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| Craynerd builds Wilding's - Woodward's Gearless Clock |
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| Doc:
Chris, I'm not into clock work so I missed this thread but today I took some time to take a look and I must say I was set back. You have done some beautiful work!!! I am just blown away by it to say the least GOOD JOB !! |
| raynerd:
Cheers Doc Tim, sorry it has taken so long to reply! I didn`t consider a backing plate. In some of the earlier pictures, you can see that the clock back plate has 3 screws, 2 at the top and 1 at the bottom. My current plan is to drill and tap some 1/4" steel plate as you suggested with two threaded holes matching the clock plate. I`ll then clearence drill the clock case and using the 1/4" steel plate, use this to clamp up the backplate to the case back. I can cut another square piece of 1/4" steel as an over sized nut for the single lower screw to hold it solid. Screwing to the wall I was planning to do as I had done with my synchronome and drill directly into my solid wall but hide the two screws up in the top left and right of the case which will be covered by the arch of the door. IF I require it, I could put another nicer screw in the bottom middle but I don`t think it`ll need it! However, do you think it would be stable enough to hang the entire case on the steel plate/strip? I do see that I could countersink the steel plate, make it slightly longer and then screw the clock through the case onto the backing plate strip already on the wall...this would however mean that ALL the weight of the clock and case would be on the two 6mm screws going through the clock backing plate!! Chris |
| spuddevans:
Which weighs more, the clock(including the weight/s) or the wooden case? I've been assuming that the clock is heavier. I would be more confident of using a backplate that all 3 screw's attach to, then all the mechanism's weight will be transferred evenly to the backplate, thereby introducing (hopefully) no additional stresses that might change the timing of the clock. Another thing to be careful of, it sounds that you are wanting to fix the backing plate to the wall? Have you thought what would happen if the bottom of the case is pushed to one side (maybe knocked by accident by a family member) if the top of the case is fixed firmly to the wall? It sounds like it could lead to potential cracking or breaking of the case, made more likely by the length of the case. Would it be better to have the backing plate able to pivot on a single fixing, such as a screw in the wall that the backing plate is hanging on using a keyhole milled into the backing plate? Then if the case is pushed/knocked it can move without causing any damage to the case or clock. Tim |
| raynerd:
Hi Tim, thanks for your continued interest. The clock case is solid oak with a just short of 1/2" thick back of ash so the case is pretty heavy. That being said, the brass of the clock and a weight of 1.5kg along with a similar weight pendulum - expect the two are not far apart in weight! I understand your thoughts about a plate to hold all three screws and agree this would be a better option so I`ll go for this. Your thoughts about the clock being knocked are interesting. The clock does have a hanger on the back of the case: I was told NOT to use this to support the clock by the maker of the case and just use it for initial fixing....if I`m being honest, I don`t really understand the function of it. The problem with suspending it from one screw or two screws but on a keyway incase they are knocked, other than my concerns about weight, would be that with the off centre pendulum, it will rock the case and clock and effect the time keeping. If my Synchronome was not screwed to the wall, with a block of 3" dia by 8" still sat at the bottom, it would rock from side to side! This clock I expect wouldn`t be as bad but my thoughts are still that it would need to be solid to the wall. Perhaps a blued screw neatly in the centre behind the pendulum would be needed to support the bottom if knocked? Chris |
| spuddevans:
--- Quote from: craynerd on December 15, 2011, 03:55:41 AM ---The clock case is solid oak with a just short of 1/2" thick back of ash so the case is pretty heavy. That being said, the brass of the clock and a weight of 1.5kg along with a similar weight pendulum - expect the two are not far apart in weight! --- End quote --- That is a pretty heavy case!! Just as a side note, and you are probably well aware of this, but any fixing holes drilled through the back would need to be made larger than the screws going through to allow for seasonable changes in the wood as it expands and contracts across the grain (it also moves along the grain, but much much less than across the grain) it would be such a shame to have the back split because of not having the freedom to move. --- Quote ---I was told NOT to use this to support the clock by the maker of the case and just use it for initial fixing....if I`m being honest, I don`t really understand the function of it. --- End quote --- He probably added it without much thought, then realised afterwards that it wouldn't be suitable for taking the weight of both clock and case. --- Quote ---The problem with suspending it from one screw or two screws but on a keyway incase they are knocked, other than my concerns about weight, would be that with the off centre pendulum, it will rock the case and clock and effect the time keeping. If my Synchronome was not screwed to the wall, with a block of 3" dia by 8" still sat at the bottom, it would rock from side to side! --- End quote --- I had forgotten about the pendulum being off-centre :scratch: :coffee: I still wonder if it would rock the case, maybe it would if the bottom of the case was hanging free from the wall, But surely the weight of both the clock and case hanging on a single pivot (ie a screw in the wall into a keyhole in the backing plate ) would not just hang free from the wall. It will rest the bottom of the case against the wall too, wouldn't it? You could even add a couple of rubber feet to the back of the base of the case to both prevent marking of the wall, and to provide grip against the wall from any rocking motion being transferred from the pendulum. I would be tempted to try this 1st, as milling a keyhole in the back of the backing-plate would not take much effort, and if it works out ok and doesn't rock then you are set. If it proves not to be enough to stop any rocking of the case, then your suggestion below sounds a good one --- Quote ---This clock I expect wouldn`t be as bad but my thoughts are still that it would need to be solid to the wall. Perhaps a blued screw neatly in the centre behind the pendulum would be needed to support the bottom if knocked? Chris --- End quote --- |
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