Mechanical Problem

[Bogie]

Guys, this is NOT off topic... Trust me... I want to build a neckturning driver. I'll show y'all some pics later...

Does any of the multitudinous multitudes in this place know if there is a readily available, relatively inexpensive way to do the following?

I want to put a 3-jaw "drill type" (like a Jacobs) chuck on a gearmotor shaft, which will probably be about a 3/8" smooth steel rod. Have not purchased the chuck or the gearmotor. I'm looking for fairly high torque, at about 75-100 RPM.

 

[nswgru1]

I can't believe its this easy! LOL

Here you go:

Grainger catalog #392 www.grainger.com

Stock # 1f610 that is a 0-1/2" keyless chuck for $13.62 (that is cheap cheap) I might be a little scared of the quality, but the chucks I usually have to have cost over 100 just for a chuck. That is on page 213 and it mounts on a 1/2" motor shaft.

Now let me give you some advice on the gearmotor selection. Get an AC/DC gearmotor and get about 2X the amount of horsepower you think you need and 1.5 or 2X the output speed you think you need. The reason why I say that is because with an AC/DC motor you can connect a dimmer switch (like you use on lights) and you can have an inexpensive variable speed motor setup. I have done this making welding jigs for welding circular parts for production stuff in my shop. It is a LOT cheaper than buying a DC motor with a potentiometer. By the way AC/DC motors are called "universal" motors. They are on page #239 and run about $177.00.

If you need any more help email me and I could look through some of our catalogs in the library here and find something else but thats pretty cheap to get setup for under 200 total.

 

[Bogie]

I want a nice consistent speed - I didn't know I could use a dimmer switch - Could I just do that with a paid-for drill press? It just goes down to 220 RPM, and I want about half that...

 

[SlackO]

sounds like someone's been watching battlebots... VERY COOL!

 

[Bogie]

Nope - not battlebots...

Neck turning brass for precision loads is a VERY tedious process if you're doing it by hand... Best speed is around 100RPM, but it takes a pretty fair amount of torque. A $200 Harbor Freight drill press goes down to 200 RPM, and the $40 version goes down to 600 - It'd be nice to be able to drop the 600 one down some...

 

[rhedley]

Bogie

It just goes down to 220 RPM, and I want about half that...

Are you looking for high torue and 110 rpm's? sounds like you are twisting pickets for a wrought iron fence. Think about using a power pipe- vice..

 

[C.R.Sam]

Take a good look at the top of your drill press....might have room to drop in a different set of pulleys. Maby same number of steps but more difference tween biggest n smallest grooves.

I put a two speed washing machine motor on my Walker Turner drill press after the original moter died (40 years in a job shop). My slowest speed right at 100 rpm and I got lucky as the electric switch hits right in between the pulley ratios. Used a two way light switch to control speed, mounted it in steel box next to the stock on/off switch.

Sam

 

[nswgru1]

First: you probably cannot use the dimmer switch on your drill press. It has to be a universal motor or AC/DC motor. If you connect a dimmer switch to a regular AC motor you will most likely burn up the motor. You can look at the plate on the motor and see what it is. It will have a plate that will state wether or not it is a single phase or 3 phase motor, voltage, hp rating etc. Unless it has AC/DC just like I just typed on it it will not be a universal motor.

Now you could use your drill press like C.R. Sam said but you need to be careful. You will have to measure the pulleys and note the ratio of reduction in size between say pulley number one and two and then do the same thing for the other pulley. Once you know the reduction between the pulleys you can TRY to find some off the self pulleys somewhere that will match up. This is very tedious to do but if you get the sizes for me I will try to help you in your search. If you just simply go out and buy a pulley you will most likely not get the reduction right and the belt will fit on one set of the pulleys but not the other sets because the center to center/circumfirence will not be right.

 

[labgrade]

I'm a bit "curious" regarding the eccentricity "problems" you may run across.

Neck turning is not just a process of "removing some metal." You do want to ensure proper alignment/concentricity of the neck relative to the chuck/collet/parent material of the brass.

Just because it'll be faster doesn't mean it'll be better. You may just ruin your brass quicker ....

Something to consider.