Shopsmith Forums

JPG wrote: ↑Fri Mar 26, 2021 9:40 am After reviewing the patent drawings I 'discovered' that although the wheel bevel angle is 2°, the blade tilt is 1° 15'. Rubber tire being squeezed ? ? ?

Is this not the wheel cant The measurement depicted is with reference to the axis of rotation of the wheel.

Yes it is.

What I am having an issue with understanding is WHY that cant angle is 1 1/4° .* I understand it is the compliment of 89°+ 22.5/90°. (why? two different angle description nomenclature in a single drawing???) Only thing I can come up with is the blade spine deviates from the back edge of the wheel as it traverses the wheel.

I have been guilty of describing all this from the wrong drawing(fig 18) caused no doubt by that drawing being oft referenced elsewhere.

So the cant angle is not 4°, BUT 1 1/4°.*

* Fractional degrees is non ambiguous.

Maybe SOMEDAY we will all understand this animal.(including SS CS).

JPG wrote: ↑Fri Mar 26, 2021 4:34 pm Yes it is.

What I am having an issue with understanding is WHY that cant angle is 1 1/4° .* I understand it is the compliment of 89°+ 22.5/90°. (why? two different angle description nomenclature in a single drawing???) Only thing I can come up with is the blade spine deviates from the back edge of the wheel as it traverses the wheel.

I have been guilty of describing all this from the wrong drawing(fig 18) caused no doubt by that drawing being oft referenced elsewhere.

So the cant angle is not 4°, BUT 1 1/4°.*

* Fractional degrees is non ambiguous.

Maybe SOMEDAY we will all understand this animal.(including SS CS).

?

Are you certain that they are complimentary angles??

89 degrees 22.5 minutes equals 89.375 degrees (89 degrees 22 minutes 30 seconds plus 0 degrees 37' 30" equals 90 degrees)

They HAVE to be.

Nomenclature/ annotation / whatever is making confusion. That is why I went to fractional degrees.

1° 15' is 1 + 15/60- 15 minutes out of 60 minutes/degree == 1 1/4° .
Now that 89°-22.5' is 89 - 22.5/90 do not know what to call this == 88.75° .<<<<<<< that is simply dead wrong!

After having read part of the patent description regarding the 89°-22.5' I realize that is 89 degrees 22.5 minutes(out of 60 minutes).

The upper wheel axis IS 1.25° from horizontal. The blade angle is 37.5 minutes from vertical(hence the 89° 22.5' in fig 15). That 89+ angle is the blade angle relative the the wheel axis.(either one) At least that is what the verbiage says. There is no explanation for the 37.5" blade angle. I have to assume it is the result of the blade tracking on the wheels. I believe the position of the back of the blade relative to the back edge of the wheel(rim?) varies through the +-90° the blade travels on the wheel.

Ignore for a moment the blade and/or blade angle. Are the two wheel axles in parallel horizontal planes? I say no.

The upper wheel cant prevents that. The planes are at a 1° 15' angle from each other.

P.S. complimentary angles are a pair whose sum is 90°.

I believe I have a basic understanding of the Shopsmith/Magna Bandsaw and the relative position of the upper and lower wheels as depicted in fig.15. I hope other are getting the same basic understanding too. For anyone working on their Bandsaw it is important to know that the cant exists in the upper wheel and if missing needs to be restored for proper operation. For me I am happy to know that the engineers at Magna made a more user friendly Bandsaw than others found on the market.

JPG,

you said

Maybe SOMEDAY we will all understand this animal.(including SS CS).

I think we are getting pretty close and have a least a good working knowledge of how it functions. MAYBE someday SS CS will catch up. Unfortunately they only have what someone has previously written down to reference. Maybe the quote in my post on March 1st from Everett was him getting information that was misunderstood by the CS representative he spoke with.

Upper Wheel angle - From Everett January 15 2016 in a forum post.

I just got off the phone with Shopsmith Customer Service and was told that the 2° Bevel was added in April 1984 to the upper wheel. Prior to that, they said they were flat like the lower wheel. That may answer some of the questions since many of us have Bandsaws from early and later production.

Maybe April 1984 was when someone noted the reference currently used that the Bandsaw's Upper Wheel has a 2° Bevel and assumed it meant that prior to that it was flat. Who knows for sure. Maybe CS should refer questions like these to the Forum so customers can get more accurate information. Sorry CS for bashing you here but you can only give the information you have available to you.

We have wandered a bit into the more technical side but I am wondering has anyone had a problem leaving the table in the factory position as apposed to changing it to have the table at 90° to the blade? I remember John mentioned cutting trunnions and other cuts leaving overcutting the intersection because of the factory angle. I guess it still boils down to what type of cutting you use your Bandsaw for.

Is just over 1/2° from vertical an issue except for thick free form cutting?

JPG wrote: ↑Fri Mar 26, 2021 8:54 am Go get the patent drawings Dusty. Or have you forgotten them? I will look for the thread.

Here's the drawing.download/file.php?id=52513

"A" is 2°.

I hope every one reading this thread reads all of it carefully while paying close attention to the detail. There has been a boat load of misinformation. This pictures, posted to clarify, is not of the Shopsmith bladesaw.