A new scanner design using plastic tubing

[fadedsoulz]

Thanks for all of the help so far David! Do you have any suggestions on an alternative way to connect the platen to the base structure? I've been trying to find a metal T connector, but the ones at my local hardware store were way too big (6 inches). Could you also clarify how the platen is supposed to be attached? In addition, do you have any suggestions for the dimensions of cradle and base? Also, what type of drawer runners did you use?

[PossumPete]

I've been trying to find a metal T connector, but the ones at my local hardware store were way too big (6 inches).

Have you looked at Home Depot or Lowes?
3 inchers should be very easy to find.

Stanley-National Hardware 2-Pack 3-in x 3-in Zinc-Plated T Plate Brackets.
http://www.lowes.com/pd_315655-1277-DPB ... facetInfo=

[fadedsoulz]

I've been trying to find a metal T connector, but the ones at my local hardware store were way too big (6 inches).

Have you looked at Home Depot or Lowes?
3 inchers should be very easy to find.

Stanley-National Hardware 2-Pack 3-in x 3-in Zinc-Plated T Plate Brackets.
http://www.lowes.com/pd_315655-1277-DPB ... facetInfo=

Thanks Pete! I will try to visit Lowes. The last time I went, my local Home Depot only had the 6 inch ones, which would have been way too big for our purposes and would cover up the platen.

[davidlandin]

I don't see why an L shaped piece wouldn't work, if they are more readily available. The T shape isn't really essential.

David

[davidlandin]

Do you have any suggestions on an alternative way to connect the platen to the base structure? I've been trying to find a metal T connector, but the ones at my local hardware store were way too big (6 inches). Could you also clarify how the platen is supposed to be attached?

Here are a couple of pictures - Ihope they help. Sorry one is a bit out of focus

T shape screwed to platen

T attached to platen.jpg (16.66 KiB) Viewed 8503 times

T attachment.jpg (122.41 KiB) Viewed 8503 times

As I said in another note, if you can't find T shaped connectors, you could use L shaped connectors (corner mending plates) like this

Corner mending plate

corner mending plate.jpg (14.47 KiB) Viewed 8503 times

In addition, do you have any suggestions for the dimensions of cradle and base?

The sides of my cradle are each 40 cm x 22 cm, and the base board measures 40 cm front to back and 46 cm wide

Also, what type of drawer runners did you use?

I found these ones on eBay

Drawer runners

drawer runners.jpg (64.56 KiB) Viewed 8503 times

Hope this helps you. Please don't hesitate to ask any more questions you may have.

David

[mnesnay]

Hi,

Love your design. I was checking out other designs on this site and was trying to see which was the best way to go. Your invention seems to solve a lot of the issues I would have. We are trying to start scanning in a few weeks and your assembly seems like this machine could be made in a weekend. So I was wondering, if I wanted to scan books larger than 11x14":

I simply take my width and use the formula you mentioned? So, for instance, to have the final size of the platen be 14 x 18 (to fit a book a little larger than 12x16) I would take the width (14) and ---- 14x14 + 14x14 = 392 sq rt = 19.8 + 1 inch for the T hangers. That would make the inside of the supporting frame and the back of the counter balance frame 20.8 inches?

Then, based off of how tall the platen's center is, that gives me the height for the bottom part of the base below the pivot bar? After that I would add 1 inch for the bottom board which is on rollers, add another inch for the pivot bar, and lastly add 4 or more inches to the top bar above the pivot? I am trying to figure out the measurements according to your previous posts and diagrams so I can get supplies.

Thanks for any help.

[dtic]

David, Have you tried the cradle without the drawer runners and if so what was the disadvantage? I'm thinking tha at a flat wooden base could slide right/left into position by itself when the platen is pressed down.

[davidlandin]

Hi, Love your design. I was checking out other designs on this site and was trying to see which was the best way to go. Your invention seems to solve a lot of the issues I would have. We are trying to start scanning in a few weeks and your assembly seems like this machine could be made in a weekend. So I was wondering, if I wanted to scan books larger than 11x14":

I simply take my width and use the formula you mentioned? So, for instance, to have the final size of the platen be 14 x 18 (to fit a book a little larger than 12x16) I would take the width (14) and ---- 14x14 + 14x14 = 392 sq rt = 19.8 + 1 inch for the T hangers. That would make the inside of the supporting frame and the back of the counter balance frame 20.8 inches?

Then, based off of how tall the platen's center is, that gives me the height for the bottom part of the base below the pivot bar? After that I would add 1 inch for the bottom board which is on rollers, add another inch for the pivot bar, and lastly add 4 or more inches to the top bar above the pivot?

Thanks for your nice comments!

The figures you have given look about right. You definitely want to work from the size of the platen to the size of the overall structure. One easy way to work out the upper width of the V shape of the platen is this. Get four sheets of regular office sized paper, and stick them together using tape to form a much larger sheet. Next, starting at one corner of the paper mark a length equal to the short side of your platen, in your case 14 inches. Mark the edge of the paper 14 inches from the corner. Repeat the exercise working from the same corner, but along the adjacent side. Mark it again. Now draw a ruled line from the first mark to the second mark to make a triangular shape. Measure the length of this long diagonal line. In your case it will be, as you correctly calculated 19.8 inches. (using Pythagorus' Theorem - I knew that school geometry would be useful one day !) If you then cut across the diagonal using scissors, the triangle will show the crossection of your platen when finished.

If you are in doubt about the lengths of each part, err a little on the large side - you can always cut off a bit more tubing to make it fit! Also fit the whole structure together BEFORE you glue, as the glue is quickly permanent. Don't forget when gluing - DON'T glue the 2 tubes that join the upper part of the structure to the base part - just slot them in to the two Ts at the back. That way the top part can be removed and packed reasonbly flat for carrying the scanner around.

Hope this helps

David

[davidlandin]

David, Have you tried the cradle without the drawer runners and if so what was the disadvantage? I'm thinking tha at a flat wooden base could slide right/left into position by itself when the platen is pressed down.

I think that although the base board might slide a bit without the drawer runners, the more weight you apply, i.e. the heavier the book, the more friction there will be between the base board and the table. These runners are cheap and really work almost automatically as you work your way scanning through the book, adjusting the position of the baseboard, cradle and and book to the left or right with the lightest touch. So I would get them if you can.

I did find with my drawer runners that they needed to be loosened up a bit using WD40 to lubricate them, and slightly loosening them so that they run completely freely when they are tipped. I got them running freely before sticking them to the base board.

David

[davidlandin]

So I was wondering, if I wanted to scan books larger than 11x14"?

I forgot to mention - did you see the very large scanner that another team has made, using this model, which you can see described on this site here

http://diybookscanner.org/forum/viewtop ... =14&t=2976

It's very impressive, and they will use it to scan historical archives of old newspapers and ledgers.

David