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Home made compound Sine Plate

Posted: Wed May 06, 2009 8:31 pm
by HotGuns
I need to make a compound Sine Plate about 12 to 14 inches long.

Does anyone have any plans or pics I could use to fabricate one?
Thanks.

Posted: Wed May 06, 2009 8:38 pm
by GlennW
Now that's an ambitious project!!!!

Posted: Wed May 06, 2009 8:46 pm
by HotGuns
Yes it is. If I ever get one built, I'll post some pics of it.

Posted: Wed May 06, 2009 9:27 pm
by JimGlass
Bob;

I have made several sine plates. One was 10 or 12 inches.

A sine plate is mostly just a precision hinge. The hinge can be made a number of different ways. The easiest way is to have bushings on half the sine plate and a step pins on the other half to form a hinge. Then a solid pin 5", 6", 10" from the hinge and you have a sine plate. Use a DRO to establish the distance.

You will need to machine some kind of nest for the hinge pins and solid pin to establish a known distance between the pins. You can tilt your mill head to 45 degrees and mill "V" grooves for nests. Another option is to use a ball nose endmill with the same radius as the hinge pins for nests.
If you have a surface grinder, you can grind a "V" groove or dress a radius and grind the nest. The cross feed of a grinder should be precise way for establishing the distance between pins. In all cases the nests will need to be parallel, the same depth and width.

If you already have a sine plate look at how it was made and either copy it or design your own.

The last sine plate marked "77" is 3" X 6" and is a 5" sine plate. I used it very often for 30 years working as a Toolmaker. The size made it handy for grinding and layout purposes. I made the magna sine plate 2 or 3 years ago and it has been handy in my home shop for grinding. I use the magna-sine all the time.
Jim

Posted: Wed May 06, 2009 10:50 pm
by GlennW
I have a compound magna-sine with a hinge setup similar to Jim's last pic, but with adjustable tension. I'll try to remember to get some pics of it tomorrow if that would help. It's 5" centers.

Handy little things they are!

Posted: Thu May 07, 2009 6:58 am
by GlennW
Here's the hinge arrangement and view of the precision surfaces on the lower plate.
Does anyone know the significance of the exactly .100" downward step in the precision surface just to the right of center?

Image

Here's another view of the compound hinge arrangement. The .100" step is in both lower surfaces.

Image

This shows how the hinge bores are split and use a SHCS down through them vertically to set tension or lock the hinge.

Image

Hope this gives you some ideas!

Posted: Thu May 07, 2009 7:10 am
by GlennW
Since it's a Sine related thread:

Here's a handy chart for a 5" sine plate or bar someone else might find handy. It's good as long as you don't need too many decimal places! I keep it with the gauge blocks for quick setups so I don't have to search for my calculator (which is always somewhere else) or root through the Machinist Handbook.

Image

Posted: Thu May 07, 2009 8:23 am
by easymike29
Glenn Wegman wrote: Does anyone know the significance of the exactly .100" downward step in the precision surface just to the right of center?
This is for setting small angles that require less than a .100 gage block. You merely add .100 to your requires stack and place the blocks down in the lower step.

Gene

Posted: Thu May 07, 2009 8:35 am
by GlennW
Thank you Gene!

Great feature!

The best part is that I never even noticed it was there until I opened it up fully and was wiping it off to take the pics. :oops:
Pretty observant sometimes!

I used shim stock and thickness gauges one time when I needed to grind a very slightly tapered shim!

Posted: Thu May 07, 2009 4:49 pm
by HotGuns
Thanks for the pictures gentlemen.

I've got a 15 incher in the shop at work that weights 175 pounds.

I'd like to make one for my home shop thats a bit smaller that I can carry and walk off with. I am well on the way.

I am using some scrap 516 plate that is one inch thick. It cleans up pretty well when put on the surface grinder.

Its sure to be time consuming. Might take me forever to build the thing.

Sine Plate

Posted: Sat May 09, 2009 11:22 pm
by Mid Day Machining
I have a sine plate I made about 10 years ago and I have used it about twice. It is a 10 inch sine plate with 1 inch rolls. It is made of 6061 aluminum and has a hole pattern for 3/8-16 screws on 1 inch centers.

If you're interested, I'll take $150.00 for it, and I'll pay the shipping.

If interested, you can reach me at 714-420-2453