Need some Suggestions on Creating a tool path

[jjp24]

i need to create the tool path circled in red and have no idea as to how to create it or what to use. it also tapers from the cutting depth of about -.25" at the bottom to zero at the top.

thanks in advance for any help and suggestions.

http://i20.photobucket.com/albums/b227/beezachoppa/ballpath.jpg

[steve_g]

Roger...
Other than a true 3d machining, we'll be approximating I think. Is the cross section a section of a circle? What I'm hoping you can do in 2d is do a taper or even a "v-carve" with a ball nose bit.

SG

[jjp24]

hi steve

yes, the cross section is circled at the bottom. thanks for the response.

[dana_swift]

Since it is a 0.25 taper over what looks like a long distance, how about slide a quarter inch shim under the end that should be 0.25 deep, then cut a pocket at "zero" depth. As the material rises.. it will get cut on a taper.

Precision may be difficult to obtain, but close should be easy that way.

Use a ball nose bit to make the round shape. Is it from a pinball machine anybody would be familiar with?

D

[steve_g]

Dana's method is the easiest if you can hold it reliably... it will however require you to cut that one feature in a separate fixtureing. Using a "v-carve strategy with a ballnose bit of the same diameter of the semi circle will let you cut it in one fixtureing but the radius of the narrower portion will be a section of the larger radius and not a semi circle. Clear as mud?

SG

[steve_g]

I thought I'd add a picture of what I was trying to say...

SG

[jjp24]

this is for a prototype whitewood playfield.

it's about 14" long and .98" at the widest point. i would think it would be a rather costly bit

[jjp24]

I thought I'd add a picture of what I was trying to say...

SG

that is for sure what i'm looking to do!

[steve_g]

An arc .98" wide and .25" deep is a section of a 1.2104" circle... would a 1.25 ball bit be close enough?

SG

http://www.magnate.net/index.cfm?event=showProductGroup&theID=224 (http://www.magnate.net/index.cfm?event=showProductGroup&theID=224)

$ 31.80 ... not too bad!

[jjp24]

i think that will do it!!
thanks for the link and the help.
i will try to remember posts the results

[gary_n]

Or use a 1 1/4" core box bit from MLCS for $21.00 plus free shipping

[jjp24]

Or use a 1 1/4" core box bit from MLCS for $21.00 plus free shipping

free shipping is good!

[srwtlc]

You could use the fluting tool with the above mentioned cutters also.

[Kyle Stapleton]

Might be way off but could you just ramp it in the whole length to make the taper?

[steve_g]

Many ways to skin the proverbial cat! The only reason I would go with the "V-carve" method is that you have a visual clue with the vectors as to what your cutting strategy was when you come back some date in the future...

SG

[dana_swift]

Another easy way to cut a path like that is to mount a ball nose of the appropriate radius, then create a custom tool path of:

! Header and start router code
M3,0,0,&SafeZ ! locate the bit above the cut start
M3,0,0,0 ! Move the bit to the top of the material at the start of the trench
M3,0,20,-.25 ! Cut a descending trench
M3,0,20, &SafeZ ! Retract the bit out of the cut
! Turn off the router

Vectric tools are nice, but sometimes they make easy tasks hard. Why we cant cut a line or pocket with a sloping bottom is a missing feature. The ShopBot can do it with just a few short lines of code. Its the "labor saving" tools that are making the process difficult.

Go figure..

Hope that helps.

D

[srwtlc]

Good one Dana! Sometimes we can't see the simplicity for all the tools. Back in the day, 2000 for me, that was the way a lot of things were done whilst trying to learn VectorCam.