New Bench Grinder

[Troutsqueezer]

I bought this Delta GR450 8" bench grinder yesterday from Lowes. I had an accumulation of five $25 dollar gift cards that were given to me as awards for one thing or another at work so the grinder really only cost me $25 out of wallet. So I headed out at lunchtime and picked it up.

When I got back to my computer I decided to see what the opinions about it on Amazon were. Ugh...they were not very good. Some gave it 5 stars but it was equally split between 5 stars and 1 star. The biggest complaint was vibrating due to uneven casting of the wheels. I thought I could live with that if it wasn't too bad. I could always buy new wheels and still come out way ahead cost-wise.

Turns out it vibrates much less than the H.F. 5 inch grinder it replaces so I wasn't unhappy. However, when I turn the variable speed knob down to the lowest RPM setting it sets up a fairly loud hum and I can't help but think if I left it there the windings might overheat or something. I don't plan on using it at that speed but was wondering if anyone else here has the same bench grinder and what their experience has been with it.

-trout

 

[rake60]

I have the Delta GR275 6" bench Grinder.

Only complaint I have is the cost of the light bulb!

It runs very smoothly and low speed is great for fine sharpening.
The groove in the left tool rest on mine is supposed to be the perfect
angle for sharpening drill bit. In fact it is, but you still need to free hand the
grinding of the reliefs of both flutes for clearance at the cutting edge.

I think you will be happy with your purchase.

Rick

 

[Artie]

Trout I like the look of your machine and am intrigued by the speed switch as Ive never felt the need to slow one down at all. I have no idea re: your question but I just wanted to make a comment on bench grinders.

I have only had two grinders in my life. The first was a Durst unit, in fact it was in place when I bought my workshop and very old then (mechanic by trade, well first trade anyway). That was 30 years ago and the workshops current owner STILL has it in use today. The switch has failed so its wired to turn off at the powerpoint but it simply spins for literally five minutes after switching off.... amazingly free of friction and vibration.

The second is a Skil unit (which my dad bought over 40 years ago) and this is the one I use today, and its ok. My point is this, it still has the glass shields fitted... how many of you have taken them off or not repaired them when broken? (rhetorical question, no need to incriminate yourselves.. ;D)

I use safety glasses but also the shields regularly as I did once have a piece of swarf bounce up and behind my glasses, burnt my tear duct and wasnt that painful.....

Trout, good score and as you say, the price was RIGHT. Hope you enjoy.

Artie

 

[Rustkolector]

Trout,
I bought the same grinder a few years ago. It been a good grinder. It did vibrate a lot when I got it. It had one bad wheel. The wheel clamping washers had oversized bore holes which allowed them wobble and attributed to the imbalance. I got replacement washers and a new grinding wheel from Delta at no charge. With just a little work the grinder now has little, or no perceptible vibration at any speed.

I may improve the cheap tool rests when I get around to it, but other than that it is a pretty decent grinder.

Jeff

 

[Hilmar]

Take it back. New wheels will not improve the problem by that much
First I made a new hub for the wheels and balanced the wheels .
That did help more than a bit. The wobble comes from something different.
It is a lousy design. The inside flansh has only a 0.025 " rim to rest against .
Then when you tighten the lock nut with that lever action it will pull the wheel to one side.
there is nothing to hold the wheel in a 90° position to the motor shaft.
It took me some time to figure out what the problem was.
I finely made a larger shoulder and pressed that on to the motor shaft. I turned the flansh true and got rid of the locking levers on the nuts. So now I am happy. sort off. Oh I forget to mention I also had a bade motor control and the speed is still to high for a grinder . Not what you want to use on your tuning tools. A 6' would be better.Less surface speed.
Hilmar

 

[Troutsqueezer]

Thanks guys.

I don't have a vibration problem with it. It's a lot smoother than my Harbor Freight 5" and when I shut it off it does take a few minutes to come to a stop.

I plan on upgrading the rests as well but at least the ones that are there are cast iron. My last one had flimsy sheet metal and wouldn't adjust the angle.

-Trout

 

[phlegmatic]

beginners might not know you must let the wheel spin for a while after grinding wet to trow off any water in the wheel! Just a helpful hint!

 

[New_Guy]

beginners might not know you must let the wheel spin for a while after grinding wet to trow off any water in the wheel! Just a helpful hint!

not sure why you would grind wet unless it was one of those slow speed sharpening wheels designed for it

NEVER use a grinder that has had coolant run on a stopped wheel you will probably only find this on a surface grinder but yeah the coolant seeps into the the wheel and makes it unbalanced IT WILL EXPLODE!!!!!

sorry for the OT post i just had to say it

back to the topic..

 

[PhillyVa]

Hey fellas,

When I trained as a saw filer a while back, we would run a new grinding wheel (12") for five minutes before we would dress it true and to shape. The reason it could explode, was from a defect of manufacture or miss handling, storage. We would check for cracks by ringing the wheel with our knuckle or wooden handle...if you heard a dull thunk when rapped it was cracked and set aside for exchange.

We had several grinders that had coolant shooting at the point of grinding for the reason of cooling and material removal and finner finnish. One grinder was so old that one part of the wheel was in the coolant and would pull the fluid onto the grinding surface. None exploded unless there was operator error. We only had three wheels blow up in the 25 years that I was saw filing and they where the dry grinding wheels.

Using a diamond dresser to true the wheel may take care of a small vibration but, if it wants to take the bench for a walk...change it out.

Regards

Philly