SCX24 KOH Build

[motiracer38]

I picked up an SCX24 on a whim a few months back and although it was fun I never really found a use for it. Mainly it lived in the motorhome and we'd drive it around when the whether was bad in the desert. That all changed when the kids got a 3D printer for Christmas from their aunt and needed something to print.

Inspired by @JP98_ and his ultra 4 build I got to work designing up a chassis to transform this thing into something worthy of driving. My first design was a single piece print that had all the design of a modern rock racer so I pressed print.


I woke up to a half chassis due to a break in the filament but it was enough to mount up and verify fit and clearances. It also highlighted the mess of supports needed and the aggravation of cutting them all out.


I took the lesson learned and redesigned it with modularity in mind to speed up prints and enable redesigns of different sections.



This print went a lot easier and built up nicely. I found an interference in the front section, had to widen and reprint, and took advantage of the modularity. I extended the front wheelbase and had to redesign again to suit and settled for now.





I even built a roof with scoop, but not sure I love it.


To round out the performance package I printed some wheel wideners off of Thingiverse and added some brass knuckles.


This has been a fun little project to pass the winter month in SoCal and the ideas just keep flowing.

[vinceherman]

That is awesome! Did you put these up on thingiverse?

[Brake Weight]

Originally Posted by motiracer38

This has been a fun little project to pass the winter month in SoCal and the ideas just keep flowing.

Chassis looks good though. The 3 part design is a good idea as well because you could dove tail front/back pieces for stock track width if you wanted or widen them or whatever you wanted. Complete redesign to body/fenders and keep the center. Options is what I’m getting at.

[Shape_Shifter]

Well done!

[motiracer38]

Options is what I was trying to plan for. For example the race style rear bumper drags on everything when couch crawling so may be replaced with a lower profile one soon. I'm trying to get some oil shocks in place and larger tires but everything is out of stock it seems.

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[nathanotis]

Very cool. Never having done anything like this, how easy is it to do this kind of designing for a 3d printer? Do you need to be comfortable in CAD style programs?

[motiracer38]

Creating the model takes a ton of time and verifying the fit of all screws and interfacing parts requires a few prints to verify fit. I'm fluent in cad and still have about 30 hours of computer time to get to this point. Granted that was after hours on the couch with the kids involved, but it still irks me when people ask for a free copy.

There are free cad programs out there to get started on that you can get up to speed pretty quick. Tube work is always a bitch though.

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[stolps]

Love it. I printed the one on thingiverse and man the supports were a real challenge to remove. I am in the early stages of designing a multi piece cage as well similar to the ryft. Your method of fastening the sections together is great. No screw heads exposed. Looks like it warrants a redesign in those areas for me. Keep the ideas coming. Thanks.

[Vitamin_J]

Yes, CAD takes time but so what? Are you planning to sell it or what? Thingiverse is awesome people just put their stuff out for the world to see and use as much as they want. You put in the effort already so it's only a few mouse clicks and the rest of the world can enjoy the fruits of your labor as well! If you are selling them then of course you shouldn't put them up for free but if you are just going to forget about it and move to the next project I say put the models up for free download!

E: I'd print one! Your chassis looks super cool.

[motiracer38]

Originally Posted by Vitamin_J

Yes, but so what?

That's always been my opinion on model sharing. For now let's leave it at I am sharing how I believe to be a more efficient way to print one of these chassis and enjoy the ride of how far my boredom can take it.

I finally found Scramblers in stock and have a couple sets coming so I can revise yet again. This one was well scaled with the stock wheelbase, width, and tires but I have a new one in the works based around the updated proportions, just waiting on tires and wider axle shafts to ensure it all works together.

Has anybody found metal balls to use in rod ends with either a 1.5mm or 2mm hole? I've found Du-bro 2-56 which is 2.2mm, 1/16 Erevo has 2.5mm, but nothing smaller.

[Vitamin_J]

Originally Posted by motiracer38

Has anybody found metal balls to use in rod ends with either a 1.5mm or 2mm hole? I've found Du-bro 2-56 which is 2.2mm, 1/16 Erevo has 2.5mm, but nothing smaller.

It takes time to piece together custom parts like that. Irks me when people ask for the fruits of my labor for free

[motiracer38]

Originally Posted by Vitamin_J

It takes time to piece together custom parts like that. Irks me when people ask for the fruits of my labor for free

Oh wow, you're a special one aren't yah?

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[CODYBOY]

Originally Posted by motiracer38

Oh wow, you're a special one aren't yah?

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I think J was just driving home a point, this site is all about sharing and passing it forward! I spent many many hours on putting together some of my builds and always took the time to post every step of how to and encouraged questions if some one got lost. Believe me, nothing more flattering than to have someone copy what you're doing. Just my 2 cents!
Ernie

[motiracer38]

RC4WD Scrambler tires were back in stock so I whipped up an internal beadlock wheel. I was able to hide the lock screws on the backside and be able to clear +4mm brass hubs. Gotta tweak the some tolerances but the first print was close. Went with an Ultra style as that's all the rage in TTs this year.




I also found some 2mm balls to use. Uxcell M2 ball ends on Amazon. Still wouldn't mind some 1.5 but I can make these work. Had to print up some test fits to ensure the ball doesn't bind. .205" diameter worked the best for me.


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[JP98_]

That thing looks totally rad man! Love the modularity! I’ve been thinking about designing something similar glad to see someone finally did it! Keep up the good work man����

[motiracer38]

The Scrambler tires are so big it was throwing the scale off a bit so I made the chassis wider and taller. I also added Duratrax Mini Quake shocks I had sitting around. It required a new rod end, top bushing, and lowered shock mount but they ended up fitting nicely. Now I'm battling spring rate as the 3/8 OD springs are too stiff and the only place I can find softer is Lee Spring but they are $8 apiece. I also printed the wheels in silver to replace the black and am liking them much more

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[Shape_Shifter]

This is so awesome...

[SurlyBurly]

Originally Posted by motiracer38

but it still irks me when people ask for a free copy.

Don't sweat it for a second man, it's not just the hours it takes to compile a model like this but the years invested in becoming adept at modeling in the first place.

Originally Posted by motiracer38

There are free cad programs out there to get started on that you can get up to speed pretty quick. Tube work is always a bitch though.

Do you recommend any one in particular for an amateur, especially in regards to 3d printing as an end goal?

[motiracer38]

I'm not sure what is still available, that would be a question for a 3d printing forum. I use solidworks so haven't kept up on that front. A surface modeling program like Rhino is better suited to R/C designs. It would be very challenging for me to mimic body panels or grills with the sweeping lines.

[motiracer38]

I ended up finding springs from thespringstore.com for fairly cheap. Picked up three rates while I was at it.

It worked well but I got bored and started building a bulkhead diff and arms. I went pillow ball style to maximize arm length and able to get 1-3/8" travel out of +6mm width with minimal bumpsteer. Took a couple tries to get the correct gear mesh, minimize friction, and optimize slop but it all seems promising now. Need to modify some diff cups and assemble the dog bones still. Next up is a chassis to hold it as well.


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