Guster Posted October 15, 2012 Report Posted October 15, 2012 Cleaned up and refitted... lower, narrower, new seat etc. http://farm9.staticflickr.com/8195/8078 ... 8f4f_b.jpg Quote
jhn.holgate Posted October 15, 2012 Report Posted October 15, 2012 Your link doesn't seem to be working for me.... Quote
Guster Posted October 15, 2012 Author Report Posted October 15, 2012 Your link doesn't seem to be working for me.... Tried to inline the image which the forum garbled so I reduced it to a link. Kept wanting to shorten the url with '...' in it. Just wrapped quotes around it and seems to work now. Quote
jhn.holgate Posted October 15, 2012 Report Posted October 15, 2012 That's impressive! What's the rear axle? Quote
Guster Posted October 15, 2012 Author Report Posted October 15, 2012 The axle is 3x 3ply Fijian Kauri and fibreglass laminate. Kauri is used in a lot of older wooden yachts still in use in the pacific. Similar to a blend between Cedar and Maple. Also have a foil profile stainless axle that just needs mounting tabs welded on. Here's the story of the original... http://buggy-builder.blogspot.co.nz/200 ... me-to.html Mark 1 was a testbed for a few ideas hence oversized in a few aspects. First day out it clocked 79kph. Mark 2 trimmed out all the gaff. Since I fitted it with Kenda BR's and made a new laminate axle. The original axle is on my barrow buggy. http://buggy-builder.blogspot.co.nz/200 ... ng-in.html It's not light but well within the the 60kg Euro race limits last time I checked. Should be even lighter now I trimmed it. Quote
jhn.holgate Posted October 15, 2012 Report Posted October 15, 2012 Very nice Suspension and strength in the axle plus the added bonus of having somewhere to put the stubbies.... Quote
Chook Posted October 15, 2012 Report Posted October 15, 2012 That looks just fantastic!!!!! I like the leading link on the front a LOT. I do love the chicken mounting too. I'm really impressed with a laminated rear axle as well. I've been testing mine, to get just the right amount of spring. You can hold a lot more kite, when your wheels remain in contact with the ground, rather than riding on top of the corrugations, or pulling you sideways . With the same tyre pressure and the axle now stiffened back up, (to compare apples with apples) the roosts/tyre tracks are a whole lot larger where the buggy is loaded by the kite. With the compression of the laminated axle, the stored energy is quite noticeable as acceleration as the kite sines. I still have a long way to go to perfect it though. Its trial and error (with much error) to get the slump or initial curve of the axle right with your body weight. I found if it's setup flat when your seated in it, it's much too firm and there isn't enough flex to get any stored energy out of it. My “ideal” would be a counter lever system of short arms that transfer the load of the downwind axle, to the other side for even traction. It's very noticeable on a solid rear axle that the downwind tyre is always working slightly harder. On the laminated axle both rear tyres seem to disturb a very similar amount of soil. All good fun though. The Mrs reckons I'm just scratching about like a bloody old chook looking for worms. At the end of the day, I AM a bloody old Chook. Quote
Guster Posted October 16, 2012 Author Report Posted October 16, 2012 I tried to maintain the load stiffness on the axle so that camber does not change too much when the kite takes weight off the buggy/pilot on the upstroke. This had the added benefit of not having the buggy frame 'roll' towards the kite under traction - ie. kite side bending under kite strain. As you can imagine both of these scenarios can introduce some tracking issues. Then I tried to 'deaden' the laminate and used copstrand in preference of longstrand fibres so the axle would not load up on bounces ie. kill returned energy and thus absorb bounces to some extent. The main idea here being that you do not transfer wheel bounce to the frame. Not so much for ride comfort but more as Chook elaborated on keeping rubber on the ground to maintain traction. This allows you to hold your line and get the most out of the kite especially when the beach is not 100% smooth. The rest of the mechanics was just around keeping the axle in centre to avoid any tramping. I tested a classic tube axle back to back with the springboard axle on a particular area of the beach where I know the washboard surface prevents me maintaining my speed. Initial runs on the tube axle only allowed me to maintain 59kph max before the wheels would judder so much that I slip sideways. Powered turns were also near impossible. With the springboard axle I topped out at 76kph on the day and maintained it through the washboard surface, maintaining speed through turns without the washout problems on the tube axle. Quote
Clive Posted October 16, 2012 Report Posted October 16, 2012 I'm impressed with the rear axle statistics, the concept of give and traction into the washboard effect makes sense. I wonder just how the buggies with suspension went with that factor. Interesting of note that race buggies are all ( as far as I know ) solid axles. You reckon that much advantage would be useful. Quote
zahra Posted October 16, 2012 Report Posted October 16, 2012 Wow!!!! Talk abt big wheeels!! Looks super, how is the ride? Quote
Guster Posted October 16, 2012 Author Report Posted October 16, 2012 Those stats are under extreme conditions where it’s easy to illustrate an improvement in performance. Every setup will be slightly different and every material has a its own harmonic frequency. The length of material can alter the affects as well. For instance, my shorter 1.2m stainless tube axle behaves much worse under those conditions than the 1.5m axle I used for the baseline comparison. Principle was just an exercise to find a material and setup that has improved behaviour to what I experience with my solid axle in the conditions that I found hardest to maintain control. Also don’t forget this is in combination with the leading link front I already have set up which in itself improves performance. what I have not yet discovered is where this setup starts to misbehave... It’s smooth, stable, heavy and turns like a truck compared to my barrow wheel buggy… it rocks! I’m looking forward to chasing the +100kph club. Quote
sherwinelioreg21 Posted October 18, 2012 Report Posted October 18, 2012 overall, this looks fantastic.. and what's the chicken doing at the rear? lol Quote
Guster Posted October 18, 2012 Author Report Posted October 18, 2012 That's my 'chick' posing for the promotional photo shoot! Probably just thought there was food available or something. Ended up in the background of all the photos I took. Only noticed it when I got them of the camera. Quote
zahra Posted October 18, 2012 Report Posted October 18, 2012 Thats quite a rooster u have! Well spotted Sherwin! Quote
Guster Posted October 18, 2012 Author Report Posted October 18, 2012 Hen actually... Funny nobody spotted the 'hood ornament' Quote
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