Tool bit grinders

[baldrocker]

WE
Forgive the newbie ? but I have given some thought
to water cooling on my bench grinder and am
unsure of the electrical safety of the idea.
I would welcome ypur comments
BR

 

[steamer]

Baldrocker,

Yes water and electricity don't mix well...this is true. That is very observant of you and I commend you for thinking of it

However.

My baldor ( Asian clone) grinder has factory installed one....that is why I mentioned it

Here is why they get away with this apparent engineering gaff.

It is a small drip, not a forceful stream and it is aimed at the perifery of the wheel and not to an exposed bit of wiring. To get internal to the grinder motor would require that the water over come the centrifugal force and get by the shields/seals of the bearings and then find a piece of wire without an insulator on it

Additionally, centrifugal force will sling it out and turn it to mist quite quickly.

I would not suggest a mount for the garden hose mind you. Everything in moderation. ;D

http://www1.mscdirect.com/CGI/NNSRIT?PMPXNO=1676305&PMT4NO=50815847

Here is a link to one ( the genuine article...yikes its expensive!) for sale on the MSC catalog page.

Regards,

Dave

 

[baldrocker]

Ahh. Thanks.
BR

 

[wareagle]

baldrocker, if you are worried about a shock hazard, then you can also put your grinder on a GFCI receptacle and that will keep you safe. As steamer said, the ideas isn't to submerge the wheel and the bit being ground, but it is to let the heat turn the water to vapor to carry the heat away from your bit.

 

[ronm]

I have the HF version, runs nice, no problems, but the "green wheels" that came with it appear to be green painted concrete, they don't do what I would call a real good job on either HSS or carbide. One of my priorities when I get more shop time is to upgrade the wheels, one green & one Alox-haven't really had time to do much looking for better wheels.
Edit: I intended to ask about a diamond wheel...worth the $$$, or not?

 

[Tin Falcon]

a good diamond wheel should last forever in a home shop. it is best if diamond is only used on carbide. steel tends to degrade diamond.
I have used cheap diamond wheels and burs on a Dremmel for doing profile cuts on HSS I have noticed no ill efects but these are small cheap wheels that i will not cry if they have a short life span.
Tin

 

[Andrewinpopayan]

Sorry to butt in here, but Baldrocker, if you put an isolation transformer and an RCD into the grinder supply line then even if you do get a short you won't get a shock and the RCD will trip to warn you that have a fault.

The only reason that you get a shock is because YOU form the circuit between "live" and ground. If the supply is "isolated" it means it is isolated from the ground and no current flows to ground (thru you). Of course touching both of the wires you will still get a shock.

 

[Bernd]

Edit: I intended to ask about a diamond wheel...worth the $$$, or not?

Check at the speed that the diamond wheel should be run at. Bog's once told me they should be run slow. Now any of the HF grinder look a likes that have been talked about on this thread run in the neighborhood of 3600 RMP. Is that to fast for carbide or not?

Bernd

 

[Lew Hartswick]

If youre grinding carbide a diamond wheel can be run fast 1800 3600 rpm but if doing steel it should
be run slow enough to not heat the diamond to the point where it will disolve in the steel. Sort of in the
100 rpm range and kept wet with water. Like the Glendo Corp. Accu-Finish device. (very nice for
polishing the edges of a HSS bit)
...lew...

 

[gunboatbay]

I have hade the same HF grinder for about a year now and, after a few tune-up modifications, couldn't be more pleased with it. I purchased the medium grit diamond wheel from CDCO ($59) and use it only for final touchup on carbide tools, so speed hasn't been a problem, so far. I did find that the green wheels that came with the machine require frequent dressing as they tend to glaze over quite rapidly instead of eroding away as they should. I've since replaced one with a better wheel and it works great. The two major modifications I made were an enclosure for one of the wheels with vacuum port for my shop-vac. Wow, what a difference that made on the amount of grit/dust around the machine!! The second major mod was to the mitre-gauge. As purchased, the mitre-gauge slot in the table was typically 'chinese-rough'. I deepened it ever-so slightly and smoothed out the sides, then made a new mitre-gauge carrier out of brass to fit the bigger slot.

 

[Bernd]

Gunboatbay,

Good post. Sounds like you've taken care of a few problems. I still need to do some mods on my grinder. Sounds like you did some nice ones. Any chance of a pic or two of those mods?

Bernd

 

[gunboatbay]

I'll try posting some pictures as soon as my wife gets back from holidays with the camera.

 

[gunboatbay]

I took some pictures of my grinder, but unfortunately can't find any instructions on how to post pictures in a reply. Can anyone help me?

 

[CrewCab]

For information on posting pictures have a look here

http://www.homemodelenginemachinist.com/index.php?topic=108.0

Basically it's showing you how to host your pictures on an external site such as Photobucket then put a link in your post.

Another way is click on "Additional Options" below the box your typing in, this will open another sub-menu, to the far right of the word "attach" you can "browse" through files on your computer and add them to your post ........... note the limitations though, only 4 pictures per post with a maximum file size of 4096Kb ............... one advantage of photobucket is that it will resize photo's for you.

If that doesn't help I can talk you through it when I get home after work.

Best Regards

Dave