Scale model cockpit FPV

cool scale cockpit video

Funny Zoo Snap

man enjoys elephant My wife noticed this in the family archives.

RC Nitro motorcycle racing

rc motorcycle Motorcycle racing in Lilliput.

Manned RC Multicopter

manned multicopter
Here’s an RC multicopter big enough to ride on!

Make: Talk 004

make: Talk 004
I had a fun time talking to Mark Frauenfelder in episode 4 of his new podcast, Make: Talk!

One Man Basement Band

one man band
I feel like I could be getting more mileage out of my right foot.


liberty vintage motorcycles An Etsy portrait. Thanks, Danny.

Tequila Sleeve

tequila the champs
Champs sleeve

Wolf-Stelzer Book Lamp

Book Lamp
My friend Tess just made the cover of ReadyMade with her cool lamp design.

Tree Stump Bug

Can this be for real? The design is so awesomely Thunderbirds. Via

The Nothing Box

nothing box


Thunderbirds are go
Are Go!

Command Center

command center
Sweet assemblage spaceship’s bridge.

Four Drano’s

Watch the sink slowly, all but disappear from the design .

Toothpaste Aerosol

toothpaste aerosol
Aerosol toothpaste

Build a car out of foam


Robert Q. Riley has been designing, prototyping and selling DIY plans for innovative Build-it-yourself vehicles since the mid-1970′s.

The Tri-Magnum is a 3-wheeled car with a motorcycle in the back, a VW axle up front and body built by sculpting the car ouf of foam sheeting and applying a fiberglass skin. The car originally appeared in Mechanix Illustrated magazine, February 1983.

Riley’s fiberglass Over Urethane Foam contruction method works much like building a model boat or airplane, with the basic shape fist being defined by formers and stringers, then skinned in foam and covered in fiberglass. You get to choose the donor motorcycle based on availability, or to achieve specific perfomance or fuel economy levels.

If the Tri-Magnum is’t up your alley, you can also get plans for electric cars, hovercraft, RV’s, personal watercraft, whacky bicycles, submarines, and all sorts of good stuff. Link

37 Responses to “Build a car out of foam”

  1. Dave Says:

    I remember first seeing pictures of the Tri-Magnum way back in junior high or early high school (mid-70′s) and just about wore out that issue of Mechanix Illustrated. I probably still have that copy around somewhere! The idea of building your own car from spare parts, foam, and fiberglass is just too good to pass up. Unfortunately, 30-some years later I still haven’t done it. Maybe my middle son and I will dive into the project when he gets closer to driving age.

    Dave — Yeah, I have the same idea with my sons. I am working on a design for a tri-magnum type vehicle, but with a slightly more foreward seating position, and a flat area for cargo in the back. kind of a ranchero type thing.

    One of my partners on http://www.gadgetopia.com wrote a post about the T-Rex a while back, and I plugged the Tri-Mag on that post. There are some similarities between the Tri-Mag and the T-Rex, but the cost of the T-Rex is way out of line. If a Tri-Mag could be built with something more substantial than a VW front end, that would be a wicked ride!

    I have an engineer friend who has an ongoing interest in high-performance trikes. He is excited about the potential for re-using some quad / ATV suspension conponents in his design.


    Thanks for the great site; lots of great info. I found my way here by way of Jalopnik.

  2. Jason Martin Says:

    Around the same time the Tri-Margnum appeared, one of the kit
    car mags had another three-wheeler that looked something like
    a Sterling. It used the tail lights from an ’83 Camaro, and looked
    really sharp. Any memories out ther of this other trike, and
    where I can get info on it?

  3. Mike Says:

    I’m interested; can I get more pics and information on this?

  4. Joe Toffton Says:

    Dave wants something besides a VW front end ?? Let him get a good front wheel drive, Strip it down center one wheel in the rear, form the body to your liking, fire it up and hang on, Handling is improved as the weight is on the front wheels. Cornering with power is a breeze.

  5. Steve Says:


    If only the Corbin Merlin Coupe had come to fruition:



  6. Bob (Bart O Blackhorse) Says:

    Riley has the answer to your entry about front wheel drive. the doran is such a car. With a diesel from vw instead of the subu motor gas milage is over 60. There is a new tri wheel out called suntrike but not in kit form. There is the Grinal scorpion & Malone skunk out england ….the other three wheel that was sharp & kit based was the Fire Aero by David Stowery. My little group is working on a tri wheel that we hope will go out as kit form…we blended some frame stuff from the Locost builds/Ron Champions book…gives some good basic frame design stuff…

  7. Dave Says:

    Bob, the Suntrike has a limited speed of only 40 mph. My idea of fun driving must, at the very least, blow the doors off my Acura Integra. The Malone Skunk Supertrike seems to be just that, where you sit wayyy in the back by the rear tire in an open cockpit with a Cobra-looklike body. My only problem is I live in Florida where it rains alot, so I gotta have a roof, and ac. I have the complete plans for the U-build-it Tri-Magnum and also a brochure from a company in California (I think they no longer exist. Seems to be the same song with kitcars) that made custom chassis just for the Tri-Magnum, and also they made a complete factory-made body. The chassis sold for around 600 bucks. I somehow misplaced the brochure. I forget the name of the company. They were located in Irvine CA.

  8. Allen Says:

    i wonder if anyone has tried to mod a suntrike yet by putting in a larger motor?


  9. Ozzie Says:

    On the topic of the SUNTRIKE there is now a 150cc version. While it won’t blow the doors off any car I know, it offers easy 50MPH crusing and decent acceleration for everyday street use. The engine is good for 60MPH but the MFG chooses to restrict it for liability reasons. Stay tuned to my site http://www.cycleimports.com those people into cool faster three wheelers will soon (6-8 months) be pleasantly surprised.

  10. dave Says:

    Bart, I’ve been looking at a similar concept. Have you guys made any progress? Is your project front wheel drive?

  11. Terry Dodds Says:

    Folks, stay tuned! I am just about finished designing and building a new three wheeler. It has modern un-equal double wishbone front suspension, tandum seating, Susuki 1200cc motor and a centre of gravity that is unbelieveable. It will be available in plan form on the internet mid 2007. It is a cross between the Tri-Magnum and a Cobra in looks and is cheap, easy to build from parts available world wide. The power to weight ratio is approx 300 HP / ton and the wheel track 1800mm, wheelbase 2350mm. It is Australian Design Rules compliant and a home builder should build it for less than 12K AUD. If you want more email me on swampthing@westnet.com.au

  12. Bart O Blackhorse Says:

    To Dave and the rest. We are making progress as time and funds allow. wea re working on two types. one full body, roadster version with hard top removable and the other a striped down frame speedster. Our model will be powered by a motor & trans that will take the torque that the Motorcycle trnasmission cant. The trick in all of the three wheel, two forward designs is stability. Which means a formula of length weight and front wheel base plus power to move it consistantly with out burning clutches. We have a good base and are continuing in the prototype….while seeking investment funds….yeee haaaa. Dont get me wrong guys there are some great machines out there…each with there own plus and minus. We set out to build a affordable, maintainable machine with common parts. Not needing a lot of machine shop parts. We set out to build from auto parts store available , and other common parts that will there next year.
    I can be reached at blkhorse2@yahoo.com Please understand I am not able to disscuss the project in detail as we are not to market yet.

  13. Chris Edwards Aguilera Says:

    The VW front end on a Tri-Magnum leaves a lot to be desired, I won’t go into all the problems inherent in a 40 year old mechanical part or technology. The biggest drawback is that the torsion tubes invade the cockpit and you have to rest your legs OVER the front axle. That can’t be comfortable

    I am currently into a similar project called the Vortex that also uses a motorcycle engine and single rear wheel in the back but the front suspension is independant A-arms giving you much more leg room.

    Triumph Spitfire has been used and other suggestions are Fiero, Miata and such. Remember the frond end has no engine so you don’t want heavy Corvette or Mustang parts.

    Additionally, the project chassis is engineered with an inexpensive and lightweight yet natural composite material. Yes, a plywood chassis, like the Marco, is cut and glued and strengthened with steel sub-chassis, there is also an electric modification if you choose to go green.

    See http://vortexplans.com and check out the Yahoo users group Vortex3wheeler too. Tell them Chris Edwards sent you, the Parts Manager from defunct kit car manufacturing giant Classic Motor Carriages.

  14. Stan Reynolds Says:

    Stan Reynolds Says:

    Ozzie is the man to pay close attention to. He designed the SUNTRIKE and has produced hundreds if not thousands of them.

    Keep a close eye on his web-site if you are interested in being on the cutting edge of fun and fast three wheel power. He is at http://www.cycleimports.com.

    Thanks everyone for sharing your knowledge. It is a great help to us of very limited understanding. What you share can help others to save time and money or not to make the same mistake.

  15. Cheryl Says:

    So are there any of these around?
    If so please send pictures.

  16. Cheryl Says:

    That e-mail address is estatesalesbycheryl@charter.net

  17. Cheryl Says:


    Where are they now? And do you have any idea how many exist? Thanks,

  18. Jake Says:

    Ha,ha ha ha ha, this thing sucks!!!!

  19. Allister Says:

    Hey Jake, want to fight about this you jerk!

  20. Jake Says:

    Bring it on loser, what is so good about this car that it is AMAZING!! Its a pice of junk that I will destroy!!

  21. Allister Says:

    OHH! Its on now, were do you live you mother *@#$er. I am going to kick your @**.

  22. DeLane Dunn Says:

    I saw a notice about a year ago about someone using a VW engine (I have a diesel) as a doner in a Doran type front engine 3 wheel car. Does anyone have any new info on this option. I have been wanting to do this for several years (25) and now have the VW Diesel doner to start. I know there will need to be frame changes to the original Doran design, I have the Doran plans from several years back. Any help would be appreciated.

  23. JOSH Says:

    Hello my name is josh, I have never been to this site before, I will bookmark it. I am planning on building a trike. Two wheels in front one it back. I have purchased a 1993 yamaha r6 as a donor bike. This bike is prefectly ridable but I am considering it as the donor. The bike has a 600cc , 96 hp motor, 1300 rpm redline, 5spd transmission. I am in early design phase. I am looking for ideas for both body, and frame. I currently do “out of thte box” installs on cars. Sound systems, lighting, hydrogen generators ect. Various stuff right. I can work with fiberglass well so I believe the majority of the body will be fibergass or carbon fiber. There are things that I have never had to deal with though like How to build a frame to attach the bike or good steering setups. I know i WILL be using a air ride system since I have access to parts and such, no reason to skimp out and get busted old springs. anyhow. One bid thing is where to get custom glass, I dont know anyone who makes custom windshields. Any help would be great im in the design phase the next couple of months. Please help! Ive been looking at all the sites listed contact with those who have done this a time or too would be great! My email is tenoaksonline@yahoo.com thankyou all

  24. Kenny Says:

    looking for any good 3 wheeler kits out there, does anyone know of a good kit?
    The Suntrike is a nice little day toy, but I am still finding it hard to look at that front end, I think it needs to be more streamline like the t-rex
    just my .02

  25. Tim DuBos Says:

    I think this is a cool sight , Im building a three wheeler out of a corrolla front wheel drive 5 speed and rear trailing wheel , Im calling it a TRYOTA. I was going to use a rear swing arm from my 600 ninja I bought , but found out the axle is bent. so Im leaning toward maybe a trailer tire drum brakes that Id hook up to the emergency cable. kinda like Jim Comptons on three wheeler .com #017. hope to meet some interesting friends and exchange thoughts about our dreams and passions. Tim DuBos.

  26. Robert Works Says:

    Does anyone know where i can get plans for a Tri-Magnum?
    Featured in the Feb 83 issue of Popular Mechanix mag

  27. John Says:

    Kenny, If you like the T-Rex but don’t have $50K laying around and want a kit, check out http://www.g-2.ca/an/faq.htm

    I’ve actually talked with the guys at this site in Carlisle
    and sat in their T-Rex clone. They don’t have any information on their cobra site but they make a t-Rex clone. I don’t know it these two groups are one in the same , but their pricing was $20k USD. Sitting it next to a real t-Rex I had to really get technical to tell the difference, and the kit actually has some superior changes from the original.

  28. tri magnum Says:

    [...] a motorcycle in the back, … I have the complete plans for the U-build-it Tri-Magnum and also a …http://www.finkbuilt.com/blog/tri-magnum/Talk:Tri-Magnum – Wikipedia, the free encyclopediaTalk:Tri-Magnum. From Wikipedia, the free [...]

  29. build car body foam Says:

    [...] up front and body built by sculpting the car ouf of foam sheeting and applying a fiberglass skin.http://www.finkbuilt.com/blog/tri-magnum/trackback/Ev Archive for March 1999 … they look like pieces of furniture. &gt &gt If Lonnie wants to build a [...]

  30. tom Says:

    Chris Edwards Aguilera,
    I find it amusing that the Vortex plans are $90 and if you pay with Paypal, they charge you an additional $3! Wow, my philosophy is that if you buy online, you should pay online, not stone age money orders, checks etc. These people actually penalize you for paying online. It’s amazing how stupid and backwards people still are.

  31. frank harvey Says:

    I’d like to build a 3 wheeler too but I hope to find one that’s partly done. I’ve started projects, gotten too busy and sold ‘em. I thought I’m probably not the only person that’s happened to – so I’m hunting for someone else like me!

    I prefer to have 2 wheels up front. Anybody’s wife wanna sell me a project ?! (my divorce is 11 years in my rear view mirror and my present girlfriend hasn’t gotten her hooks in deep enough yet…)

  32. Josh Says:

    What is the size of tire on that wheel in the picture?

  33. Josh Says:

    What size of tire is on that wheel pictured?

  34. car part Says:

    Oh!the auto is just like spaceship.

  35. Charles Dedriksen Says:

    Hello all. Today is Dec 21 2008. I started working on a Tri Magnum 8 months ago and I am about half finished. Took it for a test ride yesterday without the foam fimberglass body and it was a kick. All the frame and mechanical is done and working well. I wanted to build one since it came out in Mechanix Illustrated Feb 1983. I kept the magazine and last year my boss gave me a wrecked Honda ST1100 which is shaft drive water cooled V4 95 HP engine. I found Robert Q Riley the original builder on the web and ordered the revised plans. If there are other tri magnum builders out there I would love to chat and exchange modification ideas and pics. Drop me a line at cdedriksen@yahoo.com

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