New DIYLabs Fresnel

[sadd3j]

As of today.. since I was checkin DIYlabs.org for whatever reason, the news page says that Alan has added another 12.2" x 12.2" double fresnel which has FL 13" on one side and 8.8" on the other. This sounds a lot like what could be used for split fresnels on OHPs.

http://people.eecs.ku.edu/~astaples/projector/lensinfo_fresnel12.2x12.2.htm

I have a question for those of you who've split fresnels (cruser, proto, gui_999 and whoever else) especially on the Elmo a305. Since you're putting the top fresnel a couple inches up.. I read in one of the older threads that you also have to raise the projection lens? How are you accomplishing this with the A305? Since the arm is fixed at a certain height.. 😕

TIA,
rep

 

[gui_999]

Well I didn't raise my projection lens and it worked. I think it's proto5 that had to raise it.

I just tryed it without raising it and it worked. But if you want or need to raise the projection lens, the way I would do it is to unscrew the projection lens from the arm. Then put something like a 1" or 2" wood piece on the top of the arm and glue it on. Then screw the projection lens on the wood piece.


______
|_____|_ <--- Wood piece, with projection lens screw on it
|_______| <--- The ohp arm with the wood piece glued on it
|-|
|-|
|-|
|-|
|-|___________
|-------------------|
|-------------------|
|-------------------|
|________________|

 

[sadd3j]

Hey gui,

Did you manage to get a camera yet?? Still waiting for those photos you promised in your "success" thread!

I guess I'll take things a step at a time, try without splitting etc, play around with it etc.

Hmm, noone has an opinion on the fresnel at DIYlabs? It sounds an awful lot like the Elmo fresnel at 12.2x12.2 and focal lengths at ~8.8 and ~13". I would love to pick one of these up and split it cause I'm iffy on splitting my -only- fresnel. I'm planning on getting the 250mw ballast / bulb from Alan to serve as a "base" system so might just add this fresnel in if it looks like it'll serve the purpose.

Now I just have to find someone with a dremel

 

[Psionic]

I read in one of the older threads that you also have to raise the projection lens? How are you accomplishing this with the A305? Since the arm is fixed at a certain height.. 😕

Arm is fixed at a certain height??
Dude, you gotta be kidding me!
Just detach the lens and mount it with something else
Use some enginuity!

 

[Psionic]

I've got a dremel

You can drive down to Fenwick from Guelph if you like 🙂

 

[ace3000_1]

hehehe psionic i got one too, as they say a dremal is all u need lol i cant live life without mine now, as for the lens needing to be higher that would depend on your throw distance i can imagine
from the screen.

trev

 

[gui_999]

Someone is supose to come tomorow to take some pics of my setup!

 

[mhelin]

Could someone take photos on splitting the fresnel, with the tools to do the job etc.?

 

[snootch]

I would be interested in seeing that, I would hate to bust a brand new fresnel by a spliitng attempt the wrong way.

 

[cruser]

Could someone take photos on splitting the fresnel, with the tools to do the job etc.?

heres the way i did it i tryed the dremel and it does work but the razor sharp edge you get from a router is "the catz ***"

 

[cruser]

next

 

[cruser]

and the razor sharp edges 🙂