab. The cage I painted with a combination of oil rubbed brone and flat black. I would dust it with one color then the next. It turned out a beautiful almost black color that would show a glint of dark brown metallic glint when the liht hit it. It was way too pretty and not the look I was after. So I dusted it with the orange then washed it with with flat grey and desert tan.





Still have a lot of work to do. I plan on making a back to the cab to fill in that empty void under the B pillar. I have styrene or I could try to 3d print something. Not sure which I will do yet. Still need to mount the windows, handles, windshields and wipers. I also need to decide how I want to mount it.

[DeoreDX]

Got some more work done last night. I hated the little plastic spacers and the big unfinished gap under the B pillar. I removed the spacers and designed and 3d printed some spacers to fill in the gap. I made the body spacers the same thickness as the little plastic spacers that came with the body. It looks like that puts it about 1.2mm short of lining up with the B pillar. If I make the spacer thicker it will push the cage away from the body and it there will be a gap where the 3 screws from the middle of the cage screws in just under the rear window. I'm probably going to modify the spacer and extend the body line a little bit but offset the surface of the mounting holes a bit so everything will line up correctly at the rear edge of the B pillar lines up better. I also mounted the fenders. The fenders were made from a rubbery material so I'm not sure I can weather them.