Rpm

[paulmcohen]

And, for the record, I like Mickey Mouse. (Although I've always liked Annette Funicello even better...)

With all good wishes,

Very glad sales are up, equally important my whole family LOVES Mickey Mouse and my nearly adult boys don't know who Annette Funicello even was. We own a Disney Condo and go to visit as often as possible, nearly every wall in my house has Disney art and we have several limited edition Mickey cells and original paintings.

Even with all my Shopsmith "toys" I think Mickey is a much more expensive hobby.

[taquin]

Happened to come across this thread and thought this tach would be a good fit for those that want to know their exact RPM.

http://mkctools.com/tachulator.htm

Then low and behold, under their mounting examples, someone already installed it to the Mark 5.


http://mkctools.com/tachulatormv.htm

[sandyj]

I like Nick's reply and would like to add another into the mix - frequency - Us that run at 50Hz have a different speed range to the USA 60Hz - divide by 60 and multiply by 50 - or just turn the darn dial to Saw!

Works for me

Regards
Sandy in NZ

[JPG]

late post from a "newbie" to forum. Paulmcohen if you are listening, thanks! The chart attachment worked. Now if only power station "numbers" were on it.

Ch...oxin: I agree!!!!

However "accurate" speed settings are impossible because belt wear and motor load slip (speed variation) are direct factors. CLOSE/TYPICAL/AVERAGE speed indication would be ACCEPTABLE (after all the speed control is "infinitely variable")!

Wear/slippage of speed dial, wormgear, sheeves also contribute to speed variation relative to dial indication.

AGAIN approximate would be acceptable! (A - W is REAL approximate)

In regard to "other output shafts", the upper shaft (both quill end and opposite end) rotate at the same rpm (same shaft). The intermediate (lower) [for jointer] rotates about 1.6 X faster (1 rev top shaft approx 1 5/8 rev lower shaft. Wow! this means top speed of 8450 rpm.

Now I know why Jointer is so sluggish when mounted to power station running at full speed.

All that being said, think about the (I think) original intent/thinking of that/those individual(s) who created this situation in the first place.

The objective was to indicate on the dial a "range" for use of different "basic functions" i.e. Jig Saw; Disc Sanding; Drum Sanding; Magna Dado; Sawing/Jointing; and Routing/Shaping. These ranges can be seen on dial near outer edge. Now this was all well and good; except; along came SPTs!

Not enough room on dial to put them all (and any future SPTs not thought of yet) so as a compromise, put letters A - W so that a recommended speed chart (using said letters and again a 'range') can be included in manual for each SPT.

If you want to be creative (rather than beating a dead horse) you could make (you are a 'craftsman' after all) make an overlay to put on the dial with settings appropriate for your SPT(s). Maybe even make one for each SPT using velcro backing.

After all we should be observing how our machine is behaving during ANY operation and adjusting speed for proper results thus ignoring dial markings entirely! Use them only as an initial setting!

The key point is that we should be setting within a RANGE not an absolute speed.

As a "NEWBIE" I posted this before discovering pages 2,3,4!!!!!! So I now discover I repeated some of what has already been said. Sorry about that! Never the less look again at my last statement....RANGE......!

[JPG]

I like Nick's reply and would like to add another into the mix - frequency - Us that run at 50Hz have a different speed range to the USA 60Hz - divide by 60 and multiply by 50 - or just turn the darn dial to Saw!

Works for me

Regards
Sandy in NZ

Sandy!!! Are you using a motor designed to run on 60 Hz????? It may be running HOT as well as slow! How about Voltage??????

[charlese]

Sorry! I never did find out why the number of revolutions per minute are at all important!

I never have been shown that specific number of RPMs are useful in woodworking.

Some of the previous posts elude to a myth that rpms are necessary in wood turning. I can agree that relative rotation speed of the surface of turning wood has importance as it will strike a lathe tool at a specific speed. However, for supposedly wise and well informed turners to find anything other than RPM numbers to be Goofy (thought I'd give Mickey a break) is actually laughable. Why do these turners think RPMs are so important? Is it necessary for them to memorize specific RPMs for each species of wood turned? Is it necessary to know the proper RPMs to turn the outside 6" of a turning? Do they use another specific RPM to turn the inside? - or to turn a different diameter?

Of course - The answer to all of these questions is NO. If it is not necessary to know the specific rpms - by species or by diameter (surface speed) of the wood being turned. Why even is there any interest in RPMs at all?

I really don't know, Can someone explain? (Of course there will be more questions)

[beeg]

The Fathers day catalog on page 33 has a chart of the dial settings and speed. That you could cut out for reference.

[a1gutterman]

Well, as long as we are all voicing our opinions, I will throw mine into the mix. IMHO, I think that jpg40504 has it right when he talks about "range". As far as I can tell, there is a range of rpm that will work effectively for each operation. The range that SS specifies on the speed dial IS a guideline and going outside of those guidelines will not cause the "machine speed police" to come looking for you. Experience is what will determine the range that each of us uses. For any particular operation, you will knot want to go so slow that the motor bogs down, nor will you want to go so fast that burning occurs. The types of material will also determine a faster or slower speed for the same operation. Safety concerns will also dictate a certain speed limit. Again, IMHO, SS speed settings are a good place to start, but as you progress with your woodworking, your experience will guide you when it is a good time to turn it up or turn it down. Choosing a specific rpm for a specific operation is too confining. You have got to get "the feel" of the work each time you use your equipment to determine what the best speed will be.

[drl]

Here is my opinion on speed settings: I would agree that the general settings on the speed dial are adequate. Also with experience one will learn what speed works best with whatever you are attempting to do. However where a reasonably accurate speed setting should be observed are with grinding wheels where a max RPM is advised. There are also other "rasps" (Microplanes for example) that have a max RPM rating of 2,500 RPM (between M & N). FYI
Regards,
Dwight

[a1gutterman]

Here is my opinion on speed settings: I would agree that the general settings on the speed dial are adequate. Also with experience one will learn what speed works best with whatever you are attempting to do. However where a reasonably accurate speed setting should be observed are with grinding wheels where a max RPM is advised. There are also other "rasps" (Microplanes for example) that have a max RPM rating of 2,500 RPM (between M & N). FYI
Regards,
Dwight

Absolutely! That wood be those "safety concerns" I was referring to. However, the maximum rpm rating is not so critical that if (using your figures) you had your SS set at "N" and that meant that it was going at an rpm of 2600, things will fly apart. There is always some leeway in those ratings. The manufacturers protect themselves by reducing the maximum rpm on their products to a point below what they know is safe. I AM NOT ADVOCATING SETTING HIGHER SPEED SETTINGS FOR AN TOOL THEN WHAT IS RECOMMENDED, I am simply stating that you only need to be close, but if the max speed setting is a concern for you, set the speed dial at "M" to stay under the 2500 rpm limit.