June 2022 Tech Tip - Drilling and Tapping Holes
I am thinking this month we are going to go over drilling and tapping holes. This may be a subject that intimidates some of you out there. Others it may seem like second nature and wonder why I would go over such a subject. Everyone has to to start somewhere in the hobby and people have all different skill levels. For those who are new to the hobby and may not have grown up around tools, working on cars or what not, you may not even know what drilling and tapping holes is referring too it is OK.
I keep getting people asking questions about what glue to use; wanting to glue gearboxes on to cars instead of drilling and taping screw holes to attach the coupler gearbox or replacing trucks. I even have people asking questions about using and were to get self taping screws for mounting couplers and trucks because they don’t want to tap a screw hole. Lets first just say gluing gearboxes is not recommended and should be avoided. A glued on gearbox is permanent and if your coupler height is even just a fraction to high then you will have to brake out the dremel tool and grind or file the gearbox off the car to shim it down. No one wants to do that, and ignoring it will result in coupler being mounted too high. Thus, causing couplers to come apart over track transitions, rough spots in your track, sluggish uncoupling or even nonfunctional uncoupling.
Just be aware if you are wanting to use self taping screws you may still have to drill the correct size hole for the self taping screw. There is a limited number of times a self taping screw can be attached & removed before the material will strip the treads out. Then you have to decide to either putting a larger screw in the hole or fill the hole with an appropriate filler for the material you are working with and drilling and tapping a hole. (Note: Filler is not a durable as the original material you are working with and may strip out easier.)
Before you start drilling or tapping. Safety is important, Cutting tools may shatter when broken, wear an approved form of eye protection. If you are new to drilling or taping a hole practice on something else and get a feel for it before you try it on your new model car. First, determine what tap you need, this is decided by the size of the screw to be used. There is a chart that came with your tap and drill set. Do not substitute drill sizes since a slight difference in diameter can cause unsatisfactory results. Locate the position for the hole and mark it with a center punch. Drilling by hand with the #240 pin vice, care must be taken not to break these tiny drills or taps. Apply lubricant if drilling into metal. Make sure you are holding the drill at a right angle to the part as you drill. Clean away the burrs when hole is complete. Place the tap in your pin vice, apply lubricant if drilling into metal and tap the hole by turning clockwise. Hold the tap in a straight line with the hole at all times. Reverse the tap a half turn at frequent intervals to break the chips loose (metal). Remove the tap after five or six complete turns, wipe off any chips and apply more lubricant and continue. If you countersink the hole slightly before tapping, it makes it easier to start the threads. Avoid forcing the tap. If it won’t turn, back it out and see why.
Do not over tighten any screw, especially in plastic.