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View Full Version : What exactly makes cheap air tools so crummy?



alanganes
08-12-2017, 07:43 PM
I have the typical home shop mix of air tools, some are decent quality, most are lower end tools. I've had most of them for over 10 years and all serve ok for my fairly low level of use. Not too long ago, my cheapo right angle air die grinder broke, so I took a bit of a chance and bought a slightly better grade Ingersoll-Rand one for about 75 bucks. I know that for that price, I was clearly not getting one of the IR industrial grade tools, but hoped that it would be at least a cut about the $19 equivalent from Harbor Freight or similar.

My unscientific conclusion is that it is, in fact a noticeably better tool. Besides a just better and more solid "feel" to it, it seems be more powerful and somewhat more efficient in its use of air. I've used lots of real top shelf industrial air tools, which of course are better still.

What I can't quite seem to picture is what makes the cheap ones so crappy? I don't mean longevity or things like noisy gears, cheap bearings, etc. What I find hard to grasp is why a simple tool like a straight shaft die grinder could feel so different, particularly in the air consumption/efficiency aspect. Air vane motor are pretty simple gadgets, beyond one being something like grossly out of balance, what makes one so obviously better?

AD5MB
08-12-2017, 07:53 PM
bearings on the same axis and in the same plane.

the mechanism that actuates the air valve.

the air valve

CalM
08-12-2017, 07:55 PM
Tolerances of the component parts.

When things "fit", they work in harmony.
Ignore the fit, for the sake of production costs, and the hand can feel things move around.

I also have used and am equipped with a variety of air powered hand tools. I worked aviation for a number of years. The difference between an Ingersal- Rand 1/4 inch hand drill and Any similar tool sold in the hardware stores makes even thinking about the $20 version pathetic.

It sucks to be spoiled! ;-)

metalmagpie
08-12-2017, 09:50 PM
The uniformity and accuracy of the heat treating in the critical parts.
Parts support.
Collet closers that actually grip your shanks.

Stuff like that.

metalmagpie

CalM
08-12-2017, 10:22 PM
The uniformity and accuracy of the heat treating in the critical parts.
Parts support.
Collet closers that actually grip your shanks.

Stuff like that.

metalmagpie

How does "parts support" enter into a "crappy" sensation to the operator prior to any need for parts?

Just wondering, as I have terrible parts support for the old and obsolete air tools in my tool box. They still work and feel very fine in hand.

TRX
08-13-2017, 08:08 AM
The problem I'm most aware of is wide clearances or absence of seals inside the tool; all of the cheap air tools I have seem to leak a lot of air internally, at least from the sound and lack of power. I have a 1960s Rockwell air ratchet that just sips air compared to the no-name Chinese ratchet.

The die grinders have all been such a hassle I've gone back to electric.

JoeLee
08-13-2017, 08:34 AM
Everything !!

JL...............

alanganes
08-13-2017, 09:41 AM
The problem I'm most aware of is wide clearances or absence of seals inside the tool; all of the cheap air tools I have seem to leak a lot of air internally, at least from the sound and lack of power. I have a 1960s Rockwell air ratchet that just sips air compared to the no-name Chinese ratchet.

The die grinders have all been such a hassle I've gone back to electric.

I can see this conceptually, but can't quite picture where the poor seals would be. The vanes on the rotor of an air vane motor pretty much seal by the centrifugal force pushing them against the outer wall of the bore, so it would see that so long as the bore were reasonably smooth it should seal pretty well. At the ends of the rotor somehow?

The worst offender that I have is one of those cheap abrasive cutoff tools with the 4" wheel. It was given to me and is a really handy tool at times, but it gobbles air like nobody's business. I also have a 7" Ingersoll Rand right angle grinder (about $1100 new, got it for free as part of a trade but WAY too big for my compressor. A serious tool though) that is rated something like 11CFM consumption and that silly little cutoff tool drains the compressor tank about as fast. That cutoff tool is essentially a stright die grinder, but at times it can get into a position where won't even start, you push the trigger and air just blows out the exhaust ports. Have to release the trigger, turn the wheel a bit of a turn and then it will go. I suppose I should take it apart and see what's up in there. It'd be hard to make it any worse, so nothing to lose really.

JoeLee
08-13-2017, 10:31 AM
A few years ago my bro inlaw bought one of those Chicago Pneumatic look alikes at HF. It lasted about 2 months with very light use. Sheet metal and body panel work. The first issue was he felt air blowing against the palm of his hand when he was grinding. Come to find out there was a pin hole in the casting by the trigger and it was leaking. Secondly it vibrated terribly. After the first month he had to give the grinding disk a spin with his hand to get it going because when the the trigger was depressed all it did was pass air, so it needed a little coaxing to start spinning.
It had no power what so ever and would just about come to a stop when the wheel hit the work. Shortly after that the trigger valve started to leak and the shaft started wobbling.
Think he got his monies worth???

JL.................

GNM109
08-13-2017, 10:35 AM
At the risk of some embarrassment, I must confess that I have an entire set of Harbor Freight air tools. I use an 80 gallon 20 SCFM vertical air compressor (USA with Canadian real 5hp Motor) to operate them and they work quite well. I could care less how much air that they use since the compressor puts out more than enough.

I am just getting ready to retire my most recent 4" cutoff tool. It's been run constantly for the past 10 years and now it's gotten a bit weak. No worries, I have two more new ones that I bought on sale for $8.95 each. I'm good for the next twenty years.

I also have a 3/8" right angle air wrench. It's got an amazing amount of power. but the jury is still out since I've only used that one intermittently for about ten years. Then there is the 1/2" impact wrench. That one has been used over and over again literally hundreds of times to remove wheels and tight bolts since 1994 and is still going strong. The only problem that I had with that one was that the plastic trigger broke. I used the original trigger as a pattern and milled out a new one from 1018. It's still going.

I've also got a right angle air grinder that works well enough, although it didn't come with a guard so I'm wary of that one.

Then there is an air hammer somewhere in one of my drawers in the barn where I work, the type that will cut sheet metal and comes with several tips. That one does a great job.

Oh, I almost forgot the 20 ton air over hydraulic unit that I added to my Vulcan (Taiwan) 20 ton press last year. That thing is amazing and all it takes is a shot of oil now and then. That doesn't qualify as a "cheap air tool" however since it cost me $59.95 with the 20% off at H.F.

Lastly, there are the two spray guns, the HVLP one with the plastic reservoir on top and the little trimmer gun. Both do an excellent gun. I also have an H.F. Air brush but it doesn't see much use since the tip is rather small. I prefer my Paasche guns for air brushing although I do have a small H.F. air compressor to drive the air brushes.

My attitude on this is if the air tool will do the job, what does it matter what it cost, since most of them are made in China anyway? Yeah, I know that some tools are better than others, but I don't have a lot of money to spend after buying tooling for my 1994 Enco 13 X 40 lathe (Chinese) with its SINO DRO (Chinese) and the 1987 Webb 4VH Milling Machine (Taiwan) with its 2 Axis Mitutoyo DRO (Japan) and it's 5" Mitutoyo Z scale indicator (Japan).

Please place scorn and abuse below this line. LOL.
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mickeyf
08-13-2017, 11:48 AM
all it did was pass air

Yeah, I've had tools (and business associates) like that.

wierdscience
08-13-2017, 11:51 AM
I think it comes down to the finer points of design.In an air tool,especially something like a die grinder,the position,size,shape and finish of the ports means everything.

Take for example these two extended shank die grinders,both are made in China,but the performance is vastly different.The first is sold under the Pit-Pro label by various outlets.I have at last count 5 of these-
http://www.kbctools.com/products/POWER%20@@2f%20AIR%20TOOLS/PNEUMATIC%20POWER%20TOOLS/DIE%20GRINDERS%20-%20AIR/8295.aspx

It has good feel in the hand,runs very well balanced,ample power and the collet chuck actually works as it's supposed to.Then we have the model from HF which failed in all categories-
https://www.harborfreight.com/air-die-grinder-with-3-inch-extension-99698.html

Then we have the difference between brand tiers.The $39 Pit-Pro die grinder is close enough in performance to the $140 Aircat or the $365 Master that it isn't justifiable to spend the extra money.I however have a Cleco air drill that is heads and shoulders above everything else I have tried in air drills,even some $200 IR and CP offerings.

metalmagpie
08-13-2017, 11:58 AM
I have a Cleco air drill that is heads and shoulders above everything else I have tried in air drills, even some $200 IR and CP offerings.

I get air impact drivers. I get air grinders. I don't get air drills. Not trying to hijack, but why would someone use an air drill instead of an electric drill? Is it just that it's lighter? But air hose is heavier to drag around than electric cable.

metalmagpie

alanganes
08-13-2017, 12:36 PM
I'm enjoying the discussion. I am in no way intending this to be an "I hate tools from [fill in the country]" as I am of similar mind to GNM109, I use what does the job I need. While I'd live a bunch of cabinets full of top shelf stuff, it's not where I am financially or need-wise. So it goes. I'm pretty sure that the IR grinder I have is made in China, but it is a clear improvement over the few Harbor Freight ones I've had or used.

I have a couple of air drills as well, and have to admit that I rarely use them. I guess they may make sense if you are working in a very wet environment where getting shocked is a concern. I might guess that drills may be an instance where a really well made one would be much lighter and smaller for a given amount of power than a similar electric. If you are slinging one around all day like folks at aircraft assembly plants and such, maybe there is an advantage. Though I might think with the modern brushless motors and electronic controls available now, that may be less the case.

GNM109
08-13-2017, 01:15 PM
I'm enjoying the discussion. I am in no way intending this to be an "I hate tools from [fill in the country]" as I am of similar mind to GNM109, I use what does the job I need. While I'd live a bunch of cabinets full of top shelf stuff, it's not where I am financially or need-wise. So it goes. I'm pretty sure that the IR grinder I have is made in China, but it is a clear improvement over the few Harbor Freight ones I've had or used.

I have a couple of air drills as well, and have to admit that I rarely use them. I guess they may make sense if you are working in a very wet environment where getting shocked is a concern. I might guess that drills may be an instance where a really well made one would be much lighter and smaller for a given amount of power than a similar electric. If you are slinging one around all day like folks at aircraft assembly plants and such, maybe there is an advantage. Though I might think with the modern brushless motors and electronic controls available now, that may be less the case.


Of course there are many air tools that are superior to the Harbor Freight items. They come at a premium, however, and it all depends on your budget, of course.

I draw the line at my hand tools. I have a mix of mostly Snap-on and Craftsman. I ignore the ones at H.F.

Tony Ennis
08-13-2017, 01:44 PM
At the risk of some embarrassment, I must confess that I have an entire set of Harbor Freight air tools.

I bought a 10 gal compressor from Home Despot. I also bought from HF framing nailer ($70?) and stapler/brad nailer ($25?)

I could not be happier with the value. I built chicken coops, chicken runs, nest boxes, and a hutch using this stuff, and it was wonderful. My bum elbows could not have swung a framing hammer long enough to get this done. I got my $100 back time and time again. And my wife is delighted.

Would I take these on a daily job where time is money? Probably not. But as an occasional user, these tools owe me nothing.

JoeLee
08-13-2017, 01:53 PM
I get air impact drivers. I get air grinders. I don't get air drills. Not trying to hijack, but why would someone use an air drill instead of an electric drill? Is it just that it's lighter? But air hose is heavier to drag around than electric cable.

metalmagpie I have a couple air drills, one, the Snap On is variable speed. They were great when I was doing auto body work. All I had to trip over was one air hose that took care of all my tools. No extension cords to get tangled up with the air hose. It made life a little easier.

JL...............

GNM109
08-13-2017, 01:59 PM
I bought a 10 gal compressor from Home Despot. I also bought from HF framing nailer ($70?) and stapler/brad nailer ($25?)

I could not be happier with the value. I built chicken coops, chicken runs, nest boxes, and a hutch using this stuff, and it was wonderful. My bum elbows could not have swung a framing hammer long enough to get this done. I got my $100 back time and time again. And my wife is delighted.

Would I take these on a daily job where time is money? Probably not. But as an occasional user, these tools owe me nothing.

Good to hear this. A good machinist will be able to look at a tool and tell whether or not it will suit his (or her, for that matter) needs. Not it all situations will you need to have the best or most precision unit.

I also have one of the large H.F. Bead blasting cabinets. I had to do some modifications to get it to work properly but mainly getting a good blast gun did the trick. I also added some better lighting inside and I have a large exhaust fan to remove the dust. It's not perfect, but with a few changes, a cabinet is a cabinet.

epicfail48
08-13-2017, 03:05 PM
The problem I'm most aware of is wide clearances or absence of seals inside the tool; all of the cheap air tools I have seem to leak a lot of air internally, at least from the sound and lack of power. I have a 1960s Rockwell air ratchet that just sips air compared to the no-name Chinese ratchet.

The die grinders have all been such a hassle I've gone back to electric.

This is my impression of it too. I use the harbor freight tools a lot, they work but its always been my feel that they use way more air than they should, a problem not shared by my, ahem, 'quality' tools from kobalt and similar brands. I've always chalked it up to lower tolerances allowing air to leak

dave_r
08-13-2017, 03:44 PM
I get air impact drivers. I get air grinders. I don't get air drills. Not trying to hijack, but why would someone use an air drill instead of an electric drill? Is it just that it's lighter? But air hose is heavier to drag around than electric cable.

metalmagpie

I bought one specifically for clearance, they are smaller/more compact than electric drills. I needed to make some holes in the frame of my truck and didn't want to remove the engine to do them...

flylo
08-13-2017, 03:52 PM
What exactly makes cheap air tools so crummy?
China, no quality control, poor materials, poor workmanship, lack of pride in workmanship, corporate profits before company reputation, greed. I don't mind Harbor Freight because they don't hide where it's made & YOU roll the dice & take your chance. Sometimes you win & sometime you lose. They do have good customer service. What makes me mad are the good old merican tools that for pure greed went offshore & never told a soul, like Wheeler & all the Battenfield gun smithing products. I hate that lying company & their p*ss poor business practices. Moved offshore & never told a dealer or distributor. They can tot in H*ll before they get another dime from me. Was I unclear about my love for Battenfield?

Alistair Hosie
08-13-2017, 04:12 PM
I think the name of the company for companies like I Rand, is extremely important to them. These companies know you are paying extra not just for the superior quality tools and machinery , but also included is a part of your purchase payment is for the name. The name usually comes with complete satisfaction that you are buying from a company whose logo name is a form of subliminal guarantee it will last long after the cheaper ones do so the longevity of the product gives us a lot of peace of mind. Of course your purchase price will include the normal guarantee which is in writing, please do not forget you are not getting something free the guarantee is your property every bit as much as the tool. If you resell the tool you should automatically be able for those reasons given to pass on the outstanding warranty guarantee you paid for it, it is therefore a part of the purchase price. We mostly also know when buying from some distant foreign companies who are here today and still here tomorrow under a new name and therefore if you plug in your new grinder and there are more sparks from the inside of the machine than on the item you are grinding then you and your hard earned money have been foolishly and sorrowfully parted forever. Of course if you buy through ebay Amazon they will keep you covered.
We had a very big court case here when a company imported to England, from American , a ship load of Levi jeans, they resold them all within hours to eagerly waiting buyers hungry for a large bargain, because the difference in the American
price was so vastly different from the much higher prices paid here in the UK, for exactly the same item . In court you will not believe that Levi said the high cost was paid by the brits because they were in fact not just buying jeans, but also buying the logo, label ,call it what you will ,the court agreed and they won. The same thing happened with automobiles in the European union we brits were paying on average around a third and more higher for our cars that our neighbours in Germany Holland Belgium etc. companies shrewdly set themselves up in Europe to buy in right hand drive cars or converted lefties cheaply and you could rightly order a car in Belgium etc go and collect it and be home in time for tea. The motor manufacturers started to be uncooperative with guarantees on the vehicles and were in short a lot of dirty devils. God Bless Alistair

wierdscience
08-13-2017, 06:20 PM
I get air impact drivers. I get air grinders. I don't get air drills. Not trying to hijack, but why would someone use an air drill instead of an electric drill? Is it just that it's lighter? But air hose is heavier to drag around than electric cable.

metalmagpie

Well for me anyway several reasons,they are more compact,an air hose on a retractable reel is ever present at work,extension cords not so much and the particular drill in question has a two speed trigger,the first step is high torque/low speed (150rpm) and the second step is low torque/high speed (3000 rpm) so I can pilot drill on high and finish drill/power tap on low.

old mart
08-14-2017, 07:08 AM
When I was in manufacturing of aircraft components, our bench section were using air tools all day long, and even the top quality ones required constant servicing and new parts. Our maintenance man carried a large number of spares, so we kept to one brand if possible to minimise the costs.
With cheap tools the tolerances, finish and hardness of parts means lower life, you get what you pay for.
Always put a couple of drops of oil down the air inlet before using, this will make the air motor and on off valve last longer. Bearings have to fend for themselves.

CalM
08-14-2017, 10:41 PM
I get air impact drivers. I get air grinders. I don't get air drills. Not trying to hijack, but why would someone use an air drill instead of an electric drill? Is it just that it's lighter? But air hose is heavier to drag around than electric cable.

metalmagpie

Such a sentiment can only come from someone who has never had occasion to drill out a thousand rivets in a single day to replace some structure or skin.

A good drill motor becomes an extension of the hand. Easily guiding the drill tip exactly where it is needed. I've NEVER found that feeling in an electric drill motor, Ergonomics!

PeteM
08-14-2017, 11:04 PM
I get air impact drivers. I get air grinders. I don't get air drills. Not trying to hijack, but why would someone use an air drill instead of an electric drill? Is it just that it's lighter? But air hose is heavier to drag around than electric cable.

metalmagpie

Good air tools are generally more powerful/smaller/lighter than their electric counterparts. Main reason is the motive force is back at the compressor. With flexible hoses, maybe a balancer, air tools can be comfortably used all day in jobs like automotive assembly.

Another reason for air tools is use in abrasive or potentially explosive environments. Airborne grit, even from fiberglass, can tear up armatures.

By varying pressure, the effects of stalling an air tool vs. an electric tool can also be safer. Stall a big electric drill and it may break your hand. Stall an air drill, maybe not so much.

As for the differences between cheap and quality tools, most have already been covered. When a plant is running hundreds of air tools (my first job after grad school was at Ford in manufacturing engineering), the cost of running compressors and piping was a big deal. A hundred tools with tighter tolerances on vanes etc. saved money and production time.

Good air tools are also meant to run near 24x7 and be rebuilt. Cheap air tools are meant to be thrown away when their cheaper bearings give way, gears strip, vanes wear.

Doozer
08-15-2017, 07:54 PM
I have a Black and Decker 1/4" die grinder, a flea market buy.
It has 1/8" npt air inlet (oddly small) and uses very little air.
Bearings are as smooth as a Swiss lathe and it runs rather quiet.
This is when B&D made good stuff, like pavement busters and
the like.

I also have an Atlas Copco 1/4" angle head 90deg die grinder,
another flea market find. The this has so much power and a
really good muffler system. Again, for the size of the motor,
it does not use a ton of air. One thing I like, judging from the
size of the 90 deg gear box in the head, it must have good size
gears compared to the Taiwan cheapies. A real pleasure to use.
It has a motor big enough for 3" wire wheels and 4" cut off discs,
on the appropriate mandrel.

I have a another die grinder, the brand is Detroit Air Tool, or something
like that. I got it from work. The collet chuck was all clapped out, from
the welding department using vise grips to tighten it. I took it apart and
found the collet chuck part comes off, via a 3/8" fine thread shank. I then
made a new mount for it in the lathe so it could use 5/8" bore cut off discs.
The air motor was really big for a die grinder, but perfectly sized for the
power needed with cut off wheels. So the new mandrel turned out perfect,
with a few tenths runout. It is now my go to cut off grinder.

--Doozer