let's see your craftsman block grinders

[Pupuhd]

To simplify things, set up your 110v tool (e.g. compressor, grinder, etc). Without powering it up, measure the voltage at the switch relative to neutral. This should be 110v. Let's call this "v1". This is your open-circuit voltage (a.k.a. Thevenin voltage). Now, while the voltmeter is still on these wires, turn on the tool. You will now see a voltage lower than 110v (let's call this "v2") because of the voltage drop across the wire leading to the tool. The wire resistance is your Thevenin resistance. The difference of these two measurements (v1 minus v2) is the voltage drop across the wire leading to the tool. Remember this voltage drop value.

/QUOTE]

Absolutely, and let's go a bit further and put this in perspective.

My basement shop has a 50 foot run from the breaker box to the furthest wall. So 100' of 12AWG wire for the circuit (power and return). 12AWG is 1.588 ohms per 1000', so 100' amounts to .1588 ohms. With that 1/2hp block grinder drawing 6 amps under full load, the IR drop to it is .158 x 6, or roughly 1 volt.
I defy anyone to notice a 1 volt difference, especially when wall voltage varies 5-10 times that amount throughout the day. But of course there will be those that have 200' of run and believe they feel a marked improvement when they configure their grinder to run at 3 amps of draw on a 220v outlet. They might be ignoring the fact that it's different circuits making the difference rather than purely the voltage, or they have underspec wire running the distance.....
I see a 220 volt religion forming here.


EDIT: Bonus question.

Since most of the old block grinders were engineered to yield full power at 115 or 230 volts, and contemporary voltage is actually 120 or 240 volts, how many feet of 12 gauge wire can you use before the grinder drops below its rated design voltage?

I knew it, I knew it! There was going to be a quiz after this. [emoji32]

I "see" said the blind man to the deaf man as he picked up his hammer and saw.

 

[torqueman2002]

I knew it, I knew it! There was going to be a quiz after this. ...

 

[JZiggy]

To simplify things, set up your 110v tool (e.g. compressor, grinder, etc). Without powering it up, measure the voltage at the switch relative to neutral. This should be 110v. Let's call this "v1". This is your open-circuit voltage (a.k.a. Thevenin voltage). Now, while the voltmeter is still on these wires, turn on the tool. You will now see a voltage lower than 110v (let's call this "v2") because of the voltage drop across the wire leading to the tool. The wire resistance is your Thevenin resistance. The difference of these two measurements (v1 minus v2) is the voltage drop across the wire leading to the tool. Remember this voltage drop value.

/QUOTE]

Absolutely, and let's go a bit further and put this in perspective.

My basement shop has a 50 foot run from the breaker box to the furthest wall. So 100' of 12AWG wire for the circuit (power and return). 12AWG is 1.588 ohms per 1000', so 100' amounts to .1588 ohms. With that 1/2hp block grinder drawing 6 amps under full load, the IR drop to it is .158 x 6, or roughly 1 volt.
I defy anyone to notice a 1 volt difference, especially when wall voltage varies 5-10 times that amount throughout the day. But of course there will be those that have 200' of run and believe they feel a marked improvement when they configure their grinder to run at 3 amps of draw on a 220v outlet. They might be ignoring the fact that it's different circuits making the difference rather than purely the voltage, or they have underspec wire running the distance.....
I see a 220 volt religion forming here.


EDIT: Bonus question.

Since most of the old block grinders were engineered to yield full power at 115 or 230 volts, and contemporary voltage is actually 120 or 240 volts, how many feet of 12 gauge wire can you use before the grinder drops below its rated design voltage?

OK, I'll bite.

In the 120 to 115V scenario, you're looking for a dV=5V @ 6A, so R=0.833, length = 525' based on 1.588 ohm/1000'

In the 240 to 230V scenario, you're looking for a dV=10V @ 3A, so R=3.333, length = 2100'

What we're seeing is that using higher voltage minimizes the effect of small resistances in the circuit (extension cords, connection points, etc.) because the current load is lower.

 

[jakemac]

My brain hurts.

 

[exmaxima1]

OK, I'll bite.

In the 120 to 115V scenario, you're looking for a dV=5V @ 6A, so R=0.833, length = 525' based on 1.588 ohm/1000'

In the 240 to 230V scenario, you're looking for a dV=10V @ 3A, so R=3.333, length = 2100'

What we're seeing is that using higher voltage minimizes the effect of small resistances in the circuit (extension cords, connection points, etc.) because the current load is lower.

Bingo!

So then it is agreed that anytime your power line is over 525 feet, the grinder should be wired for 220 volt operation. Perfect. Settled

 

[McBrownie]

Bingo!

So then it is agreed that anytime your power line is over 525 feet, the grinder should be wired for 220 volt operation. Perfect. Settled

 

[JZiggy]

Oo-oooh! Is that pot of gold for me??

 

[alpinewhite]

More info: Wire size is dictated by the current that goes through it and not voltage. Thus, transmission lines (aka "high-tension wires") are all high-voltage to minimize the current going through it. Remember that power = current x voltage (P=IV). Thus, to have the same amount of power, the electric company can get away with thinner wires but they have to increase the voltage. Then, locally to an area, they utilize transformers to step down the voltage to a safer one to be used in homes.

 

[exmaxima1]

What we're seeing is that using higher voltage minimizes the effect of small resistances in the circuit (extension cords, connection points, etc.) because the current load is lower.

Another thing you'll find, particularly at exhibit halls and larger venues, are distribution transformers to increase/decrease the line voltage. I recall once at a trade show in Las Vegas that the inrush current of some of our gear was tripping the power supplies due to insufficient line power. We contacted the show's electrical guys and they changed the tap on the distribution transformer to the next higher voltage, and the problem went away. So having a higher nominal wall voltage can indeed alleviate many issues caused by excessive voltage droop.

 

[sector9]

I have been messing around with making a new label in Adobe Illustrator. On the left is my "faithful" reproduction of the label. The middle is a picture of the label. The right has a larger Craftsman crown logo without the Sears logo.

If there's any interest, I plan to make these available (once they're more finalized) to other blockheads

 

[altersaddle]

I think the font for the original label is Futura T Demi.

 

[torqueman2002]

I have been messing around with making a new label in Adobe Illustrator. On the left is my "faithful" reproduction of the label. The middle is a picture of the label. The right has a larger Craftsman crown logo without the Sears logo.

If there's any interest, I plan to make these available (once they're more finalized) to other blockheads

Great looking labels. Thanks for the generous offer.

 

[bulletpruf]

GN: i think we talked about switching over to 220 a lot with the commercial or industrial 1/2 HP+ blocks, but couldn't see the real advantage of doing so. Pretty sure Scott is the only one to make the switch to 220 so far.

Scott: any difference in the 220 that you notice over maybe a block running on 110 if you had one? also besides the wiring on the inside of the block to change it to 220 don't you need to change plugs or is that the 2 minute change to swap plugs?

Drives -

I'm using the same plug, but have to use an adapter because the outlets here are different.

I only have one block, and I really haven't used it yet. Still setting up my garage after all of my tools arrived from the states about 2 weeks ago. Plan to get cranked up for some actual work next week on the 72 Alfa Romeo GT rebuild.

Scott

 

[sector9]

I think the font for the original label is Futura T Demi.

Excellent!! Looks like a great match to me based on web samples. Will do more searching later in the week to see if I can find a downloadable version that is free, or cheaper than the $20 I just found
How the heck did you find that?

 

[Bobioz1]

Sector9, I'm interested. I like the one on the left.

 

[altersaddle]

Excellent!! Looks like a great match to me based on web samples. Will do more searching later in the week to see if I can find a downloadable version that is free, or cheaper than the $20 I just found
How the heck did you find that?

Back in college I had a professor who was pretty enthusiatic about fonts (aka typefaces). There are signature characters that make them unique. This one has a round G, angular R, diagonal slash, angled M and W, and round 3.

Also, Futura is an old design, so it's a likely candidate for a vintage power tool, more likely than a modern font made for the computer age.

 

[Shiftless]

OK, I'll bite.

In the 120 to 115V scenario, you're looking for a dV=5V @ 6A, so R=0.833, length = 525' based on 1.588 ohm/1000'

In the 240 to 230V scenario, you're looking for a dV=10V @ 3A, so R=3.333, length = 2100'

What we're seeing is that using higher voltage minimizes the effect of small resistances in the circuit (extension cords, connection points, etc.) because the current load is lower.

JZ:
Nice job coming up with that answer


All:
Don't forget that if you have to run long lengths of wire and are worried about one or two percent voltage drop, remember that you can move up to a bigger size wire. 10 AWG. is only .999 ohms per thousand feet

 

[nine4gmc]

This thread is progressing rapidly!! Great job on the labels and you guys are on top of things with all the math!!


Sent from my iThingy using Tapatalk

 

[Shiftless]

Here is one I am NOT buying. Hard to believe a guy was using this the way it is

Am I just being too cautious with all my guards and eye shields in place?
I don't generally use my full face shield when grinding with my half horse block, but my prescription glasses are always on my face and they are made from polycarbonate impact resistant plastic.

Anybody want to chime in on best practices when grinding with our old blocks?

 

[exmaxima1]

Anybody want to chime in on best practices when grinding with our old blocks?

I have no guards on my wire wheel block grinder, and I wear face mask to combat the flying wires. I would NEVER use a grinding wheel w/o a guard---safety glasses won't keep a chunk of rock from breaking your teeth or tearing a chunk off your face.

 

[jakemac]

Anybody want to chime in on best practices when grinding with our old blocks?

If you haven't bled by the time the job is done, then you didn't do it right.

I try to stand to the side so that I'm not directly in line with the grinding wheel, wire wheel, blade, or belt. (I'm not always successful)

 

[torqueman2002]

Good question.

When I grind and/or wire wheel:

• stand to side
• safety glasses w/ side shields
• full face mask
• wheel guard & covers in place
• spark arresters adjusted ~1/16" gap
• tool rests, adjusted to ~1/16" gap
• good light
• no gloves
• small pieces held with vise grips/small hand vise

For more information on Grinder Safety, see post #1, in the following link.
http://www.garagejournal.com/forum/showthread.php?t=249539

 

[drivesitfar]

ALL: I started a Grinder safety 101 thread that is pretty graphic over in general tools if you haven't seen it you might want a reminder.

http://www.garagejournal.com/forum/showthread.php?p=5279409#post5279409

before i joined GJ i probably would have used a stone on a grinder without a guard and maybe even used it on the side for some work. my neighbor still uses his 10 inch Jet grinder's side of the stone for some work and he's been a machinist for Boeing for 30 some years now.

anyway a stone flying apart will not only hurt you it could KILL you so bee careful.

i use a wire wheel without any guard on it on one of my grinders and will put one on my balder buffer if needed, but full face shield and thick clothing are a good idea. i've been stuck with wires from my bench grinder and the hand grinders a lot but don't want one in the eye.

great stuff on the 220 guys.

 

[Uncle_Charlie]

I mentioned this also in the new tool thread, but it should be here, instead. I picked this up today at a local flea market. The price wasn't outstanding, but I'm ok with it since the condition is mighty good. A bit of windex to clean it up and it'll be fine. Both wheels are C-man, though the one on the right is rough. I may even build a dedicated stand for it. With the pos it is replacing, I simply bolted it to a table saw. This deserves better.

 

[torqueman2002]

I mentioned this also in the new tool thread, but it should be here, instead. I picked this up today at a local flea market. The price wasn't outstanding, but I'm ok with it since the condition is mighty good. A bit of windex to clean it up and it'll be fine. Both wheels are C-man, though the one on the right is rough. I may even build a dedicated stand for it. With the pos it is replacing, I simply bolted it to a table saw. This deserves better.

Nice Block!

Is this your 1st Block grinder?

Welcome to Block grinder care a preservation site.

See the 1st link in my signature line to a thread with resources for a quench tray, owners manual, ....

BTW, I think the tool rests originally were on the opposite sides.

 

[Uncle_Charlie]

Nice Block!

Is this your 1st Block grinder?

Welcome to Block grinder care a preservation site.

See the 1st link in my signature line to a thread with resources for a quench tray, owners manual, ....

BTW, I think the tool rests originally were on the opposite sides.

Yes, it is my first block. I'm at a point where I've had it with cheap tools. I've decided that as tools need to be replaced, I'll only go with tools that have a proven track record like the block grinders. Regarding the link in your signature line, I referenced that thread to verify it was indeed a block grinder. I think it's the first post that has the item number prefixes.

 

[alpinewhite]

Nice Block!

Is this your 1st Block grinder?

Welcome to Block grinder care a preservation site.

Don't do it. You'll get hooked. I'm at 4 now. Stop while you can.

 

[sector9]

New version of the Craftsman Commercial block label, updated with Futura font. Wasn't able to get the exact one that altersaddle mentioned due to price but the Futura Condensed Medium is reasonably close IMHO. It is a little heavier (more bold) than the original

Thoughts?

 

[drivesitfar]

Charlie: welcome to the group and good choice.

Sector: ok the label looks great so can you provide me one with a 3/4 HP block attached to it.

 

[IMSA GTO]

No affiliation, just saw this and passing along to anyone in NOVA looking for a block. 1/3 hp asking $80

https://washingtondc.craigslist.org/nva/tls/5320156662.html

 

[torqueman2002]

New version of the Craftsman Commercial block label, updated with Futura font. Wasn't able to get the exact one that altersaddle mentioned due to price but the Futura Condensed Medium is reasonably close IMHO. It is a little heavier (more bold) than the original

Thoughts?

It's got my vote!

Great work.

I doubt the font differences would be noticeable, unless they were side-by-side.

 

[bagged89s10]

New version of the Craftsman Commercial block label, updated with Futura font. Wasn't able to get the exact one that altersaddle mentioned due to price but the Futura Condensed Medium is reasonably close IMHO. It is a little heavier (more bold) than the original

Thoughts?

that looks pretty perfect to me.

 

[sector9]

I posted a thread with the label and files here http://www.garagejournal.com/forum/showthread.php?t=310883

 

[NJ Marty]

Got 2 more today at the same sale. Both 1/2HP. I will sell the Champion blower I paid $10 for to offset the $100 price I paid on both grinders.

 

[JZiggy]

I scored a couple little guys today: 1/3hp flat top and 1/4hp round top. Both in really nice condition. These will be either Xmas gifts or flips!

 

[exmaxima1]

Got 2 more today at the same sale. Both 1/2HP. I will sell the Champion blower I paid $10 for to offset the $100 price I paid on both grinders.

That gold pre-block grinder must weigh over 50 lbs with that cast iron deluxe base! You ****!

 

[NJ Marty]

That gold pre-block grinder must weigh over 50 lbs with that cast iron deluxe base! You ****!

Yes it is heavy, Im guessing about 60lbs. The base is the first thing I noticed then how heavy it is. I wonder how much the deluxe base added to the cost back in the day.

 

[cbacres]

Here's a new addition to my herd. Found at a estate sale. Plugged it in, so smooth, unplugged and marked tag sold!
The sale guy and a customer where heading toward it and spotted it spinning down as I told him I'm buying it. The other guy was saying how he was thinking about buying it........ That was close.
It's complete, born in 1970.
May have to sell off some the others now.

 

[Kaervak]

You guys finding these complete 1/2 HP blocks, I'm jealous. I've been looking for a wheel cover for mine for three years now. You ****!!!!!

 

[Kaervak]

1/2HP in Fort Wayne for $20. Doesn't run, but might be an easy fix
http://fortwayne.craigslist.org/tls/5315244737.html