Cordless grinder

M

Mith

Active member
Apparently such a beast does exist!

I've come to the conclusion that a cordless grinder would be a perfect addition to my collection. At the moment grinding out of the workshop involves a generator and the loader which makes 'quick' jobs not so quick.

So far, I have only been able to find one made by DeWalt. I'm a little dubious as to the quality of their tools.
DeWalt grinder
Its bloody expensive too, after buying batteries and a changer I wont have much change for £250 (~$375). One of the reviews I read elsewhere said battery life left much to be desired, not much good.
For that kind of money I may as well get one with an engine.

Anyone have any thoughts. I think cordless grinders are quite new to the market?
 
Hmm, for £250 I could fit an 240V inverter to my truck so I can run a normal grinder off it.
 
Mith said:
Hmm, for £250 I could fit an 240V inverter to my truck so I can run a normal grinder off it.
Click to expand...

And having a high capacity inverter could be handy for other things.

For one it would supply mains power for the tea kettle. :whistle:
 
Mith, I have a set of Ryobi cordless gear, and I've considered their $35 cordless grinder.

I already have an inverter to plug my Ryobi mains charger into. (actually two chargers, rotating three batteries).

Note Ryobi is at best 'homeowner grade' tools, not professional, but this grinder might meet your needs.
 
California said:
Mith, I have a set of Ryobi cordless gear, and I've considered their $35 cordless grinder.

I already have an inverter to plug my Ryobi mains charger into. (actually two chargers, rotating three batteries).

Note Ryobi is at best 'homeowner grade' tools, not professional, but this grinder might meet your needs.
Click to expand...

Thats a good looking grinder and a good looking web site.

Jim
 
Jim, thats my thinking. Kettle and a nuker and I could pretty much live in there :D

Cali, I went hunting, I think I found the same one on a website over here. Its alot cheaper than the others, but you see the price difference from you guys. Its ~$120 over here. Must say though, the reviews werent too hot.
On that same website they also have Matika ones, selling for ~$160. Looks like you can get a kit with batteries and a charger for ~$470.

I would quite like to get a professional one, it will be seeing commercial use. However, they are quite expensive to say the least!
I must admit, the inverter is looking increasingly attractive.
 
I have that DeWalt grinder and it's handy for certain.

Any serious grinding and the battery depleats within five to six minutes (fully charged and fairly new batteries too).

I am one of many that's not happy with the cycle life of their 18V batteries. I have the partial sets, and the complete set of every cordless tool DeWalt makes and I (painfully) make annual trips to replace the batteries. Over four years, I have eleven dead batteries.

I also have a Milwaukee 18V Recip saw, circular saw and hammer drill.......same story! I have six dead 18 volt batteries that also need recycling.

It's painful to say this but I now have Hitachi 18V tools and I'm very impressed. Especially the 2000 cycle life of their Lithium-Ion batteries. Each charge and depletion of every battery is one cycle. And they are better made and more reliable then my DeWalt and Milwaukee sets (:( ).

Mark
 
Ryobi also just came out with Li-ion (or whatever they are) batteries that fit these previous One+ (One-Plus) series of tools. I don't think they need a separate charger so the only cost to upgrade existing tools is for the new expensive batteries. But I still wouldn't rely on Ryobi for commercial service.

I'm having pretty good luck with the $50 Ryobi One-Plus chainsaw for light work. I estimate about 30 cuts per charge. That's plenty for making manageable 8 ft chunks out of old apple trees that rotted out and fell down, so that I can carry them to the burn pile. Its far simpler than maintaining a two cycle saw for such a small amount of work.
 
I'm having good luck with Makita 14.4v lithium ion batteries. few of them are approaching their 5th birthday and still going strong. I have a few of the Milwaukee 18 volt nicads that are a couple of years old but they haven't seen much use.

Jim
 
I have the dewalt grinder as well, it's about 3 years old and no, the charge does not last - but it's handy when I really need it.
deWalt also has Li-ion batteries that are backwards compatible with all their older 18V tools, but you have to buy a new charger.

Another brand you might look into is Rigid -- if you buy them at Home Despot you can register the tool and get lifetime free replacement batteries.

other option for Mith - buy your tools online through Amazon or the Home Despot website and ship the tools to yourself. With luck they'll cost less that way.
 
5-6 minutes? Man, thats bad. That'll never do, I'd have to have a pile of batteries.

You arent the first to say you are pleased with Hitachi, Mark. They are certainly up there in price. I think between you and Erik the DeWalt tools are out. I've always been a little suspicious of DeWalt being as they are essentially B&D.

I'm glad to hear something good about Makita Jim. I'm thinking that might be the way to go.

Erik, I'll probably buy from the tool shop down in town. It'll cost more, but its worth it for the service.

Cheers guys.
 
5-6 minutes? Man, thats bad. That'll never do, I'd have to have a pile of batteries.

You arent the first to say you are pleased with Hitachi, Mark. They are certainly up there in price. I think between you and Erik the DeWalt tools are out. I've always been a little suspicious of DeWalt being as they are essentially B&D.

I'm glad to hear something good about Makita Jim. I'm thinking that might be the way to go.

Erik, I'll probably buy from the tool shop down in town. It'll cost more, but its worth it for the service.

Cheers guys.
 
One thing I notice with the older lithium ion batteries is that they don't seem to hold a charge long term. If I charge them and it is a couple of weeks before use they will only operate for a few minutes. Fresh from a charge they seem to have full capacity.

Jim
 
My dewalt grinder is pretty much the same. Battery lasts maybe 5-10 minutes, depending on what I'm doing. For cutting, it drains the battery pretty quick, but for cleaning up welds and such, like using a flap disc or similar, the bettery lasts a lot longer...
A big inverter capable of running a mains 230v grinder with any bit of gusto would work out pretty expensive, wouldnt it Mith?

Another thing I dont like about my Dewalt is that metal filings have a nasty habit of sticking to the outer plastic covers. Obviously theres some heavy magnets in there as part of the motor. Not as noticable on my mains powered grinders, but very noticable on the dewalt 18v grinder for some reason.
 
Dewalt is a lot cheaper in the states too Mith. I bought a Dewalt combi in either HomeDepot or Lowes I cant remember which :rolleyes:, in Florida a couple of years back for $500usd. It came with 18v Hammer action drill, Reciprocating saw, Circular saw, Impact driver, flashlight and a charger. Oh yeah, and a big Dewalt tool bag (still in the plastic, never used...lol.)

If I were to buy that lot of tools over here I'd be looking at about $2500usd at least.

Dem yanks have all the luck over there mate... lol
 
Seems to me that an inverter large enough to run a grinder will require a special and expensive alternator on your vehicle to feed it.

Using US standards:

A simple grinder uses 120 volts and at least 5 amps. (Pro grinders may use 11 amps). 120v x 5a = 600 va. And 600 va at 12 volts = 50 amps.

Most original automotive alternators are 35 amp or less. So with a 120v 5 amp grinder you will need the engine roaring and still won't stay ahead of the grinder's current draw.


Unrelated point: I think Home Depot bought both Ryobi and Rigid. Rigid tools may now be relabelled Ryobi stuff. I thought I saw an example where the same battery will fit both. Also, I have a 12 volt Ryobi hedge trimmer that is several years old, from before that HD purchase. It seems that Ryobi abandoned that model's battery and went to a battery with the same specifications but a different connector, at the time of the HD purchase. This of course obsoleted all the original Ryobi stuff. That old battery is now expensive and near unobtainable. Hmmm ... maybe I should wire a 12 volt cord on it, and run it from the tractor battery!
 
Q, I think I'm pretty much discounting DeWalt now. Sounds like the batteries are poor, and they arent even cheap (over here anyway)!

Too right on the inverter cost, but if I'm spending £300 on effectively a single tool (inc batteries and a charger), then say £500 to fit an inverter doesn't seem that bad when it'll run all sorts.
As Cali correctly points out, I would probably have to upgrade the electrical too. I'd probably put it back to a 24V system actually if I'm going to have 100A+ alternators. I'd want atleast 1KW output from the inverter if I fitted one, then I'd have enough juice for most situations.
We have a pretty decent sized inverter in the work truck, I have used that for grinding and drilling etc. Using the grinder for 15 mins continuously the stock alternator didnt have any worries keeping up with the engine on idle.
I dont really know much about these inverters. I see in my northern catalogue they sell an inverter that provides 5KW continuous. Now by my calculations, at 12V thats a shade over 400A. Most batteries cant even discharge that quickly! 400A is a heck of alot. Apparently the surge voltage from that inverter is 19000W, or about 1600A at 12V. I must be missing something here?!

Or, and here is a wild thought. Belt drive a conpressor off the engine, and use an air grinder. That could be done with second hand parts pretty easily I guess. On board air would be pretty handy actually.
Maybe I'll just buy a battery grinder eh :D
 
Mith said:
Or, and here is a wild thought. Belt drive a conpressor off the engine, and use an air grinder. That could be done with second hand parts pretty easily I guess. On board air would be pretty handy actually.
Maybe I'll just buy a battery grinder eh :D
Click to expand...

Not a wild idea at all. Several of our work trucks with air brakes had an air quick connect so we could use air tools. If the engine in your truck came in a model with air brakes maybe you could find the bracket and compressor for it.

Jim
 
There are air compressors available for the diff locks, but I dont think they are large enough to run tools. Air brakes are an option on the truck, might have to look into that.
I could just run one off the PTO on the trans, or I was thinking of belt driving it off the pulleys on the crankshaft.
This is quite interesting, I might have to learn more about air compressors.
 
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