Posted by Jim Pollock on October 26, 2009 at 22:12:05:
In Reply to: Re: More Barber #12 hobber questions posted by BillS on October 26, 2009 at 00:56:07:
Thank you very much for the well informed reply. I am working on fixing the loose keyway. The keyway was loose enough that the gear would rotate almost the distance of 1/2 of a tooth. Hopefully with this tight it will drastically reduce the backlash seen at the flywheel. I am going to clean everything up and try to remove as much backlash in everthing as I can without causing any seizures. By the way, you are right about this machine being full of steel running in bronze bearings. I don't think that there is one ball or roller bearing in the whole machine. I am not sure but I assume that this machine was probably made in the 20s or 30s. I was surprised at how good the bevel gears look after running in all the sludge that was built up under the hobslide. These gears are hardened. I figured that they would just be soft steel or cast iron.
AS I stated before, the ways are a little worn but not as bad as you might think considering the age of the machine. The gib was probably actually adjusted a little too tight for the area of the ways that I was using to cut my gears. I am going to try to rescrape the ways to make them straight and then adjust the gib to suit.
The feed screw nut is definitely worn and I am thinking about making a new one of these. Do you think that if I get this tightened up that I could climb hob with this machine or is that just asking for trouble?
I haven't taken the hob spindle all apart yet but it really doesn't seem to have much play at all. The inner part of the outboard support bearing was missing when I bought the machine. I made a new one using an old outboard support from a horizontal millng machine. I mounted it on an 1 1/4" arbor and ground it on a tool and cutter grinder with a power work head to match the taper of the bronze outer bearing. This seems to work well.