CrackerBox Test Chassis
 

I started this build at Indy. It's purpose is to test different RPM gear motors and motor/transmission combinations. Actually wasn't going to put a cab on it, figured it would never get out of the basement. That being said I have some styrene so I thought I'd give a Crackerbox cab a try, it's pretty straight forward with no weird curves, shouldn't be that bad to do. (Famous last words!)

http://i1116.photobucket.com/albums/...psknetjzws.jpg

http://i1116.photobucket.com/albums/...psrlekymis.jpg

http://i1116.photobucket.com/albums/...ps8tjxbqiu.jpg

http://i1116.photobucket.com/albums/...ps8qqy2zib.jpg

http://i1116.photobucket.com/albums/...psloe5ku9s.jpg

Thanks for looking!
Kent. :D

Re: CrackerBox Test Chassis
 

That's pretty cool than you can do that flat of a drivetrain.

Is the steering tierod too short, or is it just the picture angle?

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Hi Kent would you share what motor you have in your truck ? Thanks .

Re: CrackerBox Test Chassis
 

Hi Frizzen, no it's not too short, it's just not adjusted yet, I also straightened the tie rod out and removed the front shocks. I found, after deciding to build a Crackerbox and got some critical dimensions online that I had to move the axle forward.

Hi Mikem, I get them from Servo City, the one in the chassis is 437 RPM. I have one in my dump truck connected to the screw drive, it's 313 RPM and a 165 RPM on the shelf, I ran it in my dump for a while but thought it was too slow, all kinds of power though. I have to give credit to Reg (RPC57) for the motors, I found them in one of his threads and he told me where to find them.

https://www.servocity.com/motors-act...ry-gear-motors

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By the looks and outout RPM, one might think that Servocuty and Servonaut use the same source.

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Hi Kent thanks for the info will order one today

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I think you're right, there are some differences in specs but I'm not sure if that has to do with translation or not. Servo city is just easier for me to deal with and prices are a lot better.

Great, hope you like them. So far I think they work well. It's kind of why I'm building this chassis, there are so many RPM choices it's hard to decide what works best.


Got the radio mounted on the cab floor. Now is all I need to is build a drive shaft so I can watch it move!

http://i1116.photobucket.com/albums/...psjbl0awej.jpg

Re: CrackerBox Test Chassis
 

Very Nice, Always been a fan of a crackerbox.

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Re: CrackerBox Test Chassis
 

Great looking build so far! That motor and tranny set up is so clean and simple, I'll never use a Tamiya 3 speed set up again! :D
Just imagine the power you could pack in that cracker box if you went with a lipo:rolleyes:;)

Oh, and is the driveshaft built yet? :)

Re: CrackerBox Test Chassis
 

Thank you, me too!


Thanks Paul, since I don't have a mill readily available I decided to break the bank :rolleyes: (a whole 4.99) and buy one of the mounts that Servocity sells for these motors and use it as a pattern for the crossmember I mounted it to.
As far as the Crackerbox goes I wish I would have known that. I would have stuck with my original plan and cut up a globe cab to put on and let you do the Box justice ;). This was just a kick around test chassis that originally wasn't going to see the light of day and wasn't even going to have a cab.......but I couldn't stop there.:lol::lol:


Yeah I just haven't pulled the trigger on lipos yet, if I had a Foxville to play in I'd probably be there by now but the cost and everything to support them just to play a couple times a year isn't worth it, that being said I was shopping and found a 12v NiMH, now if I could find a decent ESC that will handle it and the hobby fund can support I might think about it!

The drive shaft was started, finished and installed about 15 minutes after I posted that and I was tired and quit since I grabbed the wrong bit and over drilled the front cross by .10 mm. :mad:, for those who don't Know the shafts on these geared motors are 6mm. This is the first time I've been back in the shop.

When building my shafts I use the method that Tamiya Cowboy posted, Thanks Paul! It's a sticky in the Mechanical tech section. I use Traxxas parts and brass tube due to local parts availability, but the construction methods are the same.
If you have all the parts they go together quite fast. I think I have maybe 30-40 dollars total in ALL the shafts I have in 3 trucks that includes the 6x6.


Thanks Mario, good hearing from you.

http://www.rctruckandconstruction.co...read.php?t=708

http://i1116.photobucket.com/albums/...psv9pltplv.jpg

http://i1116.photobucket.com/albums/...psu4ylvcuf.jpg

Thanks guys! :D

Re: CrackerBox Test Chassis
 

Driveshaft looks great and driveline angle looks perfect.

Ya, been quiet lately, life sure can change quickly. It's been weird to go from having an awsome backyard meet and one week later house is on the market and now all those things around the house that need fixing I been putting off are getting done to make it all nice for perspective buyers now. Paying for my procrastination right now.:eek::lol:
so no time or desire to RC lately....:(

Re: CrackerBox Test Chassis
 

A couple update photos, long way to go yet!

http://i1116.photobucket.com/albums/...pskn5jjrj8.jpg

Well maybe one photo. Photobuckects being a PIA and won't load my pictures. Has anyone found a reliable photo hosting program other than PB?

Re: CrackerBox Test Chassis
 

Nice start on the cab! That's looking cool.

I've been hearing good things about imgur, but haven't tried them yet. Photobucket has become really unusable

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I store all of my stuff on google drive, if you have a Gmail etc. you have it. Works great!

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Thanks Frizzen.

Thanks Trucker Jo, I do have gmail and will check it out!

Re: CrackerBox Test Chassis
 

LOOK'IN GOOD Kent!! Keep us updated.

-Terry

Re: CrackerBox Test Chassis
 

Great start on the cab Kent!

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Thanks guys, not much new. Spent yesterday on the Bridgeport at work redoing a part of the frame rails on the dump trailer in the photos and driving an hour to the LHS to find some clear sheet to make Windows for the Crackerbox. Missed a delivery from the post office that had some planetary gear motors to try in this chassis and screw drive components for another dump build coming later. :D

Kent

Re: CrackerBox Test Chassis
 

Short update, got a little more done on the Cracker Box and got the dump body mounted on the trailer frame with the lift motor and mechanism working. Need parts to finish it up. Got to pick up some suspension parts and tires. Here's a shot of where the cabs at.

http://i1116.photobucket.com/albums/...ps84reqges.jpg

Re: CrackerBox Test Chassis
 

:jaw::jaw: Looks Great, very nice Work.

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Looks good can't wait til it's done !

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Thanks guys, I cant wait till its done either, to many projects I want to work on!:D

Re: CrackerBox Test Chassis
 

LOOK'IN GOOD Kent!

-Terry

Re: CrackerBox Test Chassis
 

Looks great Kent! Fantastic job on the cab. You working from scale drawings or photo's?

Re: CrackerBox Test Chassis
 

Thanks Terry!

Thanks Dennis,
Besides all of the photos on the internet I found a spec brochure that has profile drawings with the over all dimensions and expanded the drawings in my copier until I got the dimensions according to scale and went from there, you have to start with good drawings because they become very pixelated as you expand them. if I'm happy with it when I'm done I'll build a dedicated chassis to the proper wheel base and see if I can find nice spoke wheels and other period correct details for it.

Re: CrackerBox Test Chassis
 

Here's a reason why I built a dedicated test chassis. I bought one of these motor/planetary drives, 437RPM @ 12v. The volt range on the motor is 6-12v so I ran it off my 7.2V battery realizing it would be a little slower. It was actually to slow however smooth and controllable. So while taking a break from other projects on the bench I started playing with some stock cans I had laying around and found that bolting this Axial 27 turn up to the planetary gives me a good top speed and plenty of power. The true test will be going to a meet and load some construction equipment on it. Surprisingly I haven't found a less expensive alternatetive to replace the 3spd with. Buying new, the 12v planetary combo is $40 & the 27t Axial is $14, just need to figure out what to do with with the extra 12v motors down the road. :D:rolleyes:

http://i1116.photobucket.com/albums/...pspysa0nqk.jpg

Re: CrackerBox Test Chassis
 

Kent,
I just picked up one of the servo city gear motors to try in the wrecker to save space over the 3 speed. Very nice looking unit, but I have 1 question. Did you pull the stock pinion off the 12v motor and reuse it as the picture appears or go to a different style pinion?
Thanks

Re: CrackerBox Test Chassis
 

Kent lookin great. Nice details - headlight buckets and the relief cut top center look good.

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I have 3 trucks with the 437 rpm planet motors I like them a lot . I like the speed and they still have enough power to pull my grandkids on my Flatdeck . What to with the trannys now

Re: CrackerBox Test Chassis
 

Hi Dennis,

Yes I just slid the pinion off the servo city motor and pressed it on the 550 I used, don't care for that type of pinion but its worked running around in the house so I'll run it until it fails.

Hi Izzy, good to hear from you, thanks for the comment, just remember when you see it in person stand on the other side of the room LOL, its all hand cut and the hand isn't as steady as it used to be.

Mike, I'm in the same boat but i'll figure something to do with them. What battery are you running with your motors? I just run 7.2 nimh and they seemed a little slow since those are 12v motors, that's why I swapped the motors, made a big difference.

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I'm running 7.2 batteries just like you haven't tried motor swap yet. But I can't play outside yet too much snow still .

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We haven't had any snow to speek of just a lot of rain, been doing all my test runs in the basement. Let me know what you think when you get a chance to run.

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Thanks for the information Kent.
I'm planning to swap out the 12v motor for a nice 27 turn 7.2 motor I have on hand. I tried 12v motors in a tank on 7.2 volts down at Danville back in the day. No power and way too slow.

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I can't test in the basement too many trains in the way ! And this weekend we are getting 3 inches more snow !

Re: CrackerBox Test Chassis
 

Kent - busy, my free hand is for turds as well. Grab a straight edge or I like to pre score using my calipers. Kind of hard on the tool but they've held up.

Re: CrackerBox Test Chassis
 

Got some color on it, but the paints not done, going to bring it along later this week as a roller. Guess it's time to start planning a chassis.

http://i1116.photobucket.com/albums/...pseqkrwika.jpg

http://i1116.photobucket.com/albums/...psleaclq87.jpg

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Now I know where I saw this ! I've been watching it all along !

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Ok now I get it, I couldn't figure out why you made that comment :lol::lol::lol: