View Full Version : Baby Cracker Box

12-12-2013, 12:15 PM
While back, while building my wildthing, my boys wanted another one so the two can be raced, soooo the cracker box was born, with help from this forum.
I cut out the balsa, and let my lad glue it together.
Sacrificial pool noodle
Top on
dodgy setup to get even coat of west systems resin on it.

12-12-2013, 11:25 PM
Looks good. Doug

12-13-2013, 03:20 AM
What scale and size is it ? Now you need a little set of drivers.

12-13-2013, 03:40 AM
I understand the scale thing, but couldnt give you a exact ratio. Its aprox 12" long. Crammed the plans on an A3 page, and went from there.
Always after an excuse to buy more tools! :)
Splash of paint:
Balsa blown big block
SS tig rod as drive shaft

12-13-2013, 01:20 PM
Very creative build. I love the dummy V8 engine. small outrunner powered?

12-13-2013, 01:21 PM
That's a real nice little cracker.Figuring from the minimum and maxium size of real crackerboxes,yours is between 1:14 and 1:15 scale.You might be able to find some r/c airplane pilots in that scale range to serve as drivers.Also a set of numbers on each side with a P either before or after the number will make it look even better.
I have the plans for about a 20" one ,but have never built it yet. I've built two 1:4 scale crackerboxes,a Dumas powered by a modded 30cc Ryobi/Homelite engine and one from Jerry Dunlap plans by a Sikk 26cc marine engine.

12-13-2013, 10:00 PM
Very creative build. I love the dummy V8 engine. small outrunner powered?
Originally had a brushed motor from yester-year when i was a kid. Years ago, had some model balsa models made by Aeroflight, now Pacific Balsa, which used silicone tube as a coupling. With the bench testing of the cracker, this was just spinning & failing. So yes, brushless inner rotor motor it is. Outers are unable to disipate the heat as quick as the windings are inside a magnet ring. Same issue as brushed motors. When i have a sec, ill post more pics.

12-15-2013, 03:54 PM
Depending on how wide the drivers area is, the first and second drivers on the page might look nice. http://www.offshoreelectrics.com/products.php?cat=21 Don't want the drivers to look to small or large for the boat.You might be able to go with a 1:12 scale. The drivers in the OSE site are 36mm(1.417") and 39mm(1.535") tall

12-16-2013, 09:15 AM
Drive train:
Hmm, you might get a surprise who the driver is!!

12-17-2013, 10:35 AM
You guys are going to kill me for this!

And due to it unable to even get on the plane...... Brushless & surface drive.


First run. No matter where i had the battery, or the drive angle set up, it porpoised. 27mm prop with 1.4 pitch.
Trim tabs next.

12-20-2013, 11:17 PM
Crackerbox class ,has to have two drivers. You need a little Shaggy.Bigger boats I believe want the CG between 28 and 30% of the length of the hull. Trim tabs would probably benefit the boat.You can make trim tabs pretty easily.Do you have a skeg on the bottom ? My 47" Dumas crackerbox balanced at about 13.5" with everything in or on it.Here's a pic of my girl drivers.

12-24-2013, 01:43 AM
Here's a pic of my girl drivers.
Looks like your girls have big........... smiles!
I moved the battery as far fwd as possible, but made no differencein hull attitude. Even using extremity adjustments on stinger drive wouldnt change the jumping. Trim tabs on now, and much better. Just have to have some time to set them up properly.
With the battery fwd, the COG is 30% from the rear.
As for the skeg, i had one on, made out of stainless sheet. Removed it now, as i was sick of handing out band-aids. Another reason i removed it, was when the boat was on the plane, it was hardly in the water.
When on the plane, a moderate turn would have the boat "drifting" sideways, even with the skeg. As much as it looked cool, occasionally, a dig in would cause a flip. Hence your turn fin?
Nice work on your cracker old dog.

12-29-2013, 11:02 AM
Trim tabs on....
2172 2173

01-06-2014, 02:03 AM
Well it might be a while before you see this pup again. Opened the rola door & a gale came through which blew the boat off a 7' shelf. Boat landed on the edge of a ladder, that was laying on the ground.
Kind of like egg shell really. :(
Down side to using balsa i guess.

01-06-2014, 02:26 PM
Shame it got damaged.It was a nice little boat. Did Scooby get hurt ?

01-06-2014, 11:20 PM
Scoobys fine. :)
Ive stripped all the hardware out, and cut out all the dammaged balsa. When i have a sec, ill tack together with CCA, and seal with fiberglass resin.

01-12-2014, 10:04 AM
Had some time this weekend, used polyester resin to seal the balsa, and auto body filler to make it remotely flat..
2183 2184

01-26-2014, 12:26 PM
Rev 2...

01-26-2014, 07:11 PM
Great paint job. Doug

02-02-2014, 09:25 AM
Considering it was 44.7 deg C here today, baby cracker is almost done...
2245 2246 2247 2248

Color scheme was my lads. I preferred the blue & white...... what we do for our kids!

02-06-2014, 04:26 PM
"What we do for our kids"

Now you know you have to build 2 more of em! dont try to skim off the top LOL!
Scooby never went anywhere without shaggy and scrappy.

Nice paint scheme. What kind of paint did you use?

02-09-2014, 03:31 AM
yes, lol.
The paint brand is "power plus" made by Holts. Its automotive acrylic that is supposed to match OME paint codes. Dries fast, smells like acetone, and is very hard when dry. Just have to do the usual trick and paint under lights so you see the wet edge.

02-12-2014, 09:36 AM
Well, manages to get her wet last monday. Takes a bit to get on the plane now with the tabs on, but does not porpoise any where near as bad. While it is sitting low pushing water, there is no steering? I have added a turn fin on the starboard side out of sheet ss, same size as the rudder. Do i need to cut it down? Ive noticed some crackers have large fins, and others 1/8th of the rudder.
Here is a link to the video.... enjoy.
Link fixed

02-12-2014, 11:03 PM
Small brushless has got some kick!

02-13-2014, 12:15 AM
Looks like fun! Doug

12-24-2014, 03:31 AM
Have a wonderful Christmas guys!

10-08-2016, 12:36 PM
hi there im heli_1flyboy Ilove that boat very nice