grins 8th annual old lumens machine made entry

I love what you do grin. :slight_smile:

Awesome work, great job!
It looks fairly easy, but i know it isnt

Thanks, anyome can do this if they are determined enough. But it is pretty exciting being able to make custom one off reflectors. I have also been thinking of ways to manufacture parabolic mirrors to make them more available to people with smaller budgets. Soon I may have the space to setup a dedicated workshop to do it.

Wow! What a marathon polishing session. :+1: :beer:

i thought the use of a plastic template was a brilliant idea. How did it survive all the sanding operations?

Impressive. Took as much time to polish as I spent cleaning out my garage (though I spread that across a week)

So true Agro. Could not have said it better. :beer:

The first one I ran into the job a few times which caused the damage to it. The second one didnt wear at all. The profile doesnt actually touch the mirror it is just to push the paper onto the job. Once the tension on the paper is even as it moves between the profile and mirror it is time to move to the next grit.

So the primary mirror is just about done so I will leave it at that for the time being. Next I turned the billet around and cut a bit Of material for the drum and bezel.

The light comes through the vertex of the primary and there needs to be something to condense the light for the secondary hyperboloid. A lens would work but I have chosen to use a 50mm hemispherical reflector because I have a bit of practice cutting them and I cant grind a lens. Yet. :smiley: a few pics will explain how I do it except handle sanding 8t with 1500 and 2000grit.




I cut the chatter marks out turning the lathe by hand and end up with this.

And ready for final polish.

That’s a beauty.

i have a cutter bit like that with one side ground down so it’s not trying to cut both sides at the same time. That is a huge contact surface to cut, but it sure turned out great with all your pro tricks.

That chatter reminds me of the reflector surface in a Convoy, like they put some chatter marks in the reflector mold that shows up in the plastic part.

Nice. :beer:
More black fingers to come.

If you ever need a job as a Machinist, let me know :sunglasses:

Great project and very inspiring, I sent you a PM.

Zandar

Little bit of progress drum is made the billet for led heatsink driver/battery compartment is threaded


:open_mouth: Wow!!

Yes to this. :beer:

I love your vision and determination grin! :beer:

I hope you get time to finish this grin. I’m lovin’ what you’ve come up with so far. Even if you don’t finish in time please finish it eventually :slight_smile:

I will be back on it this week, everything I have ordered is here. Today I should have the hyperbola profile for the secondary ground. I have made the new profiles from 45mmx8mm high speed steel and they work very well. My lathe doesnt have enough power so I turn the chuck by hand with a 15inch shifting spanner.


I have 5000 7000 and 10000 grit wet and dry sand paper to finish them before polish.

After a major setback I have had some progress. This I how I make the profiles.
First I plot the curve on graph paperand epoxy it to the HSS blank with high temperature urethane.

Clean up

Honed with a diamond steel