PDA

View Full Version : Need to talk to motor guru about an OT project....


Metalsmith
Sat 21 April 2012, 11:38
I am looking for a small motor with good torque to power a hand held small belt sander.. I am thinking 4" x 8" long x 3 " wide Motor will set between 2 rollers front and aft, with a cogged belt drive along one side, with a sheet metal coverfor belt. Are there any motors that are 3" w x 3"square ???I have a hand drawn layout done ... Will 1/4" aluminum and will try to get some of the Florida guys to maybe cut out the proto -type plates ... Right now motor is holding me up ....am looking at a small marine pump motor ...

KenC
Sun 22 April 2012, 06:07
They don't sell motor by the inches... :(

Torque is a relative quantity &"Good torque" meant nothing when no reference is established...

A simple question can sprawl into a whole academic principle if you want to do it correctly.

You gotta find out what Torque, rpm & operating voltage... & type of electricity you are going to use. i.e. 110V, 230VAC single phase or 240V,415V,600V 3 phase or even DC...

one of the very basic formula for determining what you need is as follows:-

Power (watt)= Torque (in N.m) x 44*RPM/420 (in rad/sec)
(I don't work with imperial when it comes to power, learning in metrics is enough hassle & I wouldn't wish to remember another set of numbers & formulas in imperial)

After this, don't forget to ask yourself if you prefer to direct drive or geared or gearbox, or electrical gearing... etc etc... & factor in the efficiency.

Metalsmith
Sun 22 April 2012, 14:46
I am dyslexsic in math, but have great 3-D perspective.... I can build things by sight....I know how I want it to look, in my head. My problem is showing everyone else !
I need a motor that is between 76.24 - 88 mm ( 3- 3.5 " ), ac-115v, 60 hz, single phase, 1500 rpm with a square body or mounting flange.
I can convert to metric if I have to , but don't want it shoved down my throat....a cheap HF digital calipher settles that problem.
I did say it would have a simple cogged belt drive...change pulleys for rpm change
.................................................. .................................................. ...................
The rollers will have a slight crown the keep the belt centered and spray rubberized coating.....The rollers will be held in with ground hex-head shoulder bolts and and a small roller will be used in between the end rollers to adjust belts
I know there are mini- belt sanders out there but I refuse to play $300-500 us for a piece of plastic crap. Will build to size of available belts for Paxxson mini's...

Working on a drawing....by hand...LOL

KenC
Sun 22 April 2012, 23:03
Use a power drill.

Metalsmith
Sun 22 April 2012, 23:21
This will be used to shape wood on surfboards....if I wanted it gouged, I would use a sharp piece of rock ! never mind, I will google ..." Small ac electric motor"...