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Focus now fully adjustable!

Air Raid

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It bothers the heck out me that the BB2 optics are so temperature-sensitive. At 70 degrees, the image is in focus. At 40, the focus is unacceptable. So, I revised the camera design to allow the lens focus to be optimized at any temperature.

Uses existing screw thread:
1736

Adapter added:
1737

Adapter has a female thread:
1738

Spanner wrench holes added to the lens assembly:
1739

The result is that the ridiculous limitations of Parrot's design can now be dealt with by adjusting the focus for the prevailing temperature. Razor sharp video in any conditions!:cool:
 

Attachments

  • body, spanner wrench.PDF
    70 KB · Views: 22
  • camera barrel.PDF
    63.8 KB · Views: 20
  • fisheye camera.PDF
    70 KB · Views: 19
  • lens receiver.PDF
    67.9 KB · Views: 20
  • MODIFICATION, LENS ASSY.PDF
    66 KB · Views: 21
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Reactions: IronSky1
Boy I could see someone making some money on this :) If I only had the needed tools to make this happen. Awesome job
 
The original modification description is in this thread: Findings regarding blurry images at low temp

I attached all the drawings. I hope they are useful.

Which parts did you have to make? In your article I beleive you said the threads are already in two lens components the other parts a easy to make. Putting the spaner hole can be done easily with a jig.

Very nice idea I want to create a few and see how they correct the focus issues which has always been a problem on BB2

Thanks Again
 
Which parts did you have to make? In your article I beleive you said the threads are already in two lens components the other parts a easy to make. Putting the spaner hole can be done easily with a jig.

Very nice idea I want to create a few and see how they correct the focus issues which has always been a problem on BB2

Thanks Again

The lens receiver is the only new custom part.

Here are some considerations:
My initial investigation shows that the axial adjustment of the lens has to be in the realm of microns. One one thousandth of an inch ( 25 microns) is significant. That means that the image plane has to be as parallel to the sensor as possible in order to get sharp focus throughout the image.

The end of the reworked camera barrel is a tilt reference, so it needs to be machined very parallel to the back of camera barrel, which I assume is very parallel with the sensor surface.

The rotational adjustment needs to be set within say 18 degrees. (That's 3 seconds on a 60 second clock dial.) The total range of meaningful rotational adjustment is no more than 30 degrees.
The diameter of the male screw thread is an oddball. It measures around M9.8 X 0.5.
The big chamfer of the lens receiver interfaces the o-ring. The lightly greased o-ring provides among other things, a controlled rotational resistance so the the focus can be easily set and then it doesn't move during flight. I wasn't sure how much o-ring compression I needed so I did some "cut-and-try" to get the size of the chamfer right.
 
Thanks for details. As a journyman Tool and Die maker in my past life not sure if this would be worth the effort unless users really want to pay 150-200 for machine parts. Sounds to me like Parrot dropped the ball here being that the one part is already threaded.

Respect your professional rework.

Very nice work though.
 
Thanks for details. As a journyman Tool and Die maker in my past life not sure if this would be worth the effort unless users really want to pay 150-200 for machine parts. Sounds to me like Parrot dropped the ball here being that the one part is already threaded.

Respect your professional rework.

Very nice work though.

Thanks. Yeah, it's all for fun. It would be too costly and complicated to try to commercialize this retrofit.

Parrot took shortcuts / made assumptions. You just don't do that in any serious product development. The BB1 camera system was much better.
 
Hello. I've looked at your drawing and what bits need making. The drawing are a good jod. I work 6 axis cnc machines. Making them would be easy. Is the build easy to do? Could knock the parts up over the week? What plastic? Was you thinking? Is there anything you would change like smaller pitch thread for focusing? Let me know? Could easy make some mods
 
Hello. I've looked at your drawing and what bits need making. The drawing are a good jod. I work 6 axis cnc machines. Making them would be easy. Is the build easy to do? Could knock the parts up over the week? What plastic? Was you thinking? Is there anything you would change like smaller pitch thread for focusing? Let me know? Could easy make some mods
Sorry for the delay. The plastic of choice is Delrin (acetal) of a dark color. Delrin is a really good machining plastic and is stable. If it is not dark, you should apply black paint to the end of the threaded adapter that faces the sensor.
You should cut back the camera barrel first, and then carefully measure the ID. Mine was a few thou out of round which made it easy to create a slight interference fit to the threaded adapter. Pay careful attention to how you fixture the camera. You want to get the end face of the camera barrel as parallel to the sensor as humanly possible. That said: no vice! Clamp it down to a horizontal plate. Also, cut a slug of clean, closed-cell foam to stick in the camera barrel to protect the sensor. I think I did a pretty good job of keeping the sensor clean, but I still went in with a swab and some alcohol, and gave it a careful wipe before I glued the adapter in place.

You'll need some 1mm X 3mm dowel pins for the spanner wrench. I got mine from McMaster-Carr. I found that a #60 drill created a nice, snug fit to the pins.

The o-ring is a -111 size. Mine happens to be Viton, but a standard Buna o-ring will work just fine. Again, McMaster-Carr. Remember to put a fine film of grease on the o-ring prior to assembly.

I chose JB-weld epoxy for assembly. Epoxy is not normally a good adhesive for hard plastic, but this particular one specifies plastic right on the pack. DO NOT USE CRAZY GLUE, SUPER GLUE, OR ANY OTHER INSTANT ADHESIVE! It will bloom, and permanently contaminate your optics!

To answer your question on thread pitch: I had no control over it, but yes, if I could, I would have gone finer.
No, in spite of my self-criticality, I can't think of anything I would change.

Please read my post from last Monday, the 8th.

-Lars
 
I like it! Always wondered why my image would go "unsharp" at various times.

Nice little weekend project for my lathe.....;)
 

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