steel tubing question

[Szigtopher]

Hey guys me and my brother are going to make a very light go kart, 1 seater with 6.5hp engine. Is 1" by 1" steel tubing 16 gauge too thin or will it work? We only weigh 170 lbs so it won't be holding up a ton of weight and there is no roll cage so it shouldn't be too heavy. So can i get away with this size square tubing or should i go 1.5" by 1.5"? Thanks!

 

[Szigtopher]

Also if the back axle is used with pillow blocks and the front wheels are on spindel brackets welded to the front sides of the kart then it is ok that the front wheels are like 1" higher set then the back?

 

[firemanjim]

1¤1 16 gauge (.065) will work but if you can get it @ .085-.095 thick would be better. Im building a mini kart (kart called kricket) and I'm using the same 1x1x.065 square tubing. To add strength and rigidity, use angles.... you dont want all your up-rights straight up n down....

 

[buckwheat]

Check out this kart currently on EBAY it is built with 1" square tubing.
http://www.ebay.com/itm/Vintage-SAE...047?pt=LH_DefaultDomain_0&hash=item35ca47c5ef

 

[buckwheat]

Build your frame as pictured this EBAY kart. Notice how the rear frame is dog legged to lower the center of gravity. Also, the rear section comes forward and acts as side restraints for the seat.This section also acts as a truss to give strength to the chassis at its midpoint. The entire layout and rear axle arrangement should be copied on your kart's design.
Link: http://www.ebay.com/itm/vintage-go-...436?pt=LH_DefaultDomain_0&hash=item1c355f689c

 

[firemanjim]

Also if the back axle is used with pillow blocks and the front wheels are on spindel brackets welded to the front sides of the kart then it is ok that the front wheels are like 1" higher set then the back?

Put the pillow blocks on the bottom of frame to raise the back end up. If its already on the bottom, get longer bolts and cut another piece of tube same length as blocks drill holes and put between frame and blocks. Do not use a stack of washers because its NOT the same thing.... washers can shift/shimmy out of place and screw up your alignment.

 

[Doc Sprocket]

Do not bolt the pillow blocks through the frame. First, the pairs of holes will weaken the frame. Secondly, tightening the bolts will begin to crush the tubing. Retightening the bolts can crush it further creating a vicious circle. Either use axle hangar plates and flange bearings, or- weld either plates or angles to the frame and bolt the pillow blocks to them.

 

[Szigtopher]

1¤1 16 gauge (.065) will work but if you can get it @ .085-.095 thick would be better. Im building a mini kart (kart called kricket) and I'm using the same 1x1x.065 square tubing. To add strength and rigidity, use angles.... you dont want all your up-rights straight up n down....

Ok I want to use the 16 gauge because i have welding wire for that and not for the 14 gauge.

Build your frame as pictured this EBAY kart. Notice how the rear frame is dog legged to lower the center of gravity. Also, the rear section comes forward and acts as side restraints for the seat.This section also acts as a truss to give strength to the chassis at its midpoint. The entire layout and rear axle arrangement should be copied on your kart's design.
Link: http://www.ebay.com/itm/vintage-go-...436?pt=LH_DefaultDomain_0&hash=item1c355f689c

Hmmm is there any problem with not raising the back up higher? I was planning on just a flat frame

Do not bolt the pillow blocks through the frame. First, the pairs of holes will weaken the frame. Secondly, tightening the bolts will begin to crush the tubing. Retightening the bolts can crush it further creating a vicious circle. Either use axle hangar plates and flange bearings, or- weld either plates or angles to the frame and bolt the pillow blocks to them.

Thanks! We were planning on welding some plates to it for strength! Will attach pics of my design in a sec

 

[Szigtopher]

 

[philip metzner]

I would build it like a azusa kart. That is, dual side rails. Its not very hard to do and its very strong.
http://gokartsusa.com/Go-Kart-Kits.aspx
I think if you build it with a single rail frame with that tubing its gonna bend.

 

[firemanjim]

Do not bolt the pillow blocks through the frame. First, the pairs of holes will weaken the frame. Secondly, tightening the bolts will begin to crush the tubing. Retightening the bolts can crush it further creating a vicious circle. Either use axle hangar plates and flange bearings, or- weld either plates or angles to the frame and bolt the pillow blocks to them.

and again ,I slip up..... When i run a bolt through square tubing, I drill over size and weld in a piece of round tubing to prevent crush,I like to have my nuts and bolts TIGHT. If thats not possible or practical, I'll weld in a piece of plate or channel iron... With the channel, you put it over the tube,open side down. The blocks sit against to walls of the channel giving it the crush-proof rigidity. When its welded to the tubing, the channel walls wont just spread apart and you can tighten 'er down good....

 

[Doc Sprocket]

Good ideas- And I like your sig line, too!

 

[Szigtopher]

I would build it like a azusa kart. That is, dual side rails. Its not very hard to do and its very strong.
http://gokartsusa.com/Go-Kart-Kits.aspx
I think if you build it with a single rail frame with that tubing its gonna bend.

Don't really get what you mean by dual side rails but we plan on having cross bars welded in under seat and one for engine mount. Will all those prevent bending?

 

[OzFab]

I've said it before & I'll say it again: If you cut up a manufactured kart frame (manco dingo, yerf dog, etc) you'll find that the frame is made from 16ga steel tubing...

I built my daughters kart with 1"x1" 16ga square tubing (SHS). First outing, her brother hit a telegraph pole doing about 10mph & didn't even dent it...

My kart is made from 1" 16ga round tube & is super light but very strong...

 

[philip metzner]

Take a look at the pic on the link Instead of one piece of tubing going down each side of the kart, there are two. That forms the frame like a wedge that meets at the front axle. The rear axle goes through the two frame members at the rear and bearings bolt to plates welded to the upper and lower tubes.