Slit Saw for small mill

[Iain DownsParticipant @iaindowns78295]

Having overloaded my CMD 10 I thought I would seek advice before purchasing a slitting saw.

The particular piece I want to slit is 20mm x 50mm aluminium. I've just spent half an hour cutting this 20mm slice off a 50×50 block with a hacksaw and don't fancy a retry.

RDG have got a one inch 2MT arbour for 15 quid with saws for 5 or so.

Arceurotrade have various 2MT arbours for around 20 – 25 quid.

Should I be aiming for smaller diameter bore with a weak mill – or a bigger one to grip? What is a realistic slice I can take with my mill – in a pinch I can go in from both sides. What impact does the width of the saw make?

Oh – and for you hard lads that think I should get the hacksaw out again – nah. Life's too short!

Iain

[Iain DownsParticipant @iaindowns78295]

[Frances IoMParticipant @francesiom58905]

suspect you would be better off putting money towards a metal bandsaw eg the H80 from Chester (currently at ?195) tho might well be ‘pre loved’ machines elsewhere – would mean you could take slices from larger + thicker bars etc

[Roger Provins 2Participant @rogerprovins2]

I have an ancient Burgess Mk1 band saw (the one with a very slow speed) fitted with a bi-metal blade from Tuffsaws. It slices through 50mm aluminium bar in in a couple of minutes, brass and ms round bar takes longer but it will do it. As a bonus it will also cut fancy shapes in sheet material.

Can't remember what I paid for the BS from a car-boot, a tenner I think, and the bi-metal blade cost about sixteen quid. Done loads of work with it and still going strong. Rarely used a hacksaw since I set it up.

Edited By Roger Provins 2 on 16/03/2016 20:48:44

[oldveloParticipant @oldvelo]

Hi

A use a 1.5 mm thick blade with flood coolant and a slow and smooth feed rate.

Take 3 to 6 MM depth of cut with about 30 metres a minute tip speed.

On a vertical spindle mill you are very restricted in the size of the work piece you can handle.

Depending on how much you will use it a bandsaw is fine if if you can afford the cost and the space.

A small power hacksaw will be cheaper with a smaller foot print.

Eric

[peak4Participant @peak4]

May sound daft, but for cutting ally bar, I do sometimes use a hand hacksaw, to supplement my Manchester Rapidor.

The difference is, that rather than using a normal 12" hacksaw blade in it, I use a 12" length of bandsaw blade; holes drilled in the end with a centre drill.

Much coarser teeth and a thinner blade makes the job a lot quicker than a conventional hacksaw blade.

[EmgeeParticipant @emgee]

Hi Iain

After getting the right size MT shank you need to consider the saw hole diameter for the range you are looking at. Slitting saws are available with hole diameters from 6mm upwards, most popular for ME work are the 5/8" and 1" or metric equivalents. Outside diameters are from 2" up to 6", I use mainly 3" because I bought a box of many different thicknesses years ago, these are 5/8" bore.

When considering the outside diameter to buy remember the inner hole plus some allowance has to be made for driving the blade so the depth of cut is lessened by a good amount but a 4" blade should cut the thickness mentioned in your post. Thin blades are prone to running off line, especially if there is a lot of unsupported blade or if you "rush" the cut. As Frances says you may be better to go for a mechanical saw of some kind.

Should have looked at the type of machine you have first as it does not appear to have a draw bar facility, if this is the case I wouldn't recommend using a slitting saw on the machine in case the side load releases the MT with dire results.

Emgee

Edited By Emgee on 16/03/2016 21:05:18

[Iain DownsParticipant @iaindowns78295]

The Bay have some powered saws but they appear to be either older than me (not necessarily a bad thing) or quite pricey.

The Chester bandsaw looks reasonable value for money and I most certainly would like a powered saw proper – but I really don't have the budget for it. I'm not sure I have the space either.

Apart from the sheer grunt of the cutting, the handsaw on the 50×50 bar wandered rather more than I would like. I haven't reliably mastered dead straight cuts by hand over significant distances . A machine is more controllable. I hope.

Emgee – the CMD10 does have an M10 drawbar and the MT sits nice and tight. I'm a bit tempted to spend 30 quid on the ArcEurotrade setup and go for a powered saw when my ship comes in.

In passing I have a reasonably decent sized wood chop saw – can I do basic cutting off with that with the correct blade? I think it will cut 3 inch by 6 inch wood in it's current configuration.

Iain

[John RuddParticipant @johnrudd16576]

Posted by Iain Downs on 16/03/2016 21:19:46:

 

In passing I have a reasonably decent sized wood chop saw – can I do basic cutting off with that with the correct blade? I think it will cut 3 inch by 6 inch wood in it's current configuration.

Iain

Even with the correct blade for cutting metal, I think you will find the blade tip speed too fast for cutting metal…..what speed is your machine spinning the blade at?

I have a Rage Evolution 2 mitre saw that has a 355 mm blade, it runs at 1400rpm, I also have a Rage 3 Pro with a 255mm blade, that runs at 2500rpm…..

Edited By John Rudd on 16/03/2016 21:30:50

[Frances IoMParticipant @francesiom58905]

I have a metal cutting Rage chopsaw bought prior to buying the bandsaw and little used after that purchase – it was somewhat cheaper than the H80 bandsaw but tho effective wasn’t easily used in my small cellar workshop as it threw bits of metal quite far but could get though 60mm mild steel easily enough – one option I use for cutting SS rod is a small angle grinder in a stand + fitted with a thin (0.8mm) cutting disc – that combination cost me about ?30 – gets thru 40mm SS rod

I bought the ArcEuro 2MT stub milling arbor + 63mm 16mm bore saws (the largest bore for a 2MT is 80mm dia saw on a 22mm bore thus max depth is a few mm under 28mm wch should be possible I think in soft Al but very much doubt in steel

Edited By Frances IoM on 16/03/2016 23:12:54

[oldveloParticipant @oldvelo]

Hi Ian

It is possible to fit an abrasive blade to to ferrous metals on your chop saw.

Down side is lots of sparks with a fire risk with lots mess and with burned edges on the workpiece.

Eric

[Iain DownsParticipant @iaindowns78295]

I did cut a piece of scrapyard steel in half with my angle grinder a while back. I got through 8 inches of 1 inch thick steel of quite uncertain nature.

I started in my workshop but very quickly stopped and as the sparks were melting the window frames. even outside it was a bit daunting! Fear for my neighbours reaction and the difficulty of controlling the grinder has prevented me from trying again (and lack of need, to be honest).

I'd thought to make a stand for it if I needed to do chunky work again (and a thinner disc), but it hasn't come up since.

Order on it's way to ArcEuroTrade! Thanks for the advice from all.

Iain

[John FieldingParticipant @johnfielding34086]

Iain,

Try using proper slitting discs in your angle grinder. I was introduced to them a few years back and have been using them ever since to chop stock bar material into lengths for the lathe. The thinnest disc is only 1mm so the wastage is about the same as a kaksaw (yep I did write that) and they walk through most materials but normal eye goggles etc recommended.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by John Fielding on 17/03/2016 13:34:24:

Iain,

Try using proper slitting discs in your angle grinder. …

.

Can someone please recommend a suitable disc, designed for Aluminium alloys.

… Thus far, I have only used the angle grinder on ferrous metals.

Thanks

MichaelG.

[Chris Evans 6Participant @chrisevans6]

To get straighter cuts with a hand hack saw try using "all hard" blades. I can not cut straight with the flexible bi metal ones but get reasonable results with the all hard versions.

[Neil WyattModerator @neilwyatt]

Posted by Iain Downs on 17/03/2016 07:46:30:

I started in my workshop but very quickly stopped and as the sparks were melting the window frames.

Don't look closely at the glass on one end of our conservatory

When I was teenager my dad had a similar problem when he lopped the roof off a comma van to fit a high top.

Neil

[Ian S CParticipant @iansc]

It's far from impossible to build a power hacksaw from scrap metal and a 1/4 hp motor from an old washing machine, it is handy to have a welder to stick it together, and a power hacksaw to cut up the steel, I had one that I built until I bought a band saw.

Ian S C

[Howard LewisParticipant @howardlewis46836]

You may well find , in the future, that a Slitting saw is quite useful. I often use 4 inch ones, so as to get a reasonable depth of cut, when needed. (A 4 inch saw on a 1 inch arbor will cut inch and three eighths deep, max.)! If finances will run to it, a Bandsaw is also very useful. (Because of space limitations, mine lives outside under a cover made from Curtainsider materia, and regularly sprayed with oil)l

I started with a small bandsaw, but it used blades faster than I can eat chocolate, so exchanged it for a 4 1/2" one.

Use plenty of coolant, soluble or neat cutting oil, and don't overspeed. If in doubt run slower, and feed gently. Over feeding will cause a saw to wander, or jam or both. When you mount the saw, do not use a key, rely on friction for the drive, otherwise, if it jams the saw may shatter.

Having been narrowly missed by a saw when it shattered, you do not want to be nearby if it happens!

H T H

Howard

[Iain DownsParticipant @iaindowns78295]

Ian – learning welding is in my future. I bought a welder and then discovered it's not that easy! It's on my list.

I've also thought of building a saw, but I seem to be stacking up tool projects at a great rate!

Howard – thanks for the advice. My slitting saw arrived today, but I've not unpacked the bits year. I will take care…

Iain

[Iain DownsParticipant @iaindowns78295]

I'm impressed with my slit saw. Mainly.

It's actually worked well, cuts smoothly and to a reasonable depth. I got through my 20mm thick piece without much trouble.

Where I did have an issue was with mounting the piece to be cut. The Arbour (link) is quite clunky and I actually came unstuck with a later cut because the nut at the bottom touched part of the web of my bigger vice (a 4 inch drill press vice), came partly unscrewed, led to a jam, which stripped my mill gears. Again. Still, there is no concern about the blade shattering with this mill! I must admit I'm not very clear on why this arbour is so complicated (lots of rings) and more particularly how to mount pieces in future. Maybe I need to make a vice for the purpose(another mini project)! Or use a shorter nut. Hmmmm.

What I made was this

It's a £10 lamp from B&Q with the base cut off and a couple of clamps (one for right-left, one for up-down) formed by splitting the two blocks down the hole of an appropriate diameter for rod to mount on the mill top and the lamp stand..

At the moment it seems to work quite well, though I'm tempted to replace the lock not with a nut-on-a-lever (whatever the right name is) so I can slide the light up and down as well.

Iain

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