One of my buddies told me about this thread so I was curious and took a look. I didn't read thru all the replies but I kind have an idea what is going on. Let me summarized by thoughts on this thread in a few short and concise points.

1) It is great to want to build your own buggy if you want the experience and the bragging rights to say that you made it yourself.
2) It is cheaper to buy a starter buggy then build one. Custom buggy .. that's totally different.
3) Copying one of the worst buggy ever built ( Peter Lynn) just set you back years in buggy design. Yes, it was the best thing since sliced bread in the 90's. But it's 2016.
4) No matter how much engineering you learned in school , it will never equal experience. Engineering doesn't tell you things like needing correct back support if you don't have abs of steel.

I started building buggies years ago because I wanted to build a better mouse trap. If you've seen my older threads you will see my crazy ideas of a single sided front fork .. that' didn't work.. lol.

After 3 years of building buggies on the weekends , I stopped building buggies on a regular basis and only do it here and there on my spare time. I probably have about 30 VTT buggies out there ( Cricket, Black Widow and Stinger Race ). Why did I stop? Cost. If I wanted to maintain the quality, I have to raise the price to keep selling. I was loosing money making these buggies. I've spent over $25K in tools to build these buggies and they weren't paying for themselves. If you do it right, it will cost money. If you can build it cheap .. I guarantee you that you will spend more time on the beach fixing that buggy while others are out riding.

OffAxis, feel free to email me or give me a call if you need help with your build. Folks on this site know I am always open to any questions. I don't keep any secrets about my designs or what I learn. Always happy to share.

listen to Van... He is the man!

I had many many email and text exchanges, even phone conversations with him over the process of my work on his buggies... He is very willing and to talk and share his experience.... A VERY valuable asset for you as you move forward!

Van, thanks for the insight brother! I'm sure I get in touch with you eventually. The design is not locked into the PL buggy, it was just a frame of reference as a starting point. With all the feedback I have been receiving, I have been iterating the design. I have been super busy lately and haven't found the time to keep working on the model but there's no rush.

I just got back from what is probably the best rc flying event ever. http://flitefest.com/. It's like a huge family reunion. Lots of crazy planes were built crashed and built again. Records were broken. Also lots of fun and fellowship with friends we see once a year!

Great .. that's good to hear. It is good to keep an open mind. I changed my buggy design many, many times ... I learned alot from others on this forum also. I learned from their success and I learned from their mistakes. Most of my design are not original , yes I've talked to other builders and borrowed a few ideas here and there. Why do you think all the high end buggies look the same?? We find the features that work and incorporate them and throw out the ones that don't work.

Save whatever money you have for the build and make sure you get to WBB!

There will be all sorts of buggy designs there to pull inspiration from. Like the RC group you will be among friends who want to share what they know and encourage you. Or at least send you home on a more clear path.

You have never really replied to what you have for pilot skills and kites? 90% of this game is kite control. An engineering degree ( or even pilots licence ) can't give you that.

Notice how even Van suggests that you are better off getting a basic starter buggy and building from there. If you listen to ANYBODY, listen to Van. He has been through exactly what you are trying to do.

Yea you should build after WW...come have a look/see

Welp, after busting out a rim on my kite trike I've decided to rework the design and get more serious about building a better buggy. The kite trike will then hitch as a tandem to this buggy when needed. Here's what I've come up with for general shape and fit. My wife laughed at me sitting on the floor measuring out what I think would be ideal buggy size for me.

Here are the specs:
Me: 5'10", 175lbs, 32in waist, ~38in chest.

Oh, you were expecting buggy specs...:

Material: Plain Carbon Steel
Tires: Midi (16/6.5-8) or Barrow wheels
Axle Dia.: 20mm all around
Length (Axle to axle): 66in. max, 51in min.
Axle Width: 57.5in.
Trail: 2in, 3.125in, or 3.9in
Head Angle: 65deg
Seat Back Angle: 60deg
Seat Base Angle: 15deg
Rear Axle Tube Dia.: 1.5in sch40 pipe
Seat Frame Tube Dia.: 1_1/4in sch40 pipe
Fork Width: 8.7in
Fork Tube size: 1in sch40 pipe
Neck Tube size: 2.5in sq. x .120in tube
Sheet metal parts: .250in or .3125in
Frame Weight: ~65lbs
Est. Total Weight: 100-110lbs

Rear axle adjustment length: 7in, 1 in increments
Neck Adjustment length: 8in
Seat position from front axle: 41in max, 33in min
Seat position from rear: 25in max, 18in min
Seat Clearance height: 7in
Seat Back height: 15in
Seat Width: 16.5in
Seat bottom length (back rest to clamp): 16in
Foot peg height: 8.9in to 11.8 from ground.

Comments: I won't always be riding on a beach, so I think a good amount of ground clearance is better. Maybe I should add some fork angle adjustment into the clamp design. I need to clean up the fork design and decide on a the fork bearing setup yet. Also need to add hitch point to the rear axle.


The lines shown in the picture represent the seat and body position at max chassis length.


Question to you all: How much adjustment is necessary to be able to dial in the buggy to achieve the proper tow point. The neck adjustment allows for setting the proper length between the seat and pegs, which also messes with your Center of gravity and tow point. To compensate for this change I've added the feature of being able to slide the axle forwards or back to help compensate for setting proper center of gravity and tow point. Is this feature necessary? I fully expect that once the buggy sets off on the maiden voyage, the neck and axle location would be adjusted as necessary then probably never adjusted again.

I have the seat 3in in front of the centroid of the triangle formed by the tires. The centroid should be close to the center of gravity of the buggy. From my reading, people recommend the back tires breaking loose first, so I bumped the seat forward a bit to keep the weight a bit forward. Let me know if this is bogus thinking and the seat should be located near the midpoint between the front and rear axle.

Let me know what you guys think.

OffAxis,

Nicely done. I'm way curious, as I'm thinking of following along in your footsteps. I used to be an automotive design engineer, I'm a decent TIG welder, have tools and access to some decent tools, including high powered hydraulic tubing bender with complete set of mandrels. Unfortunately I'm a kite cart newbee, and I don't know a soul around here who has a cart that I might try. I've still got a lot of kite control (learning) work to do.

At the same time somebody offered me up a set of 3 small trailer wheels (4 stud on 4" radius), with two hubs. A hub for the front runs around $47 for sealed tapered bearing setup, from our friends in Azusa, CA.

Been looking closely at your content here. I'm really curious to know how those trail numbers work out for you.

In fact I have one tool that might be of interest to you (and anybody else here). I spent a whole lot of time looking at custom bicycle and other related frame designs. I rewrote software to do all sorts of tubing miter work. Its online and free, includes simple miters, decorative sleeving, Seat Tube to Seat Stays joint, round to tapered, oval to round, engine exhaust collectors, airframe cluster joints, etc...

Hosted on my site, all my work, feel free to use. The software generates full size paper templates. Cut on the line, wrap the tube, use a felt tip pen to mark the cut boundary, throw it into a vise and cut away. I've also included reference markings to make component lengths perfect.

Click here for the TubeNotcher software

Code is currently written in JavaScript, so it runs right in the browser, creates full size templates on paper (including large diameter tubing). Nothing to download beyond Adobe Acrobat Reader.

Possible to get a copy of your solidworks model in exchange? I suspect I will want less ground clearance than you, (I'm only on a dry lake bed, and its way flat...) and I certainly have to accommodate my oddball little trailer wheels, but a model like yours would be a place to start.. I do have some specific ideas on a different front fork design I'd like to try. If my request is out of bounds, no offense intended.

Many thanks for sharing the details you've already provided...

Zip

Quote: Originally posted by Zipzit

OffAxis, Nicely done. I'm way curious, as I'm thinking of following along in your footsteps. I used to be an automotive design engineer, I'm a decent TIG welder, have tools and access to some decent tools, including high powered hydraulic tubing bender with complete set of mandrels. Unfortunately I'm a kite cart newbee, and I don't know a soul around here who has a cart that I might try. I've still got a lot of kite control (learning) work to do. At the same time somebody offered me up a set of 3 small trailer wheels (4 stud on 4" radius), with two hubs. A hub for the front runs around $47 for sealed tapered bearing setup, from our friends in Azusa, CA. Been looking closely at your content here. I'm really curious to know how those trail numbers work out for you. In fact I have one tool that might be of interest to you (and anybody else here). I spent a whole lot of time looking at custom bicycle and other related frame designs. I rewrote software to do all sorts of tubing miter work. Its online and free, includes simple miters, decorative sleeving, Seat Tube to Seat Stays joint, round to tapered, oval to round, engine exhaust collectors, airframe cluster joints, etc... Hosted on my site, all my work, feel free to use. The software generates full size paper templates. Cut on the line, wrap the tube, use a felt tip pen to mark the cut boundary, throw it into a vise and cut away. I've also included reference markings to make component lengths perfect. Click here for the TubeNotcher software Code is currently written in JavaScript, so it runs right in the browser, creates full size templates on paper (including large diameter tubing). Nothing to download beyond Adobe Acrobat Reader. Possible to get a copy of your solidworks model in exchange? I suspect I will want less ground clearance than you, (I'm only on a dry lake bed, and its way flat...) and I certainly have to accommodate my oddball little trailer wheels, but a model like yours would be a place to start.. I do have some specific ideas on a different front fork design I'd like to try. If my request is out of bounds, no offense intended. Many thanks for sharing the details you've already provided... Zip

Zip,

I'm pretty familiar with that lake bed you describe. :karate:

In fact, I'm wearing an IBX2017 t-shirt right now. As you may be aware, there was the year's biggest buggy (etc.) event on Ivanpah just a few days back. Sorry we didn't see you there.

What sized guy are you? I ask only because there are several great buggy guys that live in the greater Vegas area that are sponsored riders and have some great buggies in their own rights. You might be able to hook up with them. Brian Holgate and Bobby Muse (beamerbob here).

I'm not a machinist or anything like that, but my one piece of constructive input would be to say that if you are going to go to the immense effort to custom build a buggy (a super cool project btw) then I'd want to ensure that your wheels are the type you want for Ivanpah and not simply build your buggy around the wheels you have. Maybe your wheels are just right, but if it were my project I'd want to get just the right wheels. Just sayin'.

Go for it!

Steve

Zipzit, nice tool ! My 36 yrs of experience has shown me this one important thing . You don't need that CAD stuff,it's all fancy ,but if you can't draw it (and I don't mean on a pc),you can't build it.
Get a square , a set of dividers, a straight edge, a protractor, and level and draw it out full scale on the shop floor or fab table. All views........ Then build it .

Good luck guys, post build pics !

Quote: Originally posted by WELDNGOD

My 36 yrs of experience has shown me this one important thing. You don't need that CAD stuff, it's all fancy, but if you can't draw it (and I don't mean on a PC), you can't build it.

I've been a cabinet maker for the last 10 yrs roughly and I learned drafting with a T-square and achitect'scale, a boatload of triangles and a pencil... and it's still what I use. Even when reworking my own buggy, I also used the T-square and pencil ... I'm not necessarily old, but I do it old school.

I won't ever make my own buggy but if I did these are a few things I would try and achieve.

I would try to design my front fork so it will accommodate a variety of tire types. From barrow through big foot to racing discs.

I would design the back rest bar and side rails to move my seat forward and back for balance.

I would make it break down fast and easy for transport / storage.

I would build in height adjustability on the back axle. + a tow hook.

I would want to feel confident enough in my build to go over 50mph without worries.

I'll never be able to build anything to live up to that last request of myself. Too bad because quality home builds I have seen can be pretty awesome. Taking buggy design places it has never been before!

Best wishes to all of you on your builds. I can only suggest you don't cut corners to save on cost. The buggies that I have seen that work are built with no expenses spared.

WELDNGOD, Windstruck, soliver

I appreciate and respect your input. And yes on the Computer Assisted Drafting (CAD) thing, its all about the old dog --> new tricks thing.

The problem is, that I spent 30 years in the automotive industry as a OEM design engineer (+) and I've been actively using CAD since 1984 (IBM with Autocad) I've done ACAD, Prime-Lundy, Catia, Solidworks, etc... for so long, I can't think of anything else. Nevermind car parts (don't quit your dayjob), I was designing windsurfing sails in the early 1990's with ACAD (but I will say the transfer from 1930's NACA airfoils 3D shapes to flat patterns on the sailcloth drove me crazy... ) I've been designing custom bicycle frames in the past ten years. Apologies, but I'm an old dog hard glued to CAD.

While that is definitely not true for everyone, I suspect I have enough skills to make this work.

The one thing that CAD does for me, is it does give me the opportunity to do three or four different design iterations before touching a single piece of steel tube. Do I always get that right? Heck no, but I really want to understand the concepts..

Two things I'd love to know.. what is minimum ground clearance (3"?) for a dry lake and what's optimal trail? I would guess three or four inches for trail, but I'm not really sure... I suspect trail is related to overall buggy weight / rolling inertia but I really don't know. It makes sense to me to build a buggy with adjustments as a test bed, but I'm sure many of you have already been there...

And one more thing. I have no problem sharing my work on this. OpenSource for the we-all-win.

Many thanks, Zip.

So I think Zip is going to fit right in here in the Monkey House. Always room for a few more good chimps!

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I just saw this post yesterday. I read the hole post. Things on the forum have been kinda slow, so looking at older posts.

Now I was left wondering did you ever build the buggy?

And what did it look like if you did build it?