inaccurate chop saw

[Dangle_kt]

Hi everyone!

I'm getting very stuck into my trailer project but I'm having real issues with my chop saw. Some angles it cuts fine, others it WAAAAAYYYYY out.

I'm cutting 45 corners to make a frame from 50mm box, and whilst most are there (or there abouts) that can be made to fit with a small root gap at one end or the other the short peices are causing a real problem.

Becuase they are short the clamp doesn't hold them, so I hold them by hand, and the inevitable twisting happens.

My question is - how do you fix a peice of metal that has cut like the picture below? If I try to recut it the chop saw just follows the same path becuase the disc has no strength against side to side motion, and I can't turn it the other way and cut from the other side as the chop saw disc isn't big enough to cut - plus it will just be as inaccurate even if I managed to use the extremitiies of the disc.

What do you guys do? and how would you fix this cut?

 

[rusty69bus]

with a set square, a pen and an angle grinder

 

[Dangle_kt]

thats what I was hoping no one would say! I havn't got a vice, so holding the angle grinder in one hand, and the steel in the other sounds like it will go horribley wrong.

****!

 

[Hitch]

Work the angle grinder into it, true it up by eye.

Try and cut small bits from bigger bits so you can clamp them up in the jaw. Very bad practice to hold stuff in a chop saw with your hand.

If you have to cut small bits, mark them out and cut with a grinder whilst clamped down to a bench or in a vice.

A cheap combination square and a carbide tipped scriber is ideal for marking out mitres.

 

[Dangle_kt]

thanks hitch - seems I need to invest in a few more tools.

 

[Hitch]

A cheap combination set probably set you back £10/15 and a couple of quid for a scriber.
Biros work to a point, the ball is pretty hard.

 

[Luke]

I'd say investing in a vice, square, scribe etc is well worth whole.

you can G-clamp the metal to the bench, if you haven't got a vice.

 

[gavuk]

don't use chop saws so don't if i'm a bit off the mark ,(on my bandsaw)i've used flat steel to extend the working range of the vice,usually need a small offcut or adjustable screw at opposite end of part being clamped so vice doesn't twist or, tack weld short pieces to other material and use vice normally then cut off and dress with grinder afterwards,would also recomend cheap combination square and scriber some clamps and even jig magnet ,sure u will use them for other projects as well.hope this helps.......

 

[zzr1200]

with a set square, a pen and an angle grinder

Plus a Hacksaw

thats what I was hoping no one would say! I havn't got a vice, so holding the angle grinder in one hand, and the steel in the other sounds like it will go horribley wrong.

****!

Large G clamps (6" and above) are useful as well.

 

[rtbcomp]

Are you using too much pressure on the chop saw? thus forcing the disc out of true?

 

[Dangle_kt]

Just made it back from machine mart, I haver a carbide scribe, welding corner magnets, g clamps, combination square, 5 plasma cutting dics for the angle grinder and a nice smallish but solid vice.

£60 mind!

Still they will all do for other projects, so are an investment.

 

[Hitch]

Cant be bad, all that for £60!

The thing with tools is to always buy the best you can afford. Even if you anticipate only using them once, its rare it happens like that!

 

[Dangle_kt]

I guess so, its just knackered the budget on my bike trailer thats all, means I won't be able to afford to get it galvenised now for less than I could have got one second hand.

Never mind! At least I have got them for future projects too.

 

[scarecrow]

Your chopsaw should be cutting more accurate than that. I usually use of 45° set square to set the angle of vice you could also use a small square to check if the blade is falling and 90° if you put much force on the blade specially at 45° the blade tends move out along the peace. the trick is to apply very little force until its cut into the peace if you don't understand I'll post a few pictures for you

ps
if the bit you are cutting is very short try tacking it to some flat