Is there such thing as a jig for a hacksaw?

[Can'tWeld]

Hi,

I have the need to make perfectly straight cuts in things (box section mostly). I know what I really need is a chopsaw, but I can't afford it right now. I'm finding it difficult to cut straight by hand with a hacksaw and even more difficult with a grinder.

Just wondering if anyone has any experience of buying or making a 'jig' for cutting with a hacksaw? I don't mind how long it takes, I just need the edges to be straight!

Or... can anyone recommend a mitre saw that will cut metal for £50 or less?

Cheers

 

[rtbcomp]

Something from here may take a hacksaw blade?

http://www.screwfix.com/cats/A335557/Hand-Tools/Saws/Mitre-Saws-Boxes

 

[series2]

I have a mitre saw from B&Q, I originally bought it for cutting architrave when I was fettling the house. It came with a 'metal' blade & I have used it for cutting box & angle since and it works well.

I think it cost around £15.00, and they have spare blades for them (or did).

I've never seen one that takes a standard hacksaw blade though.

 

[MrFluffy]

Actual ability to get straightness out of a hacksaw depends on three factors mostly. The rigidity and straightness of the frame, how even you apply downward pressure and (biggest imho) the quality of the blades.

However, cheat's way out on tube (and box if your an animal and tighten them up so they distort into the box shape) is to put a jubilee clip on the tube and then clamp it in place, and use the edge of it as a saw guide for the hacksaw blade. The blade will skid down the edge rather than cutting into it thus giving you a neat straight edge
You could rig up something more perm if you have lots to do with a bit of box section thats slightly larger that you can clamp in position.

 

[rkde]

I use an adapter from machine mart for my angle grinder, basically turns it into a chop saw

http://www.machinemart.co.uk/shop/p.../path/14-angle-grinders-polishers-accessories

 

[Tin Can]

Just like rkde i brought the same stand for use with my angle grinder

HOWEVER check that it will accommodate the box section you are using, if not Axeminster tools do a larger version for 9 inch grinders

http://www.axminster.co.uk/product....le+grinder+stand&user_search=1&sfile=1&jump=0

 

[Can'tWeld]

Thanks everyone. Have decided to start by getting some 1mm cutting discs for my grinder, I'll see how accurate I am with those, if I'm still crap I'll look at one of those stands. Thanks

 

[MaxRPM]

I've got a stand you can have for the cost of the postage if you want one, it's for a 9 inch angle grinder though.

 

[Mick.R]

MaxRPM you have a p.m

Cheers

 

[fluxcored]

Thanks everyone. Have decided to start by getting some 1mm cutting discs for my grinder, I'll see how accurate I am with those, if I'm still crap I'll look at one of those stands. Thanks

I bought myself a cold saw and after spending all that money found that I could make as neat a cut and as precise with my 115/125mm grinder although it takes a bit longer.

I followed these steps:
a. Marking out should be done carefully. If I want to be super accurate I use marking blue and a scribe.
b. 1mm discs of course.
c. Stability. Make sure that your work piece is rigidly clamped at waist height and restrict your body movement as much as possible. I try to keep the grinder as close to my body as possible and lean against the work table or piece. Do'nt rush or force the cut.
d. When cutting box I cut one face at a time.
e. I do'nt start the cut on the scribed line but very close to it. Most of the time once the disc start to bite the first 1mm of metal I maneuver it exactly adjacent to or precisely on the line and start cutting.
f. Sometimes I finish off with a file or may use a belt sander.

(c) is very important in my book. If you do'nt have full control over either your movements or your work piece or your grinder you'll never cut straight or accurate. Just be very careful - use a guard, tuck your shirt in and wear eye protection. You'll be very close to the spinning disc and sparks.


(a) also rates very high - a scribed line will be more accurate than a chalked or pencilled one.

My grinders are still the most used tool I've got. Just got a Makita 115mm as a gift - mighty pleased about that.

 

[rtbcomp]

I use pretty much the same as Fluxcored, additionally I make sure there is plenty of light on the workpiece and move the grinder away from my body so the marked line is not obscured by the grinder.

 

[Can'tWeld]

I did have a go with the 1mm discs (well, actually they're 1.2mm) the other day. They do seem to cut a lot more accurately (and far faster) than my other cutting discs which are the big hefty ones. Still found it hard to cut the box section straight with them but I'm sure that will come with practice and I think fluxcored's suggestion of cutting one face at a time will be useful.

The main reason I want to do this is to cut mitred joins in box section to join them at a 90 degree angle, as it will be stronger than butt jointing them. (Yes, it's for my camper project - I wasn't happy at all with what I ended up welding together the other day so I've cut it up and I'm starting again, I want mitred joints. Perfectionist? Me? Perhaps...)

I'll have a go tommorrow on some scrap lengths and post the results. The other thing that throws me slightly is that this box section I have isn't actually square, the corners are rounded - which is another reason I need to mitre them to get a good neat join.

 

[Can'tWeld]

Well, I just couldn't cut straight with an angle grinder. I tried, and I tried, but I failed.

So I decided to treat myself to a cheapo abrasive chopsaw. Got this from Machine Mart for £46. It's by a name I've never heard of before, but I won't be using it much and it does, after all, have a warranty...

It actually cuts very cleanly (by my standards). Obviously I shall have to see what it's like long-term when the bearings start to wear out, but I'm quite chuffed with it for now.

Here is a mitre joint I've just done with it...

Just thought I'd update for the benefit of anyone else who is cr*p with a grinder

 

[Pete.]

Free-hand cutting with a grinder does get a lot better with practice. I'm quite good at it but I know folks who are much better. If you use the 1mm blades it's a lot easier because they cut rather than bounce. The trick is to get a tidy line marked out, then but very lightly with the thin blades and to work in a comfortable position.

You can't beat a chop/cold cut/bandsaw though.

 

[Can'tWeld]

Only problem with that chopsaw seems to be that it eats discs. Already used one today

The disc isn't that worn, maybe 1-2cm, but the machine is designed in such a way that it will no longer cut all the way through the piece once the disc is worn to a certain point. No way to adjust it either.

Will have to get some more. 6 inch chopsaw discs don't seem to be too easy to find for some reason.

 

[brookie456]

Only problem with that chopsaw seems to be that it eats discs. Already used one today

The disc isn't that worn, maybe 1-2cm, but the machine is designed in such a way that it will no longer cut all the way through the piece once the disc is worn to a certain point. No way to adjust it either.

Will have to get some more. 6 inch chopsaw discs don't seem to be too easy to find for some reason.

Norton Abrasives used to do a 9" "slitting wheel", nothing better for getting rid of overly-interested customers when you point out the fragments int the roof If they still do it, it's designed to erode - if they glass up, PING Be careful.