Acute (a cute?) tool sharpening system

[JimmehParticipant @jimmeh]

I've just seen that Gary has begun uploading some of his videos explaining how to build and use the Sharpening System. These videos are well worth a look!

**LINK**

[Eccentric EngineerParticipant @eccentricengineer]

Hi all,
Thanks for that Jimmeh, Yes, I’ve been uploading videos over the past few days on how to build and use the Acute Sharpener.
I’ve tried to include machining hints and tips and alternative options/setups where possible. I was looking at doing a voice over but ended up going with subtitles: at least that way you can pause the video for anything that’s not clear.

I’ve made a few improvements to the kit since it was first launched.
The end caps with the “O” rings are now supplied as a CNC machined item as they were one of the trickier items to make.
I’ve been able to find screws 5mm shorter for the table adjustment so they don’t have to be cut down anymore and the fence is now supplied virtually finished, it just needs one 4 mm hole drilled.

I thought I’d solved the burring issue on the laser cut discs recently by getting them heat treated. Unfortunately it was not to be. The trial parts went fine and machined without leaving rags but when I had the rest of them done they came back from the heat treaters with slag/scale inclusions from the furnace all over the surfaces .
Now I’ve got 2500 laser cut parts that I have to individually remove the slag from with emery tape and a scraper. Ah well, we live and learn.

We’ll be attending the Doncaster Show later this month so I’ve been filming and editing solidly for a bunch of weeks now to try and finally get the DVD finished. Apologies to all our customers for the time it’s taken.
The videos on YouTube will be the same as that used for the DVD.

Well I’d better get back to editing Part 2 of the Work Arm video so I can get it on YouTube and hope to see some of you at Doncaster (stand 97) on the 20th-22nd May.

Cheers
Gary

[Neil WyattModerator @neilwyatt]

Posted by Eccentric Engineer on 02/05/2016 11:40:48:

Now I’ve got 2500 laser cut parts that I have to individually remove the slag from with emery tape and a scraper. Ah well, we live and learn.

Try chucking them in brick cleaner for a few hours first. You'll need to neutralise then oil them to stop rust.

[Eccentric EngineerParticipant @eccentricengineer]

Thanks for the tip Neil but I had the guys down at the blackening plant put them in the acid dip for 20 minutes and it did nothing apart from cost $250. I assume brick cleaner is a type of acid ?

Also tried a wire wheel and the sand blaster. Sand blaster might have done the job eventually but I'd have been there till Christmas.

I'll bring along a couple of bits to the exhibition and have a competition to see who comes up with the best way of getting the slag off

[Ady1Participant @ady1]

I'll bring along a couple of bits to the exhibition and have a competition to see who comes up with the best way of getting the slag off

For preparing really tough stuff (like descaling) at sea we used chipping hammers and air powered needle guns

edit thought:

Perhaps, for small jobs, the hammer action of a drill with a blunt masonry drill would suffice

Edited By Ady1 on 02/05/2016 14:11:59

[Tony Pratt 1Participant @tonypratt1]

Posted by Eccentric Engineer on 02/05/2016 11:40:48:

I thought I’d solved the burring issue on the laser cut discs recently by getting them heat treated. Unfortunately it was not to be. The trial parts went fine and machined without leaving rags but when I had the rest of them done they came back from the heat treaters with slag/scale inclusions from the furnace all over the surfaces .
Now I’ve got 2500 laser cut parts that I have to individually remove the slag from with emery tape and a scraper. Ah well, we live and learn.

Gary,

How on earth did you think 'heat treating' would get rid of burrs on a laser cut part?

Tony

[Enough!Participant @enough]

Posted by Tony Pratt 1 on 02/05/2016 18:52:45:

How on earth did you think 'heat treating' would get rid of burrs on a laser cut part?

Having worked on some of the parts and discovered how hard they are around the laser-cut surface, I assumed Gary intended the heat treating to reduce that hardness and allow burr removal subsequently.

[pgk pgkParticipant @pgkpgk17461]

I wonder if tumble polishing would work..(visions of a cement mixer full of shingle, parts and coolant wash)

[Enough!Participant @enough]

I have a small tumbler-polisher and did some of my parts for about 8 hours. It didn't do much around the laser-cut edges.

[Eccentric EngineerParticipant @eccentricengineer]

The slag inclusions are really too small for the drill idea but thanks for the thoughts Ady1.

How on earth did you think 'heat treating' would get rid of burrs on a laser cut part?

Tony

Ah perhaps I'd better explain the issue fully.
The bright mild steel that the laser cutter uses is quite ductile which I assume is so it can be readily bent in a press like the brackets for the grinding table.
The ductility means that the steel is a bit gummy when machining. When you drill a part the exit hole leaves a larger rag than normal and that has to be removed each time with a countersink or deburring tool, a bit of a pain but not the end of the world.

I would say the steel has been pickled to achieve the ductility as it has too low a carbon content for proper heat treatment.
After speaking to the heat treater we decided to try a heat and quench to see if it would remove the effects of the pickling.
As I mentioned above, that worked fine, small rags and the swarf tends to chip now rather than longer strings when turning. The downside is the cleaning up I've had to do.

Having worked on some of the parts and discovered how hard they are around the laser-cut surface, I assumed Gary intended the heat treating to reduce that hardness and allow burr removal subsequently.

To be honest I haven't had any issues with tool wear but I do try and make sure the first cut is deep enough to get all the way through the skin into clean metal.

I tried putting all the parts through my vibratory finisher after the acid dip, it didn't take off any of the inclusions but did give them a nice polished look

[Ady1Participant @ady1]

If you need to jackhammer tiny details then a power engraver can get in there, you can make your own tips too

My lidl one was about 15 bananas

I wouldn't fancy doing hundreds tho, sounds like a job for sand or shot blasting, some car/driveway power washers have a sand blasting attachment facility.

Edited By Ady1 on 03/05/2016 22:19:39

[Dave CeeParticipant @davecee80929]

Hi People.

I have an Acute system kit and will be ordering an extra table on it's own also.

I am comfortable with making the tables but I don't have a mill as yet so can't do the crucial milling operations that are shown in Gary's vids.

Would anyone be interested in milling the parts for my kit please ? I didn't want to just message people to ask them, so I thought I would put a post on this thread rather than starting another one.

Will pay up front for anyone's services.

Thanks in advance.

Dave.

[Author]

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