1/6 Willys Comp Crawler Build

[Bitter End]

Just as a segue; these are some of the first drafts of renderings that Duck sent my way. Looking at the modeling I wasn't sure what I had gotten into! First thought is, this guy sure has a wild imagination if he thinks that I can pull off that design...

And so it begins. Ducks trek began each Sunday, braving the 50+ mile route south. Taking dead aim through the heart of downtown Seattle traffic in his trusty steed (well... sometimes not so trusty... blue smokin mobile) and his always attentive better half Titus the super dog!

We would spend four to five hours nearly every Sunday tinkering with this and that, sometime making great leaps and bounds and other times wondering what the heck took us so long! I figured this collaboration would take us about 60 hours in total, so I told Duck it would take 80. Undeterred, he pressed on, penciling in the meeting for the next Sunday afternoon before saddling up for the trip home.

As Duck mentioned at the beginning of this thread, he's not able to hold a screwdriver... well, I didn't let him off the hook on any component of this build other than when I was putting fire to metal on the cage. Every jot and tittle wholly belongs to his crazy mind, I just turned the screwdriver! 8)

Another very cool layer of this build other than Ducks mad computer skills; he is a master at the 3D printer! And has one! Some of the things that you might see on this thread are parts and pieces that he designed and printed.

Got a profile pic?

Need a driver too 8)

Looks good, don't have to worry about damaging the body on a rollover "thumbsup"

The first time I was in Ducks workshop, he had his other RC's in various stages of... "disrepair."

Me: What the heck happened to that one?!!
Duck: Well... me and the boys were blowing off a little steam.

I thought the full cage would be a great addition too!

My favorite snap of the build (before additional details installed this Sunday, yes including the driver ;-))

A quick edit of this post to show the other side.

A few more snaps of the exo-cage and roll bar trying to follow Duck's design rendering.

The toughest part of the build of the exo-cage was the front cage. Everything was on a different plane, xyz's in every direction. Once we had one side complete, we then had to try and duplicate it for the other side... matching the same off angles in reverse. I think we got it pretty close. One big tumble down the rocks will get her all squared away! "thumbsup"

You might also notice hinge points on the front of the forward cage. It swings up and out of the way to gain access to the hood (attached to the front stubby bumper). A very cool design that Duck came up with!

You probably also noticed some very cool printed 1/6 scale seats! The final print design utilizes a two piece seat configuration that is hinged to accommodate any different angle that you need to get Joe into the right attitude for his ride! The fasteners that hold the upper and lower seat together also provide a perfect mounting location for the seat belts!

A little test fitment of the roll cage. Like a glove, almost like it was made for it.

 

[DuckTruck]

Dude! What an epic montage!! The scale garage of Bitter End made for a perfect backdrop. Looking forward to his future scenes and dioramas. 8)

@Taco, agreed on the wheelbase. We set it when the rear wheelwells were intact... 'ol Bitter is experimenting with solutions. ;-)

<img src='https://bigfishgames.box.com/shared/static/ow6ug3hupkzm17g414ea4p6e2rf4dnik.jpg'>

Topsy-turvy world.

 

[Mike Flea]

My only critique here is the driveshaft angles, as evident in post #29. Hopefully the cage and driver are heavy enough to relieve those angles, or at the very least go with a shorter set of shocks. I noticed the tops of the shocks are also leaning back over the axles. You'll get better articulation if those shocks are more vertical, or leaning towards the center of the body

 

[TacoCrawler]

My only critique here is the driveshaft angles, as evident in post #29. Hopefully the cage and driver are heavy enough to relieve those angles, or at the very least go with a shorter set of shocks. I noticed the tops of the shocks are also leaning back over the axles. You'll get better articulation if those shocks are more vertical, or leaning towards the center of the body

I'll agree that the driveshaft angle(s) look excessively severe.

Over-all chassis weight will also affect the static ride height.

--------------------

Softer coil spring rates may help some.
Not the shock length mind ya... the coil spring rate(s).

The neutral static ride height should be nearer 60/40 (1:1)
^ meaning: 60% compression (down) and 40% up travel.

~ I personally set my TJ's static ride height to 50/50 ~

Of course adding more weight to the chassis
could drop down the static ride height some. (ie: Mike F )
But that will need be determined after everything is mounted
onto the chassis/body.

The shocks would natutrally become more vertical
when the wheel base is lengthened.
The rear seems to need that WB extension the most.
But the front could go foward just a tad.

The WB extension will ease up the driveshaft angles somewhat...
but still might not be enough if the the shocks are fully extended
most all of the time.

Longer link lengths (both upper and lower) will increase the wheel base.
Tho' this can affect your driveshaft lengths as well...
so be sure those can extend at the slip splines without coming apart.

I personally do not like progressive mounted shocks
on a scale rig.

^ not as supportive to the rig's static weight
as a progressively mounted shock reduces the coil spring rate.
and the resulting articulation is way more then what a 1:1 bodied rig could net.

 

[Bitter End]

My only critique here is the driveshaft angles, as evident in post #29. Hopefully the cage and driver are heavy enough to relieve those angles, or at the very least go with a shorter set of shocks. I noticed the tops of the shocks are also leaning back over the axles. You'll get better articulation if those shocks are more vertical, or leaning towards the center of the body

Yup, she does squat down when loaded. On my build, I'm experimenting with different length shock hoops to further the lowering of the CG by raising the top of the unloaded shock and to find the optimal shock angle. I'm sure I will find a happy sweet spot. On Ducks rig we used the standard Axial hoops. I'll get a set built for his if it works out the way it should. (it looked good on the cocktail napkin anyway:lmao

 

[TacoCrawler]

My guess is you will need strengthen those hoops.
Because the leverage from the shock's compression
could bend those.

A simple fix is...

either add a horizontal tube going inbetween the hoop(s) at the upper sides
and tying those together...

or having a third tube coming from the top of the hoop(s)
diagonally down to the topside of each frame rail.

Triangulation or boxing (square) increases strength
and reduces the chance of leverage bending those shock hoops.

 

[Bitter End]

My guess is you will need strengthen those hoops.
Because the leverage from the shock's compression
could bend those.

Could very well be. Quarter inch steel brake line, it's pretty ridged right now. But as the weight and gravity work against the flattened attachment points it could become a problem.

 

[DuckTruck]

Yea, we've got some technical hurdles with the suspension set up, but nothing insurmountable! Bitter End has shown sound judgement in that department. If I had been clearer with the direction from the get-go we could've planned it better. As it is, we have to iterate on the design in the 11th inning. Word to the wise. figure that stuff out beforehand! :roll:

Still it's not the end of the world. A bigger challenge was the front cage. My design called for an exo cage that enshrouded the entire front end. The challenge was to find a way to make the electronics under the hood easily accessible with the proposed cage design. We went with a hinge on the front bumper, which to me, really stands out compared to other rigs with a 'standard' stinger. :mrgreen: The crowning feature to me though is the latching system (or whatever you want to call it). "thumbsup"

We threw some ideas around on how to latch the hood piece down and ended up going with your standard cotter pin used in a conventional manner in an unconventional place.
<img src='https://bigfishgames.box.com/shared/static/gjo58kwmvvcmqzwige822xvuyzna5biu.jpg'>

<img src='https://bigfishgames.box.com/shared/static/u6wtx1ay95cpvefg0wr66z0m8e4j0g97.jpg'>

<img src='https://bigfishgames.box.com/shared/static/esz5tprjazhhsfuxam0s7ges3vf3kje3.jpg'>

 

[TacoCrawler]

I really like that the front of the exo can pivot up/forward 8)

Tho' in all honesty...
can't say I'm a fan of that pin protruding below the rocker/skids.

Gonna be something to get hung up on a rock or other...

Think if there were another way to lock that front exo into position
I'd probably go that route instead.

Besides... I'd probably lose those clips and need replace them too regularily.

You seem to come up with plenty of other genius ideas...
possibly you could brainstorm on this one as well ?

 

[Bitter End]

Tho' in all honesty...
can't say I'm a fan of that pin protruding below the rocker/skids.

In final dress that pin sticks out about 1/4 inch and rounded over. It's tucked up far enough behind the front tire we hope we don't have that issue of getting hung up. Fingers crossed. In the photo we had just brazed a pin in place to get all of the pieces in position before cross drilling the hole for the body pin and cutting off the excess length.

In my mind I'm going to have a hard time getting Duck to take it off the shelf when she is finally done! :lmao:

A few more snaps of the final fitment and tweaks of the cage. We had just came up with a solid way to hold it down into position at this point, so you can see the pins in place as they will come to rest on the outer running board just behind the front tire. We had tried a few different ideas; attaching from the sides, clasping to the rear section, even magnets.

We broke it all down and cleaned up all the metal work and got it ready for paint. Duck had an interesting paint scheme in mind... I was just a little more than skeptical when he wanted white with red accents and brushed aluminum metal work. But I had to take it all back when we started to put it all together. The more pieces we added the more I liked it!

 

[TacoCrawler]

In final dress that pin sticks out about 1/4 inch and rounded over. It's tucked up far enough behind the front tire we hope we don't have that issue of getting hung up. Fingers crossed. In the photo we had just brazed a pin in place to get all of the pieces in position before cross drilling the hole for the body pin and cutting off the excess length.

Yeah I think the 2nd picture is more reflective of that 1/4" length
but is not a side profile picture ?

Probably shouldn't be much of any real concern.

Sorry if I was sounding critical of your work... I was mostly just curious.
I really do like the engineering ideal and simplicity of that pinned/hinged exo.

So congrats for making that happen "thumbsup"

In my mind I'm going to have a hard time getting Duck to take it off the shelf when she is finally done! :lmao:

Lol... he's got to run it at least once before it gets shelved... No ? Lol

 

[DuckTruck]

Haha, yea we have no idea how it'll play out. It's really out of the way all things considered but I imagine at some point it'll get snagged! Bitter End did an amazing job fabbing it all up. Smooth fitment "thumbsup"

 

[Mike Flea]

Ya, you're going to need to get shorter shocks, or weaker springs, even with the weight of the driver and cage it still sits too high, and kick that rear axle out a half inch or so."thumbsup"

 

[Bitter End]

Hopefully this week will get the rest of the accessories installed and the electronics in place. It'll be great to put the B+ to it and drive it off the end of the workbench! (Just kidding :shock: DT)

The driver was built and finished last week so we just need to plug him in and get him belted in.

 

[robbo]

Siiick cage work....!

Sent from my HTC6545LVW using Tapatalk

 

[DuckTruck]

We finally got 'er dusted and off and finished up! ....well almost. Here's a running video in the drive way.
https://youtu.be/TeQl1PJMOY8

Just needs a light bar and some more accessories. Also, probably a new esc unless I just run 2s. Overheated on 3s after about 5-10 minutes like this.

 

[TacoCrawler]

did you gear lower for that 3s voltage ?

Overheating can be due to insufficient gearing as well as the weight increase.
That exo can't be great for the rigs COG nor over-all weight.
but it seemly rolls along acceptably.
If ya lower the suspension a bit the wheel base should lengthen slightly.

I must've missed the discussion regarding what e components and drive settings this build utilizes ?
~ possibly I'm becoming senile ~

--- please refresh - enlighten me with details ---

What's working under that shell ?= mtr type - wind, gearing, etc.

How much does it weigh now ? :razz:

If you go any faster, yer likely to flop or roll it causing grind/rash :shock:

I've run 6s thru my HH's 35t TM mtr geared low (6.21)
and the motor becomes just barely warm to the touch.
Could probably gear taller for more top end... but I've plenty of wheel spin for trailing and crawling.

But if speed is your addiction... then a brushless/sensor setup is in your cards. just $$$. :mrgreen:

 

[DuckTruck]

Thanks for the comments Taco! Here's the build specs (also in the video).

1/6 Hasbro Willys Jeep body (custom cage and 3d printed parts)
2x Axial 27t motors
Axial esc
3s lipo
Pro-Line Interco TSL SX Super Swamper 2.2
Gear Head RC 2.2 Trail King EZ-Loc Beadlock Wheels
2:1 transfer case
Junfac Driveshafts
Axial Wraith Axles (locked diffs)
Gmade Zero shocks
Hot Racing links

The motors were around 90 degrees and the esc was up to 140 before it started shutting down. I figured the motors would've been hot if it was a gearing issue. It seemed likely that the esc wasn't designed to push 2 motors and was working too hard on 3s... what do you think?

I havent weighed it yet, but it's pretty heavy. The cage isn't that bad on it's own actually (brazed breakline), but there's a lot under the hood and the ess-one isn't light. the CoG is pretty high but I kind of like it that way right now. I'm sure that'll change the second I roll 'er

 

[klampykixx]

cool truck for sure, my opinion says its too high, like its on a huge lift and short arm suspension....

but yes, if youre going to run 3s, id gear it right down using two motors they will present as a 13turn to the ESC and it will run hot.

or, you could swap over to a pair of 45 turns, to bring the electrical load back to a theoretical 22.5turn motor. which will also bring your speed down a touch.

also, the double triangular links plus a servo on the chassis is just asking for bump steer if you ever "comp" it...

well done on the build tho, its beautiful otherwise! Jeeps rule!

 

[DuckTruck]

Hopefully this won't be my last post on this thread. On Friday my house was broken into and someone stole all my toys, including this jeep! Mark and I were going to finally do some crawling this weekend to... :x

Anyway, here's what was stolen. If you see any of these, let me know!
ericrea at gmail.com