I now have the need for a fairly small, light mill to go in the garage section of a truck camper we are building. I don't have set limits on size and weight but I certainly can't take my 7000 pound Shizuoka bedmill with me when we sell the house and start our travels. I want to be able to still do some wood, plastic, and aluminum machining while camped out for weeks on BLM land or whever we may go. It may also be nice to be able to make parts for our truck camper as I am doing now with my cnc mill and lathe.
I want quality and have been spoiled by AC servomotors, ballscrews and box ways. I happen to have six Adept/NSK linear robot modules new in the box old stock. Five of them have 500mm travel and one has 300mm travel. They have 10mm pitch ground NSK ballscrews, 4 linear carriages on square rails, and 300 watt brushless servomotors. I have plenty of EN-204 Control Techniques drives which can drive 20 pounds attached to one of these modules at 1400 IPM, 200mS acceleration and a following error of less than 2.5um during travel and 10um on axis reversal.
Obviously I would like to use these modules as they would speed up construction of a small mill considerably. Since I only have one 300mm slide, I was thinking of using it for the Y axis. The travels would then be 500mm X, 300mm Y, and 500mm Z, or about 20 inches x 12 inches x 20 inches. Depth of throat always being a limitation on a classic XYZ mill, I don't see a reason to make Y more than 12 inches in travel. 20 inches in Z seems excessive, but those are the lengths I have on hand.
I have put together a quick CAD drawing of what the base xyz configuration might look like. I am considering making most of the Z support and the main baseplate out of 1 inch thick ground aluminum plate and the saddle plate connecting Y to X of 5/8 inch thick ground plate. In the pictures I have shown the mill at low Z and high Z limits (the blue slider) and the mill table at the ends of X and Y travels.
Do you think the 1 inch plate with the 1 inch thick triangle supports and 1 inch thick baseplate would be reasonable to support the Z axis? The brushless motor is enclosed in the top of the Z axis which makes it look taller in the drawing. The better mounting holes are on the other end from the z axis drive motor which is one reason why I have the motor end positioned at the top of the z axis on the mill. I brought the rear plate up high enough to enclose six of the 10 threaded mounting holes on the rear of the z-axis slide.
The last link is a youtube video I made years ago of these same slides in a gantry configuration. That design is not practical for our RV since I need more Z and clearance than a gantry will deliver. The video will give you an idea though what these slides are capable of. The allowable roll pitch and yaw figures referenced to the slider are around 400 pounds a foot from the slider....should be plenty beefy for this configuration.
I want quality and have been spoiled by AC servomotors, ballscrews and box ways. I happen to have six Adept/NSK linear robot modules new in the box old stock. Five of them have 500mm travel and one has 300mm travel. They have 10mm pitch ground NSK ballscrews, 4 linear carriages on square rails, and 300 watt brushless servomotors. I have plenty of EN-204 Control Techniques drives which can drive 20 pounds attached to one of these modules at 1400 IPM, 200mS acceleration and a following error of less than 2.5um during travel and 10um on axis reversal.
Obviously I would like to use these modules as they would speed up construction of a small mill considerably. Since I only have one 300mm slide, I was thinking of using it for the Y axis. The travels would then be 500mm X, 300mm Y, and 500mm Z, or about 20 inches x 12 inches x 20 inches. Depth of throat always being a limitation on a classic XYZ mill, I don't see a reason to make Y more than 12 inches in travel. 20 inches in Z seems excessive, but those are the lengths I have on hand.
I have put together a quick CAD drawing of what the base xyz configuration might look like. I am considering making most of the Z support and the main baseplate out of 1 inch thick ground aluminum plate and the saddle plate connecting Y to X of 5/8 inch thick ground plate. In the pictures I have shown the mill at low Z and high Z limits (the blue slider) and the mill table at the ends of X and Y travels.
Do you think the 1 inch plate with the 1 inch thick triangle supports and 1 inch thick baseplate would be reasonable to support the Z axis? The brushless motor is enclosed in the top of the Z axis which makes it look taller in the drawing. The better mounting holes are on the other end from the z axis drive motor which is one reason why I have the motor end positioned at the top of the z axis on the mill. I brought the rear plate up high enough to enclose six of the 10 threaded mounting holes on the rear of the z-axis slide.
The last link is a youtube video I made years ago of these same slides in a gantry configuration. That design is not practical for our RV since I need more Z and clearance than a gantry will deliver. The video will give you an idea though what these slides are capable of. The allowable roll pitch and yaw figures referenced to the slider are around 400 pounds a foot from the slider....should be plenty beefy for this configuration.