die grinder

[astro_al]

Give it another go with a nicer grinder. Find one with a single switch - none of this double trigger stuff, and look out for the ones with the narrow bodies, sounds like you could use something more manageable. As others have said, get the thin 'slitting' discs for slicing through bodywork etc. Just don't twist or rotate the grinder out of the cut line when using them. You might also look at investing in a full face shield.

Al.

 

[Furry Freak]

For perfect straight cuts I just use a piece of flat, G-clamped along the cut line. Leave enough gap for the width of the blade or you'll cut too far over. Once I have cut a clear deep enough groove, I take the piece of flat off and let the blade run free. I don't have plasma or anything like that and I have to cut everything with a slitter. I use 1mm INOX 4.5 " disc and I do all thicknesses up to 10 mm - clean, straight. Having the guide to start with is invaluable.

All this was cut in that way. OK I'd kill for plasma, but there you go.

 

[piman]

Hello Mrjynx,

"The thought of using tin snips makes my hands sore."

I use the so called 'aviation snips' very easy on body work and not hard work at all, however you'll need at least left and right hand ones, I rarely use the straight one.
I wouldn't be without them.
http://www.toolventure.co.uk/hand-tools/pliers-cutters/aviation-snips/

Alec

 

[eddie49]

Here's an arbour that will mount the small ( 3" ) cutting disks with a 10mm / 3/8" hole to the 1/4" collet chuck of an electric or air-powered die grinder:
http://www.silverstonefactors.com/i...ypage-ask.tpl&product_id=2293&category_id=473
That is a UK source - so it is not cheap!
For a lower price, log on to eBay.com in USA, and search for "cut-off arbor" ( without the "u" ). For example, this one is only $2.99 and they'll post it to UK for $3.25:
http://cgi.ebay.com/1-4-Shank-Mandr...150?pt=LH_DefaultDomain_0&hash=item5d2f71bf06
Additionally, I would recommend a Fein Multimaster ( or equivalent ), an air-powered reciprocating saw, and a Monodex hand nibbler - less hard work than tinsnips on thicker sheet, and no distortion.

 

[mrjynx]

So many replies I`ll try get through the important stuff.

Safety wise, yes I`m overly conscious about this, I was wearing a facemask denim and leathers.

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

As terrible as I am I really want to learn to do car body work, I`m hoping persistence will pay off. The only reason I said I didnt want to use oxy/acet was I just dont want to go down that route. I`d rather save the money and buy a compressor.

Pete. Forget using the normal disks though, get some super-thin ones

I was actually, I didnt want huge cuts on panels. I was okay using them, they just didnt last long. I`m tempted to get thicker ones next time.

astro_al Give it another go with a nicer grinder

Thats my plan,

Ive noticed other people seem to use the grinder backwards with the open side facing them so they can see what theyre doing, but this doesnt seem safe.

Furry Freak For perfect straight cuts I just use a piece of flat, G-clamped along the cut line

I thought about this but when holding the machine like this (pic related) I just couldnt.
maybe with a lighter one I could.

piman use the so called 'aviation snips'

I didnt think they would do well on thick stuff, I`ll admit Ive yet to try them but I will.

eddie49 Thats awesome, I dont mind paying for such a useful tool.
die grinders definitely on my list for when I cant use the compressor, being able to put cutting disks on it will be great.

 

[Shox Dr]

the ultra thin cutting discs will last no time if you don't cut straight.

If you can smell the disc, or can see a darkish yellow dust, or the print wears off the side of the disc, it is a very good indication you are trailing the back of the disc on the cut edge. They won't last 2mins of this is the case.

For example yesterday a was cutting the flashings for a 20x30meter building I'm doing, I used 2 discs to cut the lot! And there's plenty of life in the 2nd disc

 

[Furry Freak]

If you look at that picture of the grinder, I would swap the handle to the other side and rotate the guard through 90 degree and tip the whole thing over and have the blade vertical. Now, I am sure that's probably what you are doing already and it's just a library photo so just checking. Safety is very important but these are fibre reinforced discs and tend not to completely disintegrate, so I'd cut holding the tool's handle with my left hand and the switch grip with my right so that I am looking at the middle of the disc. I do think that you'd be better with a smaller machine that that to. I picked up a brand new AEG 115mm grinder in B&Q the other week for a tenner! Sometimes I'll cut a guide with the smaller disc and then get stuck in the the 9". You'll find that there is a point where it cuts better than other positions. If you try to cut along the surface as if you were trying to score through it, you'll find it very ineffective. Score you surface line that way then start at the edge of the metal and get the disc roughly halfway above and below the metal and start there. That's the fastest part of the disc and the thinnest section to cut through. Let the blade do the work. Once you are in the groove the disc will tend to follow the cut pretty straight. If you lay on the surface it will skip and skid all over the place.

You'll get there I'm sure.

FF

 

[astro_al]

Persistence WILL pay off!

Most, but not all, of the risk of rotating tools like this is in the plane of the blade - if it gives up and ruptures mid-spin, all the bits will fly out in the same plane it was spinning in, so there isn't as much risk as you might think in looking from one side or the other, I just try to keep my head / neck out of the plane of the blade. Its just physics, but that doesn't mean it won't bite you in unpredictable or unexpected ways!

Al.

 

[mrjynx]

I didnt think I could rotate the guard. this is the exact model. http://www.dropshiponline.co.uk/product_info.php?products_id=839 I bought it as a polisher mainly. I`m still going to go buy a smaller grinder but this is how I was holding it.
excuse the art, looking down on it I couldnt really see the leading edge.

 

[Paul.]

I can see why you are struggling now, I didn't realise you were using a 7" grinder, they are ok for heavier stuff, such as sections and plates but you really need a 115mm or a 125mm for cutting sheet metal, buy some thin disks to go with it and it will make a world of difference.

 

[eddie49]

Another suggestion that you may want to consider is to get a variable speed angle grinder. These are typically adjustable from 3,000 to 11,000 rpm using a speed control dial. At lower speeds there will be less noise, sparks, and stress. ( However, use light pressure and don't let it stall.) They are available from the better makers, such as Metabo and Makita. There is a cheap brand on eBay - item number 160618337050.

 

[Engineer]

I didnt think I could rotate the guard. this is the exact model. http://www.dropshiponline.co.uk/product_info.php?products_id=839 I bought it as a polisher mainly. I`m still going to go buy a smaller grinder but this is how I was holding it.
excuse the art, looking down on it I couldnt really see the leading edge.

Have you used this as a polisher yet? If so did it provide good results?

 

[chunkolini]

Definitely go for a 115mm grinder, watch out for the 125mm versions, they can be hard to get discs for.
When buying power tools look on Fleabay o buy it now items, there are often 'Reconditioned items' these have ben on display and are effectively brand new with a big saving.
Dont buy the cheapest you can find, these things tend to have a hard life.
The 1mm cutting discs are great, yuo can even make curves with them by cutting out a series of short straight lines and then grinding them to the profile you need. But as said be careful with them.
I always wear a face sheild when grinding.
An inline die grinder is a great tool and I would not be without mine, I had it on my list of 'stuff I would like' not on the needs list. Not esential but nearly so.

Chunko'.

 

[Delgado]

Going by your picture you're cutting in the wrong direction, if you hold the grinder like that, then it would be better to be cutting from right to left.

 

[mrjynx]

eddie49 - get a variable speed angle grinder

It IS actually 3-11k, I had at 10k, but I`ll consider it when getting one.

Engineer - Have you used this as a polisher yet? If so did it provide good results?

No I havent yet, when I got it a year or 2 ago, all I could seem to find were expensive ones, I got this cos it was dead cheap & killed two birds with one stone. however it isnt great at either function. it would be unwise to use any of the included polishing discs. having read up since, good polishers start at about 600rpm. I`ll still use it for grinding & maybe polishing the odd thing but I wouldnt recommend it.

Delgado - you're cutting in the wrong direction
Okay, wont grind again till I have a lighter 115 one which I`ll probably hold the other way around anyway.

Thanks for all the messages its been a great help.

 

[Delgado]

Delgado - you're cutting in the wrong direction
Okay, wont grind again till I have a lighter 115 one which I`ll probably hold the other way around anyway.

You're holding the grinder correctly (if you're right handed), it's just better to cut with the disc spinning the right way into the material.

 

[pedrobedro]

Definitely go for a 115mm grinder, watch out for the 125mm versions, they can be hard to get discs for.

Chunko'.

I prefer the 125mm for general use cutting and grinding and have a couple with rear handles as I sometimes have trouble gripping the bodies on the other type. I never had any problem getting discs, they even sell the 125mm slitting discs in Aldi when they have the offers on but if you can't get 125mm the 115mm use the same size centre and are just like a 125mm which has worn down a bit. Cut so the disc pulls the grinder into the material you are cutting and let it go at it's own pace not forcing it, your disc and grinder will last longer and you make less dust.

 

[Pete.]

I've seen loads of people hold a grinder the way that catalogue pic shows and it always makes me cringe. Same goes for the ones who turn the guard to 12/6 o'clock - they are spraying their own hand and forearm with flying particles - even if they can't feel them (unlil they notice the rash later). I hold a 9" grinder with the screw-handle on the left, away from the direction of turn and the guard at 10/4 o'clock so that both my hands are guarded from flying bits.

 

[PhillipM]

^^I use my little 115mm makita one handed usually, or with the second hand over the gearbox casing, so it doesn't really matter where the guard is