-Lunar Bound- Moon Buggy Build

[HumboldtEF]

Last night I worked up a drag style cut off switch.

At first I considered making my own switch with homemade contacts and all. Then decided to see if I could used a switch I pulled from a Mamba X.

So far it works well, just needs a little fine tuning. Its meant to mount to 1mm thick lexan.

I'm not sure where I'll be mounting it yet, I'm not sure I want it on the outside. Maybe I'll make a small dash panel or some interior panel for it.






https://youtu.be/_s63h679UHM




EDIT: here it is mounted to a lexan scrap. Only the lever arm is exposed, everything else is hidden behind the lexan.

[smog]

Superb cage work EF. Great build thread in all, lots to chew on there. How did you cut your 16ga steel?

[HumboldtEF]

Originally Posted by smog

Superb cage work EF. Great build thread in all, lots to chew on there. How did you cut your 16ga steel?

Thank you


I used a disc grinder with a cutoff wheel to get it close then swapped in a grinding wheel and finishing it off with a file.

[CODYBOY]

This is such a great build Casey! I'm really enjoying your attention to detail.
I sure miss our little group getting together a couple times a year!
I may have a little design/printer project for you if you have time and are up to it? ( It involves parts for a 1/20 buggy I want to build).
Ernie

[HumboldtEF]

Originally Posted by CODYBOY

This is such a great build Casey! I'm really enjoying your attention to detail.
I sure miss our little group getting together a couple times a year!
I may have a little design/printer project for you if you have time and are up to it? ( It involves parts for a 1/20 buggy I want to build).
Ernie

Hey thanks Ernie, yeah I hope we can get together this year.


I'd be happy to help out, send me a PM with some measurements and a rundown

[CODYBOY]

Originally Posted by HumboldtEF

Hey thanks Ernie, yeah I hope we can get together this year.


I'd be happy to help out, send me a PM with some measurements and a rundown

Thanks Casey, I sent you a PM.
Ernie

[HumboldtEF]

I had good enough weather to do some painting today. I didnt really have a paint scheme in mind but after checking my paint supply came up with some Tamiya Metallic blue (PS-59) for the hood and sides, White (PS-1) for the roof minus a Black (PS-5) strip in the front and a stripe on the side too.

It was starting to get dark outside and its a bit hard to pick up the blue. I tried to angle it just right in one shot.
It came out good except for the bends I put in the sides, the lexan has some tiny fractures at some of the bends. Nothing you can feel, you can just see it. I'm not gonna worry about it though.





here you can just make out the black stripe on the side, kind of looks like a VP accent or something which isn't what I intended.





I'm also working on V2 of the light switch thats converted to work like a Drag Race cut off switch. I wasn't liking how much force the first version required and thought some gears might give me a bit of an advantage and a longer throw too. First version didn't move very far.



I'm printing it out as we speak but I feel like the gear teeth may be too small. I'll know soon enough but I think I should probably order some smaller nozzles for projects like these.

[Phildirt]

Man I absolutely love this thing. Well executed.


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[B-MOW71]

It looks beautiful sitting out there on the rocks! Great color choice!

It's been fun following along with the build and seeing it all come together! Once again, great job on the metal work! That cage looks awesome!

[HumboldtEF]

Originally Posted by Phildirt

Man I absolutely love this thing. Well executed.


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Thank you, for winging it a bit I'm super pleased with the results

Originally Posted by B-MOW71

It looks beautiful sitting out there on the rocks! Great color choice!

It's been fun following along with the build and seeing it all come together! Once again, great job on the metal work! That cage looks awesome!

Thank you I appreciate that


I tend to stall when I'm close to finishing off a project trying to extend the fun of the build I guess
Thats where the cut off switch came into play. I had fun designing the geared design thats less than ideal in terms of size and complexity. I kind of pushed through with multiple iterations just to get it working and then I stood back and realized it wasnt gonna fit and i'd made it far too big.


Enough rambling here's some pics after I finished the wiring including a simplified cut off switch.


For the switch I went back to the first design moving the fulcrum closer to the switch for more leverage. I also built in some slop to the mechanism so the actual switch lever moves the distance it should.





the black part is the switch





It sticks up above the hood just a bit so I can toggle it easily. I used a long screw for the nearby hood mount which serves as the mount point for the switch, bent up some lexan and painted it silver for the dash panel.




I used some mesh wrap to clean up the wiring. It was a bit of a pain getting the right lengths and heatshrink in the right places as I built the harness. Its nicer but still a bit of a mess due to the less than simple setup (2 servos w/ direct power and light bar with inline switch)





I guess I never showed the battery tray after I installed it. Its not parallel with the rig but at an angle. I thought this would center the weight better.






you can pick up the angle from below a bit better





Speaking of weight, final weigh in with the 1400 mah 3s packs was 5.83 lbs


These seem like a nice pack for a light-ish weight build, small but with some capacity. Though I didnt like how long the wires were so I shortened them by 2 1/2" or so.




Today I spent a few hours doing the final setup, centering servos, threadlocking driveshaft pins & servo screws then the actual radio programing. I struggled with the 4 wheel steering setup for a bit and finally found a video that went over things that arent in the manual (or at least in the spot that would make sense). If you have a Spektrum DX5R C or Pro this video explains the drive mode settings you need to change to get the 4 wheel steering working:
https://www.youtube.com/watch?v=T4DE...ature=youtu.be


with that I got back on the right track. Getting the order of the drive modes to match what the rig was actually doing as I changed steering modes was...uh interesting. I tried reordering the drive modes and from the 4 wheel steering setup but as one end shifted so did the other.
I finally got them in the switching order I liked (its 4 positions). All the way up is normal front wheel steering, one click down is 4 wheel steering, next click is rear wheel steer then crab steer. I found the way to get things to match on screen with what the rig was doing was to just rename the drive modes since shuffling the order didn't work.



The 8mm (wheel) nuts for the VP axle stub need a washer which I wanted to eliminate. I got some flanged nylocks which didn't fit so I whittled them down with a file, cordless drill and M4 bolt with the head cut off.







I took it out for a short run, it was rainy and I didn't want to push it on the first run with such an open rig. From what I saw so far its behaving great, super planted and I dont think I even dragged the belly yet.


I'm just learning 4 wheel steering and how to drive with it but I think I'm starting to get the hang of it. I ended up using it so much I had to tell myself to drive a few lines with normal steering just to feel that out.





Moved my 3d printer out of my scale garage for a little shoot while its still shiny.

[CODYBOY]

Wow Casey!!! This build has turned out so cool.
I think my body is adjusting to meds finally. And you are inspiring me to get back on a build!!! It has been hard not having that fire to do something I so much enjoyed doing for the last 11 years!!
So you might see one of them pop back up on the board. So thanks for helping kindle that fire again.
Oregon Buddy,
Ernie

[HumboldtEF]

Originally Posted by CODYBOY

Wow Casey!!! This build has turned out so cool.
I think my body is adjusting to meds finally. And you are inspiring me to get back on a build!!! It has been hard not having that fire to do something I so much enjoyed doing for the last 11 years!!
So you might see one of them pop back up on the board. So thanks for helping kindle that fire again.
Oregon Buddy,
Ernie

Thanks Ernie, I'm glad I've inspired you, you've definitely had a hand in inspiring this build and to start brazing

[HumboldtEF]

So far I've ran through 2 full packs and I'm learning the ropes a bit.

First run was after a rain and the last was on dry rock and I think I can safely say that the JConcepts compound does not like wet rock. On the first (wet) run the rig did well but was losing traction a lot. This kind of left me feeling like okay this rig is nice but struggles a bit where most of my other normal-ish rigs struggle. My last run which was on dry rock was a night and day difference, this thing just dead hooked to use a drag racing phrase. My little rock pile isn't currently setup to be the most challenging terrain but I was taking what I'd usually consider bad lines and this thing just ate it up.

I'm considering grabbing some PL Krawlers as prolines compound doesnt seem to care if its wet out or not.


I got it in one position where the front left tire was just floating which I really like to see. This tells me the rig is planted enough to not just flop over.





The springs are a bit on the soft side so I may swap in some mediums once they're back in stock. It might be a while because Dlux Fab just sold his business.


I'm getting the hang of 4 wheel steer, I've got it setup on the radio in a spot I can conveniently toggle as I steer. One thing I'm learning is when using 4 wheel steer you need to expect that the rear end will shift a fair bit from what you expect out of just front wheel steering. Sometimes this will mean dropping the rear end off an obstacle you were trying to stay on.
I'm still learning but I can see now I need to try to give the (4 wheel) steering a bit less input since it steers so well and I'm best off keeping it in front wheel steer mode until I actually need the 4 wheel steer. Keeping it in front wheel steer is just way more predictable.

Crab mode has been interesting to try out but I'm still not at the point where I can see a line a know that need a bit of crab mode.


Rear wheel steer is probably the most confusing. I've been trying it out just to visually see what its doing (mostly in places its not needed but I'm just trying to learn a bit) and with the 30% overdrive up front rear steer just induces major understeer. I try to steer one way and the front end just washes out and it kind of just moves as if I was in crab mode.
I was thinking maybe I just need to be in the right situation to make it useful. Bingo, about 30 minutes later I got the rig hung up on a step where the rear just had no contact, I toggled rear steer and was able to contact the ledge with a rear tire and crawl up. I used it for all of 2" in distance.
Now I see that rear steer will be something I will use but only in very short bursts.

I'll probably shuffle the order of the steering modes so RWS is at the very bottom, I considered eliminating it but I think I'll keep it for now. I like the idea of having the most useful modes close together so I dont have to skip over RWS to get the crab mode which is what I'm currently doing.

Setting the steering trims was a bit difficult as I expected. I got the front and rear looking good visually but it steers left a bit, so I'm left wondering do I adjust the front or the rear. I ended up adjust both a little. I think I also have a bit of axle steer which makes it even more confusing.

The VP light bar is pretty much what I had in mind, bright but not piercingly bright. Though I will be running with it off most of the time.
I know this doesnt really capture it but anyway here it is.

[HumboldtEF]

I was able to get out this weekend and shoot a bit of video. It was pretty windy so turn the volume down, sorry about that. One day I figure out how to edit the audio.

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



I didnt capture the roll over very well, the rear tires hung up in a rut and rotated the rig backwards. I could really see it either.

Somebody mentioned adding more front weight in the comments, not sure what your username is here. I'd like to avoid adding too much more weight if any. I did think about maybe a winch down for the front axle but I cant recall if I've maxed out my receivers aux channels yet or not.

Oh and it wouldn't be a proper first run without a screw coming loose, I had the screw that fastens the steering and drag link to the knuckle come loose. I just happened to notice it while the screw was just about to be ejected.

The little 1400 mah packs have been getting an impressive 1 1/2 hour run times which is far longer than I had expected.

[MaX-D]

Originally Posted by HumboldtEF

Somebody mentioned adding more front weight in the comments, not sure what your username is here. I'd like to avoid adding too much more weight if any.



.

That was me.

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[HumboldtEF]

Originally Posted by MaX-D

That was me.

Sent from my LM-G710VM using Tapatalk

Any thoughts on what to do to add weight to a VP portals (for the SCX10.2)? I dont think there are any off the shelf weights for that axle but maybe? not a huge fan of weighted wheels.


Maybe I can tuck some brass into the pumpkin.

EDIT: I had a few other thoughts on changing the F/R balance. I could play with heavier links up front or a different mix all around, use a lighter driveshaft in the rear while keeping the incision one up front, plastic cased servo in the back (unlikely). I could also run a bigger battery, the 1400 mah is pretty light and my other option is easily double the weight though that probably the worst option for keeping the CG low.

[MaX-D]

Originally Posted by HumboldtEF

Any thoughts on what to do to add weight to a VP portals (for the SCX10.2)? I dont think there are any off the shelf weights for that axle but maybe? not a huge fan of weighted wheels.


Maybe I can tuck some brass into the pumpkin.

EDIT: I had a few other thoughts on changing the F/R balance. I could play with heavier links up front or a different mix all around, use a lighter driveshaft in the rear while keeping the incision one up front, plastic cased servo in the back (unlikely). I could also run a bigger battery, the 1400 mah is pretty light and my other option is easily double the weight though that probably the worst option for keeping the CG low.

Doesn't seem like they have very many aftermarket parts to add weight. Brass beef tubes upfront?

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[HumboldtEF]

I rolled the Moon Buggy backwards and landed on the nose bending the front end down a bit. I tried to bend it back by hand and ended up snapping the front piece off. This sat on the bench for maybe a year



I finally got around to repairing and beefing it up. I had no plans to just straighten it without beefing it up.

I had a few small scraps with a slight bend in them that kept grabbing my attention as the perfect shape. Originally I thought about just doubling up the front end but decided to space it down and angle it a bit.

The welds aren't the prettiest as mig welding after brazing is always gonna introduce contaminants. It should hold togehter though.





I'm also toying around with the idea of maybe swapping in the Dlux Fab portal tranny which is so small. Though I probably will just find another project for it as I would need a much slower motor (due to the minimal gear down) and maybe a different ESC. There isn't a whole lot of wiggle room for different parts either as I've built this to fit what it has now.
But man this tranny is cool, so small and compact



I'm still working on moving the ESC mount because after lowering the buggy (with Dlux Fab offset shock caps) it was hitting the links as I designed everthing to just barely clear. It probably would have been better to set the mount higher originally and just use spacers to get it to the lowest height it clears. That would have gave me the choice of just making a smaller spacer to clear instead of hacking off and repositioning the mount.

I'll update once I have that done and all reassembled.

[Lashlee]

I've got a few of those dlux portal transmissions, they are killer! Like you I went from a 2.low to the dlux unit.

[distinctive pd]

Looking good