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home brew quarter sprint

Posted: September 11th, 2016, 9:40 am
by Ognib
Hey everyone, my name is Ray. Ognib is my handle...just bingo spelled backwards. I'm an old goat, 70, & I like to build things.

Worked on cars for 30+ yrs. Started out in body shops building wrecks back in the 60's. Ended up foreman in a frame off resto shop. Mechanically certified.

I have a friend who has been in rc for several years & I've got the bug! Want to build my own. But, it's got to be big.

This is a fantastic forum & I'm real glad to be here. Thanks for the help, Al! :)

Where to begin...at the beginning, I suppose.

Chassis plans are on the drawing board.

The engine is the only piece of the puzzle that I currently have. It's a 33cc that I salvaged from a Poulan brush cutter...PP333 model.

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Two throat carb with mechanical secondary. Engine has very few hours on it & runs well, so I'll leave this as for now.

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Research to do on the clutch & the ignition & how to get a chain sprocket on the shaft.

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Want to eliminate the rope start & adapt to starting with a drill motor.

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Re: home brew quarter sprint

Posted: September 12th, 2016, 8:53 am
by Al Gibson (QSL)
Welcome to QSL, looking forward to your project!!

Re: home brew quarter sprint

Posted: September 13th, 2016, 5:58 am
by Ognib
I remember back in the 6o's there was a guy called Tex Smith who wrote for one of the rod & custom mags. He did a series of articles entitled, "the dollar a pound roadster." I like that approach to doing things...a dollar saved, is a dollar earned, so to speak. Smokey kinda had the same mentality in his work, in that he was a thinker, a "wonder what would happen if we did it this way" kind of guy. The Grump seemed to have this mindset as well. Pretty is overrated...form follows function...nothing succeeds like success.

Not tying to reinvent the wheel here, but definitely aspiring to think outside the box on this build.

Been looking at this guys work. for inspiration & a bit of a new approach over the welded tubular cage that I've always been associated with. And this build will definitely need a sturdy cage over the engine, as I have no doubt it will be violently upside down more than once. Gonna build it to be run hard, not just looked at.

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

However, in it's initial incarnation, drive & suspension will be more along these lines. However, the design I'm working on will allow for easy upgrades to more effective suspensions..just get it running first & foremost.

https://www.youtube.com/watch?v=8oj2zdDvyos

Re: home brew quarter sprint

Posted: September 13th, 2016, 6:21 am
by Ognib
P.S., comments & dialogue are always welcome & encouraged! :)

Re: home brew quarter sprint

Posted: September 13th, 2016, 7:44 am
by Ognib
Initial drawing has: overall length at 39", wheelbase at 24", highest point on cage is 12 1/2".

Ten inch tire to start with. See how the engine does in turning it. May need more displacement. But that's the thrill in this, figuring it out as you go.

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Re: home brew quarter sprint

Posted: September 13th, 2016, 4:40 pm
by Al Gibson (QSL)
Are you going to build your own chassis?

Re: home brew quarter sprint

Posted: September 13th, 2016, 5:40 pm
by Ognib
Hi Al. Yes, drawing up some ideas now for the frame/cage. Simple solid axles, chain drive etc. Mounting fixtures for radius rods, spindle blocks etc I'll cut on the mill. Also need to build engine to frame mounts.

Right now I'm looking for information on getting a clutch with drive sprocket fitted to the engine. Also whether or not I'll need to relocate the ignition in all of this. Can anyone offer suggestions...point me in the right direction on what & where to buy?

Re: home brew quarter sprint

Posted: September 15th, 2016, 8:15 am
by Ognib
As mentioned, I'm interested in exploring alternate construction techniques for the frame & cage on this, other than the popular welded steel tube cages.
I'm studying the concepts & methods that were used in the WW2 heavy bombers...light weight aluminum with gussets, spars etc., resulting in very strong structures that were light in weight & capable of handling heavy loads & stresses.
Laying out some initial pieces over the drawing...see where this goes as the pictures develop in my brain.

Also exploring the possibility of a multi ratio "transmission", if you will, to use with a chain drive.

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Re: home brew quarter sprint

Posted: September 15th, 2016, 4:54 pm
by Ognib
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Re: home brew quarter sprint

Posted: September 23rd, 2016, 2:27 pm
by Ognib
After thinking about it for a while, I've decided to put the little 2 stroke on the shelf & go with a 4 stroke engine for this. I understand 4 strokes & what it takes to make them run strong...go with what you know.
Spending quite a bit of time at the drawing board right now. Design & layout is one of my favorite parts of a project like this.

Re: home brew quarter sprint

Posted: September 25th, 2016, 9:19 am
by Ognib
Structural gusset & template. To the bandsaw.

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Re: home brew quarter sprint

Posted: September 25th, 2016, 3:15 pm
by Ognib
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Re: home brew quarter sprint

Posted: September 27th, 2016, 9:14 am
by Ognib
The center gusset will be lightened later. The mounts for the axle locator links will be anchored on it & I want those locations determined first.

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Re: home brew quarter sprint

Posted: October 1st, 2016, 11:57 am
by Ognib
Now have a matched set of sides. Get the corners cleaned up, some drilling & get a few fasteners in place so I can start developing the crossmembers & setting the engine in place.

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Re: home brew quarter sprint

Posted: October 1st, 2016, 3:28 pm
by Emilio
nice and clean work, looking forward to more progress!