45-degree angle has me stumped

teamtj · Post by **teamtj** » Wed Oct 02, 2013 10:40 pm

My 12-year old daughter is making a clock (last plan in this book: http://www.amazon.com/Drilling-Project- ... B005CP7SEE ) and I am helping her.

We need 45-degree angles and when I cut them (which was not easy to set up, in my opinion...I must be doing something wrong!) I put the cut-off and the good piece together hoping they will form a 90-degree angle, but they are not perfect.

I am attaching pictures of my table angle setup and one showing the error, circled in red.

Any advice on how to make the angles work or to correct what I may be doing wrong?

JPG · Post by **JPG** » Wed Oct 02, 2013 11:54 pm

IF I had ultimate confidence in the table angle scales, I would say you set the table about 1/4 degree off.

However I do not have that confidence in the scales(I am guessing you do!).

Question is, did you adjust the table angle all the way to the 45 degree stops?

I will assume you did.

If so the stops need to be fine tuned. You are very close.

I also assume you have never adjusted the stops.

JPG · Post by **JPG** » Thu Oct 03, 2013 12:04 am

Btw a 1/16" gap at 1 5/8" is about a 2 degree error which makes the bevel cuts about 1 degree shy of 45 degrees.

teamtj · Post by **teamtj** » Thu Oct 03, 2013 9:20 am

JPG40504 wrote:IF I had ultimate confidence in the table angle scales, I would say you set the table about 1/4 degree off.

However I do not have that confidence in the scales(I am guessing you do!).

This is my first time making a cut like this, so I have not had to use the scales...

JPG40504 wrote:Question is, did you adjust the table angle all the way to the 45 degree stops?

I will assume you did.

I did...

JPG40504 wrote:If so the stops need to be fine tuned. You are very close.

I also assume you have never adjusted the stops.]
No, never adjusted them...will have to play around a bit with them...didn't really even know they could be adjusted, but now I see they can!

Thanks for the pointers...

JPG · Post by **JPG** » Thu Oct 03, 2013 11:06 am

Assuming you have not done so, do an entire check for alignment.

Table(miter slots) to blade parallel.

Table to blade square(vertical).

Rip fence to miter slots(== parallel to blade).

Miter gauge square to bar(== miter slot == blade).

Miter gauge +/- 45 to bar (== miter slot == blade).

Table tilt stops (both 45 and 90 to blade)[90 = drill press/under table shaping position].

FWIW I wonder how the reversible table affects that 90 alignment. Makes the carriage table mount bores to way tube alignment more critical(non-adjustable).

Lastly set the tilt and miter indexes to 0.

The parenthesis above indicate things interdependent and reveal the reason sequence is important(do the first two first!).

Doing so may preclude the consternation you just experienced.

Not sure about the M7, but in the old days, alignment was the first order of business after 'assembly' out of the box.

There has been much discussion here on how to do all those things and what to use to do them. Accuracy like beauty, is in the eye of the beholder. IMHO the Shopsmith Manual Instructions are quite adequate except for very demanding cuts etc..

BTW Welcome to this forum. Ask away! There are many here who never(rarely?) shy away from helping.

JPG · Post by **JPG** » Thu Oct 03, 2013 11:18 am

The adjustments alluded to above in addition to assuring better accuracy, minimize the possibility of bad things happening.

Rip fence to blade can create pinching of the workpiece as it passes the rear of the saw blade and that can lead to kick-back(you really do not want to experience that!).

If your daughter is with you, ALWAYS make sure she is not positioned in harms way!!!:eek: Same goes for you!;)

Yes I am shouting intentionally. It is that important!!!!!!

I do not wish to scare you here, just make you aware. I surmise you have minimal experience with power tools like the M7, so I am making sure to not err on the side of assuming yer experience level is greater than I surmised.

charlese · Post by **charlese** » Thu Oct 03, 2013 11:54 am

Let me repeat what JPG said - especially in Post #5.

Every setting of the miter guage depends on setting the miter slots parallel to the blade. (or to say it a diferent way - make sure the table is squared to the blade)

P.S. This setting will also affect accuracy of the rip fence.

wa2crk · Post by **wa2crk** » Thu Oct 03, 2013 12:00 pm

Hi Morgan
If you want to cut very accurate angles you may want to invest in some form of a digital angle gauge such as a Wixie. It can be used to check the angles of setups and also to tilt the table by resting the Wixie on the fence when you set the tilt. There other devices that can be used to set the miter gauge as well
[ATTACH]22924[/ATTACH]

[ATTACH]22925[/ATTACH]
Bill V

JPG · Post by **JPG** » Thu Oct 03, 2013 12:13 pm

Like I said above 'what to use'!:D

Wixeys(and others similar) be nice.

Dusty please do not bring up the dial indicator . . . . . yet.

wa2crk · Post by **wa2crk** » Thu Oct 03, 2013 7:35 pm

JPG
He brought that up the last time I posted these pix. Less that .0015 run out.
Bill V