waynec
05-13-2008, 09:12 PM
I'm trying to decide whether to upgrade another notch on my modified PR Shopbot.
I installed BWC rails and a new Extruded aluminum gantry, along with a new controller and Mach3 software. Things are much better overall.
But I can't get the performance I'd like from my new controller because of mechanical problems. I have two sources of problems:
1) The X rails (now BWC rails mounted on the sides of the old PR X rails) are not perfectly coplaner. The BWC wheels don't ride exactly right all the way down the rails. I can't get move speeds over 250ipm without skipping off the racks.
2) The wheel mounts on the gantry have too much flex. They are made of two pieces of aluminum angle iron. With the motors on there is no movement, but when the motors are disengaged from the rack the gantry becomes quite wiggly. The gantry itself is very rigid, but the sloppy wheel mounts don't seem to hold squareness very well.
I think these problems are what is limiting my jog and cut speeds, and causing the gantry to go slightly out of square from normal operation.
I'm thinking that I might upgrade to HiWin liner guides. On the PR, these will easily mount on top of the existing rails. Because they don't allow much slop in the pitch, roll, or yaw, they really reduce the variables that are behind my mechanical problems now.
Has anybody done this? I'm not great doing the mechanical stuff. I can't seem to get my rails exactly right, and I'm losing patience to keep trying. Same with the wheel mounts. I don't really want to go thru several attempts at fabricating brackets that work better.
I'm thinking that using the HiWin guides will eliminate the need to fabricate brackets or rework the rails.
What do you guys think? Anybody used HiWin linear guides?
Wayne
White Salmom WA
I installed BWC rails and a new Extruded aluminum gantry, along with a new controller and Mach3 software. Things are much better overall.
But I can't get the performance I'd like from my new controller because of mechanical problems. I have two sources of problems:
1) The X rails (now BWC rails mounted on the sides of the old PR X rails) are not perfectly coplaner. The BWC wheels don't ride exactly right all the way down the rails. I can't get move speeds over 250ipm without skipping off the racks.
2) The wheel mounts on the gantry have too much flex. They are made of two pieces of aluminum angle iron. With the motors on there is no movement, but when the motors are disengaged from the rack the gantry becomes quite wiggly. The gantry itself is very rigid, but the sloppy wheel mounts don't seem to hold squareness very well.
I think these problems are what is limiting my jog and cut speeds, and causing the gantry to go slightly out of square from normal operation.
I'm thinking that I might upgrade to HiWin liner guides. On the PR, these will easily mount on top of the existing rails. Because they don't allow much slop in the pitch, roll, or yaw, they really reduce the variables that are behind my mechanical problems now.
Has anybody done this? I'm not great doing the mechanical stuff. I can't seem to get my rails exactly right, and I'm losing patience to keep trying. Same with the wheel mounts. I don't really want to go thru several attempts at fabricating brackets that work better.
I'm thinking that using the HiWin guides will eliminate the need to fabricate brackets or rework the rails.
What do you guys think? Anybody used HiWin linear guides?
Wayne
White Salmom WA