|An Elusive Heinkel-I Steering Wheel Center|
For the longest time having a Heinkel-I without the proper “Heinkel-I” steering wheel center bothered me. Since the part wasn’t being reproduced and was rarely offered on e-Bay, I resigned myself to my fate and learned to live with this empty spot in my car. A standard “Heinkel” steering wheel badge would have to do; who would really know the difference? Well I did, and then one day a few months ago one appeared on E-bay. I even knew the person who was selling it; I could already visualize it in my car! I contacted the seller to see if he would stop the auction and sell it to me; no, he wanted to let the auction run its course. I submitted my bid with e-sniping software for what I thought was a fair price. Well, apparently someone wanted it more than I did. It sold for almost $80! It was time to take matters into my own hands.
- Make a scanned computer model of my existing Heinkel steering wheel center
- Manipulate the design to transform the “Heinkel” Logo into a “Heinkel-I” logo
- Print the part
- Paint it
- Install in my car.
Sounds simple enough, but like many other things on a Heinkel you know that it’s not. This is the story of my 3D printing experience. But first, a little background on the state of 3D printing today.
|The Makerbot 3D Replicator|
But let’s get back to printing. Question one: how would I create an image that I could print? My first thought was scanning. I was using a Makerbot printer, and Makerbot makes a 3D digitizer. A digitizer lets you scan an image from multiple angles, and then the software embedded in the device takes over and creates a 3D model. Piece of cake?; not really. As it turns out the local Makerbot “boutique” did not have a digitizer, and the people they referred me to said theirs was broken. Reading between the lines I got the sense that digitizers do not work very well.
|Using an iPad scanning program on a Heinkel part|
This didn’t work either. The software doesn’t work with shiny objects.
|Heinkel part design in Tinkercad|
Once you have an STL image from the design program you are ready to convert it into the proprietary file format required by the 3D printer. After you load this file into the computer program supplied by the printer manufacturer you will have a chance to make some adjustments. You’ll need to experiment here; I automatically assumed that I wanted the finest resolution and quality and the program told me it would take over 29 hours to print! The fastest option was about 90 minutes. In the end I settled for a finer (but not too fine) resolution that clocked in around 3.5 hours. Once you have this file its time to actually print.
|29 Hours is a bit too long!|
The hobbyist-level printers use either PLA or ABS plastic. PLA is corn-derived and is biodegradable. ABS is petroleum-based and used extensively in the automotive industry. ABS printing produces fumes and requires ventilation, so my library chose a Makerbot printer that uses PLA. Some printers can use either, so depending on what you are doing you need to be mindful of that. Since I was going to paint my steering wheel center and not expose it to the elements I reasoned that I was fine with PLA. The plastic comes in a variety of colors on spools resembling fat fishing line. I chose a clear/white as that was what was in the printer, and I figured it would be easy to paint.
|Watching the printer|
3D printing is a multisensory experience. The melting plastic has faint odor, the machine makes all sorts of noises depending on what it is doing, and of course there are control screens and lights and printer head motion. It’s oddly fascinating to watch. Since we were printing in a public library on a busy Saturday afternoon we drew a lot of attention. Kids were very interested, and we showed them an example of what we were trying to do and you could see the wheels turning in their minds about the projects they would create.
|Removing the “raft” (top) from the printout|
|Removing the supports from the printour|
When you look at the printed design you can see how everything is constructed by the printer in tiny sections and layers. For a prototype or some little tchotchke that might be ok, but I was trying to reproduce a rare car part and it wasn’t good enough. It was hard to see how good (or bad) the print was so I hit it with some spray primer to get a better idea of what I had to work with:
|Shortcomings of the process are apparent after printing|
It looked like a movie star without makeup. This is where a little patience, a sharp knife, and some basic auto body skills came in handy. My daughter was unhappy with the outline of the letters, so she spent about an hour using a carving tool to clean them up. Then I sanded the dome with 320 grit wet sandpaper and applied glazing compound in the depressions. I repeated the process to make sure I got all the holes filled in.
|A little auto body filler|
Then I painted again with a couple of coats of high build primer. Here’s the end result:
|A Comparison- Printout is on the left|
And another picture compared to other Heinkel steering wheel centers:
|An original (on loan), the printed copy, and a German reproduction|
On the whole I’m pretty happy with how this “Version 1.0” came together. I’m going to try a Version 2.0, which will print the cap and base separately, hopefully eliminating the need for most supports (which were very difficult to remove). I’ll glue the pieces together and determine a way to secure it inside the steering wheel.
- Gear shift indicator plate
- Switch housing covers
- Fusebox cover
Since the build plate size on these printers is about 8” square, there might be a few others:
- Heater/demister nozzle
- Air filter housing pieces
And maybe a few Resto-mod pieces:
- Hubcap spinners
- Taillight lenses
Some Parting Thoughts: I don’t suggest trying to make a living reproducing Heinkel parts with a 3D printer! Not counting design time and actual printing, the setup/cleanup/painting processes probably took about 4 hours. I do think with a little work you can make parts that are not available anymore and look like the originals, or create your own custom parts. It’s worth a try and I’m glad I did it.