used GMF grinder- take 2

[jack620]

OK,
After having my original post moved I now know you aren't allowed to post links to a certain online auction website in this forum. :rolleyes:
There's a used Aussie made GMF 3/4 HP grinder on said auction site. My question was is 3/4HP single phase enough grunt for a 200mm grinder?

Jack

[pipeclay]

Yes

[Bryan]

OK, After having my original post moved I now know you aren't allowed to post links to a certain online auction website in this forum. ...
Jack

Huh? I just read the entire FORUM RULES - Woodwork Forums (http://www.woodworkforums.com/f90/), (OK, scanned them) and could find no mention of this. I have posted ebay links routinely and so have others. :?

[greg_n]

Huh? I just read the entire FORUM RULES - Woodwork Forums (http://www.woodworkforums.com/f90/), (OK, scanned them) and could find no mention of this. I have posted ebay links routinely and so have others. :?

Exactly !
FWIW certain double standards do seem to apply but i think for situations like this, here is the relevant part of the forum rules :
"The owner, administrators and moderators of Woodwork Forums have the right to delete any message for any or no reason whatsoever."

Cheers,
Greg

[Big Shed]

For the record, the post was moved to this forum (http://www.woodworkforums.com/f253/), as it is intended for just such links to Ebay and other online sales sites, see the blurb at the top of that forum.

It was then deleted by the original poster, not by one of the Admin/Mods.

[jack620]

Yep,
I deleted it because I didn't want it that forum. I wanted it this forum which is frequented by people who know about metalwork. Anyway, the rules are the rules and I got the answer I was after (thanks pipeclay).

[Anorak Bob]

Jack,

I have two 8" GMF grinders, one a Utility, the other, a Heavy Duty. Both are 1/2 horsepower and have proven more than adequate for the fooling around I do.

BT

[matthew_g]

I didn't realise it was so political around here...

[Dave J]

I didn't realise it was so political around here...

Me either,:? people post links to auction sites all the time, including me.

3/4 hp is OK, but it depends on what your doing with it. I find with mine if your grinding thick flat bar or polishing it gives it a real workout and can be stopped if you get carried away. If your only grinding smaller stuff and sharpening it's fine.
I wouldn't go any lower than 3/4 for a 8 inch grinder (some of my 6 inch grinders are 1/2 hp) I have seen them around in 1 hp and on the odd occasion 1 1/2 hp.

Dave

[jack620]

Bob & Dave,
thanks for the feedback. I would mostly be using the grinder for sharpening tools, so it looks like 3/4HP is plenty.

It's sold anyway. I shooda kept my big mouth shut!

I'll wait till a 3 phase one comes up.

Jack

[Dave J]

Thats the way it always seems to go.
I think it was Bryan that asked a few months if it was a good idea to post something up, in case someone was watching it.

Dave

[jack620]

Right, it's every man for himself from now on! :)

[Dave J]

LOL

Dave

[Metalman]

I have two 8" GMF grinders which are identical except one is single phase and the other 3 phase. Both are rated at 3/4 HP. I had a multi tool linisher fitted to the left hand side of the single phase unit and it was fine. At a garage sale I was able to buy an earlier model linisher from the same manufacturer (P&A) which fitted to the right hand end of a grinder so on to the grinder that went. Problem was the grinder did not have enough starting torque to get the two linishers going, it would work if you gave it some assistance but this was a potential motor burn out problem. I then swapped all all of the linisher bits onto the 3 phase grinder and this starts and runs well.
I also found out why multi tool linishers are designed to fit onto only one end of a grinder, if you are using one linisher you often grind your elbow on the other belt. I had to modify both linishers so that they could be pivoted upwards 90deg., this was a hassle but there were two advantages, it saved space and it allowed easy access to the underside of the belt for linishing curved surfaces.
Mm.

[pipeclay]

It would also of hopefully eliminated abrasion to the elbow.

[jack620]

Thanks Metalman. So 3/4hp 3 phase has more torque than a 3/4hp single phase? Do both of your grinder motors have the same number of poles?

[jack620]

It's back on the market. Original sale must have fallen thru. RRP has gone from $600 in the original ad to $700 in the new ad! Do GMF still make bench grinders in Oz? Where are they getting the RRP figure from?