Construction of A Powered Eight-Rat Treadmill
Keith G. Benedict
Last week both conveyor rollers were chucked up on one end and centered on the other end using a live center mounted in the lathe tailstock. This allowed the rollers to be turned for about 46 inches of their 51 inch length. The next step required the use of a steady rest. There was just one problem. I didn't have a steady rest.
When I bought my lathe, it didn't come with a steady rest. I knew I could get a new one from a Clausing dealer, but I thought it might be possible to save some money by buying a used one. I did an Internet search for used equipment dealers and located several likely prospects. I sent an email to each one of them, stating my needs and including the year, size, and model of my lathe. Within 24 hours I received a reply from Astra Tool in Grapevine Texas. They had exactly what I was looking for, at about half the cost of a new steady rest. After an exchange of emails to work out the logistics and money transfer, the item was shipped. Three days later it was in my hands and ready to use. I love the Internet!
The next step was to turn the roller 180° and chuck up on the finished end while supporting the other end in the steady rest. The steady rest has three adjustable arms with small rollers on the ends that rotate on the outside diameter of a piece. This eliminates the need to use a lathe center and allows free access to the end of the piece.
As can be seen in the pictures below, the first thing to be done was to turn off the weld and turn down the unfinished length of the roller to the same diameter as the rest of the shaft. The steady rest is prominently displayed in these photos. Note that the shafts were long enough to require the tailstock to be taken off the end of the lathe to get it out of the way.
After finish turning of the outside diameter, the end of the piece was faced off to the final length.
I knew that I would be using a steady rest on this end of the roller, so the plug in this end was drilled out to 7/8 inch diameter before being welded in place. All I needed to do was bore out the hole to 1.000 inch diameter. A carbide tipped boring tool was used for this.
After the hole was bored to size, a High Speed Steel hand forged hook type tool was used to backbore/chamfer the back end of the hole to deburr it.
After both pieces were finished on this end, they were turned 180° again. This end was finished on the outside but had to be drilled and bored out on the end. Since it was impossible to use the tailstock and drill chuck to hold a drill, an improvised drill holder was used. One of the tool holders I use has a small V-groove in it that allows round tools to be held straight and clamped in place. The clamping force is much less than that afforded by a drill chuck, so a series of four different size drills were used to enlarge the hole to 7/8 inch diameter.
After drilling, the holes were bored out to final size and backbored/chamfered to finish up.
This finished up the turning of the conveyor rollers. Next week I plan to turn the inner shafts and start on the side plates for the subframe and support plate.