Cross RC BC8 8x8 Build

[HumboldtEF]

I think I've come up with a good solution to the wire routing issue. I've installed 4 JST plugs on the controller board in order to be able to plug in the rear brake lights and indicators separately while allowing the cab lights to be soldered directly to the board. If everything is soldered to the controller removing the body would be impossible.

The JST plugs also fit the plugs on the end of the CrossRC lights so I only needed 4 instead of 8 which is nice, just pay attention to polarity as the plug can be plugged in backwards.



I was a bit confused by this at first but each of the programmable channels on the controller connect to the negative on each LED while there are 2 shared positive pads for all of the positive leads.




I've got the lights all programmed how I want them but when I tried to transfer the config to the controller I ran into an issue with the program used to transfer this file. My antivirus program flagged this file as a threat (medium) and quarantined it. I've contacted the creator to see if theres a fix on and explanation.
I'm guessing this is just a case of my Antivirus program being overly protective but I'll wait to hear back about it.

[HumboldtEF]

Ok I've got another technical hurdle to overcome, In order to flash the controller with my programming I need to ID the Com port (Serial Port) that I'm plugged into. The issue I've run into is that my PC (running windows 7) isn't showing any Com ports in Device manager even with hidden files shown. I got some help from my brother who's in IT and we were able to use an add hardware option to create Com port 4 and 5 but its not what we've plugged into or its not configured right.

When we look up the error code there's a lot of mention of Python (and this program uses a lot of Python) so I installed that in hopes that it might resolve it, I had no luck with that though.

Heres the error code ERROR: could not open port 'COM4': WindowsError(2, 'The system cannot find the file specified.')

The guy who's behind this project has been super helpful already but I'd like to avoid peppering him with petty questions so I'm trying to push through as far as I can and make some progress.

[HumboldtEF]

AH HA Eureka I've found it! The issue ended up being a bad USB cable. I ended up needing to ask the creator of the light kit a few questions along the way and he was very helpful.

I'm gonna put together a little video on testing the controller and showing its features.

[soze]

Originally Posted by HumboldtEF

AH HA Eureka I've found it! The issue ended up being a bad USB cable. I ended up needing to ask the creator of the light kit a few questions along the way and he was very helpful.

I'm gonna put together a little video on testing the controller and showing its features.

Those darn USB cables!

[HumboldtEF]

Originally Posted by soze

Those darn USB cables!

Yeah I had a feeling the cable might be the issue early on but I couldn't round up any other cables to test until today when I realized my wireless mouse charge cord is a micro USB. Plugged it in driver installed job done!


Here's a video of me testing it out and showing some of the features. I need to take another crack at my programming as I need to change a few things

https://youtu.be/GQGKTeGcluA

[HumboldtEF]

First a quick tip for anyone having trouble getting the hubcaps off

Oil filter strap wrench is about the only thing that will get these off without damaging them. Some of these suckers are on super tight.



I noticed the ride height has dropped down since the initial build so I decided to try out some stiffer springs. Just keep in mind these little internal spring (shocks) also have 2 torsion bars working with them.

Stock springs are possibly weaker than springs out of a pen.
Finger for scale



I first tried some of the stiffest springs for the Bully 2 shocks, they were too stiff surprisingly. also the coils were so thick they limited travel.



Next I tried 2 steps down (in stiffness) as well as cutting out some coils



These worked out much better, I still lost maybe a few mm of travel but I think is a fair trade for a more appropriate spring rate.

The ride height is now raised up a 1/2"-3/4", you can also see the styrene bed I'm working on.



I'm using this picture as reference











I also added a reverse light using an old axial light bucket which uses the MK4 light controller to toggle on and off.



I'm hoping to have the bed done before next Friday for the RPP Jamboree

[HumboldtEF]

I've been hemming and hawing about how to do the bumper and I finally decided to just dig into it because if I allow myself to sit and think about it I will surely stall for a while. I only had a half hour to mess around with it this morning.

I cut a length of 1/8" x 1" steel flat stock, relieved the back side where I bent the corners, I'll weld the back side later. But I do plan to add a lower angled plate as well as a filling in a few other areas.



I cut it a bit long and I'll trim it to its final length later in the process.





I'm also going to cut the ends at an angle in order to raise the corners up as much a possible (with it still looking good) as this is usually the first point the bumper will hit obstacles.
The idea is to have it fairly basic like the stock bumper but it will be a bit angular like a more modern bumper. I'm going to try my best to make it look like it belongs on the Maz though.

[HumboldtEF]

The bed is done and mounted, painted and weathered. I ended up having to make it 2 pieces in order to be able to fasten is easily. Below the bed is a platform that screws into the frame rails in existing holes (threaded for M2.5), this platform has tabs on the top so I can bolt the bed down to it.







I used some rust paint on the hubcaps



I got the front bumper mounting tabs welded in using my favorite method, cutting a block of wood thats the same width as the frame rails that I clamp to the bumper and use to locate the mounting tabs while I tack them in place. Originally I had intended to weld the mounting tabs in and come back later to drill the holes to mount it to the frame rails, but I realized the angles I had put in the first piece wouldn't allow me to get a drill in there. So I made a nice template out of some thinner cardboard to transfer the hole pattern to the flat stock. It was close but not perfect, instead of slotting the holes or just hogging them out I mocked up the tabs with 2 of the 3 bolts holding it in place and on the third hole which was off slightly I took a drill bit and ran it through which moved the hole on the chassis side a bit to get it inline. this way theres no play in the mounting. Oh and I did open up the holes on the frame rails (that the bumper uses to mount) as they were m2 sized, I opened it up to accept M3 hardware.





I cut the front piece of the bumper at an angle. I almost forgot to tack the back side of the bends first which would have ended poorly (likely would have tweaked the angles).





And after all that I noticed that I had broken off one of the handles on the body. Luckily this is one of the few parts that came with extras. I drilled it out from the back side and glued in a new one and primed it using a brush.



I'll have to be more careful when I have both of these hatches open at the same time as the handles hit each other and I have a feeling one sheered off the other.

[HumboldtEF]

Front bumper is finished, I'll take some better shots later















EDIT: here are a few more shots

[HumboldtEF]

I got a few shots at the RPP Jamboree on Friday.









I was the runner up in the Show and Shine with the Maz, though I think I would have had a better result if they had picked up my truck like the others, instead they just pointed down at it. Oh well it was nice to be runner up.

This was the only truck I felt comfortable doing the cable bridge with, crossed it no problem.


I drove up to the cable bridge with the FJ40 but decided a picture was a better idea, lol





I brought back the SCX10.2 that I won in the raffle last year



There was a sweet U4 (I assume) beetle with LS power






I didn't run the Maz in the competition on Saturday, instead I ran my Ascender K10 which I tried to run last year but had a major failure (user error ).

I picked up a new set of the KM3's (4.75 in the G8 compound) and they did great.



This year the course was different, it followed the dry creek for a while and honestly is was way too easy but it was still a lot of fun



The venture with the Ambush body took a tumble down this hill a few minutes after I took this and ended up in the pond to the left. My brother watched it tumble and just froze and watched, then another guy sprung into action leaping for the truck which made my brother realize he should also act quick and he jumped into the pond and grabbed it, time just stood still for a second. All was well in the end as it was using all waterproof electronics besides a Promodeler servo which was also still working. He finished the course with the truck with no issues.



Parking on what was once a truck, looks like a small block chevy maybe



Heres Jeffs Blazer, still in stock form

[Natedog]

Maz keeps getting better, bumper turned out great! Nice to see it in action at RPP Jamboree and glad you got to run the Ascender this year!

[HumboldtEF]

Thanks Nate!

I was a bit conflicted on what truck to run in the event but in the end it had to be the Ascender, It needed redemption for last years slip up.

We got to hang out with Jeff again this year (he had the Defender last year), he brought his new SCX10.2 Blazer and was really flogging it mostly because of the long overhangs and big body. I got his contact info and we were also talking about getting together to do a camping trip. It would be sweet if You and Paul could also join us whenever that ends up happening.

RPP just posted up a video on the Jamboree this morning

https://www.youtube.com/watch?v=Ho4FszLdfD8

[quart]

Very nice build !
It would be interesting to see the Cross RC 8x8 besides a TRX4 or a SCX10, just to get an idea how big it is :-)

[HumboldtEF]

Thanks quart

Here it is next to a TRX4 Defender and SCX10.2 and one shot at the end with the GMade Gom

Its pretty small scale wise next to 1/10 scale rigs. Though if it matched 1/10 scale it would be way bigger than I'd like since I'd have to power and carry, it'd probably add another 10 lbs.

[quart]

Thanks
You got a lot of nice crawlers!
Like you sad it would be a huge machine if it would be a full 1:10 scale

[westberliner]

Wich Springs did you used?

Bully II has 90mm internal springs.

4x 90mm Shock Spring (1.9 Spring Rate "Blue")
4x 90mm Shock Spring (1.5 Spring Rate "Red")
4x 90mm Shock Spring (0.7 Spring Rate "White")
4x 90mm Shock Spring (0.3 Spring Rate "Yellow")

Thanks for your answer.

[HumboldtEF]

Originally Posted by westberliner

Wich Springs did you used?

Bully II has 90mm internal springs.

4x 90mm Shock Spring (1.9 Spring Rate "Blue")
4x 90mm Shock Spring (1.5 Spring Rate "Red")
4x 90mm Shock Spring (0.7 Spring Rate "White")
4x 90mm Shock Spring (0.3 Spring Rate "Yellow")

Thanks for your answer.

Hey thanks for posting the spring rates and colors. I didn't keep track of what I put in but I can see what I have left over and check against your list.


Its not the yellow or blue and the other springs I have left have no markings. But between the red and white it must be the red as they were thicker than the other set.



I chose to use those springs simply because the stiffer springs have thicker coils and at full compression they might reduce the amount of up travel since they can only compress so far. But what ever spring you use they likely need to be cut to length so that you dont lose too much travel. I think I lost a few MM with the springs I used, not enough to worry about though.

[rockhugger]

This rig is super sweet and I love that lighting setup. Great work on the bumper

CAmp and crawl... Let's go!!!!

[HumboldtEF]

I just noticed this the other day on the Cross RC site, hmmmm....... looks familiar



https://www.crossrc.us/shop/cross-rc-bc8-bed-kit/

I'm still glad I made mine as I was able to make it the length I wanted (I cut a bit off the rear of the frame) so its a bit shorter.



They also have logging trailer in case the truck wasnt long and heavy enough for ya.

I'd post a picture but they're super tiny
https://www.crossrc.us/shop/cross-rc...gging-trailer/

[jamesbernatchez]

I wanted to bump this as more people should check this rig out. I wanted to say thanks to OP for this thread. Mine just arrived last night and I spent 12 hours getting to the point where it was running chassis minus the body. The size and weight is not expected, even when you know it’s a big rig. The torque in 1st is insane. I may even try to pull my car when it’s done.

I noticed they included servo spacers, two different sizes. I used the tallest ones, and the front servo hits the body. Will need to drop it down some. Powerful servos are needed. I’m running Savox SW-1210SG for the steering and they have no issue turning on carpet at full stop. Again, it’s heavy. You could workout with it.

Everything is going together well, minus the few small hiccups so far. I really hope they come out with a better trailer for it. I have no interest in the logging trailer.

Locktite is your best friend. So many screws thread into metal. Get a tube and you should have plenty.

The front skid alignment was off on the bottom two holes. I needed to elongate them a bit.

Hands down one of the best and most impressive kits I’ve ever put together. It is my first foray into Cross RC and I’m a fan!