Small saw. Proxxon or something else

[Nicholas FarrParticipant @nicholasfarr14254]

Posted by John Smith 47 on 27/04/2021 12:46:28:

@Nicholas Farr – I wonder what would a 10×5 mm square look like in close-up?

Yes, 0.1mm mild steel is exceedingly thin and is very easily bent between fingers. For my purposes right now I have been needing to cut 10mm x 5mm little rectangles of it. And the resulting steels need to lie "absolutely" flat (i.e. flat to within 1 thou – call it 0.02mm).

Hi, John, well these three pieces are approximately 10mm x 5mm, didn't get too fussy with the size, but I'm still not claiming they are absolutely flat and you might be able to make out the 0.015mm thick piece of kitchen foil in front front of them. Best I can do I'm afraid.

They are sitting on the back of my 6" Moore & Wright straight edge.

Regards Nick.

[John Smith 47Participant @johnsmith47]

Posted by Roger B on 27/04/2021 14:17:34:

Stuart,

Proxxon offer blades for the FET for non ferrous materials including the fine tooth 28730:

**LINK**

Yes but unfortunately it's ferrous mild steel & stainless steel, that I need to cut!

[John Smith 47Participant @johnsmith47]

@Nicholas Farr – Thank you so much for trying the experiment! In truth it's to tell from looking at them. To get clear my problem is that I can't use kitchen foil because it's non-magnetic. i.e. Its a magnetic contact that I'm needing to create and even the slightest air gap is to be avoided if humanly possible.

[Ian PParticipant @ianp]

Posted by John Smith 47 on 27/04/2021 20:30:01:

@Nicholas Farr – Thank you so much for trying the experiment! In truth it's to tell from looking at them. To get clear my problem is that I can't use kitchen foil because it's non-magnetic. i.e. Its a magnetic contact that I'm needing to create and even the slightest air gap is to be avoided if humanly possible.

Magnetic Contact?

I presume that its not an electrical contact, but rather you want the ferrous sheet material to be in full contact with something magnetic over its whole area. Two things come to mind regarding this.

If the magnet is strong then the thin plate will conform to a flat magnetic surface even if it has a slight curl or bow. Also unless the steel plate is bonded to something rigid its not going to be easy to remove without damaging it, a knife even with a with a very sharp edge will be needed to lift a corner and then the very act of lifting the sheet may bend it.

Obviously whatever you are developing needs to stay confidential but if it eventually becomes a commercial product these steel plates will probably need some type of protective coating. Paint might be too thick for your humanly possible minimum gap requirement so electroplating is probably best.

Ian P

[Nicholas FarrParticipant @nicholasfarr14254]

Posted by John Smith 47 on 27/04/2021 20:30:01:

@Nicholas Farr – Thank you so much for trying the experiment! In truth it's to tell from looking at them. To get clear my problem is that I can't use kitchen foil because it's non-magnetic. i.e. Its a magnetic contact that I'm needing to create and even the slightest air gap is to be avoided if humanly possible.

Oh dear! John, I was not for one minute suggesting that you use kitchen foil, it was the only thing I have in the house that has a thickness that is within your 0.02mm gap tolerance and I used it in the photo for comparison to give you the sense of size of any gap you may see between those three pieces of steel and the straight edge they are on, the three pieces are not on the kitchen foil.

Regards Nick.

P.S. if you click on the photo to see it in full size, you should be able to see the kitchen foil is in fact in front.

Edited By Nicholas Farr on 27/04/2021 22:29:07

[HopperParticipant @hopper]

The world is full of millions of small items made from sheet metal and pretty much none of them are cut with a grinding disc or saw blade in a production environment.

Traditionally a guillotine would be used to do something like you want, giving a straight cut edge. I don't know where you get your information on the rounded edge in the drawing you posted, but if the clearance between the guillo blades is zero that tiny radius on thin sheet will be undetectable by the naked eye, if that is what you mean by "optically flat". Ask your local sheet metal shop to cut some samples for you and try them out.

Otherwise, consider precision laser cutting. Something like this **LINK**

There are probably small benchtop machines available but you'll have to do your own research on that. If your budget does not stretch that far, consider contracting the job out to somebody like the linked company but local to where you live.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Hopper on 28/04/2021 09:19:57:

The world is full of millions of small items made from sheet metal and pretty much none of them are cut with a grinding disc or saw blade in a production environment.

[…]

.

Another option to consider would be photo-etching

I have seen some remarkably good work done in Stainless Steel … and once received a business-card in SS, with numerous cutouts and surface detailing.

MichaelG.

.

Edit: That particular U.K. company may be long gone … but this looks promising:

https://tmnetch.com/stainless-steel-etching/?gclid=CjwKCAjwj6SEBhAOEiwAvFRuKNPsRPSO2UiHWe47CC-WgzkpnHCefTLrn82xEkx0xDz1W3qCK9XU3xoCzrQQAvD_BwE

Edited By Michael Gilligan on 28/04/2021 09:34:57

[Roger BParticipant @rogerb61624]

Posted by John Smith 47 on 27/04/2021 20:25:21:

Posted by Roger B on 27/04/2021 14:17:34:

Stuart,

Proxxon offer blades for the FET for non ferrous materials including the fine tooth 28730:

**LINK**

Yes but unfortunately it's ferrous mild steel & stainless steel, that I need to cut!

However Stuart, who this was addressed to, was wishing that he could find an equivalent to his FET for non-ferrous materials.

[Roger BParticipant @rogerb61624]

I thought that the KS 230 might be useful for one of my next projects and as, with various offers I could get one for the price of a tank of diesel, I decided I would see what one could do.

The supplied wood blade happily cut a couple of plywood offcuts as expected. I then fitted my well used 28020 blade and cut an offcut of 3mm aluminium. This loaded the motor a bit, but I don't know how worn the blade is. There is a warning label about feeding too fast.

Next up was a piece of 0.5mm galvanised steel, no problem, and finally some 0.1mm stainless steel shimstock. This was already not flat but the saw didn't seem to produce any further distortion. There is a small burr, but as I said I don't know the condition of the blade.

I have ordered some new 28020 blades (this supplier did not stock them) and will wait for them before any further trials.

[Stuart Munro 1Participant @stuartmunro1]

However Stuart, who this was addressed to, was wishing that he could find an equivalent to his FET for non-ferrous materials.

Roger – thanks. I knew John wanted to cut steel but the discussion seemed to have widened. I repeat the plea for someone to build what i want – but so far my cries for someone to make my dreamed of chocolate bar; non-alcoholic drink…have gone on def ears.

[JasonBModerator @jasonb]

Looks like you may have to make your own Stuart, something like this for the Sherline, similar concept to the one for the Myford

[Stuart Munro 1Participant @stuartmunro1]

Posted by JasonB on 03/05/2021 18:12:56:

Looks like you may have to make your own Stuart, something like this for the Sherline, similar concept to the one for the Myford

Jason,

I actually have a Sjherline lathe – an interesting project.

Stuart

[Roger BParticipant @rogerb61624]

I got the new blades and tried them to make a couple of pieces I needed. One was a 25mm square from 0.5mm steel as a shim to go under the toolpost on my FD150 and the other was an 8mm wide strip of 0.3mm phosphor bronze for part of the injection pump on my twin cylinder engine.

Both cut easily and were true to better than 0.1mm. There was a small burr but both remained flat. The videos are here:

[Roger B]

On Roger B Said:

I got the new blades and tried them to make a couple of pieces I needed. One was a 25mm square from 0.5mm steel as a shim to go under the toolpost on my FD150 and the other was an 8mm wide strip of 0.3mm phosphor bronze for part of the injection pump on my twin cylinder engine.

Both cut easily and were true to better than 0.1mm. There was a small burr but both remained flat. The videos are here:

As a newby to the forum, I just wanted to add my voice of thanks to everyone who’s replied and commented constructively here.   I had much the same question as the original posted by @johnsmith47, that is, are there any small bench or table saws available that will cut a range of materials including thin/light ferrous stock.  I’m principally an electronics person, and my original need was /is for a small machine that’ll mainly be used to cut aluminium panels, plastic sheet and epoxy glass-fibre printed circuit boards. However, I’ve also recently also had some need to cut small pieces of thin (circa 1mm) steel sheet.  After many hours of Googling I’ve come to the same conclusion as the apparent consensus here, that is, there’s very few options. Small light-duty machines like the Proxxon KS230 and FET are said to be unsuitable for ferrous materials, and there seems to be little if anything available of a slightly larger/heavier class without going all the way to comparatively huge machines with 200-300mm blade diameter, way bigger than I need and frankly even a bit scary for the small jobs I have in mind!  I am therefore especially grateful to @rogerb61624 for posting the above videos and notes, which confirm my original suspicions that although Proxxon deprecate the cutting of ferrous materials on their table saws, the machines are nevertheless quite capable of cutting light steel sheet if used with care and the right blade.  I’ve finally taken the plunge and ordered the FET model. Given RogerB’s generally positive experience with the KS230 (and its 85 watt motor) I’m hopeful the 200 watt FET motor will cope better still, and will give me enough torque to cope with occasional ferrous work. I’ll report back when it’s all arrived…   …meanwhile thanks all, for providing all this useful debate and discussion.

[Michael GilliganParticipant @michaelgilligan61133]

Well done, miket

I’m sure your findings will be useful to a wide community

… your “use-case” must be typical of many hobbyists who can’t justify the hefty machines that would make such work simple.

Stay safe

MichaelG.

[Author]

Posts