#25 Roller Chain

I purchased the 4.0kw spindle and VFD a while back, and have just installed a PMDX-107 controller... do you have any examples of the wiring connections for the SL-240EE to PMDX-107?

If you want speed control, it is recommended to use the RS-485 connection on the VFD and use the control program such as Mach3 to communication serially with the VFD using this RS-485 connection. If you would rather use a controller such as the PMDX-107 to simulate the effect of a potentiometer using the Aref, Aout and Agnd and the Rev/Dir and Fwd/Run terminals to control operation and direction, you can connect those to the VFD. PMDX-107 Aout connects to the VI (analog voltage in). This is like the wiper on a potentiometer. PMDX-107 Agnd connects to the ACM terminal on the VFD for Analog common. PMDX-107 COM connects to DCM terminal on the VFD for Digital common. PMDX-107 Fwd/Run connects to the FOR terminal on the VFD for Forward. PMDX-107 Rev/Dir connects to the REV terminal on the VFD for Reverse. Refer to your PMDX-107 manual to correctly configure your dip switch settings and make sure to calibrate (tweak) the speed control using the trimmer next to the terminals on the PMDX-107.

How tight does the roller chain needs to be?

This will depend on the length of the chain, but in general, there should be very little sag along the length of the chain (like 1/4" - 1/2" deflection).

Hi We are considering to buy the vakuum pump controller pressure switch and the vakuum pump 3 CFM together with it. We would like to build af setup that needs to hold a vakuum for up to 3-4 months. Does this pump and controller fit theese needs? Best regards Poul Larsen

The vacuum pump and vacuum pressure switch sensor and controller are well suited together. As long as the vacuum pump is maintained, the pair will work together indefinitely. Additional Information: 20

blueChick v4.2. The #25 drive sprockets occasionally come loose especially on the y-axis. The screws are barely on the shaft when I line up the sprocket to the idler gears. Lots of Loctite or should I try the #40 drive sprocket?

The rods where the drive sprockets are located (typically the X-axis) are not flat enough, so that the set screws hold the rod securely. Taking a file tool to make the surface where the set screws can hold the rod in place a bit flatter. On the Y-axis, make sure you have the idler sprocket in the correct place being dual nuts on top corner (away from the motor (http://buildyourcnc.com/Item/cnc-machine-bluechick-v4#prettyPhoto/1/) and (https://www.buildyourcnc.com/images/bluechick%204-3%20instructions%2013_700_sm.jpg)) to have the sprockets line up perfectly. The #40 drive sprocket will not work with the #25 chain sent with the kit.

What size gear could I add to your #25 design to increase torque by around 3x?

Torque is measured from the center of the shaft to the pitch diameter divided by 2 of the sprocket in inches or feet and is able to move (rotate) with a force at this measurement tangential to the pitch diameter circle. The smaller this pitch diameter is, the less torque is required by the motor to turn the sprocket under load. If you are starting with a large sprocket, say with a pitch diameter of 5 inches (2.5 inches radius), it is easy to reduce the size of the drive sprocket to increase the mechanical advantage. All you need to do is take the 2.5 inches and divide that by 3 to find the new pitch radius.