Thread: Why you need an air micro die grinder

Originally Posted by Anorak Bob

I hope you do better than I have Bruce. Mine was delivered today. The spindle does not turn freely. It feels like there is some foreign matter in the bearings. I have not attempted to run the thing.

I have a dilemma, do I return it to the seller at a cost of $13.40 and endure the 20 minute wait in the line at the post office or do I walk out and throw it in the Sulo bin?

Bob
That is indeed annoying, as I thought with all of the buyers being happy, the units would be OK.
It could be the vanes in the rotor could be a whisker too long, that happens every so often & could cause the problem. The vanes rub on the end plates in the motor & cause a little binding.
I am only guessing but when in business a lot of my work was sorting out air tool problems, & this happened even with quality brand new yank tools which I imported at that time.
Easily fixed by taking apart & filing or sanding off a little off the canvas bakelite or plastic vanes length.
Only a guess !
Suggest hang on to yours till I get mine or perhaps others owners could comment.
regards
Bruce
ps This cheap stuff can be frustrating.

Originally Posted by Ueee

The seller seems to have run out. Must have been a rush on them....

no they haven't it was another Aussy seller that i had saved in my watch list that had run out...

Originally Posted by Abratool

Bob
That is indeed annoying, as I thought with all of the buyers being happy, the units would be OK.
It could be the vanes in the rotor could be a whisker too long, that happens every so often & could cause the problem. The vanes rub on the end plates in the motor & cause a little binding.
I am only guessing but when in business a lot of my work was sorting out air tool problems, & this happened even with quality brand new yank tools which I imported at that time.
Easily fixed by taking apart & filing or sanding off a little off the canvas bakelite or plastic vanes length.
Only a guess !
Suggest hang on to yours till I get mine or perhaps others owners could comment.
regards
Bruce
ps This cheap stuff can be frustrating.

I'll wait and see if the seller responds. The idea of buying something new and having to fix it when others have purchased the same and not experienced any problem, is galling.

BT

Here's Joe's reply -

Hi Bob

Thanks for letting me know this first.
It will get a certain friction when you rotate the spindle, for safety purpose. Coz this tool gonna rotate more than 50000 RPM, and when you turn it off, it will take too long to stop without this friction.
Would you please try it on you compressor under 90 PSI?
If there is any faulty parts, I am more than happy to replace it.

Best Regards
Joe

- melbourne_tools_shop

Then......

Dear melbourne_tools_shop,

Hello Joe,

Thanks for the swift response. This is more than dragging friction. The spindle feels like it's catching on something. It has a rough gritty feel
.
Regards
Bob.


No worries mate, I will send you a new spinder tomorrow
Regards
Joe

- melbourne_tools_shop


I guess I'll just have to wait a bit to find out what a spinder is.

I may get jealous if I see your spinder

Originally Posted by Anorak Bob

I'll wait and see if the seller responds. The idea of buying something new and having to fix it when others have purchased the same and not experienced any problem, is galling.

BT

Here's Joe's reply -

Hi Bob

Thanks for letting me know this first.
It will get a certain friction when you rotate the spindle, for safety purpose. Coz this tool gonna rotate more than 50000 RPM, and when you turn it off, it will take too long to stop without this friction.
Would you please try it on you compressor under 90 PSI?
If there is any faulty parts, I am more than happy to replace it.

Best Regards
Joe

- melbourne_tools_shop

Then......

Dear melbourne_tools_shop,

Hello Joe,

Thanks for the swift response. This is more than dragging friction. The spindle feels like it's catching on something. It has a rough gritty feel
.
Regards
Bob.


No worries mate, I will send you a new spinder tomorrow
Regards
Joe

- melbourne_tools_shop


I guess I'll just have to wait a bit to find out what a spinder is.

Bob
The friction & waiting for the 50,000 rpm spindle to stop sounds a bit of a "doubtful" story, but at least you are getting a replacement, so all could be good !
regards
Bruce

Bit unlucky on that one Bob, but might finish up with two.

Sounds like the dealer is OK on this.

Just slightly OT, I was using a stainless steel wire wheel in my pencil grinder a few days ago and when I finished I took off my goggles and felt like a hair or someting on my nose.

Found that one of the wire shards from the brush had broken off and was sticking in my nose

Didn't feel a thing at the time (very fine shards).

Could have been my eye, so be careful with these unts.

Some of the Dremel attachments around are not designed for this sort of activity, and under a lot more duress than intended.

Rob

+1 I agree. The wire wheels are bad enough on the dremel, so I can appreciate it when you try and use them on an air grinder, they fall apart easily. I use them often when cleaning up aluminium to get into hard to get places.

Incidentally while on the subject, I do a lot of cutting on ABS "plastic" car parts. I make my own cutting disks by using the bottom of an old tin can, cut a 5/10 cent round disk shape and use it to cut plastic in a controlled manner without burning it. Just a little money saving tip.

Originally Posted by GTVi

+1 I agree. The wire wheels are bad enough on the dremel, so I can appreciate it when you try and use them on an air grinder, they fall apart easily. I use them often when cleaning up aluminium to get into hard to get places.

Incidentally while on the subject, I do a lot of cutting on ABS "plastic" car parts. I make my own cutting disks by using the bottom of an old tin can, cut a 5/10 cent round disk shape and use it to cut plastic in a controlled manner without burning it. Just a little money saving tip.

What a great idea re the little DIY cutting saws.

I generally use the friction discs and get the plastic melting/burning issue as you say.

Do you serrate the edge in some way?

Must try this

Rob

Just found these on Ebay:

LOT 10 X 22mm Stainless Cutting Awtooth Blade SAW Edge Discs Grinder Dremel Wood | eBay

What do you recon ?

Looks pretty cheap to me.

Rob

Originally Posted by nearnexus

What a great idea re the little DIY cutting saws.

I generally use the friction discs and get the plastic melting/burning issue as you say.

Do you serrate the edge in some way?

Must try this

Rob

When you cut the discs just cut them to be say 20 sided, i.e. many straight cuts...that way its not a perfect circle.

Been at it again

Here's the latest video.

Pencil air die grinder speed test - how fast can a micro die grinder really go ? - YouTube

Cheers

Rob

Originally Posted by nearnexus

Been at it again

Here's the latest video.

Pencil air die grinder speed test - how fast can a micro die grinder really go ? - YouTube

Cheers

Rob

a bench that has space on it is a sign that that the owner has a sick mind


as usual another good howto vid

Originally Posted by eskimo

a bench that has space on it is a sign that that the owner has a sick mind


as usual another good howto vid

Thanks Eskimo.

The state of the bench generally reflects the rest of the shed

A while back the wife of a mate of mine visited the shed to pickup a rotary hoe I lent them, and as the door opened and the soft smell of diesel and machine oil wafted out, she commented to me "this smells like a real work shop. I bet you spend a lot of time down here", and I had to agree.

Some times things can be too clean and orderly.

Rob

I have used in the past for name engraving on things:
a. a dental technicians tool with a flex shaft that fits on a bench grinder spindle - heavy shaft, low speed
b. a hanging motor (KaVo) like the shopping mall engravers use - 20,000 rpm
c. a cheap 12v arlec supertool - cheap and nasty except that it does have multiple collets and fits tiny drill bits - did the job with bur to bore snake eye holes in steering column lock headless bolts - still the thing I use most often for fiddly little bits just because it's easy to get out and it is quiet
d. a micro die grinder just like the on in this thread that I got several years ago from tradetools (was reasonable at the time considering the alternatives) - great except for the screaming banshee noise that's hard to muffle - definitely needs earplugs; only came with one 3mm collet but I pinch the collet from the Arlec for dental size burs; I use it mostly for engraving things using dental/jewellers burs
https://www.tradetools.com/products/JW101-1K

Saw near identical product still for sale at Bunnies this week - about $30 IIRC. Also found Hitachi cordless micro grinder GP10DL similar to a Dremel cordless - on master's web site for <$100 but never managed to find a real one to look at. Never really liked the large size of the Dremel and similar.

Other option would be a dental micromotor handpiece. (eg Dental Micromotor | eBay) Thinking I might get one one day.....

For mounting in a clamp like the video in the first post, the metal body of the air micro die grinder is clearly superior. I'm guessing a dental micromotor would be a lot quieter. (Don't the fingernail shops use something like that?)

The most useful accessory I have is a German jeweller's diamond disc saw fixed on dental size shaft - got from a jewellers supplies many years ago. Chinese ones cheap as chips on ebay these days Diamond Cutting Disc | eBay

The most annoying thing about the air micro die grinder is knowing how much oil it needs to stay alive without too much oil going everywhere, or bearings drying out and dying. The supplied mini oiler doesn't have instructions an I presume is meant to supply oil "fumes" down the line somehow. Name brand air micro die grinders seem to sell in the 200-500 range.