80/20 Large Format Build

[icepick method]

Taking inspiration from http://bookliberator.org/doku.php and translucent1's sexy 80/20 build. So far all i have is a 19x23" box of 1.5" extrudes held together with 80/20's tri-corner pieces . It's going to have a 16x20" scanning area for large format books.

I originally had all kinds of elaborate ideas for a lifting mechanism for this glass and metal box with cameras and lights all over it, but the other day on slickdeals i saw a cheap $20 bike hoist and realized it'd be perfect. After looking at all the different ones on amazon today i picked out this one http://www.amazon.com/RAD-Cycle-Product ... pd_cp_hi_3 , it was only $28, and of course as soon is i went to check out it popped up OOS. hopefully they get more in. Combine the bike hoist and a cheap handcranked winch or even a cheapo powered winch, and my platen will be airborne.

For attaching the glass 80/20 sells a panel gasket to hold glass into the t-slots of their extrudes. I'm getting all my 80/20 products from their scratch&dent store on ebay, http://stores.ebay.com/8020incgaragesale.

For the actual glass i was looking at Tru Vue AR Museum framing glass from http://www.mmdistributors.com/Tru-Vue-A ... 0glass.htm. $38 for a box of 3 16x20". i'd have to trim my framing a little, but i'd rather do that than cut glass. Unfortunately that distributor has a minimum order of $50 and i'm still not sure they'll deliver to me. May have to ask around at framing shops for glass.
I'm also curious what a good thickness is for scanning glass. The tru vue is 2.5 mm (.09"), the panel gaskets are made for .188" panels, i may have to double up on the gaskets.

For the base and cradle i'm going to do basically the same setup as translucent1, 80/20 rails with UHMWPE u-channel and bearing pads.

One thing i'm not sure about with the bike hoist though is swing. would i need to put vertical rails on the sides of the base to guide it up and down to the same spot every time or would it be ok free? For safety's sake i'd probably put something around it. Then i have to think about blackout fabric around the whole thing and if side guiderails would get in the way. This is going to get really expensive if i end up building a giant railed box for my giant metal AR glass camera and light covered box to ride up and down inside of.

[icepick method]

Here's where i am so far. This is my first foray into building anything out of wood and even cutting a straight 45 degree angle has proved challenging. Whoever mentioned that MDF splits if you don't pre-drill all the holes was right. The "static" side of the cradle will be held in place with metal dowel pins instead of screws in case i decide to change things. Next is countersinking the plastic u-channel and screwing it to the base of the cradle, hanging the bike hoist and doing a dry run minus the glass (found tru-vue at a local art shop), and testing the hand winch i picked up at HF http://www.harborfreight.com/2000-lb-ca ... -5798.html and possibly make an adapter to power the winch with a powerdrill. my plan was to set the speed on the drill, plug it into a cheap footpedal switch and just reverse the drill to lower.

I've hardly even thought about camera mounts yet. i have no clue if mounting directly to the cube will be too close or not.

[daniel_reetz]

Are those plastic bearings in your extrusion? Do they work well?

[icepick method]

Yea, the four main ones are the same u-channel like translucent1 used on the bottom of his, the one on the far right is the kind 80/20 sell. I was planning on using the second kind for the slide motion of the right side cradle along with a flat 3"x.75 piece of extrude http://www.ebay.com/itm/370569145658 like that, along with one of their bearing brake kits to lock it in place. Donno of i'm still going to do that our not yet, the threaded rod pinch design seems so much simpler.

As for how they work, I haven't really put them under load yet and I think I read there's a break in period while they mate with the rail. I sure as hell wouldn't build a router out of them though like I've seen some people try.

[icepick method]

First assembly of the big pieces.


The motion up and down is kinda jerky. The bike hoist has a lock that functions like venetian blinds and the front/back don't go up quite evenly. The whole thing swings a bit as well. Maybe bungees will even it out. going to have to figure out where to go from here.

If i put it in a box with rails i'd probably change to a lift arm similar to Daniel's or the type i've seen on diy vacuformers like this one

[jcarol]

I'm curious about why there is only one 45 degree brace? Also do you find that the tri-corner connectors make a strong enough joint? They are awfully pricey.

Last question -- is the 15 series material really necessary or would the 10 profile be sturdy enough?

[icepick method]

I'm curious about why there is only one 45 degree brace? Also do you find that the tri-corner connectors make a strong enough joint? They are awfully pricey.

Last question -- is the 15 series material really necessary or would the 10 profile be sturdy enough?

Only one 45 brace because i didn't know if i'd need it or not.

The tri-corner connectors are rock solid, aside from like .5mm swivel if you try to twist the extrude screwed to it, "These pieces were removed from production because one of the alignment tabs is slightly out of tolerance." Got em for half price. Mostly for aesthetic reasons.

The 15 series weighs a ton i found out! I even got the hollow light version and it's still heavy.

Found more useful stuff about the lift arm,
http://www.tk560.com/phpBB2/viewtopic.p ... c585fefafb
And this sweet pneumatic lift system. (not doing this!)


I just moved last month so everything got put on hold. Back at it now, slowly. Instead of spending $4 each on these aluminum pivot arms 80/20 sells,
http://www.ebay.com/itm/80-20-Inc-T-Slo ... 3377e70ea5
i bought 2, and some aluminum plate to cnc my own. I bought a turnkey cnc Taig last year and need to teach myself how to use it, what better way than a simple 2D cutout. They've already got the cad files of them online, i just needed to teach myself how to use a cam program and do the toolpaths. I found out the other night just how easily 6061 aluminum gums up while boring the 3 holes in the first pivot arm. I need to work on chip removal.

I also need to figure out some odd (22 degree?) bracket to attach to the sides so it can ride up and down. Funny thing happens when you cut a square corner to corner, the new surface is longer than the others!
Can't exactly plan ahead when i have no frame of reference. Just making this up as i go along.

[icepick method]

Progress so far. All the pivot locations are completely movable so i can find the best leverage.
Is there an easy math formula for something like this?