Here is a picture of a 3/4 inch dice I made on my mini Grizzly lathe that I put DROs on all three axis. They are awesome and so is the mill. I know I've got to much time on my hands but it sure is fun.
Pat
It's only dice if you make two, one is a die. Looks good tho. How about mil-spec dominos next? [URL] http://www.metalwebnews.com/howto/dominos/dominos.html [/URL]
Sarge
I stand corrected. Dominos? well you never know.
Pat
I see the connection. The DROs made it easy to put the faces on the die. Clever choice of projects to give the DROs a good tryout... and clever little trinket to show yer buds..Thanks for sharing Pat 
I see grizzly has a 6" scale with a remote readout for $22
Ed,
Boy do I feel like an idiot. I didn't even think about checking with Grizzly for DRO's. I paid 150 dollars for my three and I see I could have got them for 100 from them. Mine don't have the remotes readouts which would sure be handy. I have used Grizzly stuff for years. I had a big lathe and big mill in my gunshop. This little mill is as accurate or more than the big one I had. Thanks for letting me know about them.
Pat:(
Nice! DRO's are awesome for any number of tasks, especially for bolt circles like these:
If your DRO does not have a bolt-circle calculator built in, years ago I wrote a PC program that is crude but does the job. You specify the radius of the bolt circle, the number of holes, and any angular offset from 12 o'clock, and it spits out X and Y coordinates to 0.0001, plus a basic image of the circle. If anyone is interested, I'll post it. I've used it hundred of times.
The best thing is the ability to completely ignore backlash. You never have to look at your handles again. And you can set the fixed jaw of your vise to Y = 0 (Absolute), and it greatly simplifies setup.
Swede,
Wow that part is awesome! I'm sure anyone that has DROs would definetly appreciate a program like that. I know I sure would. I cant' believe how simple it would make indexing. Thanks in advance if you get a chance to post your program. I showed the die to the people at work and everyone wants one.
Pat
OK, I have uploaded it to my website. Remember, it is totally crude, written for myself, has no error checking, nothing. It is just a trig engine to do bolt circles.
There are two parts, a left side for turning balls on a lathe - ignore that, but it does work. To the right is the bolt circle program.
You need to enter 4 values. The "Object Radius" is the OD of the stock, such as a 2" aluminum round. The "Bolt Circle Radius" is the radius of the bolt holes, say 1.500". "Number of Holes" is obvious. "Offset": If you enter zero, the first hole will be at 3:00. If you want the first hole somewhere else, enter the number of degrees (0 to 360) from 3:00.
Click the VIEW button and it generates the image.
Play with it a bit and it will be obvious. I usually get what I want, hit VIEW, then PRINT, then use a magnet to stick the paper to the head of my mill.
You need two files to make it work; it was written with VB probably around 1995. Download these two files and stick them in the same folder. ballcalc.exe is the executable. Total size is about 400K for both.
For PC only, Win 98 or better:
vbrun300.dll
ballcalc.exe
Good luck, hope this helps. You can create bolt circles so accurate, you can make a lid separate from a vessel, and when you put the lid on, the holes are perfectly aligned.
| Quote (Swede @ June 24 2010,10:15) |
| OK, I have uploaded it to my website. Remember, it is totally crude, written for myself, has no error checking, nothing. It is just a trig engine to do bolt circles. There are two parts, a left side for turning balls on a lathe - ignore that, but it does work. To the right is the bolt circle program. You need to enter 4 values. The "Object Radius" is the OD of the stock, such as a 2" aluminum round. The "Bolt Circle Radius" is the radius of the bolt holes, say 1.500". "Number of Holes" is obvious. "Offset": If you enter zero, the first hole will be at 3:00. If you want the first hole somewhere else, enter the number of degrees (0 to 360) from 3:00. Click the VIEW button and it generates the image. Play with it a bit and it will be obvious. I usually get what I want, hit VIEW, then PRINT, then use a magnet to stick the paper to the head of my mill. You need two files to make it work; it was written with VB probably around 1995. Download these two files and stick them in the same folder. ballcalc.exe is the executable. Total size is about 400K for both. For PC only, Win 98 or better: vbrun300.dll ballcalc.exe Good luck, hope this helps. You can create bolt circles so accurate, you can make a lid separate from a vessel, and when you put the lid on, the holes are perfectly aligned. |
cool thanks Swede!
Swede,
Thanks a lot can't wait to try it.
Pat
No prob, just remember it is as crude as can be. It was never meant to exist off of my own computer. 
Swede,
It works great on my computer! I'm going to drill some holes tonight. Thanks again. I will post a picture with the finished piece.
Pat
I'm glad it worked. It's not all that applicable to gun building, as bolt circles are not something you'll see on a firearm, but machine tools of course do more than guns.
As you work with your DRO, you will learn other tricks that will become second nature. To me, the very best is the use of X and Y centerlines as your zero, rather than the upper left corner being X=0, Y=0.
For example, lets say you have a rectangle of steel that is 3" wide by 6" long. You want to drill six holes symmetrically into the steel. Traditionally, you'd use blue and mark out. With a mill and a DRO, you'd typically set the fixed vise jaw at Y=0 using the ABSolute function. So the mill always knows that the vise jaw is Y(ABS) = 0.
So you mount the piece, and since it's 3" wide, you move the Y axis (in the ABS mode) 1.500" If the piece is odd, like 3.010", you use 1.505" Then, switch to INC (incremental) and ZERO the Y axis.
Edge find the left edge in INC mode; Zero, then move the X axis to whatever the width is, divided by 2, plus 0.100" for the edge finder. So now you are dead in the middle of the piece in both X and Y, and you are zero'd in both axes.
Now your holes become plus or minus based off that point. To do a long dice "6" pattern might be Y = +/- 1.000", and the X might be +/- 2.500", and of course, zero.
I know you know all this because you made the nice die, but working with a DRO allows one to really make some parts with perfect symmetry by locating to the middle of a piece, rather than the edge. And drilling a hole dead center through a shaft is child's play - A 1/2" shaft is mounted, the Y axis set to 0.250" ABS, and you drill a perfect hole. Takes moments! 
A DRO is one of the greatest productivity boosts you can add to a lathe or mill. Enjoy!
Swede,
Thanks for the info. I am always up for learning better ways of doing things. When I had my gunshop I used the edge finder along with the dials on the wheels to find dead center on the actions. Find the first hole position drill it and tap it then feed the mill to the next hole to be drilled by the dial. They were always right on. These DROs sure simplify things, you dont even have to worry about backlash. I can't believe how I did without them this long. Of course the prices have came down a bunch since I closed my shop in 1997. I am doing my machine work for fun now and having a great time. I work 14 days a month in a coal mine and get a paycheck and can enjoy machine work for fun. The circle program will definetly come it handy when I get my next 7 days off in a row. My last days off I made a few dice for buddys at work. Thanks again for taking the time to post all the info. I'll be looking for anything else you would like to share It's greatly appreciated. I never had any machine schooling I learned it all from books and trial and error.
Pat