Need to cut long thin strips of steel (& plastic) – e.g. with an angle grinder?

[John Smith 47Participant @johnsmith47]

[John Smith 47Participant @johnsmith47]

Hello

I hardly dare re-kindle this old thread….
"Small saw. Proxxon or something else"
https://www.model-engineer.co.uk/forums/postings.asp?th=172361&p=1
**LINK**

…However I find that I do keep needing to cut long thin strips of material. It's usually either wood/plastic (e.g. ABS/PS/Nylon), or stainless or mild steel.

My requirements have evolved since that thread so I shall this new one.

My cutting requirements are:

1. Material thickness:
My steel is generally between 0.9mm and 1.4mm.

2. Lengths:
My lengths might be say 10 to 20cm,
with a width of maybe 2 to 5mm.

3. Materials
Steel is obviously the hardest of the things that I need to cut. So a small machine that could even cut just steel would be a revolution for me. But would it be too much to hope for one machine that could cut both materials? (Like my fine-toothed hacksaw can!)

BACKGROUND/PROBLEMS
To be honest, my hacksawing skills aren't very accurate. It's particularly difficult, particularly after dark when there is less daylight to help me see what I am doing. Seeing marked lines on steel (even when using Dykem Steel Blue) is quite difficult…

So I find that I keep having to hacksaw somewhat over-sized and then hand-file or grind down and remove quite a lot of material to get them down to the precise required sizes.

==> So I find myself fantasizing about a precision/micro table saw that can also cut steel! Or possibly some rig to enable me to do hacksawing with great precision?

From memory (and without re-reading the entire previous discussion):

a) Small table saws (e.g. Proxxon) ==> just aren't designed for steel

b) the Proxxon band saw definitely wasn't

c) Larger, more powerful table saw just aren't designed for cutting small precision parts.

d) A nobody seems to make small grinding disk wheel (e.g. 1mm thick) embedded into a cutting table. [And no, I don't really have time to mess about making one!]

e) My strips are too long to readily fit onto my MF70 milling machine.

f) I don't think a guillotine will work because the leave one side of the cut steel sheet curved.

[ NOTE: As before, I do not have a permanent works space. Everything needs to be cleared away at the end of each day. So tools need to be fairly light and compact. ]

MY POSSIBLE SUGGESTIONS:
What about cutting using micro-sized angle grinder.
…And then finding some way to line up next to a ruler/straight edge?
[But how exactly? Have any of you tried this?]

A. "PROXXON LHW LONG NECK ANGLE GRINDER"
https://www.axminstertools.com/proxxon-lhw-long-neck-angle-grinder-702027

– with cutting disk fitted
or

– "For steel, non-ferrous metals, glass, ceramics, wood and plastic"
– 50mm diameter discs
– 100W DC motor.

B. Or possibly a DREMEL would be better (??)
e.g. "DSM20-1/5 710W Compact Saw 230V"

**LINK**
https://www.cromwell.co.uk/shop/power-tools/compact-saws/dsm20-1-5-710w-compact-saw-230v/p/DRE2674120F
– Blade diam: 77mm
– No load speed: 17000rpm
– Power: 710W (?)
– Weight 1.7Kg
– Dust extraction port for clean working environment (vac cleaner attachment)
– "1 x straight edge guide"

I was thinking that something that cuts with a very thin disk would create less dust, but the dust extraction port could mitigate that problem. Also claims to have "Excellent line of sight for accurate cutting"

Yes, seem like it will be damned noisy…
> Noise K Factor: 96 dB(A)
> Noise Sound Power: 108 dB(A)
> Noise Sound Pressure: 1.59 Pa
…whatever that really means, but I live with that. (With earplugs if necessary)

BUT it is quite big & heavy (at 1.7Kg), for more precise work.

Have any of you got one? Have you had much success in cutting straight lines with them by lining them up against straight edges ?

What do you think?

J

[Frances IoMParticipant @francesiom58905]

you will need very forgiving neighbours as well as an expensive set of ear defenders.

[Dave SParticipant @daves59043]

<popcorn>, <chair>, <beer>

[Tony Pratt 1Participant @tonypratt1]

Pass

Tony

[John Smith 47Participant @johnsmith47]

Posted by Frances IoM on 18/01/2022 17:59:53:
you will need very forgiving neighbours as well as an expensive set of ear defenders.

IME, wax earplugs work well.

Fwiw, on my street there is always a LOT of building work going. And much of it is exceedingly noisy being as it happens outside from rooftops… for days on end! However nobody seems to mind, and I would be amazed if anyone even noticed a new noise from indoors.

J

[RedsetterParticipant @redsetter]

Just order your materials cut to size.

[Robert ButlerParticipant @robertbutler92161]

Topic well aired in previous thread, an insoluble problem.

Robert Butler

[Anonymous]

I've just been cutting similar strips of 1.2mm stainless sheet and the weapon of choice was my wet wheel diamond blade tile saw. It's a cheap Plasplugs one about 12 years old and doesn't have a problem either freehand or with the guide giving a decent clean and accurate cut. Blades aren't that dear and last well.

[noel shelleyParticipant @noelshelley55608]

iF YOU CANNOT CUT A STRAIGHT LINE with a hacksaw then you do have a problem ! I would have suggested 4.5" X 1 or 1.5mm cutting disc in a small angle grinder. May be you need more practice. Good luck, Noel.

[JasonBModerator @jasonb]

If you can't see the line to saw to what hope have you using any other form of free hand cutter given the added complications of eye protection and sparks flying about. Though maybe the sparks will make it a bit brighter either that or get some decent lighting in your work area.

[Nick WheelerParticipant @nickwheeler]

Cleaning off the burr caused by any abrasive disc is going to be way more work, less accurate and more time consuming than just tapping any guillotine distortion straight. The guillotine will cut quicker too, and a long machine could cut several of your parts in one operation.

[HOWARDTParticipant @howardt]

Have you looked at buying metal inlay strips. Would be a lot easier in the long run than all the cutting, deburing, and flattening.

[John Smith 47Participant @johnsmith47]

Posted by noel shelley on 18/01/2022 18:59:45:

iF YOU CANNOT CUT A STRAIGHT LINE with a hacksaw then you do have a problem !

Yeah the lines are generally straight, just not in the correct direction!
Over 15 to 20cm even the smallest errors mount up.

> I would have suggested 4.5" X 1 or 1.5mm cutting disc in a small angle grinder.
Is not a small angle grinder precisely what I was suggesting?
But 4.5inches (11.4cm) is even larger than the machines I found. I don't see how a larger, heavier machine would help with accuracy.
Exactly what is your point?

> Good luck
Thanks you.

@JasonB
> If you can't see the line to saw to what hope…
At no point did I say that I "can't" see the lines, I said that it is harder to see the lines in less good lighting conditions. Yes, I have various portable lamps which I can and do set up when necessary, but you have to get the light to bounce off the metal just right to see the scribe marks properly. Sometimes this means pointing the lights to the floor… For best results, I may also need to change between different magnifications of reading glasses. Either way in practise if I need a more accurate cut then I have to keep stopping and checking multiple times.
==> Ergo, it's not about possibility/impossibility it's about difficulty, inconvenience & speed.

Look let's stop the smart-ass comments. There is no use pretending anyone here, no matter how many thousand years of sawing-by-handsaw experience they might have, will ever be able to saw as accurate parallel lines as a machine such as a table saw can cut.

@Redsetter
> Just order your materials cut to size.
When I can, I do. But not always possible.
And where possible implies delays & potential over-orderings…

@Dave_S
> <popcorn>, <chair>, <beer>
My pleasure. FOC entertainment at your service…. :^P

[John Smith 47Participant @johnsmith47]

Posted by Nicholas Wheeler 1 on 18/01/2022 19:38:18:

Cleaning off the burr caused by any abrasive disc is going to be way more work, less accurate and more time consuming than just tapping any guillotine distortion straight. The guillotine will cut quicker too, and a long machine could cut several of your parts in one operation.

Tapping it straight?!
In my experience, unless you put it through a special straightener you never EVER got the metal completely flat again.

> Have you looked at buying metal inlay strips.
I have found it hard enough to find the metals I require e.g. Grade 430 stainless 1.0, 1.2 & 1.4mm thick without trying to find the exactly correct width. In any case, I have now bought the sheets. It would be a shame to waste them.

[Brian MorehenParticipant @brianmorehen85290]

Have you looked at a Multi Tool ,I have cut most of the material you have mention using a straigh edge as a guide

saw mine in Lidli some time ago and bought , with the right blades well worth the cost has saveded me loads of time .

Regards Bee,M

[pgk pgkParticipant @pgkpgk17461]

If the lines you are trying to cut are generally straight, then adhesive tape as a guide would be more visible than scribing. You may also consider the method of printing patterns and spray adhesive them to the material.

pgk

[David NobleParticipant @davidnoble71990]

I hesitate to enter the fray but a guillotine would do it.

David

[Nick WheelerParticipant @nickwheeler]

Posted by John Smith 47 on 18/01/2022 20:12:53:

Posted by Nicholas Wheeler 1 on 18/01/2022 19:38:18:

Cleaning off the burr caused by any abrasive disc is going to be way more work, less accurate and more time consuming than just tapping any guillotine distortion straight. The guillotine will cut quicker too, and a long machine could cut several of your parts in one operation.

Tapping it straight?!
In my experience, unless you put it through a special straightener you never EVER got the metal completely flat again.

You need more experience then!

Cuts made with grinding wheels on thin materials are horrible things. Doing one or two like would be OK, but more than a couple is not acceptable. I would always trade flattening an already straight cut over cleaning up one done by hand with a grinder.

[Martin ConnellyParticipant @martinconnelly55370]

Buy a suitable mill and some slitting saws. Clamp the stock between two plates to support the material. The way this is going it will be cheaper than waiting for your perfect tool. The mill only needs to have a travel slightly more than your longest strip.

Martin C

[Ian PParticipant @ianp]

Posted by John Smith 47 on 18/01/2022 17:51:52:

My cutting requirements are:

1. Material thickness:
My steel is generally between 0.9mm and 1.4mm.

2. Lengths:
My lengths might be say 10 to 20cm,
with a width of maybe 2 to 5mm.

Table saw, milling machine, slitting saws, angle grinders and almost anything else commonly (or uncommonly) available would struggle to cut a strip 1.4mm x 2mm.

Doable with scalpel if Balsa wood was acceptable

Ian P

[Sam Longley 1Participant @samlongley1]

Get a bit of fencing wire, or copper wire 1.8mm th & pass it through 2 rollers untill flattened to the right thickness & 2mm wide. That might do the 1.4 * 2mm But I could not suggest 5 mm that way.

Years ago I had one of these cutterIt ended up a bit bent & had the imprint of the toothed wheel though. But cut the metal quite quickly

Edited By Sam Longley 1 on 18/01/2022 21:24:49

Edited By Sam Longley 1 on 18/01/2022 21:28:38

[Robert ButlerParticipant @robertbutler92161]

I would guess the normal production technique would be guillotine, stamp or laser cut. To cut thin material with a circular saw without restraining the material risks kick-back with the potential for serious cuts. As with other posts there is no solution to this problem.

I do find the posts endlessly amusing however.

Robert Butler

Edited By Robert Butler on 18/01/2022 22:07:29

[Anonymous]

Agreed that the guillotines that resemble paper cutters do result in a curved workpiece. But industrial guillotines shear without distortion of the work. I have a power guillotine, but a treadle guillotine would satisfy the OPs requirements. However, even a treadle guillotine is probably too large and heavy.

Andrew

[John Smith 47Participant @johnsmith47]

Posted by Brian Morehen on 18/01/2022 20:15:06:

Have you looked at a Multi Tool ,I have cut most of the material you have mention using a straigh edge as a guide

saw mine in Lidli some time ago and bought , with the right blades well worth the cost has saveded me loads of time .

Regards Bee,M

Please can you clarify what you mean?

If you google "Multi tool" you mostly get a lot of these sort of glorified pen-knives:

…. which I am assuming that you don't mean.

Alternatively presumably you mean these oscillating things:

…which yes, I have tried but without much success. I find them big, heavy & clunky, and I have yet to cut anything remotely close to a straight line with one. In fact I cut very much straighter lines using a hacksaw(!) but no doubt I am doing it all wrong.

What do you mean exactly? How are you using yours?

 

@pgk
> If the lines you are trying to cut are generally straight, then adhesive tape as a guide would be more visible than scribing.
Obviously I'd need to get the tape dead straight, rather than just drawing a line using a ruler, but for dim lighting conditions that sounds like a great idea! Thanks.

@David Noble
> I hesitate to enter the fray but a guillotine would do it.
I would absolutely LOVE to use a guillotine – believe me! – but I'd need to find one that doesn't put curves into what is coming off. (But maybe very expensive, high force ones exist that only put a very small curve into the metal and from which it can spring back?)

@Nicholas Wheeler
In my experience, even when using a soft hammer tapping always tapping marks and nice more or less optically flat metal is never the same again. Personally I'd rather have a bit of mess and a rough edge that has to be filed down.

> Cuts made with grinding wheels on thin materials are horrible things.
In what way are they "horrible"?
To get clear, are you calling 1mm of steel "thin"?

@Martin Connelly
> Buy a suitable mill and some slitting saws.
So the slitting saws would be horizontal, yes?

> Clamp the stock between two plates to support the material.
Sorry I don't understand quite what you mean. Can you say more about this configuration. Are you suggesting using a milling table that can do a very wide amount of travel?
 

J

Edited By John Smith 47 on 19/01/2022 01:12:00

[Author]

Posts