harryball
12-13-2006, 05:32 PM
For those that have been reading different forums about my programming a master part file and thicknessing purpleheart etc... I thought I'd give a general update.
The project master part file works perfectly. I use it to call different part files as needed and I've setup a Vcarve Pro post processor that gives me XY moves only, no Z's, no jogs.
The thicknessing subroutine is fantastic. It grabs the material thickness and creates perfect 1/2 laps in the project.
The planing of the 9" board works great thanks to Paco's surfacing program. I created a vacuum jig that holds the board in place and it takes remarkably little pressure to keep it secure. I run the program with a .01 depth of cut at 6 ips and 12,000 RPM's with a 1.25" surfacing bit. It works perfect on purpleheart, any slower on the speed or faster on the bit causes it to heat up enough to blacken the purpleheart.
This brings me to the actual product cutting. I've found the cutting speed to be 3 ips at 12K RPM cutting the roughly .75" board in 3 passes with a 1/4" downspiral bit. This magic combination does not cause the purpleheart to blacken, the machine sounds good and I'm getting chips, not dust or tear out.
Remaining challenges, feel free to offer opinions or solutions...
1) Hold down is a lady dog. I tried a vac jig and it just can't do it. I'm probably going to go with a jig that is screwed down and screw the board down. I hate using screws, but I'm just not getting the board dead still otherwise.
2) Chatter... yep... I got it. I can see it clearly on the sides of the cuts. They are impossible to sand out. It's faint but it's there. I'm going to experiment with cutting speeds and RPM's but right now I'm looking for "not black" speeds. I'll tell the customer I can improve the prototype with time.
3) Finishing. Getting the purple color back to then overcoat with Spar poly. I understand the nature of purpleheart and know if it's kept in heat or in the sun it'll go black, the spar slows it down.
I'm sure there is more... that'll be later.
Robert
The project master part file works perfectly. I use it to call different part files as needed and I've setup a Vcarve Pro post processor that gives me XY moves only, no Z's, no jogs.
The thicknessing subroutine is fantastic. It grabs the material thickness and creates perfect 1/2 laps in the project.
The planing of the 9" board works great thanks to Paco's surfacing program. I created a vacuum jig that holds the board in place and it takes remarkably little pressure to keep it secure. I run the program with a .01 depth of cut at 6 ips and 12,000 RPM's with a 1.25" surfacing bit. It works perfect on purpleheart, any slower on the speed or faster on the bit causes it to heat up enough to blacken the purpleheart.
This brings me to the actual product cutting. I've found the cutting speed to be 3 ips at 12K RPM cutting the roughly .75" board in 3 passes with a 1/4" downspiral bit. This magic combination does not cause the purpleheart to blacken, the machine sounds good and I'm getting chips, not dust or tear out.
Remaining challenges, feel free to offer opinions or solutions...
1) Hold down is a lady dog. I tried a vac jig and it just can't do it. I'm probably going to go with a jig that is screwed down and screw the board down. I hate using screws, but I'm just not getting the board dead still otherwise.
2) Chatter... yep... I got it. I can see it clearly on the sides of the cuts. They are impossible to sand out. It's faint but it's there. I'm going to experiment with cutting speeds and RPM's but right now I'm looking for "not black" speeds. I'll tell the customer I can improve the prototype with time.
3) Finishing. Getting the purple color back to then overcoat with Spar poly. I understand the nature of purpleheart and know if it's kept in heat or in the sun it'll go black, the spar slows it down.
I'm sure there is more... that'll be later.
Robert