good stuff. That one pad could not have bent and would have returned to zero unless bent. Likely was a grinding glitch--I just quickly saw that segment and maybe will rewatch it. Your ramp up you got in the corner is going to keep occuring but not much. To eliminate the issue to non measurable come back and forth several more times as in 6 or 8--and then feed out and dont go off the edge of course because that will give a ramp down.. When you come up to the wall into the clearance the wheel hits it only once or twice and not even sparked out and you then feed out MUCH too soon. Another tip by the way for those seeing the video when doing precision grinding the heat is an issue and you will grind pin cusions. You noticed he held off a bit to the side for a few seconds to let the heat bleed down in and stabilize--however that will still give a pin cusion when the entire part cools totally later. USE FREEZE PACKS to zap the heat out of there to speed things up when working without coolant. In this case it didnt matter much with the very slight dusting. The freeze packs can speed things up after roughing by 3 or 400%.. That heat if roughing lets say .002 or more with a bigger part will also go into the chuck itself doming it.. You get a feel to use them to drop the temp of the part down to about 55-60--that way after the final dust the temp will be room temp--no pin cusion effect.
Thanks for the video, I really like the work you do with the grinder, thumbs up! I'm going to guess the gauge was ground in grad and not degrees. If you convert 27 degrees to grad you get 30 grad. For those unfamiliar with grad there are 90 degrees per 100 grad making the grad division slightly smaller than that of a degree. Good Day to all.
Nice video I am looking for one to use as a Z height check on the cnc mill. You may ask why,, well 3 people in my shop use the mill. So I have in my cam post a cycle to check all the tools in a program +20mm Z height. Obvious screw ups are easy to catch and at 25% of rapid I can catch befor a crash as well as some of our tools are long and jods are usually 200mm above the table. I have even thought of putting a magnified vernier scale on the side.the issue with my gauge block is more of a go no go gauge. I could use a tool setter but there usally no lower than 50mm high and most are a little kinda clumsy.
Durn good detective work there Stan. With the reading falling off on that lower step, I would bet money that you are spot on with your theory of that thing being dropped and hitting the pin/slider. Great catch and diagnosis. I'll try to put a good word in with Santa on your behalf for that cylindrical grinder. Bonus for us because that would likely provide us with many more interesting videos to watch too. Heh-heh-heh... :-)
LOL! I made a pair of them when I was an apprentice (a LONG time ago) and the angle was dictated by the size of the stock I could find in the rack. If you have a pair, you can use them for adjustable parallels.
26.565 degrees is the arc tangent of 0.5, which means the gage will move vertically exactly half of the distance it moves horizontally. No idea why 27 would be significant though
I agree it is likely supposed to be so that it moves up at 1/2 the rate it moves back. This makes the math simple and it is easier to work under the cutter by measuring out than it is tring to measure up with the cutter and ram in the way on a planer as this is the tool for. Want to drop your tool 1/2in just slide the gage out 1in quickly measured with your scale placed along the side and you are there.
I'm trying to understand your math. At a 45 degree angle, 1 inch in would be 1 inch up. Half of 45 is 22.5 Not seeing how 26.5 degrees would allow it to move half the distance compared to the other distance.
+Shawn Andera Circular angles don't work like that. Tangent of the angle equals opposite side over the adjacent side of a triangle (rise over run or the slope). If you double 45, you get 90 degrees. Now that is not 2:1 is it? If you did not take trigonometry in school, you would never know this, and even if you did you have probably forgotten it like 95% of everyone else. Slopes are linear, and thus work with your logic. Angles are circular and thus are not linear. Sine, Cosine and Tangent are the mathematical functions that transpose circular measurements into rectilinear (x,y,z) measurements. i.e. trigonometry.
Whatever you think the angle is, say to .1 degree or 10 minutes or .1 gradian, mark it on the tool! If I picked it up in your shop to use it, I would assume it is nominally 30 degrees.
So I guess the consensus is either: 1) The angle is 27 degrees because this is 30 grads 2) The angle is 26.565 degrees because that is tan(0.5) and the slider moves 2 to 1 3) The angle is 27.69 degrees (or 27 degrees 69 minutes) for no reason given, but three people agreeing.
My sine bar tests were @ 26.5* / 27.0* / 27.5* with 27* only showing .0003 error, these measurements were done on the original grind, so I have to believe that was the way it was intended.
I *almost* feel a little guilty that from the comments on the previous video, prompted you to shoot a follow-up; nah, not really. This allowed us to get another great video! Thanks again! Also, that is an odd angle, & would be interested to know if there was any method behind the madness of 27°.
a possible theory on it not being 30?--putting strange things into a tool to make it where people cant remake it that easy--same as they by putting bizzare screws and other things
That turned out nice Stan, that does seem like an odd angle. I wonder how repeatable it is if you move the block to another position along the angled length?
good stuff. That one pad could not have bent and would have returned to zero unless bent. Likely was a grinding glitch--I just quickly saw that segment and maybe will rewatch it. Your ramp up you got in the corner is going to keep occuring but not much. To eliminate the issue to non measurable come back and forth several more times as in 6 or 8--and then feed out and dont go off the edge of course because that will give a ramp down.. When you come up to the wall into the clearance the wheel hits it only once or twice and not even sparked out and you then feed out MUCH too soon. Another tip by the way for those seeing the video when doing precision grinding the heat is an issue and you will grind pin cusions. You noticed he held off a bit to the side for a few seconds to let the heat bleed down in and stabilize--however that will still give a pin cusion when the entire part cools totally later. USE FREEZE PACKS to zap the heat out of there to speed things up when working without coolant. In this case it didnt matter much with the very slight dusting. The freeze packs can speed things up after roughing by 3 or 400%.. That heat if roughing lets say .002 or more with a bigger part will also go into the chuck itself doming it.. You get a feel to use them to drop the temp of the part down to about 55-60--that way after the final dust the temp will be room temp--no pin cusion effect.
Thanks for the video, I really like the work you do with the grinder, thumbs up!
I'm going to guess the gauge was ground in grad and not degrees. If you convert 27 degrees to grad you get 30 grad. For those unfamiliar with grad there are 90 degrees per 100 grad making the grad division slightly smaller than that of a degree.
Good Day to all.
Nice video I am looking for one to use as a Z height check on the cnc mill. You may ask why,, well 3 people in my shop use the mill. So I have in my cam post a cycle to check all the tools in a program +20mm Z height. Obvious screw ups are easy to catch and at 25% of rapid I can catch befor a crash as well as some of our tools are long and jods are usually 200mm above the table. I have even thought of putting a magnified vernier scale on the side.the issue with my gauge block is more of a go no go gauge. I could use a tool setter but there usally no lower than 50mm high and most are a little kinda clumsy.
Durn good detective work there Stan. With the reading falling off on that lower step, I would bet money that you are spot on with your theory of that thing being dropped and hitting the pin/slider. Great catch and diagnosis. I'll try to put a good word in with Santa on your behalf for that cylindrical grinder. Bonus for us because that would likely provide us with many more interesting videos to watch too. Heh-heh-heh... :-)
Thank you for deciding to show the machining. Very good video.
LOL! I made a pair of them when I was an apprentice (a LONG time ago) and the angle was dictated by the size of the stock I could find in the rack.
If you have a pair, you can use them for adjustable parallels.
glad you make these videos stan. always lots to learn.
Very interesting. Nice work. Thanks
26.565 degrees is the arc tangent of 0.5, which means the gage will move vertically exactly half of the distance it moves horizontally. No idea why 27 would be significant though
Does it really matter on what is essentially just an overgrown adjustable parallel?
I agree it is likely supposed to be so that it moves up at 1/2 the rate it moves back. This makes the math simple and it is easier to work under the cutter by measuring out than it is tring to measure up with the cutter and ram in the way on a planer as this is the tool for. Want to drop your tool 1/2in just slide the gage out 1in quickly measured with your scale placed along the side and you are there.
I'm trying to understand your math. At a 45 degree angle, 1 inch in would be 1 inch up. Half of 45 is 22.5 Not seeing how 26.5 degrees would allow it to move half the distance compared to the other distance.
+Shawn Andera Circular angles don't work like that. Tangent of the angle equals opposite side over the adjacent side of a triangle (rise over run or the slope). If you double 45, you get 90 degrees. Now that is not 2:1 is it? If you did not take trigonometry in school, you would never know this, and even if you did you have probably forgotten it like 95% of everyone else. Slopes are linear, and thus work with your logic. Angles are circular and thus are not linear. Sine, Cosine and Tangent are the mathematical functions that transpose circular measurements into rectilinear (x,y,z) measurements. i.e. trigonometry.
bcbloc02 and the screw in post is just a handle to slide it in and out of the machine. Brown and sharpe just made the handle real accurate......
Whatever you think the angle is, say to .1 degree or 10 minutes or .1 gradian, mark it on the tool! If I picked it up in your shop to use it, I would assume it is nominally 30 degrees.
So I guess the consensus is either:
1) The angle is 27 degrees because this is 30 grads
2) The angle is 26.565 degrees because that is tan(0.5) and the slider moves 2 to 1
3) The angle is 27.69 degrees (or 27 degrees 69 minutes) for no reason given, but three people agreeing.
Or 27.5 is the Whitworth half angle.
My sine bar tests were @ 26.5* / 27.0* / 27.5* with 27* only showing .0003 error, these measurements were done on the original grind, so I have to believe that was the way it was intended.
26.6 degrees gives a 2 / 1 ratio of movement I.E. along 2mm raises 1mm
Should the small pad next to the angle not have been ground to the same height at the tall pad?
I *almost* feel a little guilty that from the comments on the previous video, prompted you to shoot a follow-up; nah, not really. This allowed us to get another great video! Thanks again!
Also, that is an odd angle, & would be interested to know if there was any method behind the madness of 27°.
The only reason I can think of is... B&S didn't want it to be used as an angle standard ?
Looking Good. I just bought a used one. After I get it and have a chance to check it, what's the chance of yo grinding it for me ?
Maybe the angle is for pizza slices. That would give 13 full-size pieces, and 1/3 of a piece for one of the little kids... LOL. It is an odd fraction.
I would bet money it was dropped with a tool in it. Great video.
The length of the hypotenuse is irrelevant. What matters is rise over run. Arc tan(1/2) = 26.565°..
a possible theory on it not being 30?--putting strange things into a tool to make it where people cant remake it that easy--same as they by putting bizzare screws and other things
Thanks for the tips Stan,
Why didn't you check square on the top of the post when it was screwed in?
That turned out nice Stan, that does seem like an odd angle. I wonder how repeatable it is if you move the block to another position along the angled length?
I checked in a couple of spots, it moves a little, but only a couple of 10th's
arc tan(.5) = 26.6°
Hello . My name is Marcio and I'm from Brazil. I recently bought a machine from this jakobsen. What is the best stone? Can I use emery?
Aluminum oxide is a good general purpose wheel.
GREAT VIDEO !!
Why 27 degrees? Easy sir 2+7=9. The number 9 is the magic number.
I believe it was suppose to be 27.69 degrees. Start over..
I think you are right 27 degrees 69 min.
27 degrees 69 min? Wouldn't that = 28 deg, 9 min???
highpwr, Metric or Imperial,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, Gotcha!
highpwr, aimed at mad max
ron, you had me there for a minute since I slipped a comma in there. Hahahahaha!