This instruction is about how to make a carbon boom go shorter than original without reducing the maximum lenght. In this case a Pro Limit Team Carbon 140-190, 24.5mm, made by Aeron. With some booms, the end will slide in deeper but there are no more holes. So by adding holes, this boom can go 6cm shorter: From 140 to 134cm. This may not be possible with all booms.
Step 1: Remove the clips with a screw driver.
Step 2: Slide the end piece in one hole so there is still one hole visible.
Step 3: Take a 6.5mm short drill bit and stick it in the open hole to keep it in its place.
Step 4: Use a longer 6.5mm drill bit to drill the new hole. Be careful and drill slowly not to tear out any fibres, especially towards the end. Towards the end, the drill dust becomes white because the inside of the tube is made with glass fibre. Repeat this process 3 times (or more if there is more space to move the end piece in) on each side.
Step 5: Now you have 3 new holes with 6cm difference
Step 6: Drop a bit of super glue on any frayed fibres and drill again to make sure the holes are 6.5mm again. Grate off the frayed top with a conical Dremel bit.
Step 7: Check if the clips fit in all holes
Step 8: To find the final holes easier you can make a mark with a white Posca pen.
