Plasma dross remover aka Dross Basher

[chunkolini]

I have spent a hideous amount of hours over the years chipping dross off the back of plasma cuts, a deadly job on larger pieces of work.
Then on here I saw a mention of a drill powered device for shipping paint and underseal off. looks like a potential dross remover. But I was too tight to spend twenty quid finding out.
but today I was at a loose end.

Cut a 150mm diameter disc out of perspex, drilled it out for a bolt through the middle and put small woodscrews around the edge. Looks cool.
The first one shattered after a few minutes, my fault as I was working towards an edge not swiping away from it.
I made MkII

Success, just dont snag any edges. A bit noisy but pretty effective.
Also quite good on rust.
When it dies I will stump up for the commercial version.
or can somebody supply me with a disc of aluminium 150mm x10?
That would work a treat with self tappers.

 

[FranV8]

Cool! Why not make one out of a metal disk, but just cut the outer edge to two different diameters, like a simple gear, and let the steel edges do the job. Won't look as funky as the psychedelic spiral though.

 

[chunkolini]

First thoughts to that is too complicated.
But Mr Fran
You have got me thinking, what vehicles do I own?
Bicycles.
What do they have? sprockets.
I have a mountain of dead chainsets.
Will I stump up for the commercial version? possibly not.

 

[nodeward]

what do the commercially available ones look like? i cant say ive ever seen one, sounds like a great idea

 

[chunkolini]

Like this.

In fact mine is better as it is reversible.

 

[wheresmejumper]

wouldnt that knacker the bearings in the drill fairly quickly?150mm is big

 

[chunkolini]

Hmm.
No idea.
It is not working under much pressure and the dross flicks off easily.
Doubt it, but worth bearing in mind.

 

[Lawnmowerboy]

Or an old cam belt pulley?

 

[the snooper]

thought id post this for you chunko from a manufacturers web site

To determine if you're going too fast or too slow, visually follow the arc that's coming from the bottom of the cut. The arc should exit the material at a 15- to 20-degree angle opposite the direction of travel. If it's going straight down, it means you're going too slow and, you'll have an unnecessary build-up of dross or slag. If you go too fast, it will start spraying back. Since the arc will be trailing at an angle, at the end of a cut, slow your cutting speed and angle the torch into cut through the last bit of metal.

 

[Wallace]

Try taking two screws out next to eachother then run the drill at full tilt and watch your surroundings go b-b-b-bluuuuury! Can I have the speed controller out of the pieces for my project please?

 

[outofthefire]

You will probably screw the drill up, a grinder would be better but probably way too fast. You could do with an electric polisher. I like the idea though the dross is a pain.

 

[KemppiFrog]

You will probably screw the drill up, a grinder would be better but probably way too fast. You could do with an electric polisher. I like the idea though the dross is a pain.

Yes, but the idea behind this is that the dross comes off quicker if chipped off rather than ground. Grinding is pretty slow and uses consumables. I do find the idea of Mr C's Perspex discs a bit unerving. The stuff is pretty fragile and shatters easily. One of those bomb suits the UXB guys use might be handy.....

 

[chunkolini]

This was just a prototype to see if the the idea works.
It does, for proper use I would be looking for something less likely to fly apart.
The first one broke up when I hit an edge from the wrong side. it did not fail too violently, just fell to pieces. I was wearing a face shield just in case.
I dont see that it would knacker the drill, it is running at hardly any load or impact, I would use my big mains drill in practice.
I will have a look at bicycle sprockets next, or maybe just bite the bullet and spend twenty quid.

 

[PhillipM]

Drills aren't really meant to take side loadings, especially impacts with that kind of leverage, I'd imagine you'll kill bearings pretty quickly.

 

[chunkolini]

There is no real load or impacts going on, it is just flicking it off, there are always a few bits that need to be knocked off, but this gets rid of most of it. the stubborn bits get a whack with a chisel.
I have wondered about motorised chisels and scrapers.

 

[blacksmithstris]

Hi Chunkolini, maybe a better plastic would be polycarbonate instead of perspex? We make our machine guards out of it at the school where I work and we're not allowed to use perspex because it shatters.

 

[brightspark]

Hi Chunkolini, maybe a better plastic would be polycarbonate instead of perspex? We make our machine guards out of it at the school where I work and we're not allowed to use perspex because it shatters.

or lexan edit its the same stuff

 

[Paul.]

Hi Chunkolini, maybe a better plastic would be polycarbonate instead of perspex? We make our machine guards out of it at the school where I work and we're not allowed to use perspex because it shatters.

Perpex is a trade name that covers a range of plastic materials including acrylics and polycarbonate, If I was considering making on of those (which I'm not) I would use polyethylene, its much more resilliant, we are using it nowadays instead of stainless steel for conveyor side frames, and a lot of food safe conveyor belting and drive sprockets is from p/e, because its less likely to shatter, it can be worked with wood working tools and will take a self tapper without splitting.

 

[blacksmithstris]

Sorry, I stand corrected. I always assume that perspex is acrylic, as we have a mishmash of offcuts at work that lose their labeling, and I tend to err on the side of caution but you are correct they also do polycarbonate. I also assumed that the perspex that Chunkolini used was acrylic as it shattered. Perhaps I should have said "Acrylic perspex might not be the best plastic to use there may be better alternatives out there"

 

[KemppiFrog]

Perpex is a trade name that covers a range of plastic materials including acrylics and polycarbonate, If I was considering making on of those (which I'm not) I would use polyethylene, its much more resilliant, we are using it nowadays instead of stainless steel for conveyor side frames, and a lot of food safe conveyor belting and drive sprockets is from p/e, because its less likely to shatter, it can be worked with wood working tools and will take a self tapper without splitting.

Paul, I would question the use of Perspex in connection with polycarbonates. I always understood it was an acrylic, whereas polycarbonates are something else. And Lexan is the US term for PCs. (tradename from DuPont?)
KF