Manufacturing of the lamp holder for rear lantern of Gazelle Trim Sport 1983

[Dr. Romano]

Hello!
I would like to share my experience in restoring plastic parts for vintage bicycles. I was unable to find these parts for sale. Plastic deteriorates greatly over time, even if you do not keep it in the direct sunlight. So, I think it is very difficult or even impossible to find these parts in good condition. I will start with a description of the production of the lamp holder for the rear light of the Gazelle Trim Sport 1983. It had cracks several years ago, small parts were broken off and lost. Recently, it finally broke into 3 parts, while driving. It is good that I noticed this and did not lose the glass.

1. Catastrophe!

Broken lampholder

IMG_4997.jpg (212.82 KiB) 1153 keer bekeken

I also would like to invite everyone to my Facebook pages, where there are other photo stories of restoring Gazelle bicycles.
https://www.facebook.com/profile.php?id ... tos_albums

[Dr. Romano]

I couldn't find such a lamp holder on sale. I also tried to order its production on a CNC milling machine. It turned out that the piece is too complicated, a very cool machine is needed. The Edison E10 thread caused particular difficulties. Also, most manufacturers immediately refused, having learned that only one piece needed to be delivered. They were ready to consider drawings if it was a question of producing a batch of 1000 pieces. It was also not possible to print the part on a 3D printer. The lamp holder turned out to be too fragile. It was also unclear how to make the thread. 3D printers cannot do this yet. It was also not possible to find a tap for E10. It was decided to try to cut the part out of a piece of polyamide. It is clear that this is labor, but only one part is needed. In addition, polyamide is even more elastic than even the original plastic. There is no chance that the part will crack - unless you keep it in the direct bright sun for 10 years 10. So, a piece of polyamide has been found, you can start sawing. At my work, in the workshop, the hacksaw blades are awful. They are not capable of cutting straight.

A large block of polyamide is sawn into small pieces.

IMG_2692.jpg (337.29 KiB) 1125 keer bekeken

[Dr. Romano]

The polyamide block is cut to size and roughly processed with a file. Now it can be marked according to the drawing. The block is intentionally made longer so that it can be held comfortably (e.g. in a vice).

Marked block of polyamide.

IMG_2694.jpg (194.96 KiB) 1109 keer bekeken

[Dr. Romano]

The holes are drilled. The hole on the left is for threads. The hole on the right will not have threads.

The holes are drilled.

IMG_2706.jpg (205.22 KiB) 1093 keer bekeken

[Dr. Romano]

The work continues at home. Longitudinal cuts are made with a small hacksaw with a 150 mm blade. Now the processing continues with surgical scalpels and a jeweler's jigsaw.

Longitudinal cuts

IMG_4926.JPG (195.46 KiB) 1078 keer bekeken

[Dr. Romano]

IMG_4927.JPG (236.78 KiB) 1071 keer bekeken

[Dr. Romano]

Upper portion is more or less ready.

Upper portion

IMG_4956.JPG (220.77 KiB) 1054 keer bekeken

[Dr. Romano]

Time to work on the lower portion.

Lower portion is marked

IMG_4957.JPG (235.72 KiB) 1048 keer bekeken

[Dr. Romano]

IMG_4963.JPG (249.97 KiB) 1043 keer bekeken

[Dr. Romano]

Lower portion is almost ready

IMG_4964.JPG (259.88 KiB) 1037 keer bekeken