Lever Actuated Platens

Built a scanner? Started to build a scanner? Record your progress here. Doesn't need to be a whole scanner - triggers and other parts are fine. Commercial scanners are fine too.

Moderator: peterZ

Joe Reeser

Re: Lever Actuated Platens

Post by Joe Reeser »

I did a little revamp on the spring assist. I changed the spring to one that is longer and bigger around. Here's the difference in the two springs:

Image

Now that everyone is thrilled with that here is the spring assembly with the platen up:

Image

Here is the assembly with the platen lowered:

Image

And here is the spring assembly holding up the platen. If one were to accidentally let go of the lever the platen would drop about 1-1/4" and then stop because of the spring tension. If your hand slips off the lever while lowering the platen below this point, the platen simply stops moving. The spring will stop the downward movement but is not powerful enough to raise the platen on its own.

Image

I like the looks of the single spring much better and it works just as well. With the larger spring, a slight push on the lever is required to set the platen all the way down. As noted above, the platen will not lower by itself with either spring assembly.
User avatar
daniel_reetz
Posts: 2812
Joined: 03 Jun 2009, 13:56
E-book readers owned: Used to have a PRS-500
Number of books owned: 600
Country: United States
Contact:

Re: Lever Actuated Platens

Post by daniel_reetz »

I've never seen a compression spring like that, with the wire insides. Is it a standard thing? Neat stuff.
StevePoling
Posts: 290
Joined: 20 Jun 2009, 12:19
E-book readers owned: SONY PRS-505, Kindle DX
Number of books owned: 9999
Location: Grand Rapids, MI
Contact:

Re: Lever Actuated Platens

Post by StevePoling »

I wonder whether the sliding/nested PVC pipe would admit a pneumatic/hydraulic approach. Remember that idea using a turkey baster to push the shutter? Perhaps a bellows with a LOT more volume would work with a foot-pedal to lift the platen. Anybody got an old pump organ laying around?
User avatar
Gerard
Posts: 154
Joined: 17 Oct 2010, 07:15
Number of books owned: 0
Location: Berlin (Germany)

Re: Lever Actuated Platens

Post by Gerard »

i always dreaming of a cordless drill with a thread bar in its drill chuck and a nut on the thread bar,
cordless drill are cheep, strong, have a power supply and the force can be adjust, the controller can be throw out and the power supply can be connect directly to the motor and then it is very easy to control the motor with a switch
User avatar
jck57
Posts: 376
Joined: 23 Nov 2009, 15:21

Re: Lever Actuated Platens

Post by jck57 »

StevePoling wrote:I wonder whether the sliding/nested PVC pipe would admit a pneumatic/hydraulic approach. Remember that idea using a turkey baster to push the shutter? Perhaps a bellows with a LOT more volume would work with a foot-pedal to lift the platen. Anybody got an old pump organ laying around?
http://www.horrorseek.com/home/hallowee ... cCylinders
Joe Reeser

Re: Lever Actuated Platens

Post by Joe Reeser »

daniel_reetz wrote:I've never seen a compression spring like that, with the wire insides. Is it a standard thing? Neat stuff.
It's standard storm door hardware. It's supposed to help keep the wind from whipping the door open too hard and breaking the hinges. I saw one at Ace hardware today for $5.29. Didn't buy it 'cuz I already have two. :mrgreen:
Post Reply