just the type of site I've been looking for! this is my first post, so i'll tell a little about myself- sorry for being long-winded.
Im very interested in custom body design. the article in this months' Super Street about the chop-top FD (RX7) was VERY inspiring to say the least. I am now on my way to signing up for Foresee online car design classes + body/paint classes.
I have never gotten such inspiration from a car featured in that mag as this FD by Tamon Designs in Japan. for about 5 years, I have wanted to do something having to do w/ fixing up USDM spec Japanese cars, but never knew exactly what it was that I wanted to do until I read this article. I really wish they had more tech info though- very lacking in this department.
anyhow..for now, I need a basic explanation of how to make custom (one-off) body kits>> I know that it starts w/ sketches, then making some sort of resin or clay mold, but then what?
how do I get the fiberglass body kit material to form and 'dry' in the original mold?
what do I use to make the mold?... material + tools?
are there any 'how-to' books (w/ pics)on this subject? or any free online resources w/ pics? I remember seeing something about this on RIDES last year.. but really dont remember much of what they did.
so I could design the parts on a PC w/ rhino, or some other app(s)- and then send to a company and they will make the parts for me? I bet that would cost a fotune!
anyone else have some good links for this subject?
to move forward with this project you have many options,
first you need to decide on your budget for time and money, obviously knowing that it must be a fine balancing act between both, you can have the labor done for you and increase the money factor or do all the legwork yourself and increase time....
You can start at several different places,
First option : obtain a digital model of the car to build a body kit around in a 3d package. This can be done via laser scanning or photogrammetry, I am with a company Direct Dimensions and we specialize in obtaining this data.
Second option : start by building a clay model off the existing car and hand modeling it until you are happy with your finished design.
Now that you have your design established you can go about actually starting the process to manufacture the kit....
If you chose option 1: you can take your newly designed 3d part and either have a CNC plug made on a 5 axis mill or if the geometry is simply enough you can create the part by cutting cross sections and filling the cross sections with foam and smoothing the surface until you have a plug....
If you chose option 2: you can either take a mold off of your existing clay body or you can have that data digitally scanned,,,, checked for symmetry and modeled for design intent and then recreated on a 5 axis CNC mill.
The next phase will involve producing a useable part because clay doesn't hold up to well to rush hour traffic.
Once you have your plug you can either make a mold from it or have a mold made at a composites shop and the last step would be a compostie layup...
In a one off situation very few people can justify that cost. Best bet use you Dona car as the base, mask up the various areas, make sure you set the vehicle on a level plate, Floor, ( 3/4" MDF sheets stuck to the shop floor with bondo ) ensure the car is not sitting on the wheels /suspension as it will move, jack up on the frame in as many points that you have jacks for ( Go to a local scrap yard and get 6/8 screw jacks from Nissan/Honda/Toyota etc ) DONT use hydraulic jacks as they will come down.
Now you have a level playing field, grid out the HDF with basic reference grid 100mm square. then you can transfer your sections from side to side.
Start with Styrofoam ( White or better Blue ) build your basic shape cutting with bread knife, Elect carving knife, Chain saw , when you have the rough shape use a hot air gun to melt the outer skin of foam , this will harden up the outside, then start packing clay, if you have done the foam work correctly you should apply around 1/2 to 3/4 of styling clay, try not to go over 2inch, it get heavy and will fall off.
Create simple sections by hand , then make a template to drag through the clay surface, changing the temples for the various styling details.
When everything is as you want it, take a quick mold using Hydracal or Ultracal 30 Gypsum plaster whist every thing is still on the car, then make your FRP parts from that. Don’t spend the time Digitizing, scanning, CAD modeling . In 30 plus years of Prototype design, Claymodelling I have yet to see any concept that has gone from 3D model , Milled Master, Digitized and re modeled, etc etc. without at least 50% rework by a Claymodeller, Save you time and money do it right the first time.
Look at www.claymodeler.com for information, links to materials and tools etc.
Originally posted by clayman: That all takes time and money.
In a one off situation very few people can justify that cost. Best bet use you Dona car as the base, mask up the various areas, make sure you set the vehicle on a level plate, Floor, ( 3/4" MDF sheets stuck to the shop floor with bondo ) ensure the car is not sitting on the wheels /suspension as it will move, jack up on the frame in as many points that you have jacks for ( Go to a local scrap yard and get 6/8 screw jacks from Nissan/Honda/Toyota etc ) DONT use hydraulic jacks as they will come down.
..... .....
Don’t spend the time Digitizing, scanning, CAD modeling . In 30 plus years of Prototype design, Claymodelling I have yet to see any concept that has gone from 3D model , Milled Master, Digitized and re modeled, etc etc. without at least 50% rework by a Claymodeller, Save you time and money do it right the first time.
I wouldn't say it takes time with our approach, just money. Sectioning the car by hand and gridding it takes a great deal of time.
In the world of business time is money,
So weigh your options, If you are on a deadline and are serious then getting help with someone who can do the job accurately could be the way to go, if you are just doing it as a hobby and only donate your time and limited funds to material then the approach clayman has shown will be a good approach.
These two different approaches will suit two different styles of design. If you are more comfortable modeling in a computer then sculpting with your hands then digitizing is the only way to go but if you are old school and have been doing something a certain way for 30+ years then you might want to stick with what you are comfortable with.
And clayman, just because you have done something for 30 years a certain way doesn't mean there aren't other options, a lot has changed in the last few years on the technology side of things and these changes should make you take a 2nd look at other options....
From what I read from Shooly's post, he is interested in a one off product, probably for his own vehicle. In that case the hands on approach would be the most cost effective, especially if the design is changing to suit his taste. No doubt there will be a lot of design changes and that can only equate to money when you are relying on an outside company to build the design in CAD. A one off scan of the existing vehicle will probably be in the $2000 range. He has only to supply his time and the materials will easily fit inside a $2000 budget!
If the design was fixed then sure you could build it as Blkaplan has suggested and have the tooling made to suit, but you will need more than one customer for you to make a return for your money.
Technology is a great thing and yes the modeling scene has come a long way from the purely hands on sculpting of the past but needless to say most automotive companies use CAD as a tool for removing the "Donkey" work out of the program. New design requires many hours of fine tuning so by packing the clay and milling the first iteration of the design straight off the tube reduces the manual labor and gets an instant 3D result. From there on in it's a combination of technologies both old and new to attain the final result.
Your points are well received and for a one off side project, this is probably the way to go.
With the scanning and modeling aspect you would only need it scanned and modeled once, from that initial model you could adjust the model virtually and try as many iterations as you would like. Once you are happy with your virtual model you would have it milled to produce molds or you could use the cad model to create cross sections to aid you in building a plug via manual buildup.
