Apple2Steward wrote:
"A2Aviator" <a2aviator@gmail.com> wrote in message 9fc85027-93eb-444b-aa1e-fe8044e7016d@a16g2000pre.googlegroups.com">news:9fc85027-93eb-444b-aa1e-fe8044e7016d@a16g2000pre.googlegroups.com...On Feb 2, 4:03 pm, dog_...@macgui.com (D Finnigan) wrote:A2Aviator wrote:The problem with nail polish is .. it tends to be permanent.Not even with nail polish remover?On a potentiometer? ..and perhaps have some of the loosened materialflow into the mechanics of the part? No thanks. When that hardensagain, you can almost be sure thats the last time you are going toadjust that. The whole conversation is slightly overkill anyway, we're talkingminscule amounts, yes it can be cracked loose, but the principal of it is that compounds generally used for this purpose can be flicked off with a scribe tool in a second, and leave for all intents, no trace oftheir prior existence. A dab from a glue gun falls into the same category. It's easily removed by just plucking it right off.Nail polish on the other hand could prove a little more challenging ifone wanted to actually remove it, and certainly would be more challenging to get out of the slot on many pots thus potentiallyrendering it hard to turn due to the lack of the ability to put a toolinto the slot. Pressing on some of them to dig out the hardenedcompound could also ruin or at least change the physical behavior insuch a way that it would not work either.Threadlockers are applied to the threads, not across the head aren't they? Something like Loctite 222 or Loctite Green should work fine for small screws.My assumption was that the blob applied across a screw head was just used as a telltale to see if someone had tinkered with an adjustment screw.
The threads on a trimpot are not accessible--and shouldn't be. Just a dab bridging the screw to the case of the pot is all that would ever be required. But the purpose of the factory dab is twofold: to prevent vibration- induced movement (very unlikely in any case) and to provide a visible sign of "tampering" (irrelevant now). Therefore, there is no need to "seal" the speed-adjustment pot (or any other, for that matter). However, Bill was asking about the screws that fix the seek stepper to the frame, that are loosened to adjust alignment. In this case, the only purpose for doing so now is to prevent slippage, and that would mean bridging the stepper lugs to the frame--the screws are not as important, but the heads of the screws could also be included if it is a problem. I've never seen those screws loosen from use (after being adjusted), so I strongly doubt that re-sealing is useful. For that matter, once the alignment is adjusted, it will never need to be re-adjusted unless the head assembly or seek cam is changed in some unusual way. Alignment is forever. ;-) Put another way, if a drive's alignment is off, either it was misadjujsted from the factory (unlikely) or the drive has suffered some physical trauma. Most users will have no need to re-align a drive, and the task is not easy to get right without a factory-recorded alignment disk and an oscilloscope. An original "disk diagnostic" disk (not a copy) may also be useful, but I'd be concerned about accuracy. Using any user-recorded disk will only propagate the recording drive's alignment errors to any drive it is used to align. And with only I/O errors to guide the adjustment, alignment can only be done approximately in any case. -michael NadaNet and AppleCrate II: parallel computing for Apple II computers! Home page: http://home.comcast.net/~mjmahon "The wastebasket is our most important design tool--and it's seriously underused."