die grinder

[mrjynx]

I had my first experience cutting metal with an angle grinder & cutting disc today, the results were really poor, wonky lines mainly due to the big chunky heavy grinder. as much as I`d love a compressor and air tools its just not a practical option atm.
So Im looking for something electric but small to take 3" cutting discs.
I own a dremel which I dont really want to use.

I dont want to spend £500 so Im looking at £180 tops.

But I still dont understand some stuff.

I also saw a Proxxon long neck angle grinder but this only takes 50mm discs which seem impossible to find.

Ideally I want 3" discs with a guard. But I dont know if you can get a guard for a die grinder or if/how the discs fit. do they need to have a shaft attached?

 

[PhillipM]

Tried a smaller, lighter grinder? The little Makita models are light enough to use one handed or just stabilise with the other hand.

 

[john224]

What about a heavy dute flexy drive using 3" discs of air grinder?? they do a flexdrive that takes 1/2 drill/bits so could get a harbour made to take the discs,,,
Also what about a small wood workers router take the bits of the end and use like a LARGE DREMMAL,,,

 

[mike 109444]

You could look at the rota zip range ant the various attachments (not the cheepest option) such as the rota saw... Another option which I use is a small light weight router such as early B&D 1/4" ones or small bosch ones. But you may have to makeup a guard to suite .

 

[mrjynx]

I read here that flexi shafts arent good at high speed & dont want to go modding things. I definatly want to use discs.
I still think even the smallest 115 grinder is going to be too chunky.

 

[mrjynx]

I just came across rotozip tonight, will have to look into that more. the unit seems a bit chunky.

What do you put on the router to cut?

 

[astro_al]

If I were you Id just get better with a grinder, they're not exactly heavy. It's a baseline tool and skill in metalwork, just get used to it and save your cash for something useful.

Al

 

[Engineer]

If you must have 3" cutting discs, then look at Makita, Bosch, Dwalt electric die grinders, with an arbor fitted to take the discs. However a 115mm angle grinder with 1mm cutting discs will do almost any form of cutting, unless space is very restricted.

 

[mrjynx]

My other thought was get a cheap dremel copy off ebay, doesnt really matter if I burn it out. I just know using an angle grinder theres no way im going to be able to get into tight spots with car body work.

 

[Paul.]

If you cant make a straight cut with a 4 1/2" disc you will certainly struggle with a 3" or smaller, you say that today was your first attempt, like all hand tools you need to learn how to use them, and develop the correct technique,
I accurately cut loads of sheet, mostly stainless using thin cutting discs on 4 1/2" grinders, there are a few tricks which will help you,

If working on a bench make sure the piece being cut is securely clamped down, any vibration will soon destroy a disc,

support the offcut so it doesn't sag,

get a firm but comfortable grip on the machine always 2 hands,

sometimes it helps to run the disc along the cut line to define the cut, don't force the disc, let it cut at its own pace, if you press too hard you will wear out the disc prematurely, and the edge will overheat and expand causing the disc to wobble, it may even snag and break the disk.

Die grinders are useful for tight spots, but for basic material cutting the angle grinder is better, unless you have access to a guillotine.

 

[mrjynx]

What is this arbour you refer to? those were the brands I was looking at. I just cant find the "thing" to make the discs fit.

 

[mrjynx]

If you cant make a straight cut with a 4 1/2" disc you will certainly struggle with a 3" or smaller, you say that today was your first attempt, like all hand tools you need to learn how to use them, and develop the correct technique,
I accurately cut loads of sheet, mostly stainless using thin cutting discs on 4 1/2" grinders, there are a few tricks which will help you,

If working on a bench make sure the piece being cut is securely clamped down, any vibration will soon destroy a disc,

support the offcut so it doesn't sag,

get a firm but comfortable grip on the machine always 2 hands,

sometimes it helps to run the disc along the cut line to define the cut, don't force the disc, let it cut at its own pace, if you press too hard you will wear out the disc prematurely, and the edge will overheat and expand causing the disc to wobble, it may even snag and break the disk.

Die grinders are useful for tight spots, but for basic material cutting the angle grinder is better, unless you have access to a guillotine.

Today I was, using my quite large polisher/angle grinder. with the metal at waist height (was cutting out a washer) I had the handle on the let side with the sparks flying away from me, cutting to my right, so I couldnt really see if I was cutting straight.

 

[PhillipM]

^^The big ones with the trigger on the handle at the back?

They're a waste of time, you want something like this:

http://www.screwfix.com/p/makita-9554nb-4-240v-angle-grinder/53964

There's a link on here somewhere for a cheaper firm.

 

[octo0072000]

cutting

you could always do it the old fashioned way pair of tin snips, electric hacksaw reciprocating saw,
or as i think you are meaning cutting out hard to get at bits on a car the good old gas axe oxy/acet torch or you just have to cut out bigger bits then weld the tight bits then re-weld in the other bits back in after no real easy way

 

[mrjynx]

^^The big ones with the trigger on the handle at the back?

They're a waste of time, you want something like this:

http://www.screwfix.com/p/makita-9554nb-4-240v-angle-grinder/53964

There's a link on here somewhere for a cheaper firm.

Actually it has 2 buttons that you have to press, one on the side and on the back so you cant manipulate it, and can only hold it one way away from yourself. I will buy a smaller one & give it a go.

octo0072000 - The thought of using tin snips makes my hands sore. I dont think I`m quite ready for oxy/acet just yet.

 

[piman]

Hello Mrjynx,

to repeat what other say, an angle grinder will do most of your car body work. I use an air saw for really tight areas, but don't know if you can get a small electrical version? Don't forget that snips will get into corners if you cut most of it away with a grinder?

Alec

 

[astro_al]

octo0072000 - The thought of using tin snips makes my hands sore. I dont think I`m quite ready for oxy/acet just yet.

Have you thought about paying someone else to do the work?

 

[Engineer]

I did car bodywork for many years and have to say that not once did I ever have the need for 3" cutting discs!

 

[Delgado]

I would also say get good with the 4.5" grinder, Takes a bit of practice, but once you do you'll be able to cut straight lines, curves and circles with no fuss.

here's some tips, appologies if any of this has already been said;

When cutting straight lines, put the handle on the grinder it makes it easier to keep it upright.

Mark your lines with a scriber (and pen if you like) as once you start cutting, the scribe lines kind of 'light up' and are easy to follow.

Use the front edge of the grinding disc (cutting away from yourself) and it'll pull itself along on pretty much on its own, don't let it dig in too much, if it starts to go off course lift it out slightly and correct, don't just try to angle it back straight.

Wear goggles (or a full face sheild) not specs (a P2 mask is also a good idea, as are gloves), so that you can get in and see what you're doing without worring about the sparks getting in your eyes (the Bolle ones are quite good).

HTH

 

[Pete.]

Have to agree with the 4.5/5" grinder advice. Forget using the normal disks though, get some super-thin ones and you'll never look back. I am currently using Inox stainless disks and they are pretty good.