Glad to hear that the repair went well ("fingers crossed" :). I'm doubtful = about the long-term effectiveness of JB Weld when subjected to the stress a= nd vibration of planing.
I recently experienced a similar AP12 breakdown and thought it might be hel= pful to the AP12 community to describe it here. My failure, like Ron B's, w= as related to a jam-up of the feed roller drive train. In my case, the jam-= up was clearly caused by planer chips packing into the drive chain recess i= n the side of the planer frame casting. There apparently was a build-up of = chips between the drive chains and the outfeed roller drive sprockets which= caused the chains to ride up on the sprockets and jam against the side of = the drive chain recess. The drive chains were so tightly stretched around t= he sprockets by this build-up of chips that I had to snip the chains with a= small bolt cutter in order to disassemble the chain drive. Of course the j= am-up resulted in several sorts of mahem in the feed roller drive mechanism= . In my case, there was no damage to the drive sprockets. The gearbox casti= ng broke in the way Ron describes. Also, when I got inside the gearbox I di= scovered that all the teeth had been sheared off of the small pinion gear w= hich sits in the middle of the gear drive train.=20
While an argument could be made that the best course of action would have b= een to throw the planer in the dump and buy a new one, I decided to see if = I could fix it. I was able to buy all the repair parts I needed from ToolPa= rtsDirect.com, (a really good source for repair parts for all sorts of tool= s and machinery) for about $100. This included a new gearbox housing, beari= ngs, bushings, gears, chains, shafts and keys. I did not cut corners here a= s the disassembly/reassembly process is time-consuming and I wanted to end = up with a reliable piece of equipment.=20
I am presently waiting for the replacement parts to arrive. In the meantim= e, while the machine is disassembled, I have decided to cut inspection port= s in the steel sides which support and guide the cutterhead so that I will = be able to monitor chip buildup and easily blow chips out of the feed rolle= r drive system before they cause problems. I cut these ports or windows by = drilling holes at the four corners of each port and then saber sawing betwe= en them. They measure about 5 x 4 inches and are covered by pieces of clear= lexan attached with small machine screws in each corner.
I see that Ryobi has replaced the AP12 with a redesigned 13" planer which m= ay avoid the problem of chip build-up in the inaccessible feed roller drive= system.
Pico C. Cle Elum, WA