agp.cooperLaser Cut MPRT
The irony that I am building Daren's design and Daren is build my design has not escaped me!
I have got back the laser cut original MPRT:
Now the fit is not overly tight (the laser cut width varies from top to bottom is more that the assumed 0.1 mm width. However the movement is less than a degree.
Here is a closeup of the gear fit:
Now your can't expect better than that! It does move, perhaps 0.5 of a mm.
When I sent the design off to be cut I had not resolved what to do with the protruding star bolt heads. I should have just cut a hole in the retaining cover. But today I will just drill out or counter sink the bolt heads in the star gear.
The Result
My gear cover need work and the star gear is off-centre. Not sure why, changed the hub and still off-centre. May be a design fault or bad alignment or problem with the laser cut (it is not that accurate even visually).
But I did get it working, sound like it is grinding sand. Wobbles a lot and sometimes stops for a moment and then restarts.
I have uploaded a video into the files area.
The result is it need more work.
Review
I pulled the gear box apart this morning. The axle and hub are true. There is a slant to the cut on the sun gear. This is a problem I have had before with this laser cutter service but I had not had to rely on the edge so it is was not important then. Gluing the gears together make the problem worse. I tried measuring the slant and it is at least 2 degrees:
May not sound a lot but it is too much for a gear box.
If I pursue the laser cut gearbox, I will have to find another laser cutting service and there has been for a long time only one that is "retail".
AlanX
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Projects in my mind need to have an "end game". My Dalek project just wore me down with problem after problem. Having said that the concept of a "use" for an idea is a major "innovation" in my mind.
Anyway, I do have another design I want to explore but I need to find another laser cutter service. These gears to too small to cut with my CNC machine. If I want to cut something like this with my CNC I have to design "pin" gears. The end-drill being the diameter of the pin. I have a load of pins waiting to be put to use (a clock project that never left the drawing board). Sound like another fork!
Did you look at the video? It is noisy and wobbles around. What a disaster! The only saving grace was that the backlash was less than a degree.
AlanX
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I had chosen not to comment on it. I appreciate the sheer effort involved to get to that point, but the result was less than stellar I have to say. There is nowhere to hide when you include the audio in your post. :)
I'm pretty sure you just have some issues with distortion of your sun gear though, so it may be a relatively easy fix. <EDIT> Reading your actual post instead of just watching/listening to the video, it seems that is the issue </EDIT>
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The fact I moved ahead with your idea, and you stayed behind to finish up mine, is not lost on me either. :) Ooo look, shiny thing...
I do appreciate the knowledge base and sheer will/effort that you have brought to this project. Bringing an idea into the physical world is very not straightforward. Thank you.
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