Dotco not so good

[Vinko]

My Dotco grinder, which I put a photo of in this thread, has had it's trigger hold snapped off through very minimal use.

http://www.garagejournal.com/forum/showpost.php?p=388168&postcount=5

Sigh....


A little thing, but a pain to operate none the less.


It's cheap plastic composite piece.

I might as well have to good grinders, but do I go with another Dotco while I send this one in to be fixed, or do I try another brand...like Dynabraide.

I guess I'll call the guy who I bought it from. Still you pay about $400 for what you think is a top-notch product, and it's a bummer to have to deal with all the hassle.

 

[Vinko]

It looks like you've got a rubber band around it....

That was the way it came shipped. But it looks like I'll have to put that rubber band back on, eh?

 

[alex71]

I have that same grinder.. hasn't seen much use yet, but seems like a quality unit... having said that, out of all my die grinders (and I have many) I like the atlas copco units the best. far and away the best.

here's some reading material for you: http://www.garagejournal.com/forum/showthread.php?t=29604&highlight=grinder+mania

 

[Vinko]

I guess I'll send this one in to Dotco for repair.

It's a ******** design -- the materials aren't rugged. I don't get the hype. Maybe the composite grinder is a new model and haven't been proved

Is Atlas the company that makes tools that are used in mining? I've got a machinist who recommended we get that grinder.

 

[Merkava_4]

I've got a Sioux 1954HP. Excellent die grinder - lots of torque.

 

[speed bump]

I have that same grinder.. hasn't seen much use yet, but seems like a quality unit... having said that, out of all my die grinders (and I have many) I like the atlas copco units the best. far and away the best.

here's some reading material for you: http://www.garagejournal.com/forum/showthread.php?t=29604&highlight=grinder+mania

How do you like those IR Cyclone grinders? I ran into one today for $45 and can't decide whether I should pull the trigger on it or not. I also ran into an older Dotco (doesn't say Cooper on it and is all metal) for $20 that I will most definetely be buying after I get paid on the first.

 

[alex71]

The IR grinders are good. not great...Atlas-Copco makes the best pneumatic grinders, hands down. As merkava mentioned, Sioux units are also excellent.

 

[speed bump]

The IR grinders are good. not great...Atlas-Copco makes the best pneumatic grinders, hands down. As merkava mentioned, Sioux units are also excellent.

Well since I don't do a huge amount of grinding and being a full-time student I think the Atlas-Copco or Souix is on hold until atleast next year unless I suddenly find a lot of grinding to do with a good air source nearby.

When you say good what do you mean? I will constantly complain its a piece of **** or it will work pretty well for the once a month it gets used.

 

[alex71]

if you find a good one it will work well for you. be careful with used IR grinders. a lot of them, especially on ebay will need a full rebuild, regardless of how well the seller says it works. I wouldn't buy a used IR unless I could test it in person--and by that I mean put a carbide bur in the collet and lean it into a piece of 3/16 or thicker steel. Just hooking it up to air and pulling to trigger to see whether it spins or not is not sufficient.

Edit: I'm referring to the IR industrial line. their cheap grinders are the same as everyone else's. might as well save some money and buy harbor freight. or buy one of the used ones I have for sale (which are tested good, and cheap) hint hint

 

[Vinko]

The IR grinders are good. not great...Atlas-Copco makes the best pneumatic grinders, hands down. As merkava mentioned, Sioux units are also excellent.

Why are Atlas-Copco superior to Sioux?

What sort of work do you do with your die grinder?

I'm going to research the Atlas and the Sioux and try to make a decision.

I sent my Dotco in for repair. Admittedly, it was the housing that was the problem, but I can't use it on the shop floor. It's an OSHA fine waiting to happen.

 

[oldtools]

Is Buckeye any good?

 

[alex71]

Why are Atlas-Copco superior to Sioux?

What sort of work do you do with your die grinder?

I'm going to research the Atlas and the Sioux and try to make a decision.

I sent my Dotco in for repair. Admittedly, it was the housing that was the problem, but I can't use it on the shop floor. It's an OSHA fine waiting to happen.

Having used AC, dotco, and sioux quite a bit, I like the feel of the Atlas-Copco die grinders better. Power is about the same for similarly rated tools, chatter is MUCH LESS with the atlas-copco when using a carbide bur or a sanding drum. Something about a suspension for the air motor and shaft on the atlas-copco die grinders. if you're not using a carbide bur or sanding drum (i.e. using a cutoff wheel), there's not much of a difference.

 

[engnerdan]

Having used AC, dotco, and sioux quite a bit, I like the feel of the Atlas-Copco die grinders better. Power is about the same for similarly rated tools, chatter is MUCH LESS with the atlas-copco when using a carbide bur or a sanding drum. Something about a suspension for the air motor and shaft on the atlas-copco die grinders. if you're not using a carbide bur or sanding drum (i.e. using a cutoff wheel), there's not much of a difference.

That "chatter" comes from 2 things, the trueness of the carbide bur (if the shaft is bent forget about it not chattering) and the trueness (runout) of the collet/chuck. A good/great die grinder will have a double angle collet setup just like is used on some machine tools and they are very precise and it makes a difference. You will not get the trueness (lack of runout) that these have from a HF $15 special. A good die grinder will have less then .001 of runout, you can feel .001 when using a carbide bur at 25,000rpm. An easy way to tell if your bur/grinder has runout, grind some aluminum with a regular bur, if you only have aluminum buildup on one side/part of the bur you have runout. A "true" spindle and bur will cut with the entire outside diameter which will get you much faster cutting, longer bur life , better quality finish and much less fatigue.

The second thing is a quality bur, you can't buy cheap burs and get a nice finish. I think on average a good bur will be between $15-40 each.

-Dan

 

[Monte]

what about Dynabrade ? Or swiss made Suhner die grinders ? click or Biax ? click
Suhner has on some grinders a "floating shaft" so there will be no shatter and the carbide burr will live longer

 

[Vinko]

what about Dynabrade ? Or swiss made Suhner die grinders ? click or Biax ? click
Suhner has on some grinders a "floating shaft" so there will be no shatter and the carbide burr will live longer

I was going to try a Dynabrade, but if truth be told, I only need one other die grinder right now. The old timer I bought the Dotco from told me that he thought that Dotco and Dynabrade were about the same. When the cheapies **** out, I want to replace them with better ones. I remember you posting about Suhner and have e-mailed the company for more info about dealer network. I don't know Biax, but I've bookmarked the site.

I'm also looking at Atlas Copco.

For light tasks, the Chinese and Japanese models I've gotten aren't bad. I think one's a Chicago Pneumatic and the other is a low-end IR.

The other thing is, I'm starting to agree with some people I work with that it's best to have cheap tools for the people who don't care for, appreciate or really use them right.

 

[engnerdan]

Dynabrade are great die grinders too, I have 1 ARO/IR 18K RPM, 1 Dynabrade 12K RPM, 2 IR revolutions 25K RPM die grinders. The dynabrade is my weld grinding/hogging grinder because it is rated at 1hp and there is no doubt that it is powerful.

I think dynabrade and dotco are most likely about the same in quality.

-Dan