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Drill press motor placement ? Answered

I'm building a drill press out of an old jigsaw motor and was wondering if it would be too shaky to mount on the drilling arm. If so, how could I mount it elsewhere? Would pulleys be the way to go?


First, figure out what you plan on drilling. There's charts on the Internet with generic drilling speeds for different materials. Google is your friend. Drill presses have gearing or pulleys to get more torque. Even if you just get the chuck spinning about half as fast as the motor, that would be a good start. I don't know what you mean by "shaky". Don't tell me you're trying to use the eccentric from the old jigsaw. That is useless on a drill press. Take anything off the motor's shaft that was a part of the jigsaw, unless it's reduction gearing or a pulley that fits a belt you plan to use. You can attach the chuck directly to the reduction gearing or a gear motor. That would eliminate the need for belts, but take away some of your options for different speeds.

Mounting a small jigsaw motor on the arm is entirely feesible it would need to be fairly strong however. Perhaps you could test it? Very tight rubber mountings may help to reduce vibration on the "table" (workplate) of the press. Many compact drills use this setup, for example the kit that you can buy to turn a small corded drill into a press-drill, there is also a kit for the ever popular Dremel I believe. Most commercially made drill presses use a rubber drive belt and have the motor mounted aft (behind) of the drilling arm, this is because they are quite heavy (to reduce user fatigue of lifting the motor) and also serves to reduce vibration thus increasing the accuracy and cleaner cut one can achieve on a pillar drill. This also means that the facilitation of pulleys (or very occasionally gears) to change the drive speed(s) is an option, in my local machine tool catalog there is a floor standing drill press with a massive 12-speed pulley system. (You wanna see the price tag!) Though in general use one can get away with as little as two to six "speeds" depending on application. I hope this is of at least a little help. Let me know how you get on.

I managed to salvage the speed control from it as well and so I feel I won't need any extra different speeds. I wouldn't call it small, you could fit it in your hand but would not like to be running it like this. If I were to put a few ringlets for the shaft to go through to steady it would that eleviate any wobble or would it just shift the stress to another component?

I suppose the use of bearings and washers would be a definate plus, though, having this would transfer the vibration to the frame -- so long as it was sufficiently heavy and had decent feet on it this should not be a problem. Having a speed control is a handy thing, hopefully it will be of the type that maintains torque with differing speed -- I should hope it would be anyway.