Question: Should I drill out the holes in my servo arms and/control horns when using the new VMAR CNC produced metal clevis with 2mm screw pin?

Answer: VMAR control horns work with the clevis as is. It is not necessary to drill the horns. If you are using a non VMAR horn then we recommend drilling the hole to accomodate a 2mm screw pin. See below.

You will find it easier to insert the screw through the hole in the servo arms if you drill them out to 2mm first. It is possible to self tap your way through them using the screws but we don't recommend it.

For modelers with access to metric drill bits, use a 2mm drill bit. For modelers with access to imperial drill bits use a 5/64 inch drill bit. Keep in mind that 2mm is what you really want to use... 5/64" is a touch smaller than 2mm. For comparison purposes.

• 2mm is .078740 in. 
• 5/64" is .078125 in. which is 1.984 mm

If you are stuck and have neither a 2mm drill bit nor a 5/64" drill bit you can probably find a 1/16" drill bit. This is a bit small but will open up some of the very small holes in the arms of sub-micro servos enough so that with careful pressure you can self tap your way through the arm with the clevis screw. This is not ideal but 1/16" is better than trying to work the clevis screw through some of the very small pin holes in some of the servo arms we have seen on sub-micro servos. For comparison purposes here is some information on 1/16" drill bits.

• 1/16" (4/64") .0625 in. which is 1.5875 mm