Mitre cuts

[HoSS]

Looking for input on the best way to get tidy mitre cuts on square section steel tube.

- Plasma with jig?

- Angle grinder with some kind of chop jig?

- Looked for slit discs for my bench mitre saw, but cant seem to find anything that will fit instead of the wood blade.

- Other ideas?

Needs to give a good repeatable result at 45, 22.5 deg and possibly others, on box tube to be welded.

p.s. Was looking at plasma cutters, (and r-tech rather than ebay, as i dont mind spending a bit more for quality) but is the pilot arc worth it or will the base HF model do for general sheet and chassis work?

[Lewis]

I wouldn't consider a plasma for cutting mitres on hollow section, far better to spend less money on an Evolution Rage chop saw or a budget horizontal bandsaw.

Rage = quick and loud

Bandsaw = slower but almost silent

[FridgeFreezer]

Another vote for the Evo saw here, if you have thick stuff (4mm+ wall) get a spare blade in, oh and REALLY REALLY wear eye & arm protection, they throw some serious chips when cutting metal.

[robertspark]

Plasma, get HF as a bare minimum.

There are two major options, and then a minor variant.

Scratch start, HF, then blowback start, which is an internal pilot where the compressed air blows the electrode back creating an airgap which creates a plasma pilot arc. Hyperthem work that way, and if you look for plasma cutters with Trafimet torches (s45 s60 etc), they work in a similar way.

The problem with mitre cutting and plasma is that it will only be able to cut one side before you have to rotate the tube.... Hence you are less likley to get alignment perfect with a hand cut, also plasma will harden the cut edge meaning it will be harder to file to shape

Hence why mechanised plasma cut is the way to go .... Consistent cut every time although you really want a forth axis if you are doing a lot or some means of tube alignment so you can still rotate the square tube and cut it on a X Y table flat bed

Rob

[GW8IZR]

How much do you need to cut and how often, is it for diy or occasional use? Is it worth making jigs and stuff for the amount of work.

I have both bandsaw and plasma and I'd use the bandsaw every time as its easy to set angles and get accurate cuts. cut several pieces at a time and quiet / efficient 2hp motor versus big compressor and plasma.

For a more industrial or bulk operation I might think about setting up something for the plasma but most likely not.

[mmgemini]

I used an Evolution chop saw when I cut the square tube on my trailer.Page two of my trailer build shews how I did it although with an earlier saw.

The professional Evolution blade cuts better and lasts longer

http://www.evolutionpowertools.com/uk/

Believe me that saw cuts steel easily

[steve b]

For diy project work a chop saw is perfectly good , especially as you are welding the joints - any minor error will get filled with weld .

High volume manufacturing could use laser cut - we had some round tube laser cut for a perfect fit on a hand rail a few years ago . A plasma would not give a

good joint on small hollow section

cheers

.Steveb

[Ozzy50]

Another vote for the Evolution Rage saw ,had mine for a couple of years and it's brilliant,chops anything with the same blade and if you look after the blades they last long enough ,just make sure you set the angle correctly as there is a small amount of slack in the set up .

[HoSS]

Cool thanks for all the ideas. I will look into a Evo Rage saw.

But was also considering a bandsaw. I can find Clarke and Sealey or SIP in my budget, any recommendations on those three?

It would be quite nice to have one that stands up and can have a table attached for plate cuts

[Cynic-al]

I have a really old makita chop saw, takes a 14" blade with a really odd bore, I can only get 12" blades for it but they're a bit restrictive so at some point I'm going to make an adaptor so I can go back to 14" blades. It's reasonably accurate with a bit of care so long as you support your length of tube so that it's level with the bed of the machine, not as easy as it sounds as its a narrow bed and sometimes the section your cutting bows along it's length. It comes with the same dust, noise and heat problems as using a grinder and you get a burr underneath. At some point I want to get a horizontal bandsaw, more social but spendy, especially if you want to add coolant etc.

At work I have a mec brown cold saw with coolant. Construction wise compared to a £250 horizontal band saw it's like comparing a Russian tank to a Citroen. It'll do 100mm box at 90 degrees, less at an angle, there's no heat, it has a quick clamp system for if your shuffling the work through, the accuracy is superb and the quality of cut means there's no finishing to do. The blades can also be sharpened for a bit more life. I knocked up a stand on wheels so you can support the work wherever needed and if you doing lots of cuts from the same section it follows you as you pull the material through so it's nice and quick. They often come up at industrial auctions and sometimes sell for less than a new bandsaw, they're always 3ph though so you may need to consider the option of conversion. Only downside over the bandsaw is you have to stand there pulling on the handle rather than pressing go and walking away. It's faster than a bandsaw though.

[HoSS]

We have a couple of bandsaws at work of varying quailty. One bonus is that i can get blade of the roll and weld it on our machine.

If i'm cutting big bits here, i have a homebrew automatic mode which involved a cable tie on the trigger and a lead weight hung on

[UdderlyOffroad]

Another vote for the Evolution saw.

I bought the 255 mm version about five years ago. Whilst it’s been great for house projects as well as metalwork; it’s large, heavy and awkward to carry. In other words, best suited to sitting on some kind of dedicated chop saw bench/station. This isn’t I suppose a criticism of the Evolution itself, as I presume all chop saws of that size are awkward firkin’ great lumps. That does mean though, that if you’re looking at options solely for workshop use (and not moving around to various properties when doing them up), a bandsaw might work better. Indeed I covet-eth one and had to resist the urge to buy Si’s when he advertised it for not much money on here.

Actually I fabri-cobbled a material stand/ chop saw station out of an old trolley. Wish I’d taken more time and designed it properly rather than just ‘by eye’. But it works and at least I have all my materials stored in some sort of order, for the grand total of £0

Untitled by udderlyoffroad, on Flickr

Anyway, if you're in Bristol come over and have a try at making some swarf.

Matt

[Ozzy50]

That's the 355 mm model ,can cut 170mm box at 90deg and 140mm box at 45deg ,max thickness is if memory serves 6mm ,it's out of warranty now so I dare tell you that I have cut 170x170 H section in it with no problems ,just take it steady and it s reet !.Think I have had it 2 years if not more and I would be lost without it ,use it in the workshop and on site (110volt).As others have said wear gloves and eye protection as whilst there are no sparks it does generate tiny pieces of hot swarf when cutting steel which are hot and painful!.I mentioned before that I set the angles with a set sq as there is a little bit of slop in the frame now but nothing critical ,blades are about £53 ,can't remember if that is with vat or not ,the blades are top quality Japanese made and last well if looked after although the wife is good at warping them when she cuts wood ,I keep telling her not to cut wet wood but it falls on deaf ears !,anyway it keeps her happy cutting firewood .

[Ozzy50]

Forgot to add ,I also have an R tech plasma but would always pick the Rage for cutting box/angles etc .Hope this helps

James

[simonr]

Another vote for R-Tech. I bought one of their AC/DC TIG's and am very happy with it. Get one with Pilot Arc - it's much more versitile and easier to get a good cut. HF start is a must too.

However, for what you want to do - a saw will beat a plasma.

Si

[Superpants]

Another vote for a cold saw- I found one at an autojumble for £15 which needed a new capacitor, but was single phase. It is really solid and gives a lovely finish. I would buy again if I could find one at a good price.

[HoSS]

Think i have decided on this for the mitre cuts, looks a nice bit of kit for the money.

http://www.axminster.co.uk/axminster-model-engineer-series-mcb1155hd-swivel-head-metal-cutting-bandsaw-700103

I will also be investing in a R-Tech 170A AC/DC Digital TiG

And if my budget runs to it an R-Tech Pilot Plasma.

[GW8IZR]

Good call,

I've spent many hours improving mine which yours wont need.

I have this one and everything under the yellow line is carp so for the extra 90 quid that you are spending you will have a good tool.

[HoSS]

The only thing that axminster doesnt do, which some do (i.e. Draper) is stand up straight and have a small table fitted to use as a vertical table bandsaw... shame

[Lewis]

My mate has that Axminster saw, I really like it. It's a lot better than my ancient Clarke saw. Do yourself a favour and get an M42 Bimetal blade for it, the standard HSS blades aren't up to much

Axminster in action

[robertspark]

Which rtech acdc tig did you buy si or anyone else?

I like the synergic functionality on this gys acdc 220 ... But the cost...

http://www.weldingsuppliesdirect.co.uk/gys-tig-220-dual-voltage-ac-dc-tig-welder.html

I like the semi syneric on the esab MIG 200i for the infrequent use of my MIG, hence its idiot proof to pick it up and go.

I have a cebora 160 tigstar with pedal and waveform adjustment, but it lacks the idiot proofness of the pick it up and weld a perfect bead every time of the synergic MIG (or that which the tig may offer)

I know rtech do a 250 with memory settings that may also be useful.

Problem with the rtech plasmas.... No cutting tables....IMHO

Rob

[HoSS]

The R-tech 170A AC/DC digital is the one i'm looking at. I decided to go for the digital version beacuse it seems easier to set up for a newbie. It has 9 memories.

I like the synergistic function on that GYS, but not for 600 more notes.