Power Kite Forum

Material Sourcing - Bug Build

macboy - 18-8-2008 at 10:39 AM

Yup, I got hooked this weekend (thanks RevPaul I had a blast!) Getting serious about the bug build now and want to get some hard numbers before I decide to build / buy.

I've found a source that is going to put together an estimate for me but I need to know what material it is - they have a few varieties. Can someone let me know? The choices are:

Stainless Tubing
- Ornamental Polish 180 Grit 304
- Welded Type 304
- Seamless Type 304

Stainless Pipe
- Seamless and Welded Schedule 5
- " " Schedule 10
- " " Schedule 40
- " " Schedule 80

Will any of that do the trick? If so, which? Thanks in advance for the help here. More questions to follow (separately).

awindofchange - 18-8-2008 at 12:42 PM

ON the stainless, I would suggest using either the T304 or if you can find it, T316. T316 is a stronger alloy but will cost quite a bit more than the T304.

The difference between the welded or seamless is quite big. Welded is just what it says, they take a plate, roll it around and then weld the seam together to make a tube. You can see this weld on the inside of the tube...not sure how the heck they can get a welder inside of a 20' x 1" diameter tube, pretty amazing I guess.

Seamless is actually forged stainless that is extruded into a tube, not welded. Seamless is very expensive, especially when you get into the thicker wall sizes. Seamless is usually preferred in extremely high strength applications where the welded tubing may have the slim (however rare or nearly impossible) chance of separating at or around the weld. Seamless is stronger than welded but in reality.....for buggy applications....I don't think you will ever have the stress to warrant the seamless tubing, especially if you go with a thicker wall say.... .120 or larger.

The stainless tubing is going to be much less expensive than the stainless pipe so I wouldn't bother with the other. Ornamental Polish is the exact same material as the welded or seamless except it has been sanded down to 180 grit and has a semi-dull polish on it. The weld is barely visible on the outside of the welded tubing on the ornamental...but if you look closely you can still see it. Ornamental is going to cost just a bit more than the standard welded tubing. If you are capable of doing your own polishing and don't mind the extra time working the steel then I would just get whatever is cheapest. If you want to save yourself some time with the polishing then the Ornamental is going to do that for you.

I wouldn't bother with anything thinner than .080 for the frame of your bug. You will pay a tiny bit more for .080 or thicker but you get a ton more strength. For the rear axle, I wouldn't go any less than .120 wall, thicker if possible.

Hope this helps you out a bit.

clintopher - 18-8-2008 at 01:35 PM

The price estimate of stainless is going to hurt your feelings.

flexiblade - 18-8-2008 at 02:01 PM

Round Tubing is what we expect to see a buggy made out of - this is an expectation but not a rule - here is a layout of the frame design I came up with when building my buggy - Sorry there are no measurements - I just eyeballed everything and would sit in the frame as it developed so it would fit me. The end result was padded with water noodles and wrapped in electrical tape.

frame.jpg - 197kB

awindofchange - 18-8-2008 at 06:28 PM

I fully agree Flexiblade, Round tubing just seems to be the standard but I have seen quite a few made from square tubing that work perfectly fine. I think that round tubing is a bit easier to work with on the side rails and axle - if you have a tubing bender and are fairly good at fabricating. If you don't have a tubing bender then the square tubing may be a bit easier to work with for you. As long as your wall thickness and diameter is sufficient enough, strength shouldn't be a problem with either style of material.

That being said....if you are not going to be putting a high gloss mirror polish on your buggy...or if you are not running around in the water much and don't have a rust problem, standard painted or powder coated steel can be just as strong and durable as stainless at a much lower cost. You will also put in a ton less time painting than you will putting a deep mirror finish on your stainless. With the Ivanpah buggies, it takes two of us a bit over 40 hours of polishing per buggy to get the shine that is on there. But once you see the shine that you can get it makes the work a lot more rewarding. Most of the cost of the polished stainless buggies is labor, not necessarily the material costs.

revpaul - 18-8-2008 at 08:33 PM

Kent,
what size are the tires on that Monster? Monster sure looks nice but the triple mount type set up of the Ivanpah looks to be more robust.
Paul

revpaul - 18-8-2008 at 08:36 PM

Kent,
I should have also asked what the basic dimensions are on that Monster. Seems as thought the rider would be sitting a little higher than most other bugs.

awindofchange - 18-8-2008 at 10:50 PM

The tires on the Monster are the wide ones. Same size as the standard ribbed and smoothie tires but are squared off, giving you a little better footprint and traction. You can put either style of tire on no prob. The rear can hold bigfoots but the front fork is limited and will only fit the 16" or slightly larger tire.

You do sit a bit higher in the buggy because of the suspension and side rail design - I really like the higher side rails though, makes it really nice to lock into the power and less chance of being ripped out of the bug sideways, still the bug has awesome traction and a very good center of gravity. the seat is a bit wider which I like personally as I am a bigger guy. It has fair back support, I feel it is slightly better than the stock PL or Flexi. The rear axle is much longer than the standard bugs and the Monster weighs in around 68 lbs (if I remember right)


as always, if you get to Vegas at all you can ride before you buy! Same goes with every kite we sell. :)

revpaul - 19-8-2008 at 10:21 AM

thanks for the info Kent.
Vegas... been there a couple times but not for traction kiting. what a dummy:puzzled:
Paul

revpaul - 19-8-2008 at 11:51 AM

Quote:
Originally posted by awindofchange
The tires on the Monster are the wide ones. Same size as the standard ribbed and smoothie tires but are squared off, giving you a little better footprint and traction. You can put either style of tire on no prob. The rear can hold bigfoots but the front fork is limited and will only fit the 16" or slightly larger tire.

as always, if you get to Vegas at all you can ride before you buy! Same goes with every kite we sell. :)


Sorry, trying to get a couple of things straight in my head.
are there regular BFs and BF lights? if so, will BF lights fit on Monster's front fork? are the rims of BF lights wider than the standard rims (on Monster/PL Race)?

flexiblade - 20-8-2008 at 07:23 PM

QUICK HIJACK ... The way I understand it is that bigfoot lights are bigfoots mounted onto a regular wheelbarrow rim 8x4x4 (8" tall / 4" wide where the tire bead lays in the rim / 4" from one bearing seat to the other -this changes depending on manufacturer). This makes the tire "sit up" more decreasing the actual surface of the tire contacting the ground. I have mounted bigfoot ripoffs (same dimensions as the bigfoots 8x12x21) onto 8x6x4 rims - normally used for turf tires and they worked fine. I also mounted the turf tires onto smaller barrow rims - this causes the squarish turf tires to bow out a bit on the tread, but again they work just fine.

Sand-Yeti - 20-8-2008 at 10:21 PM

Why use stainless?
It doesn't corrode but a decent powder coatng over mild steel will take care of that.

Stainless looks nice & shiny and won't argue about that.

I have used various grades of S.S. on buggies & I have had some problems with fatiguing & much more than with mild steel.

On the issue of round tube versus square or rectangular tubing, basic engineering design principles are overlooked.
The first buggies were built with side rails from round tubing & that seems to have set a precedent.

Think about how your buggy components are loaded.
Are they twisting, bending or being sheared or a little bit of each?
Keep in mind that for the same weight or cross sectional area of your tube that rectangular/square tube is superior in resisting bending while round tube is superior in resisting twisting.

I have serious downloading on my buggies in the terrain where I buggy, which creates major bending loads on my side rails. Therefore, I build my side rails today from rectangular section. I have had a lot less problems of bending & breaking since adopting this strategy.

Downtubes suffer more from torsional loading and round tube would be better for this. The downside to this is that it makes the connection to the side rails more complicated, hence a good reason to stay with square or rectangular section.

Look how chasses are made on many cars especially 4X4's . You will not see round tubes being used simply because box section for the same weight is better in bending.

popeyethewelder - 21-8-2008 at 09:21 AM

I use

Schedule 10
Schedule 40

but as always SY talks a whole lot of sense....

macboy - 21-8-2008 at 09:25 AM

Does powder coating cover or accentuate imperfections?

BeamerBob - 21-8-2008 at 10:50 AM

You can pick your finish to do whichever you want. They even have crinkle type finishes that will cover up some pretty bad imperfections. My guy said you can pick your color or colors and you can pick your sheen. He says his work is 90% cleaning and 10% powder coating. It doesn't seem to be terribly expensive. I'm looking for a test object to get done to see if I want to have other stuff done. Still tinkering with doing the Flexi frame but I really like the simplistic beauty of the stainless. It is eloquent by itself. I have a stainless trailer ball I was thinking of having done. That's one of the most abusive situations I can think of putting a finish through. I'm not sure anything can stand up to a trailer tongue grinding back and forth on it.