Shaft Rotation

Hopefully the weight is balanced. If not, do what you have to to balance it. If the device has a large diameter anywhere you can put a chain around it. A few screws will serve as teeth for the chain. I would use a drill motor for the drive. It has a gear reduction, and just hold the drive sprocket in the chuck. You can get variable speed and reverse from a good drill motor, they are reasonably priced, and easily replaced.

Good Idea never thought of that. But I am looking for more of a permanent way to rotate the shaft (unattended). Yes the load is balanced equally around the shaft. Any other ideas anyone?

can you describe shaft better?

i assume the shaft has load on one end?

or is load in middle with bearings at each end?

does the shaft extend beyond the bearings and if so by how much?

would drive be connected to ends or drive the middle?

Why balancing is required while the speed is very low, 4 rpm?

To reduce to this low speed, I suggest, the first step of reduction through chine or belt drive and second step of reduction through a 'worm and worm wheel gear box' drive.

Not enough information. 4 RPM is slow. Can you send a picture? Do the shafts protrude through the bearings. Could you attach a gear? Check out gear motors on Google or Search GlobalSpec

Belt drive will be your best bet I think.

How quickly do you need to slow it down? A simple disk brake system should work.

have a gear box of gear ratio 60:1 and then give a gear drive with a 13 teeth gear on gear box driven shaft and 91 teeth gear on main shaft u want to rotate , you will have 4 rpm of shaft

The simplist solution might be a worm gear drive.

It is a meat smoker that I am building. The shaft design has not been designed completely yet. The shaft has a plate on each end with holes to support shelves that run from one plate to the other. If you look at the end of the shaft the end view would kind of look like a ferris wheel, the shelves are swinging free so that they stay level at all times with the meat on them. I was planning on running the shaft out one end like a rotisserie on a barbecue. I don't know what size motor to use. The information about the gear tooth count and gear box ratio is very helpful. Is there not a way to couple the motor to the end of the shaft that would work maybe motor to gear box to shaft connect?

try these

http://uk.rs-online.com/web/search/searchBrowseAction.html?method=searchProducts&searchTerm=shaft+couplings&cm_mmc=Google-_-1-PCA-_-shaft+couplings-_-Search-Page

http://www.enemac.de/english/shaft_coupling.htm

http://www.google.com/products?hl=en&rls=com.microsoft:en-gb:IE-SearchBox&q=rigid+shaft+coupling&revid=508587257&resnum=0&um=1&ie=UTF-8&ei=aIh1S9m8N4yTjAexqp2_Cg&sa=X&oi=product_result_group&ct=title&resnum=3&ved=0CC0QrQQwAg

http://www.climaxmetal.com/

http://www.rotigrill.com/index.asp

http://www.electricalsales.co.uk/productdetails.asp?id=16168

you could use a car wiper motor which has a raight angled drive rotating at about the speed you need and is quite powerfull. just protect it from the heat

from the links already supplied coupled with the below you should be able to come up with some ideas to solve your problem

http://www.hansen-motor.com/stepper.php?gclid=CJqM_aml7Z8CFZAA4wod_k98YA

http://images.google.com/imgres?imgurl=http://cnyxqp.win.mofcom.gov.cn/www/8%255Ccnyxqp%255Cimg%255C2008216111128.jpg&imgrefurl=http://cnyxqp.win.mofcom.gov.cn/en/plate01/product.asp%3Fid%3D50138&usg=__a7oI4wIcjsA5nVo5y6cBjei95H0=&h=413&w=600&sz=48&hl=en&start=1&um=1&itbs=1&tbnid=7Iu9-SVH0S2kGM:&tbnh=93&tbnw=135&prev=/images%3Fq%3Dwindscreen%2Bwiper%2Bmotors%26hl%3Den%26rls%3Dcom.microsoft:en-gb:IE-SearchBox%26sa%3DX%26um%3D1

http://eao.com/euk/en/eMarketing/motors.asp?kw=stepper%20motors&fl=432797&ci=3071853742&network=s

http://www.lojercomponents.co.uk/

http://stepper3.com/shop/motor-couplings-c-69.html

http://www.anaheimautomation.com/

http://www.zycon.com/Products/Gear-Motors.html

http://motion-controls.globalspec.com/industrial-directory/stepper_motor_gearbox

It seems to me that the simplest way would be a gearmotor with a variable power supply using a sprocket and chain. Gearmotors come many sizes. There is likely to be one to meet your needs at a reasonable price.