Small angle/sine plate

I needed a small adjustable angle plate to fit on my lathe crosslide and vertical slide for a project that requires accurate angles. This is only 4 inches square and was made from the last pieces of steel plate from my scrap box, hence the extra filled holes which I can live with. There is some pitting in the working faces but they have been scraped flat to a surface plate.
Although I have a Moore & Wright vernier protractor which gives 5 mins of angle, just out of curiosity I thought I would provide a sine function to the plates by virtue of a dowel exactly 3.25 inches from the pivot point and of the same diameter which fortunately has turned out to be accurate from my checks with the protractor and a 30 deg angle gauge. This could be a way to make a sine table for those without access to a surface grinder.
As it is a small plate I opted for M5 clamp screws instead of my usual M6 and made some dedicated clamps. It pivots on hollow hardened pins and being a small surface I could not afford the support plates to be above the surface, so curved arms made from brass sufficed giving 0 to 45 deg. There is not enough room for a fence to be added so 2 location pins can be used to support a parallel when needed. This plate can also be used on the lathe faceplate for indexed milling using my live toolpost spindle, its not pretty but it will do the work I need it for.
In this size it is more suited to a model engineer but could be scaled up if one has the material available.

Attachment 22901Attachment 22902Attachment 22903Attachment 22904Attachment 22905
I even found an empty router bit box to keep it all in.
Attachment 22906

Alan,

Great job again. Sad to hear that has cleaned out your scrap box. I haven't reached that point yet but I am only too aware that I have no easy (read cheap) way of replenishing it any more. I still have a fair bit in the Aluminium box but the steel box is pretty low.

Thanks Tony,
Yes its a shame I did not keep more scrap metal when it was there for the taking, I got so used to picking it when I needed it and the factory closed suddenly, so end of. There used to be four factory's locally but they have all closed. What I did have in stock has lasted me for 13 years so not too bad.

Alan,
I have been self employed since 1973 so I haven't have much opportunity to accumulate scrap, except for the 3 years 2008-2010 when I had a real job in the US. It was like Xmas everyday when I passed the scrap bin, not just lumps of metal but bearings, nuts and bolts, gearboxes, old tooling and so on. Like you I didn't take full advantage of it. When I returned to Spain I put all that I had in a container to be sent back, along with a Bridgeport, lathe etc. The US is such a great place to get nice machine tools for little money. I like living in Spain but it is far from the best place to pursue my interests.

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Thanks olderdan! We've added your Sine Plate to our Measuring and Marking category,
as well as to your builder page: olderdan's Homemade Tools. Your receipt:

<div id="blocks"> <div class="block b1 pngfix"> <div class="bimg"> <div> <a href="http://www.homemadetools.net/homemade-sine-plate-4"> <img src="/uploads/212187/homemade-sine-plate-4.jpeg"/> </a> </div> </div> <div class="head pngfix"></div> <div class="left pngfix"></div> <div class="right pngfix"></div> <div class="blockover b1 pngfix"> <div class="title"> <a href="http://www.homemadetools.net/homemade-sine-plate-4">Sine Plate</a> <span> by <a href="http://www.homemadetools.net/builder/olderdan">olderdan</a></span> </div> <div class="tags">tags: <a href='http://www.homemadetools.net/tag/measurement'>measurement</a>, <a href='http://www.homemadetools.net/tag/plate'>plate</a> </div> </div> </div> </div>
<!-- END /var/www/html/homemadetools/protected/modules/zeus/views/tool/postUpdate.php -->

Thanks for the post! Your approach to spacing the pivots accurately has inspired me to use the same approach when I can find the time to do a similar sine plate. That is the bored ports for the pivots should be very easy to accomplish with good precision even in a modest shop. This design should be amendable to even a relatively narrow sin bar.

I had planned on making one, then I found a niceley priced nicely built 12"x10"(I think thats the size) aluminum sineplate on flebay. it would be nice to have a compound plate......so...your plans may just push me over the edge. keep up the great work guys!!!!

Quote:

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Originally Posted by tonyfoale

Alan,
I have been self employed since 1973 so I haven't have much opportunity to accumulate scrap, except for the 3 years 2008-2010 when I had a real job in the US. It was like Xmas everyday when I passed the scrap bin, not just lumps of metal but bearings, nuts and bolts, gearboxes, old tooling and so on. Like you I didn't take full advantage of it. When I returned to Spain I put all that I had in a container to be sent back, along with a Bridgeport, lathe etc. The US is such a great place to get nice machine tools for little money. I like living in Spain but it is far from the best place to pursue my interests.

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I'm sure this won't come as a revelation to you, but if there are material vendors and shops within decent radius, I recommend paying a visit. I've always worked in shops, at least half let me haul off steel at scrap rate or less. It's been .30¢ a pound long as I can remember. Others didn't restrict me at all, as long as it was drop [fall-off].

we have 1 steel place left hear around me....they eff you in scrap as well as everything else. we do however have a recycle facility that usualy sells for3x the recycle pay price witch is still a good deal....if you can find what you want. so that's another avenue to search for goodies.

could you elaborate on: "I thought I would provide a sine function to the plates by virtue of a dowel exactly 3.25 inches from the pivot point and of the same diameter which fortunately has turned out to be accurate from my checks with the protractor and a 30 deg angle gauge. "

Exactly how does the dowel work? sorry I am new to machining.

Ralph

Mechanical Sine functions depend on two rolls a known distance apart, 5" and 10" are common but any distance works. With gauge blocks stacked under the 'rear' pin, it elevates the plate a specific amount, by a simple calculation. If pivot and rear are parallel in two planes, accuracy is assured. Quality sine plates have two surfaces for gauge blocks, one being .1000 deeper. That accommodates block sets with .1000 minimum thickness, using .1001 will create the incline.

https://en.wikipedia.org/wiki/Sine_bar

Duh, you are using the hinge pin as the first roll. Thanks, that is what I was not seeing.

Ralph

Everybody (many is more accurate) complicate tools with a sine function. Distance between rolls is immaterial knowing their spacing is what makes it work dependably. Do a couple calculations at say 3.500, 5.000, or 10.000". Then insert a actual inspected length, say you determine the planned 5.000" turns out 5.006. Depending on work you do that amount will result in a small percentage, and why longer bars are more accurate. I think right here on HMT.net, Marv did one in wood or cardboard that still worked. With one or two nice plates of material you can go to town. And ignore a machining process using two vee's; takes a degree of additional sophisticated tooling. [swivelhead mill, relieving cutter, angle wheel dresser, surface grinder, and some way to generate accurate spacing, and you'll still be compelled to determine the result]
Here's a little gift.....
Attachment 25032

Quote:

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Originally Posted by Toolmaker51

Everybody (many is more accurate) complicate tools with a sine function. Distance between rolls is immaterial knowing their spacing is what makes it work dependably. Do a couple calculations at say 3.500, 5.000, or 10.000". Then insert a actual inspected length, say you determine the planned 5.000" turns out 5.006. Depending on work you do that amount will result in a small percentage, and why longer bars are more accurate. I think right here on HMT.net, Marv did one in wood or cardboard that still worked. With one or two nice plates of material you can go to town. And ignore a machining process using two vee's; takes a degree of additional sophisticated tooling. [swivelhead mill, relieving cutter, angle wheel dresser, surface grinder, and some way to generate accurate spacing, and you'll still be compelled to determine the result]
Here's a little gift.....
Attachment 25032

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These are some of my posts relevant to sine bars and angle measurement...

http://www.homemadetools.net/forum/b...-sinebar-28996

http://www.homemadetools.net/forum/s...r-errors-27695

http://www.homemadetools.net/forum/a...surement-57213

Oh Marv, you teach +(entertain) us more than we can ever Thank. The blue collar sine bar is just one example. What on earth could be a less intimidating project name? I know not just who posted the uncommon material version, habitually made it yours...:bow:
The links will satisfy ralphxyz 100%, Thanks Again.