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I have tried to learn from Harold on grinding HHS tools. I learned in the '60s how to grind tools. I used what the company had and never really paid attention to what was used. I was taught to grind tools and sharpen drills by hand with no tool rest. I am trying to regain that skill.
Here is my attempt to create a grinder. My questions are: will it work?
and should I remake the adapter out of steel? Also, is this roughing wheel OK?
I am using a HF 8" cheapo as the base machine. I made two adapters based off Harold's sketch adapted for my shaft size and to use the original outside washer and nut. They are made of 6061 T6, 2-3/4 D x 1-1/4 with 7/16 shoulders. i cut a recess in the face to allow the wheel to ride only on the outside 1/4" as the original washer. I have anodized one so far, but that is another story. I dialed in the adapter to no movement on the indicator, mounted the wheel and it runs true and smooth after some dressing. With no grinding load on the wheel there is some runout in the shaft. This wheel is a 32A 46 H8V and my next will be the 80 grit.
I have since replaced the socket head screws with set screws.
Steel would have been my first choice, but unless you are running the grinder on a continual basis, I can't imagine it won't serve you well enough. Nice job, by the way. Love the purple color (my favorite).
Also, is this roughing wheel OK?
It looks good enough, but only you can tell if it will serve well. Considering it's a roughing wheel, it should cut fast and cool. If it glazes over when being used, it should be softer. If it sloughs off too quickly, it should be harder. It will behave totally differently when grinding HSS than soft materials, and will act softer as it gets smaller in diameter, so if it's a bit too hard initially, it may be quite good when the wheel is reduced in size.
My only real concern would be the stamped steel wheel guards. Sort of light duty if a wheel lets go. Great for controlling dust, however.
I will proceed. I have some 8" dia pipe and could build some more meaty guards. I have not bought the 80 grit, so I will consider your recommendations on that wheel.
I have a pedestal that will get it to chest high also.
During a recent safety walk through at work, the state inspector took biggest issue with the lack of either, tool rest and tongue guard on some and the distance from the wheel on others. They do get in the way sometimes but are required.
I always try to work safely. I am a one person hobby shop. Sometimes insurance companies and state or local inspectors have ideas we have to abide by in a production shop. I take advise well. I will grind tools on a very limited basis. As a minimum I will have this thing buttoned up before it is used. It will have no tool rest though, it is a special purpose machine and the rest would defeat the purpose.
1) tool rest, closer than about an eight inch to the wheel, to prevent
items from getting by them and being flung by the wheel.
2) guard at the top, to catch anything that did get inside. This is probably
the tongue guard mentioned above.
3) the grinder should not restart after a power failure. Some sort of
magnetic contactor is a good idea so it won't come on unattended if
power was off and the operator walks away.
4) ventilation for grinding of hard materials is a nice idea. This can
be combined with the spark control if the wheel guards have a vent
outlet.
Always, always stand to the *side* of pedestal grinders when first
starting them up. Always be aware the grinder looks pretty innocent,
but imagine when you are pushing hard on a tool bit to rough it out,
it is just about the same thing as leaning out of your car door, and
grinding the tool on the pavement as it shoots by. One slip and your
hand is on the roadway. I personally had a 'close encounter' with a
pedestal grinder wheel that way in voc tech school. Took half the
finger nail in a snap of a second. Boy that throbbed as it healed up.
One would have no idea about how much difference wheel adapters that can be dynamically balance can have.
I have mine balanced and it went from a lousy start, to some vibration, to a noisy slow-down ... to ... almost total silence except the noise of the motor!
I joined the Yahoo Delta/Milwaukee/Rockwell surface grinders group.
If you like to see what I have done for my grinder you can visit.
You may have to free join to see pictures and post.
This board is also moderated by the owned and benefactor of chaski, Marty Escarcega .
Years ago at Ingersoll, we had to have all spindles on all attachments set to the same gage lines on a large multi machine project. We got a spindle grinding service to come in and regrind all the tapers and faces on the machines. The face grinder they used was a plain old bench grinder about like that one, just a different color. It was bolted to a plate that could then be easily adjusted to line it up to machine travels. The tool rest couldnt be in place for that job. If its a dedicated purpose tool, it will be fine.
Thanks for the comments. I am new to home machining, but not new to manufacturing. I was hired many time to do a safety inspection prior to an insurance or OSHA inspection. While my one man shop does not come under either of those inspections, I am always concerned about safety. I used to tell my manufacturing technology students that machines have no brain. They don't say, when you make a mistake, I won't hurt him today because he has been working on this machine for years. My 86 year old dad, who is very qualified on machines, cut the ends of two fingers off this summer.
If we could get machine operators to not operate their machines when their attention is else where, sick, spouse troubles, and the like, we could cut down on injuries.
Sorry, I will get off the soap box.
Thanks for everyones comments on this project. And thanks for everyone concerned about safety.
Jose Rivera wrote:One would have no idea about how much difference wheel adapters that can be dynamically balance can have.
I have mine balanced and it went from a lousy start, to some vibration, to a noisy slow-down ... to ... almost total silence except the noise of the motor!
I joined the Yahoo Delta/Milwaukee/Rockwell surface grinders group.
If you like to see what I have done for my grinder you can visit.
You may have to free join to see pictures and post.
This board is also moderated by the owned and benefactor of chaski, Marty Escarcega .
Hi all, there was a sudden rush to join the Delta Rockwell Toolmaker group. I know why now.
The intent of the ToolmakerGrinder group was for those of us with one of Delta/Rockwell Tool Maker Grinders, for help, exchange ideas on the machine and its tooling, and operations specific to this unique grinder. Not really towards Tool & Cutter or surface grinding techniques. Questions like that are best asked here!
However there are two Yahoogroups geared toward Grinding, PRECISION GRINDING and TOOLGRINDING Yahoogroups.
