Pencil Grinder Recommendation?

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ACHiPo

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I have a cheap Dremel knock-off set that is underpowered, slow, and frustrating to use. I've thought about replacing it with a Foredom tool. Of course once the decision was made that I need something better, down the rabbit hole I went. I'm now thinking an air pencil grinder might be a good addition. The question is which one. There are the HF, etc. imports for $20-$30, or at the $150 price point there are presumably better quality grinders from names I don't really recognize. The "industrial" models seem to be in the $400 range from names like Dynabrade and Dotco. I have a 4 cfm compressor with hotdog tanks, so an air hog is out of the question.

There doesn't seem to be a lot of independent information/reviews out there, so I'm soliciting input.

Thanks in advance.
 
Last edited:
ACHiPo,

I was where you are a few years ago and decided to get a Proxxon electric tool instead of an air tool. I got the "Professional" one with the steel nose and precision bearings. I like it very much, and the assorted collets make it possible to use accessories from several sources. I ended up liking it so much that I got a second one for my electronics bench.

https://www.proxxon.com/us/micromot/38481.php
When I asked your question, it was also pointed out to me that some of the air tools rev up so high that there may be danger from shattering stones in use.

I have also considered Foredom from time to time, but the price goes up considerably.

For precision work, you need a precision tool, so if you are determined to get the air tool you probably need to get above the Harbor Freight level, although getting one of those to try out might not be a bad idea.

--ShopShoe
 
ShopShoe,
Thanks. I'd forgotten about Proxxon. It looks like a good-quality alternative to Dremel, et al.

I've also been doing some more research on Foredom. I'm not interested in their hanging grinder--I don't tend to work that way. They do make an electronic grinder that goes up to 50k. I hear you on max RPMs for some tools, so will have to be careful, but I do like the control higher RPMs provide. And from the videos they seem pretty quiet. Not cheap, however!

I'm leaning toward picking up one of the highly rated air pencil grinders off Amazon for ~$40 regardless. Both Neiko or Astro seem to have quite a few good reviews and the air consumption is within my compressor's capability. It seems like it will be nice to have that arrow in my quiver regardless.

Evan
 
I've done a little more research and am leaning toward the Dremel 4300. If cost was no object I would go for the Foredom Brushless Micromotor--they are powerful, quiet, small, and with a top speed of 50k RPM they can hog material or detail with finesse. Unfortunately I just can't justify spending $1k for something I use a few times a month.

This is the review that caused me to reconsider a Dremel (plus I remembered that I don't actually have a Dremel that I hate, but rather a knock-off kit I bought at Costco for about $30):


Here's a nice explanation of micromotors compared to a Foredom shaft tool. These micromotors look like they might be a less expensive alternative to the Foredom, but Foredom has such a rock-solid reputation I'd be inclined to stick with the name brand if I felt I needed a micromotor.


Foredom has several good videos marketing their products. I was surprised how hard it was to find independent reviews, especially on the micromotor products.


I've eliminated the cheap and mid-priced air pencil. My little 4.2 CFM 4.2 Gal compressor just doesn't stand a chance to drive them, plus they sound like the dentist!

The Dremel 4300 has 1.8A vs. 0.9A for the Proxxon, and . It also has a keyless chuck so tool change is easier (one of my big complaints with my knock-off). It can take collets for high torque tools or higher precision work.

Any recommendation on grinding stones or carbide burrs?
 
I have a Proxxon and like it, no comparison with the Dremel. The Nose is cylindrical and can be easily mounted/adapted on the tool post or on the mill spindle for when you need a little more RPM for small end mills.
My air compressor is limited, I have a pencil air grinder on a flex shaft but rarely use it.
 
I have a Proxxon and like it, no comparison with the Dremel. The Nose is cylindrical and can be easily mounted/adapted on the tool post or on the mill spindle for when you need a little more RPM for small end mills.
My air compressor is limited, I have a pencil air grinder on a flex shaft but rarely use it.
Proxxon's spindle bearings and nose are definitely a nice feature. I tend to believe their claim of 0.001" TIR and they're the only company I've seen spec it. I won't be using this for a tool post grinder, however, so super-precision isn't really required. The Proxxon is also quieter than the Dremel--a definite plus.
 
I've done a little more research and am leaning toward the Dremel 4300. If cost was no object I would go for the Foredom Brushless Micromotor--they are powerful, quiet, small, and with a top speed of 50k RPM they can hog material or detail with finesse. Unfortunately I just can't justify spending $1k for something I use a few times a month.

This is the review that caused me to reconsider a Dremel (plus I remembered that I don't actually have a Dremel that I hate, but rather a knock-off kit I bought at Costco for about $30):


Here's a nice explanation of micromotors compared to a Foredom shaft tool. These micromotors look like they might be a less expensive alternative to the Foredom, but Foredom has such a rock-solid reputation I'd be inclined to stick with the name brand if I felt I needed a micromotor.


Foredom has several good videos marketing their products. I was surprised how hard it was to find independent reviews, especially on the micromotor products.


I've eliminated the cheap and mid-priced air pencil. My little 4.2 CFM 4.2 Gal compressor just doesn't stand a chance to drive them, plus they sound like the dentist!

The Dremel 4300 has 1.8A vs. 0.9A for the Proxxon, and . It also has a keyless chuck so tool change is easier (one of my big complaints with my knock-off). It can take collets for high torque tools or higher precision work.

Any recommendation on grinding stones or carbide burrs?

I’ve owned several Dremel and/or knock off smal grinders, and all of the knock offs have failed spectacularly in moderate use. I just purchased a 4300 to add to the stable, and with the flexible shaft attachment, have found it to be a decent stand in for a tool post grinder on small items like valves and cutting off cast iron rings.

I recommend the 4300, even though it’s a bit more than the next cheaper model. It just plain works!

John W
 
I have a Proxxon and like it, no comparison with the Dremel. The Nose is cylindrical and can be easily mounted/adapted on the tool post or on the mill spindle for when you need a little more RPM for small end mills.
My air compressor is limited, I have a pencil air grinder on a flex shaft but rarely use it.

Which Proxxon do you have?
 
I've done a little more research and am leaning toward the Dremel 4300. If cost was no object I would go for the Foredom Brushless Micromotor--they are powerful, quiet, small, and with a top speed of 50k RPM they can hog material or detail with finesse. Unfortunately I just can't justify spending $1k for something I use a few times a month.

This is the review that caused me to reconsider a Dremel (plus I remembered that I don't actually have a Dremel that I hate, but rather a knock-off kit I bought at Costco for about $30):


Here's a nice explanation of micromotors compared to a Foredom shaft tool. These micromotors look like they might be a less expensive alternative to the Foredom, but Foredom has such a rock-solid reputation I'd be inclined to stick with the name brand if I felt I needed a micromotor.


Foredom has several good videos marketing their products. I was surprised how hard it was to find independent reviews, especially on the micromotor products.


I've eliminated the cheap and mid-priced air pencil. My little 4.2 CFM 4.2 Gal compressor just doesn't stand a chance to drive them, plus they sound like the dentist!

The Dremel 4300 has 1.8A vs. 0.9A for the Proxxon, and . It also has a keyless chuck so tool change is easier (one of my big complaints with my knock-off). It can take collets for high torque tools or higher precision work.

Any recommendation on grinding stones or carbide burrs?

The guy sellling micro motors Never mentioned the power of the tool: in my opinion that is significant. One of the types of lies available in the arsenal of liars is to tell partial truths and not all the story, this is called 'lies of omission'. This is how salesmen ALWAYS work. Caveat emptor.
 
The guy sellling micro motors Never mentioned the power of the tool: in my opinion that is significant. One of the types of lies available in the arsenal of liars is to tell partial truths and not all the story, this is called 'lies of omission'. This is how salesmen ALWAYS work. Caveat emptor.
Fair enough, but it's not that hard to find specs online. I just liked his overview video.

Here's specs on the Marathon Micromotor System ($325 from Gesswein)
Controller
Electrical:110/220V, 50/60Hz
Output Voltage:0-30V DC (continuously variable)
Dimensions:4-1/2"W x 5-3/4"D x 3-3/4"H
Net Wt:2.6 lbs.
PHP-35 Handpiece
Dimensions:6"L x 1" diameter (tapers to 5/8" dia. at finger grip)
Net Wt:7.5 oz.
Max Torque Output:3.2 N/cm
Max Power:50W
Max Rotation Speed:35,000 RPM


Here's the specs for the Marathon brushless Handy 700 set ($795 from Gesswein)
Handy 700 Controller
Electrical100–120V, 40W, 50/60Hz
Dimensions:5-3/8"W x 9-1/16"D x 7-1/16"H
Net Weight:6 lbs.

BH-60 Handpiece - Brushless
Speed Range:1,000–50,000rpm
Max. Power:230W
Max. Torque:7.8 N-cm
Collet Size:3/32" or 1/8"
Dimensions:6-5/16"L x 1-1/16" dia. to 3/4" dia. at finger grips
Net Weight:8.4 oz.


Here's the specs for an ECO-torque 280 micromotor ($199 from Gesswein)
Specifications
Electrical:110/220V, 0.5A, 50/60Hz
Output Voltage:0-30V DC (continuously variable)
Dimensions:4-1/2"W x 5-3/4"D x 3-3/4"H
Max Torque Output:2.8 N/cm
Net Weight:2.75 lbs.
Operating Speed:35,000 rpm
Collet Size:3/32"
Dimensions:6" long x 1.1" diameter
(tapers to 0.7" dia. at finger grips)
Net Weight:7.3 oz.
Type:On/Off
 

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