On Tue, Jan 3, 2017 at 1:47 PM, Brian L. Stuart <blstu...@bellsouth.net> wrote:
> On Tue, 1/3/17, Cory Heisterkamp <coryheisterk...@gmail.com> wrote: > > What I’m wondering is if anyone is familiar with the setup/adjustment > > procedure for getting the heads set correctly. There *might* be a couple > of > > unused tracks I can relocate heads to, but my thought is that if half a > > dozen heads were already in contact, then the rest may be perilously > close > > as well (swelled drum?). My odds of setting 71 heads perfectly on a 50 > year > > old worn drum is…well…not great. > > A while back I read a procedure (probably in reference to the G-15). > Quite frankly, it scared me a little, but I'll pass it on. The idea is to > use sound. The tech would use a screwdriver as a sounding bar > between the casing and his ear. Then the head was tightened down > until you could just hear it start to brush. I don't remember for sure, > but I'd have to think that you would then back off just enough for > the brushing sound to stop. I don't recall whether the article said > that this was done with the motor running or the drum was being turned > by hand, but if it were my machine, I'd set the heads turning the drum > slowly by hand and then check for any brushing sound when the motor > comes up. > This sounds believable (but scary). With the 64 main heads out of the way, I pulled out a mechanic's stethoscope last night and carefully rocked with the drum back and forth listening to the recirculating register heads. One may need backed off just a little, but the adjustment screws are a little crude. > > Whether or not the drum is restorable, I'd still plan on building a drum > simulator. That way you can get the rest of the machine up and > running without stressing or depending on the drum too much. Plus > if the drum does turn out to be unrestorable, you'll still be able to > run the rest of the machine. As to how to approach the simulator, > I would have to think a C.H.I.P. or a Pi would have plenty of horsepower, > especially if you drop Linux and either run on the bare metal or > as an in-kernel driver in something lighter weight. > > BLS Once I can make sense of the timing tracks, I think I'll proceed with this. Not sure how I feel about using a micro-based solution though. Just seems wrong : ) -C >
