The New "Standard Scanner"

[rob]

I hope you're going to be moving to a somewhat warmer place

Can I put on your queue a glass version of the platen?

--Rob

[sarcanon]

All joints were pin glued, routed, wet sanded and then polished with red and then white jewellers rouge.

Would you mind terribly going into a little more detail about this process? For instance, what is pin gluing?

In anticipation of building my platen, I purchased some 3/16" Lexan (clear polycarbonate) which I am fearing now to be too thin. So all the more important that I get as much stability at the joint as possible. My plan is to mitre the edges at a 45 degree angle to make a nice smooth join. I've read elsewhere that a plywood blade reverse-mounted on a table saw might work to make the cuts, provided I wet the blade to reduce heat and splintering. I've got more Lexan than I need so I will be able to make a few practice cuts first.

Do you think this hare-brained scheme has any chances of success?

Thanks.

[Mathue]

Would you mind terribly going into a little more detail about this process? For instance, what is pin gluing?

Pin glueing is a glueing technique done by inserting pins in between the two surfaces you're joining. The reason for doing this is due to the glue itself actually preventing the thorough 'wetting' the entire seam. Long wide seams need to be well flooded with glue to make a full bubble free bond.

http://www.reefcentral.com/forums/showt ... p?t=169326

In anticipation of building my platen, I purchased some 3/16" Lexan (clear polycarbonate) which I am fearing now to be too thin. So all the more important that I get as much stability at the joint as possible.

3/16 would be the bare minimum if you were using a hinge on the platen, the 'slide design' I fear will put it under too much pressure.

One thing I'd like to add is that Polycarbonate's main asset is it's resistance to shattering, it's actually more flexible than Acrylic at the same thickness. It also scratches more easily and doesn't transmit light as well.

My plan is to mitre the edges at a 45 degree angle to make a nice smooth join. I've read elsewhere that a plywood blade reverse-mounted on a table saw might work to make the cuts, provided I wet the blade to reduce heat and splintering. I've got more Lexan than I need so I will be able to make a few practice cuts first.

Do you think this hare-brained scheme has any chances of success?
Thanks.

To mitre 3/16 poly on your table saw you're going to need to create some sort of fixture to clamp it TIGHTLY and fully support it along it's length as you feed it through. The last time our main fabricator did a 45°, the glued seam on acrylic was not visually very good. A simple butt joint works better.

Note my next post, I did a demo of 3/16 Bayer Makrolon Polycarbonate sheet. Look at the very end three images.

I don't expect any splintering from poly, and you'd have to go mighty slow to worry much from heat. Poly starts to change states at 280 F° or so.

So in closing, I'd certainly try it out, I'd be interested in seeing how it works. My experience however would indicate you're not likely to like the final results.

[Mathue]

Here are some images of where I am at with my iteration of the Standard Scanner.
Sorry about the quality, I over compressed the files since I was in too much of a hurry

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Pulley system for the platen counterweight.

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Note the edge glueing clarity.

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Very clear bond.

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The next three shots are of Polycarbonate that has been butt glued for Sarcanon who's purchased 3/16" stock. Polycarb doesn't glue very well, given time the glue bond will start to cloud as well.

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[oldmancoyote1]

Mathue:

That's craftsman-like work.

[daniel_reetz]

Mathue: Wow. Beautifully done. I am really impressed with how far you've taken this.

Rob: Yes, I'll try to make a glass platen. But remember, I no longer have my Standard around to test it on. Should be interesting!

(I'll tell you the moment I know if I'm moving for sure -- the last week has been an insane run of details and damage control, all for something that might not happen)

[Mathue]

Mathue:

That's craftsman-like work.

Thanks oldmancoyote!

[Mathue]

Mathue: Wow. Beautifully done. I am really impressed with how far you've taken this.

Many thanks Mr. Reetz!

I'll add some new images once it's completed and it has the cameras, lights and 'reetz switch/handle' mounted.

(I'll tell you the moment I know if I'm moving for sure -- the last week has been an insane run of details and damage control, all for something that might not happen)

Yipes, I hope this week is better for you.

[Mathue]

New image!

I worked below the scanner this afternoon. The idea was to reduce clutter and avoid a morass of wires everywhere. Using some leftover wood I glued in a small shelf in the base to attach wires and powerpacks to.

The rubber bands are temporary, they will be properly tied up later.

We also had a successful test of the cameras today once we got past the fussy software.

I still need to redo the camera mounts as they didn't turn out as I would like. I am also still trying to figure out the best way to do the counterweight. Currently it is a cheapo 5lb cast iron weight bought at the local sporting goods store. While it does work, it's rather inelegant looking.

[JonEP]

Dan and Mathue,

Those scanners are incredible! I'm excited to make one, and think I will try to use your 'new standard' approach. Sorry to clutter this forum thread, but I wanted to ask a quick question before I start buying materials. Basically, I notice that as you post images, progress reports, etc., you are getting comments and then noting where modifications need to be made. I'm assuming then that the original parts lists and measurements you provide in the earlier posts are superseded by the revisions, and that they are not being backwards-edited to reflect the new 'new standard.' I think Dan mentioned that in the future you would be posting a new instructable or something of that sort? Is that right? If so, for those of us hoping to learn from your efforts, perhaps it makes sense to wait for that, rather than to try to recreate all of the ups and downs working from the initially posted plans and parts lists and then trying to modify them as you acknowledge revisions, yes?

Thanks, I know this is a bit of an obtuse posting here, but just wanted to let you know, too, that your efforts are appreciated and we're looking forward to diving in....

Jon