Electric Grinders

[Jonas Smith]

I wind up buying a new 4.5" grinder just about every year. I have always bought the Dewalt brand. One year I got away without buying a new grinder because I bought a Porter-Cable, and that lasted 2 years, I dont know if it was because it was a better grinder, or that I did'nt use it that much that year.
One of two things consistently fail on my grinders. The 90 deg. gear, or the bearing in the head. At the cost to rebuild, and the downtime involved, it's always been easier to spend a extra $20 and buy a new one.
Well my latest Dewalt DW400 crapped the bed over the weekend while cutting up a PW frame. Stripped out the gear as usual, and the bearing had been making a heck of a noise but had'nt seized yet.
So I made my trip down to the Oxarc, welding shop to hand over my $89 annual fee for using a dewalt DW400.
I walked through the door dragging my old grinder by the pigtail, ready to start swining around like a south american bolo hunter at the counter help ( who in everyones opinion is a idiot) when I saw a aquaintance buying some mig wire who owns a fabrication business in he county.
"nice dog!" he says.

Thanks,
Anyway, he goes on to tell me that te reason of the failure is because of inadvertantly shock loading the head while grinding.

He truned me on to a different type of grinder that I had to special order.
It's made by a company called Metabo, and they are made in Germany. The interesting thing about this grinder is that it has a clutch mechanism in the head that prevents shock loading the grinder. It cost $150 for a factory rebuilt unit, and I just picked it up today.
It works well so far, and has the typical German "heft" feel to it.
I'm going to be grinding a lot in the next couple of weeks, putting the swivel joint in a different frame. enought that I am sure it would wear out a dewalt. I'll give a report on the grinder in a month and let you all know if it lets me down.

[powerwagontim]

Hi Jonas,
I have to agree on Metabo quality. I have a pad sander and a 3/8" drill. The drill is way torkier than any other 3/8" drill in the shop. It also has a feature which allows it to slip if the bit gets bound instead of turning your wrist into a pretzel. It has never slipped during drilling, only when it binds.
Tim

[Cheyenne Dave]

For whatever it's worth, I consider the 4.5 " grinder to be a light duty tool. We use the big (8"?) grinder for serious grinding and leave the the wire wheel and clean-up grinding for the 4.5". I bought a used Black & Decker Proffesional several years ago and it still performs great for the light duty tasks...no rebuilds yet. I also have a diamond blade for it when I need to cut stone and that works sweet too. However, too much of that and the stone dust will eventually kill the motor.

For tasks such as frame cut-up, it's either the gas hatched or sawzall. I bought a used Hitachi cut off saw that we use to cut up lengths of angle, flat, bar, and pipe stock. Had that for 5 years and only replaced blades and one spring, and that was broke when I bought it.

[MoparNorm]

Hi Jonas,
I 've had the same Milwaukee 4.5 for 15 plus years. It is pretty beat up but never misses a beat. If you need a tiny little pie grinder like the 4.5 (ha!ha!) get the Milwaukee and keep some Americans working.
MN

[Gordon Maney]

In recent years I have purchased almost exclusively Milwaukee power tools.

Very durable....

[Randy N]

Jonas
I used a Metabo 4.5" grinder when I was in the maintenance dept of a pulp mill. After trying a multitude of brands, the Metabo became standard issue for all the mechanical trades. I went through 2 in 5 years working there and used them a lot. I have one of my own now and have had no problems.
Now after saying that I hope you have the same success.

Cheers

[Joe Cimoch]

Jonas, have you had a chance to put the Metabo grinder to work? What are your thoughts? My Makita is ready to be retired. Whats the model of the Metabo you are using?

Thanks,
Joe

[Jonas Smith]

Used it today to put the swivel frame in a new home...

I had to junk the old frame that the swivel was in, and cut up a perfectly good frame to day to put it in. I have used the Metabo for about a total of 5 hours, since I bought it. Not a lot of time with it but so far it works great, and the declutching mechanism works as advertised. I've used it to grind out a lot of sloppy weld on the mechanism, and "V" out some cracks to fill with the Mig.
I'm also building a flatbed for a '49 Power Wagon that will hold 300 Amp engine driven DC welder and a set of torches, and all my other welding equipment, toolboxes, rear winch, etc.... so it's going to see a lot of use in the next 6 months.
I like the on-off switch a lot better than any other that I have used because it's big and easy to use with gloves on. The switch has a lock on it that keeps on switch depressed if you want. It seems a bit dangerous, but your hands suffer a lot less fatigue through the work, so there is less likely chance of getting sloppy with the grinder.
The model is just thier 4.5" with a quick connect, so you dont have to have wrenches to change out the disc.
I started using a brand of disc called razorblades and they last a lot longer, and cut better than the Forney discs I was using.

[Joe Cimoch]

Thanks Jonas. The switch on my Makita is a good idea. It locks in the on position so you don'r have to hold it down. The back of the switch is big, and your thumb rest against it when grinding. As soon as you squeeze down with your thumb the switch springs to the off position, it works well with gloves.

[Kevin in Ohio]

One other trick you can do to prolong the life of the gear teeth is to put a zerk on the backside of the head where it is out of the way. We noticed that the heat build up would melt the grease and the gears would be dry and prematurely wear. About the first of every month we'd pump several shots of corn head grease into it. We never had a problem again. You have to take it apart first to make sure all the shavings are cleaned out from the drilling and tapping but it is time well invested. We were running 7 and 9 inch grinders. Kevin