Author Topic: If you could have only one grinder...  (Read 2235 times)

Offline CrazyModder

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If you could have only one grinder...
« on: January 04, 2020, 07:33:24 PM »
I have gone through life without a grinder, so far, and have managed for decades, just fine. But there is the constant thought niggling that I should have one in my otherwise pretty decently outfitted basement.

Now, my problem is that there there are plenty of different styles around - your classic axle with two or more round disks at the end; or different styles of belt sanders (horizontal, vertical, ...). I'll ignore more special contraptions like the d-bit grinders etc.

If you could only have one, which type/style of grinder would you pick? My usage will probably be mainly to regrind drill bits, take sharp edges from freshly cut metal, general shop use, to replace/avoid as many uses of angle grinders/Dremels as possible.

Space is an issue - it would be best if it could be stowed away when not in use, or if it were small enough to live somewhere in a large shelf or something like that. Having a floor-to-ceiling old-fashioned big old loop of belt running around is definitely out of the question. ;)

Thanks in advance!

Offline WeldingRod

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Re: If you could have only one grinder...
« Reply #1 on: January 04, 2020, 08:52:38 PM »
I'd start with a belt and disc combo.

The motor and disc off a HF saw grinder makes a great little tool grinder for a little footprint, if you are willing to have two things.  Frankly, radically more useful than a two rock unit.  However, it's not great for general "knock off the sharp corners" stuff.

Another idea: change the disc above to a 6" diamond wheel!

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Offline PekkaNF

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Re: If you could have only one grinder...
« Reply #2 on: January 05, 2020, 08:26:34 AM »
Pretty much all high speed grinders have somewhat same drawbacks:
* Belt grinder/sander/linishers are pretty good in material removal, but throw a lot of particles around. Even decent size (about two meter belt length, 50 mm wide, about 1-2 kW) will litter least 2-4 m2 area pretty quickly. And good dust collection is hard to make. Check any professional model. BUT they are very efficient for shaping, breaking the edge, "prettyfying".
* Hign speed grinder stones will break. Eventually. Guarding is a must. Diamond or such discs do not shatter and work pretty well on sharpening but are not that good/economical for weld preparation and real shaping.
* And all are fire hazzard. They produce sparks and more efficient they are, more heat they will generate. There are some spark arrestor/suction units that can alleviate this problem. Least you need to stay on fire wach for least one hour after grinding.....although not much of a problem if you grind first and then work....and keeping all compustible material out of grinder quarters is a good idea. I know a person tha had a book case one metre away from the bench grinder and when he left garage, turnet lights out and had a cursory look inside was wondering what is that firefly there....it turned out be a reflection of charred catalog that was about to burst in flames, he took it outside and it started burning.

Slow speed "lapping machine" does not produce much heat and is very good for touch up of the cutting tool, but not really that productive on shaping or any coarse work.

Many years I had a double ended grinder mounted on hefty pinth and took it always outside of the garage ans shaped tools outside. Then I made some slow speed lapping grinders that work many tools but in the end I switched over insert carbide insers and started collecting dull HSS/carbide drills/endmills for "maybe one day box".

I bought "best" cheap drill doctor, but it turned out to be a disapointment. I get what it suposed to do, and it does sharpens standard helix drills, but not nearby orginal shape. Bit more advances helix angle or core shape and it does not work.

So, answer might be as complicated as need or resources are.

Offline tonyfoale

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Re: If you could have only one grinder...
« Reply #3 on: January 10, 2020, 10:30:54 AM »
I have always had what are called bench grinders, several at the moment.  More recently (maybe the last ten years) I have also had the Horror Fright belt and disc machine.
If I was starting from scratch, but with my experience of using both, then without doubt I would go for the typical bench grinder over a belt type any day.  I use the belt grinder more than I expected but it would not be missed if it blew up tomorrow, whereas I would be lost without a real grinder.

BTW I read your post because I thought that you were trying to choose between a cylindrical grinder or surface grinder, that is a subject that has been going around in my mind for a while.  Apart from the problem of choice, there is the problem that I do not have room for either.