Tuesday, June 11, 2019

New LED Dune Buggy Signal Lights Project Part 2


Things are going well this week with the LED dune buggy signal light project.  I have managed to get through all of the 3D printing that needed to be done and have started smoothing out the parts to get them ready for paint.  So with all of this progress I thought I should show you how it all looks at this point.


This part which is one of the LED light housings for this project took 35 hours to 3D print.  I am very pleased with how it turned out.  The vertical wall that you see in the part above was a support wall only used during the printing of the part.  It was removed very easily after the print was completed. 

With the two housings that I need for the project, I also needed to 3D print the mounting plates for the lights as well.  This added an additional 16 hours of 3D printing.  After having completed this portion of the project I am also more and more impressed with my Creality CR-10 S4 3D printer as well.  A real workhorse to make such nice parts for this project. 


Here are the two LED light mounting plates for the project.  The one on the right is still in primer and glazing putty and the one on the left has had all of the sanding completed along with a couple of nice coats of glossy red paint.  They will look great when both are completed and installed in the final assembly.



After the light housings had been 3D printed I decided that I should strengthen them by coating them inside and out with several layers of fiberglass.  The housings were only printed with a 20% infill (honeycomb webbing on the inside walls of the part) which kept the print time down to 35 hours.  If I had doubled the infill to 40% then the print time per housing would have doubled to 70 hours time per part.  Not something I really wanted to do.  So the fiberglass layers seemed like a smart choice.  

After the parts had cured overnight the housing now are strong enough to stand on.  Not that I would want to do that but it's nice to know that the strength is there just the same with very little additional weight gain.


Next the housings were coated with a layer of fiberglass resin and micro-balloons.  Micro-balloons are microscopic hollow glass balls which looks like a fine powder.  This is mixed with the fiberglass resin to form a thick putty.  This putty mixture is then spread on to the parts to fill the weave.  In the photo above the part on the right has the putty mixture on it just after it has been spread on.  After this putty has cured overnight it is sanded down to look like the part on the left.  A much smoother finish that is a good base to prep for primer and later paint.


Here you can see a big difference after one of the housing had been sanded smooth and painted with primer.  Not a hard task to do but it does take some time to get all of the flaws out that the primer shows in the part after it has been sprayed on. 



In order to get a perfect fit of the housing to the body of the dune buggy I first clamped one of the housing to the body just to see how close I was in designing the part.  From the photos above I am pretty happy with how it look and fits but I know it could be much better. 


I removed the housing from the dune buggy and covered the area where the housing will be mounted with a 3mil layer of plastic.  I then cut a hole for the housing so that it again could be re-clamped on to the body as before.


Here the housing is once again clamped into place.  The reason for the plastic covering the body is so that I can use my putty mixture once again to get a perfect mating surface created on to the housing that will match the dune buggy body shape and then be able to remove it without causing any damage to the body itself. 




In the photos above you can see the putty mixture has been spread on to the housing and plastic covered body where the two part meet.  This will give me a perfect copy of the body shape so that there will be no gaps between the body and the tail light housing once it has cured and been sanded smooth for paint. This will give me a perfect fit when I mount the housings once they have been smoothed and painted. 


I left the putty cure overnight and this morning I was able to remove the housing from the dune buggy with very little effort.  As you can see from the photo above it also left very little of the putty on the plastic as well. 


This is what the underside of the housing looked like once it had been removed from the dune buggy.  The micro-balloon and resin putty had fully hardened and actually tapers down toward the center of the part from the outer perimeter. 


I then used additional putty to finish this putty edge taper so that it feathers out thinner as it gets closer to the large opening in the center of the apart.  I will let this cure again overnight and then start sanding the part once again on the outside surfaces to get it as smooth as possible for painting. 

In this next week I hope to have the housings smoothed and painted and then I can begin final assembly of the tail lights for the dune buggy. I also tallied up all the hours that I 3D printed parts for this project including the housings for the front signal lights.  The grand total came up to 101 hours.  I'm very happy to have all of the parts turn out as well as they did so I can keep the project moving right along.  I'll make sure to let you know how it all turns out in my next post.  Good luck with your latest project!

No comments:

Post a Comment