how precise is abrasive chop saw

[pattaff]

first of all i would like to say hello ,this is my first post on the forum, normally i get all the info i need from reading through the different post, so i say thanks to all for that,
but now i need to ask something..

i just bought a chop saw ,my first one so i got no experience with how precise they should cut, on the one i just bought the disk has a 1 to 2 mm vertical lean. so when i cut at a right angle to the blade it cuts fine across the top of the metal but when it starts to cut down through the metal it cuts at a tilt of 1 to 2 mm, which seems like a lot to me..
if i put a right angle sitting on the base of the saw against the disc i can see a slight tilt on the disc. i checked if the disc is fixed right and it is

so my question is, if this margin of error is normal with abrasive chop saws??
or have i bought a defect

by the way the saw is a maktec MT240 the cheaper brother of makita

 

[madkayaker]

im not sure of any allowed tolerance but have always found chop saws to be a bit off. some have adjustment on them so that you can true them up.

 

[brightspark]

first of all i would like to say hello ,this is my first post on the forum, normally i get all the info i need from reading through the different post, so i say thanks to all for that,
but now i need to ask something..

i just bought a chop saw ,my first one so i got no experience with how precise they should cut, on the one i just bought the disk has a 1 to 2 mm vertical lean. so when i cut at a right angle to the blade it cuts fine across the top of the metal but when it starts to cut down through the metal it cuts at a tilt of 1 to 2 mm, which seems like a lot to me..
if i put a right angle sitting on the base of the saw against the disc i can see a slight tilt on the disc. i checked if the disc is fixed right and it is

so my question is, if this margin of error is normal with abrasive chop saws??
or have i bought a defect

by the way the saw is a maktec MT240 the cheaper brother of makita

if it was a good quality saw and was brand new it would be verry acurate cheaper saws arent so

 

[pedrobedro]

I've had a Screwfix version for years and when I bought it I loosened the bolts holding the part where upstand is held to the base and put a shim in to square the blade up. A piece of 16g did the trick then tighten the bolts back down.

 

[Wedg1e]

I have a Bosch Professional something-or-other, cuts nice and square... as long as you don't get all Grape Ape with the leverage.

 

[Chickenjohn]

This http://www.youtube.com/user/AmericanFabricator#p/a/u/2/2zd5Y17AIBQ watch 7.30-8.50 illustrates perfectly the difference between abrasive cut off saws and a decent metal cold saw.

 

[fluxcored]

Why do'nt you take it back? I've always find Makita very service oriented and always willing to assist with customer complaints. I do'nt think it'll be any different for their Maktec range.

A few years ago they replaced the quill on a brand new drill press I bought from them after complaining that's it between 0.1 to 0,2 mm out of true.

 

[Welderpaul]

Abrasive chop saws arnt noted for being the most precise cutting tool. We have a Maktek saw as well, and i think ours has a small shim to level it up. The key with using it is to cut gradually so the blade keeps fairly true. If you force the blade it will wander to one side, then keep this path giving a nasty cut.

 

[pattaff]

thanks for all the replies ,fluxcored i'll try and send it back,but i got it off ebay so lets see how easy it is send it back.. sounds like the chop saw is not the most precise ,but i do think this one is just a bit to much out to handle with,
i went to a makita shop today and had a look at their version and i have to say lining it up with a square it looked right on the mark.
so all i can do is see if he takes it back and i reckon then i'll go for the makita
cheers

 

[pattaff]

Chickenjohn just watched that vid ,ye it makes sense just cant afford to fork out for a cold cut ,but thanks for the link
, i think i watched some of that guys vids before

 

[brightspark]

cutting discs stone or metal require a fast surface speed to operate eficiently .riving into the material slows the disc down which reduces cutting power .wears the disc out faster and overloads the motor and as paul says if u cut at an angle and force it down it will run off

 

[nerdstar]

thanks brightspark exactly the info i was searching for.. good tips

 

[Pete.]

There's no reason why you shouldn't be able to hold 1mm tolerance and repeatability with an abrasive saw for cutting square across. Angled cuts are a different thing. I modified a cheapo Wickes mitre saw to take 7" cutting discs and managed to get very accurate cuts with it on 1.5" tube.

Good quality blades help, as we found out at work this week. We had some 9" grinder discs and were struggling to cut 32 and 40mm rebar with those (wasn't allowed to use oxy) until I complained and took the box back to our place and swapped it for a box of Norton discs. The difference was night and day.

 

[langy]

I have a Bosch pro jobbie and they are not accurate, a lot is to do with the blade deflection.

 

[jwt873]

I was going to get an abrasive saw, but decided to spend a bit more and got a dry cut chop saw.. I don't regret the decision.

The only downside is that it uses an fairly expensive carbide tipped metal blade rather than an inexpensive abrasive disk. But it sails through mild steel like a hot knife through butter. You get very clean burr free straight cuts with hardly any sparks and no red glowing metal and the resulting bluing from the heat that an abrasive disk can cause.

Just today, I cut up a bunch of thick walled 5 cm round galvanized tubing and some 75 mm angle. I could pick up the freshly cut pieces with my bare hands.. They were warm to the touch, but not hot enough to burn me.

Here's a link showing a dry cut saw made by Evolution in action (thanks to a forum members who posted it a month or so ago when I was trying to figure out which saw to get. The video made up my mind. (Watch it go through an 'I' beam and watch the guy touch the freshly cut end with his bare thumb).

http://www.youtube.com/watch?v=gz9fdoFFdvc