Thread: DIY power scraper

Originally Posted by Machtool

I’m not big on the rubber thing. (Wishing I could come up with a Condom joke here)
Regards Phil.

Rigid tool is better than floppy?

Regards
Ray

Thanks guys,
I'll have more of a look tomorrow and aim for something on the 15 side of 20(110) as I think it would be easier to tilt the body up if needed than down.

I'll ditch the rubber thing then.

Phil, I think Joe said somewhere you made the blade for his? is it a HSS hacksaw blade with the carbide silver soldered on the end? I've read stories that say the joint needs to be very straight or the carbide cracks, anything to that? I have some blades but I think they might be a little large, I'll measure them tomorrow if I get a minute.


Looking at the plates on RCs thread, Would some sort of rebate to hold a piece of felt for oil be a silly idea?

Stuart

Originally Posted by RayG

Rigid tool is better than floppy?

Oh dear Ray - you'll get this thread banned by the admins....

Stu, the angle on my adapter block was done purely by feel: I scraped a bit with the blade Phil made for me, found the angle it worked at best and used that angle to make the adapter.... never even measured it. I just wanted the Aldix body to be roughly parallel to the work surface.

I've been giving the idea of an 'Aldix' flaker some thought too: I think you might be onto something, Stu....
Making a way for allowing the blade to rotate a few degrees (a guess here is 10-15deg - Phil?) and then guiding that rotation with an external guide might just replicate the Biax flaker motion.... I'm still working on it in my mind.... a round bar sliding in a matching guide... a hardened guide pin sticking out into a spiral slot into the guide.... back and forth motion translated into a total of 20-30deg rotation side to side... but that would have to be in line with the blade - or is it???? On the Biax, the nearly straight blade is at the very bottom of the guide, so maybe it could be mounted at the bottom of a - say 25mm diameter OD adapter which slides in a 25mm ID guide with short spiral groove/slot.... blade angled a bit to allow clearing the bottom of the Aldix body and handle (so you can flake surfaces wider that the tool is long.... or even designing the tool to be used with the handle upside-down or on it's side like the guy on the PM forum did....
I think I'm getting somewhere!

Originally Posted by Steamwhisperer

Hi Stuart
I am considering a pneumatic scraper.

bugga...i have just bought one to see if it would work....

Oh well...guess I'll let Steamwhisperer tell me if it will or not why should I do it when someone else has offered

Originally Posted by Machtool

Nasty Nasty time. Tax I had a call from them today. I’m a few days late on a BAS.

dont you know that they really really hate that

Originally Posted by Stustoys

I'll ditch the rubber thing then.

Originally Posted by Stustoys

Phil, I think Joe said somewhere you made the blade for his? is it a HSS hacksaw blade with the carbide silver soldered on the end? I've read stories that say the joint needs to be very straight or the carbide cracks, anything to that?

Stuart

I’ve never quite understood what that rubber buffer is meant for in a Biax. Only Biax use them, the Renz doesn’t.

Those blades I’ve been making up, are just from old 18” power hacksaw blades. I’ve got a few of them here. When they are about 100mmm long, 20mm wide, they have about the right amount of spring in them.

I’ve never had the carbide crack. You need a nicely fitted joint, and I used shim solder. Just flux both sides, and squeeze them together with the shim between, and sweat them together.

I have a couple of those hacksaw blades here, if you want some to try. I pick them out of the scrap bins in my travels, so they owe me nothing.

Regards Phil.

Not much done today other than come up with a blade holder that wont make a pinch point against the body.(well unless you count the tax being done for another year, Hopefully I wont be getting any phone calls lol). I think it will mostly be a design on the fly sort of thing. Should be able to hit the mill tomorrow. I'll be cutting the front 25mm off the body to keep the overhang as short a possible.

Thank you Phil I'll gladly take you up on your offer, the blades I have a 30mm wide by 1.6mm thick(or do you think that will be close enough?) How did you drill holes in it?

Stuart

Stu, the blades are too hard to drill.
I cut a 6mm wide slot in mine with a thin cut-off blade in the angle grinder and then very gently rounded the rnd of the slot to around 3mm radius. The blade i held on with two M6 Allenhead bolts - both in the slot.

Hi Joe,
I'd thought of carbide drills and grinding holes. One I dont have, the other is a pita. Grinding a slot all the best ideas are easy once someone tells you lol
Thanks

Stuart

Originally Posted by Stustoys

Hi Joe,
I'd thought of carbide drills and grinding holes. One I dont have, the other is a pita. Grinding a slot all the best ideas are easy once someone tells you lol
Thanks

Stuart

Hi Stuart
If I have to drill a hole like that I go and buy a cheap masonry bit and regrind it like a normal drill bit. They work very well.

Phil

Hi Stuart,

I second what Phil suggested, you can get a nice edge on a masonry drill with diamond.

A couple of other methods,

1. put a nail in the drill press, and run it hard against the saw blade, the saw blade gets red hot and loses it's temper, cool slowly then drill with normal drill bits. Obviously this only works for high carbon blades, or blades that will lose temper at red heat.

2. Get a solid carbide woodworking router bit, and run it in the drill press, you can't do it free hand because it will walk.

Regards
Ray

While all three of these methods may work, I know that power hacksaw blades are pretty well dead hard - and will shatter with even a small amount of internal stress. That's why I wasn't game to try them in this case - though I have in other applications. Except the nail trick! A trick I will certainly try one day.
I have seen videos of friction/flow drilling using cobalt or tungsten carbide drills that did not have any cutting edges as such - pretty impressive.
[ame="http://www.youtube.com/watch?v=Y2GorhgZHv4"]Flow Drilling - YouTube[/ame]
Joe

Hi Phil,
I'd thought about using a masonry bit but have never tried it. Do they really drill? The drills I have used for HSS are a triangle and always seemed to me to melt their way through.
I read some where you can turn HSS using carbide, but I havent been game to try that either lol

Hi Ray,
No solid carbide router bites in my collection. I'm going to have to remember that nail trick though.

Hi Joe,
I've drilled 12mm deep holes in solid HSS punches without cracking, but I wouldnt say I knew what I was doing lol


I think I like the slot idea anyway as that would make removing it for sharpening faster(or do you guys sharpen them on the machine?)


Thanks guys

Stuart