Home > Projector > Ever have a D’oh! D’oh! D’oh! moment?

Ever have a D’oh! D’oh! D’oh! moment?

September 26th, 2011

D’oh! Moments happen. I had one last night. I had prepped everything for the VAT tilt ( see Sept. posts ) and decided, that I should have the projector image size problem taken care of before I attempt to mount the assembly on the frame. I meticulously started to disassemble the projector and got to the bottom plastic, removed the light tunnel and D’oh! I found the way of taking off the lens assembly and adjusting for focus was not the one I thought it was. It Was A Lot Simpler ( 5 screws and 3 bolts). See below:

A little twist on the lens protector and it comes off.

Uuuuu Aaaaaa! Never mind the feet-once you take the cover off and protector there are only 2 screws ( and 2 clips ) holding the front panel.

And there it is! only 3 screws hold the lens to the light tunnel. I had it completely torn down just to discover this.

The projector ( a Dell 5100MP ) is extremely easy to adjust for focal distance. All I need now is a 22mm high x 70.5mm ring to use as a spacer and I have a perfect 60mmX80mm picture with no aberration and no distortion.

I also removed the focus ring limiting screw ( not the focal distance limiting ). To do that, you have to line up the slot with the window in the focal distance ring and then line up the focus limiting screw. Now I can move the Lens assembly in and out of the light tunnel to adjust the size of the image, move the focal distance ring and focus the image more freely.  See below:

Hope all is going to plan on your build and I wish you to have less D’oh! moments.

 

P.S.  As ChrisO’s comments  defined the procedure:

1) Flip the projector upside down
2) There are 6 screws: 1 in each corner, one in the middle back, and one in the center. Some of the holes are pretty deep, and all the screws are phillips head.
3) Three of the plugs on the back have standoffs for screwing the connectors to the projector. I removed all of these.
4) Flip the projector right side up.
5) Gently remove the top. It is connected to the main board by a ribboon cable so be careful.
6) Take off the lens cap. now hold the focus ring and twist it so that it goes back towards the projector body. If you apply a little extra torque at the end it will pop off easily.
7) To remove the front plate, there are 2 screws (silver colored) near the bottom to take out. You should be able to unclip the plate and take it off easily after that.

8) Once the front plate is off, remove the zoom tab lever thing. This is the tab that sticks out of the slot above the lens when the projector is fully together. It’s just 2 little silver colored screws that are positioned with their axes radial to the lens assembly. Then you can slip the tab thing out. For this step and the following steps you’ll need a small philips screw driver, like a jewelers screw driver.

9) The lens assembly is attached to the light tube with 3 black screws. They are on an outer flange and their axes are parallel to to the lens assembly center axis. They aren’t evenly spaced around the lens; two are near the top and one is to the left.
10) The lens assembly should pull straight out easily.
11) You might have noticed the flange that held the 3 little black screws has a notch that is about 1/3 of the circumference. Set the lens assembly on the table so that notch is facing upwards.
12) Now twist the zoom so that it s almost all the way extended. There is a small, U-shaped notch in the black ring just in front of the flange with the big notch. The zoom limit screw is about a 1/4″ from the end of its travel on miune and the U-notch is pretty much centered in the big notch on the flange.
13) Twist the zoom and you should see a tiny silver screw head pass by under the U-shaped notch. That is the limit screw you want to remove. It was difcult for me to get out so I had someon hold the lens assembly for me. Then I held the jewelers screw driver down in the screw firmly with one hand and used a pair of pliers to torque the screw driver. After a few turns the screw was loose enough for me to lose the pliers and just use the screw driver.
14) … The next step is to lock the focal distance (I think that’s the correct term?).

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  1. ChrisO
    February 18th, 2012 at 21:29 | #1

    Hey Peter,

    I’m attempting to disassemble an identical projector right now and I ‘m having issues with trying to remove the top =). I had the projector lying upside down on its top and I took out 4 little philips bolts in the corners and one more in the middle near the back. I also removed the 3 feet (2 back and one front) by unscrewing the single screw in the middle of each. Then I flipped it over and tried to pull off the top, but it is still clipped or bolted in the middle back and I don’t want to break it. It feels like it is held right under the controller pad (black area on the top). Can you help me out please?

    • Printer
      February 19th, 2012 at 16:41 | #2

      Hi ChrisO,
      There is a maintenance manual somewhere on the web, but you need to unscrew ( can’t remember if it was only the DVI or also the VGA in ) connector bolts to release the top cover.
      Hope it helps.

  2. ChrisO
    February 19th, 2012 at 19:29 | #3

    @Printer

    That helps =). Also I overlooked a screw near the center on the bottom. Here are the steps I have so far:

    1) Flip the projector upside down
    2) There are 6 screws: 1 in each corner, one in the middle back, and one in the center. Some of the holes are pretty deep, and all the screws are phillips head.
    3) Three of the plugs on the back have standoffs for screwing the connectors to the projector. I removed all of these.
    4) Flip the projector right side up.
    5) Gently remove the top. It is connected to the main board by a ribboon cable so be careful.
    6) Take off the lens cap. now hold the focus ring and twist it so that it goes back towards the projector body. If you apply a little extra torque at the end it will pop off easily.
    7) To remove the front plate, there are 2 screws (silver colored) near the bottom to take out. You should be able to unclip the plate and take it off easily after that.

    8)… I haven’t done the actual removing of the lens assembly yet =) …

  3. ChrisO
    February 20th, 2012 at 03:34 | #4

    @ChrisO

    Continued…

    It is very useful to look at the pictures and instructions in the post when doing this part. I just try to elaborate on the instructions Peter has posted…

    8) Once the front plate is off, remove the zoom tab lever thing. This is the tab that sticks out of the slot above the lens when the projector is fully together. It’s just 2 little silver colored screws that are positioned with their axes radial to the lens assembly. Then you can slip the tab thing out. For this step and the following steps you’ll need a small philips screw driver, like a jewelers screw driver.
    9) The lens assembly is attached to the light tube with 3 black screws. They are on an outer flange and their axes are parallel to to the lens assembly center axis. They aren’t evenly spaced around the lens; two are near the top and one is to the left.
    10) The lens assembly should pull straight out easily.
    11) You might have noticed the flange that held the 3 little black screws has a notch that is about 1/3 of the circumference. Set the lens assembly on the table so that notch is facing upwards.
    12) Now twist the zoom so that it s almost all the way extended. There is a small, U-shaped notch in the black ring just in front of the flange with the big notch. The zoom limit screw is about a 1/4″ from the end of its travel on miune and the U-notch is pretty much centered in the big notch on the flange.
    13) Twist the zoom and you should see a tiny silver screw head pass by under the U-shaped notch. That is the limit screw you want to remove. It was difcult for me to get out so I had someon hold the lens assembly for me. Then I held the jewelers screw driver down in the screw firmly with one hand and used a pair of pliers to torque the screw driver. After a few turns the screw was loose enough for me to lose the pliers and just use the screw driver.
    14) … The next step is to lock the focal distance (I think that’s the correct term?). Looks like that adventure begins in the post after this. See you there!

  4. ChrisO
    February 20th, 2012 at 03:41 | #5

    @ChrisO

    Btw, apparently “8)” = 8)

  5. JoeP
    March 17th, 2012 at 22:03 | #6

    Hi Peter,

    Very nice documentation on your build. Thanks! I bought a Dell MP5100 off ebay and am modifying it per your instructions. I did not see any mention of removing the color wheel. Did you leave it there or remove it?

    Thanks!
    Joe

    • Printer
      March 18th, 2012 at 17:54 | #7

      Hi Joe, I have NOT removed the color wheel. If it works with it in place, why bother? Later I can try resins with other wavelengths.
      BTW: There is a complete procedure update (from ChrisO’s comments) here HERE

  6. October 28th, 2012 at 20:18 | #8

    Hi Peter,
    First of all massive amount of helpful info on your site so a huge thanks for sharing! Let me give you a short background story how i got here and why am i asking for your help: got pretty disappointed after Juniors crowdfunding campaign finished unsuccesfully because i wanted to buy the plans so i can start building my dream 3D printer. Anyway i was waiting patiently but no news since that so decided i will not wait longer but start to build it on my own. After digging a little deeper i found your documentation and that was the moment a felt ‘action time’! So went through all your posts, all the comments and started to hunt down the same components that you used. Frame is ready and managed to buy the same dell projector that you have. The projector is mounted to the frame and i modified the lens assembly(installed a 15mm tall pvc spacer ring) but i’d like to have a slightly bigger building area (something like 120mmX90)-right now i have a nicely focused 70mmX55mm image. Could be that the solution is using a shorter spacer ring, like 7 mm? Thanks for your help in advance, sorry for the long bla-bla but i am kind of stucked at my building…cheers, Martin

    • Printer
      October 29th, 2012 at 20:39 | #9

      Hi Martin,
      I got disappointed with JR from the point when I saved some blogposts and they disappeared off the face of the earth. Good thing I had them off-line. I started following his work back in 2010. I was not happy to see the campaign fail, but there was no development for over a year before it. I joined the Yahoo Group “diy_3d_printing_and_fabrication” back in April 2011 and you should too for the info that it contains. The longest wait time was actually the transport. The frame takes less than an hour to put together. The Z axis is 30 min job. The projector mod was done in a couple of hours ( partly due to having to experiment with the projector and having no service manual ), but it worked perfectly in the end. You are in the right direction: the build area you can enlarge by reducing the thickness of the ring or by using shorter spacers.
      You might even be able to do it without any internal mods, only a lens in front of the projector will do.
      If you have other Q’s let me or the group know and we will help with whatever we can.

      Cheers!
      Peter

  7. October 29th, 2012 at 23:14 | #10

    Hi Peter,
    thanks a lot for the fast reply and help! Found the yahoo group as well and my membership request was accepted last week :) so thinking of starting a topic about my building process as well. Thanks for encouraging me to ask i will try to avoid asking 100 times answered questions and read before asking but i am not that experienced in stepper motor drivers so i will might need some help on that. I have already cut some thinner rings and i will test them tomorrow and let you know how it went…thanks again, really appreciate it!!
    Cheers,
    Martin

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