Engineering Question (overhead powerfeed)

[Rob Will]

I have a large jointer and would like to fabricate a wide belt overhead conveyor-style power feed for this machine. Now before we get into the things like Joint-mate and multi-wheel power feeders, let me tell you the rest of the story. The jointer is 24" wide and I have several trees cut into 2.5" slabs. Some of the slabs are 9' long and 24" +/- wide. What I want to do is face joint these "tree sections" and a big wide power feeder sure would be cool and add a lot of safety and accuracy. I question whether or not typical power feeders will drag these trees across the machine witout slipping, applying too much pressure in one spot etc.

Here's what I want to do:

Position the jointer atop a steel tubing frame. This would raise the big jointer about 2". This frame would go toward the left rear and have a vertical post on which to mount the power feed. I do not want to mount anything on the jointer itself.

Using a small gear motor, a chain driven head pulley and a short take up unit for the tail idler pulley, construct an overhead conveyor feeder. Coming from the vertical post, this assembly would mount on a set of parallel arms from a Kinze planter (about 12" long). The parallel arms would allow easy height / downpressure adjustment. The conveyor itself would be about 18" wide and 24" - 30" long. (The jointer's outfeed table is about 36" long). The traction belt would be "rough top" similar to a wide belt sander's conveyor.

So finally, here is my question: If I want the conveyor to conform to the shape of the rough sawn (cupped, twisted etc.) slabs, and I don't want to apply too much pressure in one spot, what sort of bed slides/ idlers etc. can I use to press down on the traction belt? Are there such things as spring loaded individual idler wheels for conveyors?

An alternative method would be to use a section of roller (skate wheel)conveyor to support the belt but this would not have much in the way of suspension travel. Perhaps indivual spring-loaded UHMW slides instead of rollers?

Any ideas about how to make this feed conveyor flex?

We build conveyors all the time. Somebody help me figure out how to add the suspension(?)

Thanks!

Rob

[Steve Jenkins]

Rob I once saw a jointer feeder mounted on a 24" OLD jointer. I can't remember exactly how it was made but the feed mechanism was i believe leather or canvass with metal fingers hanging down from it. As I recall the fingers were a couple inches long and spaced about 2" apart over the entire surface area. It looked like some kind of mideval(?) torture device. It sure was effective though. You might check on the old machinery website/forum.
Steve

[Steve Clardy]

Maybe take a look at how the bandsaw resaw machines are made for the pallet industry. Baker, etc.
They run a wide, flat tread, rubber tire and wheel, mounted on top of the material, to feed the resaws.

[Dino Makropoulos]

We operated one 36" surfacer with overhead carpet feed.
The "carpet" was similar to Steve's description, "made of rubber"

In the business of recycling cut-offs and unwanted boards
(twisted-crooked - thin stained Etc.) this Thing was the ticket and the answer to save 12.000 BF per day.

Other name for the machine was the Human Hands Joiner.
You can process materials of uneven thickness the same time.
The fingers are flexing up to 1/ 1-2".

If you can find an old machine, go for it.
If you like to build a new one, Buy a regular conveyor
and attach " fingers" every 2".
Or something similar to windshield whipper's 2" to 3" wide.

Here is a thought.
A T-track across the belt every 2" that you can insert a flexible molding.
I think 2" wide 1/4" thick rubber strips can do the trick.

[Rob Will]

We operated one 36" surfacer with overhead carpet feed.
The "carpet" was similar to Steve's description, "made of rubber"

In the business of recycling cut-offs and unwanted boards
(twisted-crooked - thin stained Etc.) this Thing was the ticket and the answer to save 12.000 BF per day.

Other name for the machine was the Human Hands Joiner.
You can process materials of uneven thickness the same time.
The fingers are flexing up to 1/ 1-2".

If you can find an old machine, go for it.
If you like to build a new one, Buy a regular conveyor
and attach " fingers" every 2".
Or something similar to windshield whipper's 2" to 3" wide.

Here is a thought.
A T-track across the belt every 2" that you can insert a flexible molding.
I think 2" wide 1/4" thick rubber strips can do the trick.

That sounds like a good idea. We have built some conveyors that incorporated rubber cleats that were about 1.25" tall. They were applied with a chemical welding process. I'll bet that a taller version is avail.

http://www.flexco.com/products/scoop_cleats_conveyor_belt_cleats

Thanks,

Rob

[tod evans]

rob, dino`s got it. at least what i`ve seen that works, a carpet feed. call northfield or maybe on their website? they use carpets on their double sided surfacers. from a cost standpoint couldn`t you design a trolly that would grip the board by its edges suspended above the jointer then lower the trolly as a unit for each successive pass using the weight of the board and trolly as the pressure unit?.......just thoughts...tod

[Rob Will]

I'm trying to visualize how the individual fingers are shaped and how they grip the wood.

Rob