BMV Style Cliff Climber

[sweli]

I was looking for a mini to climb couch cushions and some home made rocks this winter while the snow flies. So I bought 'Sniders1975' ARTR Cliff Climber. Great seller - thx!

I love my BMVII 2.2 Crawler, so I couldn't leave the Couch Climber (CC) stock.

Parts:

Cliff Climber Axles
Cliff Climber wheels/tires (for now)
Cliff Climber Bronco body
HDPE (3/8") and Delrin pcs.
3/32" Piano wire
Great Planes 3/32" Rod Stops
1/8" Black PolyCarb (front skidplate)
LRP Runner Reverse (waterproof) ESC
6 cell, 2/3A, saddle pack + extra cell
Towerpro Servo (what was lying around)
GWS Pico 4ch Rx
2x3x1 Radio Shack box
Futaba S3114 Servo for DIG
(2) Radio Shack Limit Switches (275-016)Chassis:

Used Delrin for the riser blocks that stock 3mm screws pass through axle into. HDPE (what I had avail) is the cross pc above the front servo and same on the rear axle.
Piano wire front to rear, 1.5" appart. Should have spaced at 2". Without the body on, this setup has too much flex.

Piano wire enters HDPE cross pc holes and then Rod Stops in machined area (to retain wires).

HDPE center plate holds Radio shack box with DIG switches and Rx.
Front cross pc. extends forward above servo to provide mount for top of skid plate.
Skid plate is molded (heat gun) to provide smooth angled transition in front of steering rods. Mounts to axle in place of stock skid bars.Stock motors are pretty guttless. Needs updated. Trying a couple of 380 cobalts in a few days.

Right now has bushings and plastic gears.
Bearings in outer stub axles.
Replaced over-wide hexes (adds 1.5" to width) with TLT style hex's.
Have not replaced stub axles yet, so used spacers on outside of wheels to make up space.

DIG:
Followed this build thread
http://www.rccrawler.com/forum/showthread.php?t=124058

Mounted Futaba micro servo to two small HDPE blocks, then those blocks to a 1/8" thick PE sheet.
Cut a slot in the sheet for the servo horn to fit through.
Mounted the switches to the opposite side of the PE sheet. (pic below).
My butane iron would not heat up enough, so bad solder job this time around. Covered all soldered surfaces with liquid tape.
Set up my Futaba 3PM so button on grip locks rear and spins front. Normal ch3 slide switch locks front and spins rear.
On the body I trimmed fenders wells and folded sides under at a knife crease. (name of technique?)
Used small dia PVC to hold fold so body does not tear(provides bumper bar under body skin).

Heat will not remove the tires?? Not sure what glue was used?
Needs BB's to get weight down lower. Lead around inside of rims for now. Vented rims with 4 larger holes. Need to trim the foams. Any ideas how to get these tires off?

http://farm4.static.flickr.com/3061/2928409582_afa6f63e5f.jpg
http://farm4.static.flickr.com/3054/2928409184_39ac6524ff.jpg
http://farm4.static.flickr.com/3156/2928410136_0852544761_m.jpg http://farm4.static.flickr.com/3034/2927550837_8f7bb911cb_m.jpg http://farm4.static.flickr.com/3099/2928409742_9a0504d533_m.jpg
http://farm4.static.flickr.com/3082/2927550401_7479d3d7d2.jpg

I'll have new motors in, this weekend, and try and post some video.
Velcro sticks to the carpet in my basement really well, so I'm planning on fabbing some styrene rocks for winter crawling with my sons (4 and 6).

[sweli]

Hmmmm. This must be pretty plain jane to warrant no responses?

[PROTOTYPE]

You should really post pics of how the axles are mounted to the "BMV style" chassis .

And from the pictures you post ed so far, Looks like there is alot going on in the middle. Is there anyway to spread that weight across the chassis?

[TURBOFEST]

Pretty RAD man...coolest cliff climber I have seen! "thumbsup"

[sweli]

You should really post pics of how the axles are mounted to the "BMV style" chassis .

And from the pictures you post ed so far, Looks like there is alot going on in the middle. Is there anyway to spread that weight across the chassis?

The middle is:
2x3x1 ratshack box
Futaba micro servo driving dual dig switches
pico Rx
BEC (old and big) that I had laying around into a Y cable only powering steering servo


Associated AI runner reverse ESC on lid of box.

Center only weighs a few ozs. I bet. Should have used 18ga. wires on this little guy, but had 16ga on the bench.
HDPE plate the box is mounted on is heaviest middle pc. It is necessary for BMV (piano wire torsion) concept to work.

I'll get some pics of the piano wire/delrin/axle interface.

[sweli]

Thx Turbofest!

My ego feels better.

Not out for comps with this. Its a couch climber to keep my 6yr old and I busy this winter.
I want to start fabbing the styrene blocks/rocks for this thing to climb.

[coolkidjf7]

For the wheels, try boiling them, that might get the glue off, idk if it would melt the plastic?

[sweli]

Just like on a BMV, the piano wire goes through a hole, into the Rod Clamp that sits in a pocket.
I only have a dremel to fab this pocket with, so its crude. One side had to be shimmed with washers because of slop.

Top of front HDPE plate with duck-bill to support skid plate.
http://farm4.static.flickr.com/3210/2954578127_d08aaec231.jpg

Top of rear plate:
http://farm4.static.flickr.com/3072/2954577559_92b413e835.jpg

The wires pass through an HDPE center plate that is clamped on one side only, with same rod clamps.

[sweli]

Tinker tinker tinker...........

So the stock gearbox's seem to be about 28:1 when using an 11T pinion.
8 or 9T pinion would only bring it into the 35(ish):1 range.

Enter a GreatPlanes 2.4:1 airplane gearbox(s).
Brass pinion, nylon spur between two alum or powdered metal plates.

Mount the 370/380/400 motor of your choice (16.5mm OC mounting).
Lineup the gearbox where the motor normally sits on the CC axle, mark two holes (16.5mm apart). Drill and tap to 3mm (or other).
Turned down the output shaft from 4mm to 3mm.
Drilled stock CC pinion out to 3mmEnough torque to strip the stock plastic CC gears in 2 batt charges, climbing couch cushions and other stuff in the kids toyroom!
Metal gears on order for one axle for now.

http://farm4.static.flickr.com/3295/2954578535_a5727cf081.jpg
http://farm4.static.flickr.com/3064/2955424200_faacf97e9d.jpg
http://farm4.static.flickr.com/3212/2954579665_48607b66dd.jpg

Right now I am running Promax 3145 motors (neodym, 45T, 370).
I have since fab'd an alum wrap around guard. Not dirtproof, but will keep most things out including my kids fingers.

As soon as I get the new front gears I'll post some vids.

[TerribleOne]

Looks good, what is your flex like? You may be better off spreading the wires out, it will be alot more stable.

[randy1]

so it looks like that with what u have done u cant use the stock chasis anymore

[sweli]

Looks good, what is your flex like? You may be better off spreading the wires out, it will be alot more stable.

I played with the wires clamped in some pcs of wood to get the flex I thought I wanted.
Somehow when in the HDPE its too much. Not sure if the wire binds less, hole size changed, not sure.
With body off, TOO much flex. Could twist itself 110deg.
Body has foam blocks under four corners that act as shocks to the twist and limit the roll.

I will rebuild the blocks on some upcoming, un-busy [never happen] winter weekend.

thx

[jdawg53]

Sweli
You are doing an awesome job and totally taking the CC to the next level. I look forward to more on this build.
Good job with the GP gear reductions.
J

[sweli]

Thanks Jdawg!

I need to try the metal gears in the front axle, as something is making a bit of noise. Bearings and gears should be here Wed.

Got some quick wrap around alum. shrouds to keep kids fingers from becoming part of the drivetrane. (sorry, bit blurry)
http://farm4.static.flickr.com/3054/2959542899_bb2fa2bfd3.jpg

I have moabs on some old wheels, with reduced dia foams and BBs, but need something for the winter couch climbs.
Pc by pc as funds allow.

[scootertrash]

Yup, I now I see how I'm, going to make up a "BURG" like lil' Crawler, for my grandson to use this winter for just indoor's too... I'm going to fab-up a chassis using this wire twist set-up, that will be something like you got going on this lil' BEAST... To which you have really done alot of stong thinking, As to what all could be done to one of these lil' able climber's, to make them very Much able & Comp-Worthy.....That's some Great thinking there brotha'.!!! ....Ol' Scoot'er... "P.S this has been a great Tread also dude" & Please keep us posted as this come's along too & thank's for sharing all this with me too ..!!!.

[sweli]

Thanks Scooter. Post up your plans as you get them going.

Some other findings of mine are:

I should have volted this thing up to begin with. I was running 8.4v with the stock motors which gave the right wheelspeed for crawling, but not enough torque. I think I'll have to go with a better ESC in the future so I can jump over 8.4V. But with the motor and gearbox combo I have now, I can start to strip the nylon gears. Tune tune tune.
Alternate, slightly more expensive, but already enclosed gearbox is the Team Integy 2.5:1 box http://www.integy.com/cgi-bin/webc.cgi/st_prod.html?p_prodid=4797&p_catid=
It can be had on Ebay for $22+ship. Metal gears, bearings, and enclosed. You will still have to drill and tap your own bolt pattern as it is set up for a 540 can size. Hmmmmm this would allow you to run a 540 55T motor. Hmmmm.
My CG is still too high. I think this is in part to how high the piano wire chassis is on my setup. I have mine this high to clear the front steering servo. I up and overed it with delrin which was easier. I think the piano wire needs to be an inch lower and spread a little further appart (for the dia I used). I think the height my wires are from the ground (tire patch) are causing the tires to hop and loose traction.

[sweli]

Well this is a mainly indoor Carpet and Couch Cushion Crawler, so I now have some crazy tires on this thing.

Axial beadlocls, 3oz lead around each.
M3 Spike Truggy tires on the front. About 3.75" OD, but only 1/2" of foam around the lead, so they sit really squat.
M3 Step-pin Buggy tires on the back. About 3.25 OD, same 1/2" foam, but star cut every 1/2" all around, and a sipe cut down the middle.Clod stall is GONE. Looks a little funny, but after I rearrange the ESC I'll be able to slam the body down another 1/2 - 1"

OK on the rocks with some old Moabs, but now this thing climbs couches, boxes and over kids with the ease of my full 2.2.

[jdawg53]

but now this thing climbs couches, boxes and over kids with the ease of my full 2.2.

Thats awesome:lol::lol:

[sweli]

but now this thing climbs couches, boxes and over kids with the ease of my full 2.2.

Thats awesome:lol::lol:

Drawback is that the tires take away from the looks a bit.
Looks like when someone takes a decent 4x4 truck and slaps 17" lowpros on it that do not fill the wheelwells.

[ccbg]

Hey, sweli! I really like that design... :) Sounds like ur flex is limited ALOT by the body... does it bend alot?? Have u considered thicker piano wire (or something like that) and a single central body mount ... :)

And more pics (higher res too) would be great.. :)