[ADVANCED MACH.]

I Have A Vertical Milltronics Cnc Machine W/24" Of X Travel, & 18" Of Y. I Need To Put An 11deg. Angle On The Top Of A Plate. The Plate Is Wider Than My Largtest Face Mill, So I Will Have To Move Over In The Y Axis To Finish The Whole Top. A Fixture To Mill It Is Not Practical For 3 Pcs. The Plate Is 31" X 8". I Am Looking For An Economical Way To Mill It. The Best Idea I Have Come Up With So Far Is To Buy "2" Large Gromax Tilting Tables, And Bolt My Kurt Vises To Them. I Would Be Able To Put Precision Parallels In The Vises, And Mill Half Of The Top, Slide The Part, And Mill The Rest. Any Suggestions May Also Be Directed To My Website Machineguys.com. My Personal Contact Info Is Also There.
Thanks, Dave@amt

[HuFlungDung]

Can you make use of the sine bar principle?

Clamp a long straight bar parallel to the X axis. This bar would serve as a fence. One edge of your plate should be machined straight to rest against this fence.

Now, the bottom corner of the plate sits on the table, and near the opposite edge, you prop it up on something to get the correct height (using trig to figure out the sides of the triangle). You could lathe some cylinders to lay in the T slots to serve as props. You would measure the effective height of the cylinders above the table with a height guage. It might take you a couple of good guesses to turn the cylinders the exact diameter required to prop the exact angle needed.

Use edge clamps or toe clamps to keep the face of the part clear for machining.

Face the part, then release the clamps and slide the part along the fence and reclamp, repeat the machining procedure.

[ViperTX]

Hu's approach would work...but the part needs to be elevated off the table surface or you will never be able to reposition to complete the milling of the whole length.

[One of Many]

I Have A Vertical Milltronics Cnc Machine W/24" Of X Travel, & 18" Of Y. I Need To Put An 11deg. Angle On The Top Of A Plate. The Plate Is Wider Than My Largtest Face Mill, So I Will Have To Move Over In The Y Axis To Finish The Whole Top. A Fixture To Mill It Is Not Practical For 3 Pcs. The Plate Is 31" X 8". I Am Looking For An Economical Way To Mill It. The Best Idea I Have Come Up With So Far Is To Buy "2" Large Gromax Tilting Tables, And Bolt My Kurt Vises To Them. I Would Be Able To Put Precision Parallels In The Vises, And Mill Half Of The Top, Slide The Part, And Mill The Rest. Any Suggestions May Also Be Directed To My Website Machineguys.com. My Personal Contact Info Is Also There.
Thanks, Dave@amt

You do not mention the thickness or the material of this plate? Will it stress relieve(arch) when removing that much material from one side? Sending it out to have it normalized if it were steel, should help.

11deg across an 8" face is 1.555". In order to hold it in a vise, the material would need to be a minimum of 1.75 thick? If the material is net width, you may need to weld tabs along each edge to hold it down with.

I take it this is the 3 axis Milltronics and it won't allow the head to tilt?

I would get the first one done any way possible with the crudest fixture that would achieve decent results for a rough or finish cut. Then use that as the more solid fixture to do the other 2. Of course you may need to finish the first one with one of the other finished plates as a fixture.

DC

[little bubba]

You have 2 kurts, and a simple angle. May I suggest soft jaws, obviously you can't mill them bolted into the vice, but, how about a couple of pieces of 1x2 or 1x3, about 20" long, square your vices up real nice to each other, mill your angle into the jaws along with some bolt holes, bolt them in and go. No need to purchase angle plates and all that. Granted you will have one jaw spanning two vices, but I've done it before, and its not too bad.

Woops, my instant mental trig has failed, you would need about 4" deep jaws at 20' long for that. How about two seperate sets of jaws cut to 11 degrees, prop one vice up on some blocks and indicate the whole mess in.

I guess there is about a million ways to do this, just depends on what your comfortable with, how much you like your indicator, and how much you are willing to spend.

[ADVANCED MACH.]

Thank All Of You For Your Info. This Was The First Time I Stopped In. I Can Assure Cnc Z Many More Trips Back. Thanks Again, Dave@amt

[One of Many]

Thank All Of You For Your Info. This Was The First Time I Stopped In. I Can Assure Cnc Z Many More Trips Back. Thanks Again, Dave@amt

In order to make this thread useful for others in the future, it would be great to have you come back with how you ended up doing the project.

DC

[gar]

051125-1456 EST USA

If this is aluminum could you trust using a 4" radius fly cutter.

Otherwise I would send it out to some one with an adequate size machine.

.

[legger1654]

I will quite often write a incrementel (g91) programn and use a ball-nose end mill to step acros the edge of a part to obtain the proper angle.
Since you are traveling in y, you must trig out what you must travel in x and z to obtain an 11 degree angle.
Rough the angle with a .05 step over in y and finish with a .015 step over.

Example:
(main)
G90
Go xoyo (start point)
g01z0
m98 p1 (go to sub)
(sub)
g91
g01xblabla z-blabla(angle hypt.)
g01y.05
g01x-blabla zblabla
g01y.05
m99 (return to main)
Loop enough times to get across part in y
No fixtures or sine bars needed

[ctate2000]

Use the control to generate 11 deg angle on soft jaws using x and y axis. Bolt them on the vise and anything you put in the jaw will be held at 11 degs. The time you spend making the jaws will depend on the accuracy you require in the finshed part.

CT