# Lenzkirch mantle clock



## francist (Oct 24, 2020)

I’ve been fooling around with an old Lenzkirch mantle clock recently. It’s a project I started about 14 years ago (yes, FOURTEEN years) but, well, a few folks have died in between leaving estates to settle and ministering to take precedence. So you’ll have to excuse the fact that I bring this to the table already in progress.

I’m actually pretty much in the home stretch (I hope). I’ve deduced and procured a new suspension spring to enable the movement to function again, and have similarly procured and fitted a replacement glass lens for the front cover. I’ve also been running the bare movement in the test stand on and off now for several months and it keeps good time albeit a little touchy on how it wants to be wound. The work now is putting all the bits back together and in the right package.

Overall the case was not in bad shape although it had undergone a little more neglect than it deserved. The piece itself dates to about 1905 and has that old European train station look to it. What moulding there is, though, is quite delicate and there was one corner that must have taken a few hits. 

Here I am inserting some new material a little oversize to be matched in later. 















As is typical with items of this age (especially clocks, it seems) someone has been in before me. The little tabs that hold the circular movement into the case were pretty gibbled-up and bent out of alignment. So much so that I really wasn’t sure where the movement was supposed to sit relative to the case walls. I ended up doing a full-on drawing in AutoCAD to understand how all the pieces would line up and not clash in the final assembly, and this also gave me the freedom to redesign three new mounting tabs. It may be overkill, but mine incorporate a semi-circular slot to allow rotation of the movement for setting the beat. At least that’s the idea — we’ll see if it pays off.

I’m a big fan of of using paper templates for cutting, a technique I learned when cutting letters for architectural signs. Rubber cement works well for me and rubs off cleanly afterwards.
















The mounting tabs need an offset to position the movement correctly front to back. Once I had my shapes cut and finished to final on the edges, I milled the slots using the rotary table and then a traditional vise setup to machine the offset.





















More to come in a bit....


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## francist (Oct 24, 2020)

Forgot to include a shot of the drawing....


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## francist (Oct 24, 2020)

I also needed a new screw to replace one that had gone AWOL over the years, maybe the same time they trashed the mounting tabs, who knows. Anyway, it needed to be an oddball size — not quite a #4 but yet larger than a #3, and with a 1/48 pitch. But that’s why we have lathes, right?

The turning itself was pretty straightforward. Major diameter is 0.100” for a length of just less than a quarter of an inch. I decided to use brass (the originals are steel) as even though this is an important part it won’t be a high stress application. And brass turns and threads really nicely.

Shortly after I got my 618 I made a hand crank for it, and it’s times like this when it really shines. Here’s the thread coming into form through a magnifying lamp.











And here’s my setup for cutting the slot. I drilled a slightly under size hole right at the separation of two small blocks of wood, so with my threaded screw in between the pressure of the vise jaws holds the part very firmly. Firmly enough for this slitting saw anyway, which is 0.023” wide. 






And here’s the finished part, all five grams of it or whatever.






I also got to spend a little more time on the case and blended in the finishes. Not one hundred percent on my colour matching but I find I just don’t have the patience all the time that I once had. So, I might have been a little anxious to see it done. I did pad up the French polish a little though and it gives some gleam back to it.






That’s it for now, I’ll come back when I have more to show.

-frank


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## David_R8 (Oct 24, 2020)

Really nice work Frank. Seriously impressed 


Sent from my iPhone using Tapatalk


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## CalgaryPT (Oct 24, 2020)

Holy cow Frank. That's so far out of my league, I can't even relate to it properly. Beautiful work and patience I'm looking at in your pics.


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## Marc Moreau (Oct 24, 2020)

Nice job


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## PeterT (Oct 24, 2020)

Nice work Frank. I bet restorations can be more challenging than building from scratch. You did a bang up job on the finish & blending the mods to look like new.

Are these inlays marquetry? (I think that's the right word).


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## francist (Oct 24, 2020)

Thanks guys, I appreciate the kind words.

Yeah restorations can be challenging — you need to be on the money or it’s wrong whereas if one builds from scratch we tend to give ourselves more latitude. That’s not to say it’s a finer process, just different and a different approach.

As for the patterns, yes you could call it marquetry. That usually distinguishes veneered work that represents a picture or objects as opposed to just straight inlay for a monogram or something. The entire case is veneered (you can see the lighter pine substrate in the exposed edges where the front bezel fits) so a purist might say that it can’t be called “inlay” because it’s not let into solid wood, but it’s a bit of a fuzzy line sometimes.

-frank


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## trlvn (Oct 25, 2020)

@francist Would you consider doing a shop tour (maybe two?) of your woodworking and metalworking spaces?  From the first shot of your bench space, I can see that you've got some fantastic vintage woodworking tools.  That looks like a drawer full of EA Berg chisels or gouges!  I've got a thing for old hand tools [1] and I know @moderate_mixed does too.

Then there is that cool horizontal miller!

BTW, for anybody that likes meticulous hand craftsmanship in metal and wood, you might want to check out Konrad Sauer's work:

https://sauerandsteiner.blogspot.com

In addition to the blog, I posts regularly to Instagram via @sauer_and_steiner.  Always drool-worthy!

Craig
[1] I have a bit of a collection of James Howarth edge tools, primarily gouges and chisels.  Howarth was one of the many fine makers in the golden age of Sheffield, England.  If anyone has any spares, I'd be happy to talk!


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## PeterT (Oct 25, 2020)

_BTW, for anybody that likes meticulous hand craftsmanship in metal and wood, you might want to check out Konrad Sauer's work:_

Good link. Some nice craftsmanship & eye candy there.

 I also clicked on some of those custom planes <$ gasp!>


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## historicalarms (Oct 25, 2020)

That small screw is "top notch"...and there is a future for you building od-ball gun screws for the antique rebuilders if desired.


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## trlvn (Oct 25, 2020)

PeterT said:


> I also clicked on some of those custom planes <$ gasp!>


Yeah, Konrad is not afraid to charge for what he produces.  I've known him for over 20 years and I still haven't ponied up.  OTOH, his planes are both works of art and beautifully functional tools.  Consistent, sub-thou, full-width shavings in even the gnarliest wood...despite a ham-handed clod like me pushing the plane!

Plus he's a great guy.

Craig


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## Janger (Oct 25, 2020)

francist said:


> I’ve been fooling around with an old Lenzkirch mantle clock recently. It’s a project I started about 14 years ago (yes, FOURTEEN years) but, well, a few folks have died in between leaving estates to settle and ministering to take precedence. So you’ll have to excuse the fact that I bring this to the table already in progress.
> 
> I’m actually pretty much in the home stretch (I hope). I’ve deduced and procured a new suspension spring to enable the movement to function again, and have similarly procured and fitted a replacement glass lens for the front cover. I’ve also been running the bare movement in the test stand on and off now for several months and it keeps good time albeit a little touchy on how it wants to be wound. The work now is putting all the bits back together and in the right package.
> 
> ...



Interesting bar clamps. Are they British?


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## kevin.decelles (Oct 25, 2020)

Amazing work!  I'd like to be blindfolded and walked in to 'smell' your wood shop...........  then have the tour.  Nothing like the smell of a wood and/or metal shop that is well used.


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## francist (Oct 25, 2020)

Are they British? No, Japanese actually. I believe “hatakane” is the name — you can find lots of them out there. I got these ones from Lee Valley many moons ago, very inexpensive but handy as get-out for light weight jobs. They still sell them although I think maybe not by the Japanese name anymore.

The smell of the shop, yes, it can be interesting. Spicy if mahogany is on the menu or lightly acidic from walnut or oak. I have some European olive that seriously smells like pickles when you cut it, and then a plank of white sandalwood I imported from Hawaii. Should have seen the UPS driver with that when he brought it in the driveway — “ you bought this from WHERE?...”.


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## francist (Oct 29, 2020)

I took another short week again at work so got to spend some more time on the clock. I want to get it off the bench and get on to other things (I already have but don’t tell anyone).

This the movement in the case as seen from the back of the clock. You can see my modified mounting tabs with the arc-shaped slots. 






Getting screws in (slot head, of course) would be really frustrating were it not for split blade screw starters. I can’t remember the originator of this pattern but I have a set of three knock-offs that work alright. The blade has an angled split up the middle and when you slide the collar down to the tip it causes the two halves of the blade to ride up on each other and grip inside the screw slot. Works great, especially on brass fasteners where a magnetic tip is useless.






Here’s the movement in the case from the front side.






And here with the front bezel and new lens in place. 










The dial is next. It’s enamel on copper (real enamel, not enamel paint) and mounts to the bezel through the two little V-notches at 9 and 3. Super paranoid about losing these two screws — I do not want to try to cut one of these. Just for kicks I measured the width of the slot in the head, a mere nine-thousandths wide. 










More in a minute....


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## francist (Oct 29, 2020)

The back cover works much like the front bezel except instead of two screws it uses four small brass escutcheon pins driven in through the flange. Not a very robust method but nobody has to go in there on a regular basis like you would the front. There are a few really pitted scratch marks that didn’t want to polish out so I left them. 














Last but not least, the hands. There was a little surface rust on parts of them but otherwise not bad. I scuffed them a bit with some grey Scotchbrite, applied some cold bluing followed by a little rub with Boeshield T-9. The minute hand goes on first and is a friction fit onto the barrel. The hour hand is next and fits the small square on the shaft, and the whole mess is retained with a small grooved washer (had to make one) and tapered cross pin. Once the pin is snugged place, you just clip the extra length off either end and call it good.










And that’s all she wrote guys, thanks for following along. On to something else...






-frank


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## David_R8 (Oct 29, 2020)

That looks really great Frank, nice work!


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