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Power scraper and flaker mecanism difference?

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PekkaNF:
I might be missing something?

I am trying to understand how power scraper and flaker mechanism works and what sort of dance the blade makes.

Judging from Biax patent drawings drawings and pictures there are in the net, I think that that the blade stem movement is strictly recipocating cyclic movement. Like this:


As far as I see there is no other movement than linear movement. There is that orginal wobble drive mechanism and several DIY projects have scotch yoke. Is there any intricasies or just throw and rotating speed?


BUT flaking seems to be more complicated?




There seems to be slight see-saw movement and linear movement combined. Haven't seen any description on this mechanism, bit can imagine one.

My question is actually. Is there any magic in it?

Pete.:
The flaker is as simple as it gets compared to the scraper, and would be very easy to replicate. There's a swash plate on a spindle that turns, and this pushes on a bearing to make the round shaft go out. Your own weight on the blade pushes it back.
There's a pin sticking out of the end of the shaft that pokes through a hole in the arm that holds the bearing. as the shaft turns it rocks the arm side to side slightly.

The cutting blades unlike the scraper ones have a radius on the front and on the bottom. The front radius controls the size of the half-moon scrapes. Everything else (stroke and rocking motion) is fixed.

PekkaNF:
Thank you. Pretty much as I though and after a bit of googling I found pretty good thread that has dimenssions:
https://www.practicalmachinist.com/vb/machine-reconditioning-scraping-and-inspection/shop-made-power-flaker-320189/

Any idea of "rpm" of the scraper/flaker?

How does the scraper/flaker blade shape differ?

Pekka

Pete.:
I just checked and the newer ones ARE variable stroke and rpm, according to the website. 0-1800 strokes/min. Mine is fixed, not sure what rate but it's gotta be 1400-1600. I have some flaking to do tomorrow I'll take a look.

The scraper blades are dead flat with the (also flat) tip straight out from the end. The flaker blades have the tip slightly under-slung on the blade and the bottom of the tip has a radius.

Pete.:
BTW I remember that thread when it originally came out. The guy made a great passable effort of a home made flaker but made one fundamental mistake - he put the blade on top of the rocking shaft instead of underneath it. That changes the whole motion of the tip. I'm surprised that no-one pointed it out at the time.

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