Hello All,
I am in the process of designing a medium sized CNC machine to be used to cut thin aluminum sheet to build a homebuilt plane. Material is mostly 2024 and 6061 ranging from .020" to .125". The majority is in the .020 to .04 range. Also I will need to cut 3/4 MDF for the sheet metal forms. Travel of the machine needs to be 5' x 4' with very little Z so I intend to keep the Y Gantry boom fairly close to the material to cut down on flexing. I plan to use 4 axis with 2 motors being used on the long axis (Y). My question is if I use a large extrusion as the building block 40x120 can I get good rigidity with the Openrail system and metal Vee groove wheels? I once made an overhead gantry that had a travel of 10' x 20' and the vee groove wheels from bishop wisecarver worked great, however I was not worried about micro positioning. I am not worried about rapids as I am willing to travel slow while cutting since the material is thin metal anyhow. I plan to use teflon coated leadscrews with anti backlash nuts or cheap rolled ballscrews if I can afford them.
If the Vee groove system is not sufficient I have some THK HRW25 rails, but I dont think they have the travel I need. There in storage and i will have to see how long they are. I have been to the automation surplus site and they have some 30mm Hiwin rails that look promising, but i have never been a fan of Hiwin, but then again I am paying this time so I can possibly change my views to save money... I have some renishaw linear encoders I would love to use and run closed loop, but I may go open loop at first to keep things simple on the initial setup.
What say you? Has anyone built a decent machine from Vee groove wheels? The CNC mogul is close, but it looks a bit flimsy for my application.
Best regards,
Marc
I am in the process of designing a medium sized CNC machine to be used to cut thin aluminum sheet to build a homebuilt plane. Material is mostly 2024 and 6061 ranging from .020" to .125". The majority is in the .020 to .04 range. Also I will need to cut 3/4 MDF for the sheet metal forms. Travel of the machine needs to be 5' x 4' with very little Z so I intend to keep the Y Gantry boom fairly close to the material to cut down on flexing. I plan to use 4 axis with 2 motors being used on the long axis (Y). My question is if I use a large extrusion as the building block 40x120 can I get good rigidity with the Openrail system and metal Vee groove wheels? I once made an overhead gantry that had a travel of 10' x 20' and the vee groove wheels from bishop wisecarver worked great, however I was not worried about micro positioning. I am not worried about rapids as I am willing to travel slow while cutting since the material is thin metal anyhow. I plan to use teflon coated leadscrews with anti backlash nuts or cheap rolled ballscrews if I can afford them.
If the Vee groove system is not sufficient I have some THK HRW25 rails, but I dont think they have the travel I need. There in storage and i will have to see how long they are. I have been to the automation surplus site and they have some 30mm Hiwin rails that look promising, but i have never been a fan of Hiwin, but then again I am paying this time so I can possibly change my views to save money... I have some renishaw linear encoders I would love to use and run closed loop, but I may go open loop at first to keep things simple on the initial setup.
What say you? Has anyone built a decent machine from Vee groove wheels? The CNC mogul is close, but it looks a bit flimsy for my application.
Best regards,
Marc