Archive for the ‘Clocks’ Category

Taming the Rabbet

Wednesday, May 7th, 2014

My work with rabbets has always been haphazard with lousy results. Few projects required rabbets, so I never learned to do them well. Now, for the clock project I want to learn to do moldings well and the method I am following uses a lot of rabbets … accurate rabbets.

In his book, “Mouldings in Practice,” Matthew Bickford teaches how to steer rounds on the corners of a rabbet and how to steer hollows on the corners of a chamfer. So, I must first learn to make rabbets accurately and reliably.

A few hours of practice and plane fetteling have resulted in notable progress.

First, the planes. For some reason I don’t remember, I purchased an ancient wooden rabbet plane that has a skewed iron (nice) and is 1.5 inches wide. FWIW, it dates to the late 1890s and is marked “D. Malloch & Son, Perth.” In this case, Perth is in Scotland, not Australia. The iron carries the same mark. The plane body is beech.

When it arrived, I discovered the iron was ground to a very low angle, about 12 degrees, and the most important corner fractured off (no pictures). I’m almost certain the fracture was due the shallow angle. Other things were more interesting at the time, and I set the plane aside, neglecting it for a couple of years.

Wanting to use it now, I reground the iron and sharpened it. It’s still a bit off, with the trailing edge protruding a few thousandths more than the leading edge, but functional enough for me to gain some practice with the plane. … It was enough practice to realize that the bottom sides of the plane body, right at the edge with the sole, have worn quite a bit. The long edges that are critical to tracking are rounded quite a bit. Once again, I set the plane aside.

photo of Sergeant #79 planeI turned next to a Sergeant #79, another rehabilitated plane. It is a metal “moving filletster and rabbeting” plane. When I have attempted using it with the side fence and the depth fence, the results have been almost usable. OK, actually lousy if we want to be truthful. I removed the fences from the #79 and used it as simple rabbeting plane following the techniques Matthew describes in his book, pp 42-47.

He shows taking two passes with the plane tilted into toward the scribe line at 45 degrees. These passes provides the logical equivalent of the “knife wall” that Paul Sellers teaches for accurate sawing. This little “v” groove establishes the reference for accurate rabbeting. From there, the plane can be put back perpendicular and within 2 passes be tracking neatly along the line. Voila! Such a little point that makes such a big difference. THANKS Matthew!

photo of leaning over at 45 degreesMy practice led me to three important points. (2 of the 3 mentioned in Matthew’s book)

The edge of the iron needs to protrude ever so slightly from the plane body to ensure cutting a perpendicular wall.

The edge of the iron must not cut, or it will cut into and move the wall. I rounded over the edges of the iron, above the bevel, to minimize this problem.

Scribe the line with a marking gauge. (I use gauges with pins, nit knives.) The tilted metal plane will track to the scribe line. It won’t track to a pencil line. :) This is where I discovered the wooden plane is too worn for this technique. The vertical wall does move inward a very slight amount, to the other edge of the “v” produced by the scribe pin. Keep this in mind and compensate if needed.

Half a dozen practice rabbets showed improvement with each attempt.

photo of wooden rabbet planeWith that success, I looked at the wooden plane again. It is sooooooo much easier on the hands than the #79. In the vise it went! I planed down each side until I got very crisp and square corners at the sole. Yes, that sacrificed a fraction of an inch of width, but most rabbets are going to be much narrower anyway. The alteration also made the iron a bit easier to adjust. Before removing material from the body the iron was right at the point of barely reaching the right edge. That might be due to the tang being a bit mangled; it has seen some use. Now, it can be adjusted for that extra thousandth, or so, as mentioned in point 1 above.

Using the wooden plane, I can make a rebate of exactly the same quality (still not perfect, but very much better) as with the #79 and it’s a lot more comfortable on the hands.

I’m now a much happier rabbeteer!

Jeweler’s Regulator – Plans for Moldings

Monday, May 5th, 2014

Slow progress on this project; other distractions take precedence.

photo of molding drawingsThis is the first project on which I’ll use my hollows and rounds. A lot of practice coming up. Additionally, I want to change part of the detail in the set of moldings for the crown.  Profile drawings are scattered about the 8 sheets of plans, but I’m the kind who wants to see them all pulled together and in full scale. I’m also fortunate enough to have a real drafting table with a floating parallel rule and various other drafting tools. Did you know that plastic drafting triangles bought in 1963 haven’t warped or become covered with “patina” since?

So, a few drawings. Next along this line is to change one shape in the crown and decide which egg and dart pattern I want to use.

Jeweler’s Regulator – Stock Prep

Friday, April 25th, 2014

The lumberyard I use for hardwoods, Maurice Condon in White Plains, NY, has a great selection. Like most good yards, they don’t mind customers combing through stock as long as they put things neatly back in the racks. About this time a year ago, I pulled out a small collection of cherry boards. They were so nice that one of the guys working there said, “Wow, you found that here!? We have stuff that nice?”

Of course, there’s always a “…but…” Specifications for Cherry say that sapwood is not a defect. Yet, cherry that has been stacked in a rack almost since it came from the mill has had so little exposure to light that sapwood is not apparent. Get it out in daylight. Sticker it for a few weeks. Then the sapwood fades into view, and there’s always more of it than one wants. Despite that, it turned out to be a very nice collection of boards. Some have already become boxes.

the first of 8 pages of drawings, showing a list of partsNow, let’s find a clock case in those boards. One side of each board shows mostly heartwood, the other not so much. Turn the boards to show all the sapwood and start finding parts within the heartwood. I need 30-some pieces and found most of them within three boards.  All but the long pieces for the sides and door are four-squared. The rest are now rough cut, leaving a bit of length until final prep.

a board marked for cutting 11 foot board on a 12 foot long benchProcessing  long boards is a real joy when there’s a bench that can handle them with ease. The twelve foot long bench was originally for boat building but handles this sort of work superbly .. when not affected with HSS (Horizontal Surface Syndrome, which attracts all sorts of stuff randomly collected and in the way).

This wood has been here about a year and well acclimated. It is also straight grained enough that little tension is apparent. There’s no cupping among the cut pieces and only a slight bit of twist that already existed on one piece.

a stack of about 35 rough cut pieces of woodVery well behaved wood!

Jeweler’s Regulator

Friday, April 18th, 2014

Since my 47 year old mechanical school clock left home, there’s been an empty spot on the wall where eyes land several times a day, finding little but a faded outline and silence. It’s time to change that.

Jeweler's clockBack when clocks and watches actually had mechanical things inside, watchmakers and watch repairers (often jewelers) needed an accurate timepiece from which to set and check times. “Regulators” were accurate enough, probably not quite as accurate as H4, or other chronographs used for navigation, but close.

Many case styles exist for regulators. Two of my favorites are movements with longer pendulums, the Vienna Regulator and the Jeweler’s Regulator. Here we have a Jeweler’s Regulator that has been offered for many years by Klockit. I’ve admired it for as many years, keeping it on my bucket list as one of the clocks I want to build. Nope! I am NOT building a kit. Klockit offers drawings for this clock, 8 large sheets. I’m working from those drawings and using some Cherry that I bought last year. However, I will be using the mechanical movement components the clock was designed around, a Hermle regulator movement. When I built that school clock 47 years ago, mechanical movements were very plentiful and reasonably affordable. That was a decade and a half before the rise of quartz movements. The transition to quartz is now nearly complete and mechanical movements are becoming rarities. Demand has fallen, resulting naturally in fewer choices and dramatically higher prices.  So, I caught this one during a 20% discount sale before its cost escalated yet more.

Rarely do I build from plans. In this case, I’ll stick close to the plan but will make some alterations, specifically to allow some carving. At the moment, I’m thinking the biggest change will be replacing the dentil molding in the crown with egg and dart. Maybe more…

In any case, we now see the reason I jumped on that set of hollows and rounds a while back. They were bought for clock moldings. Learning curves ahead…

A Clock is Running Again

Wednesday, October 28th, 2009

clockThis lull between boat building projects is a good time to complete a project that was set aside a few years ago. Back when the Emperor Clock Company had a very wide range of offerings (1968), I put together a School Clock from their supplies. The case is a design from Albert Neely Hall who produced a great many “Craft Patterns” in the first half of the twentieth century. I built the case from Cherry and installed a mechanical, spring driven movement. The movement is a pendulum regulated 8 day clock. It chimes out “bim-bam” counts on the hour, and a single “bim-bam” on the half hour.

The clock ran for 37 years with virtually no attention, other than winding once a week. Once a year I would stop the clock for an hour for the fall change from Daylight Savings Time to normal time. The change in 2005 didn’t work out so well. Restarting the clock left it running for no more than a couple of minutes. Well, that’s no surprise. 37 years of no maintenance probably means dried out oil and various other bits of accumulated tarnish.

Many horological specialists recommend simply replacing a movement of this age. That’s because the replacement costs less than the (professional) labor needed to clean or repair an old movement. Being neither a horological specialist nor a professional clock restorer, and also discovering that the original manufacturer, Jauch, no longer exists, I decided to ignore that advice and clean and restore it myself.

clock disassembledThat was back in 2005.  I got as far as removing the movement, making some drawings and photos of it, tearing it down to pieces, and then setting it aside until … Did you know that a circlip, an unladen European circlip, can travel up to 20 feet unassisted? …  until I found the time to learn enough about what to do next.  Most of my learning is thanks to The National Association of Clock and Watch Collectors which has an excellent collection of information and some very helpful forums.

The movement was actually in quite good shape. None of the pivots had excessive wear and there were no other major problems. Cleaning was mostly a matter of ultrasonic cleansing to remove grime and polishing of pivot and bearing points.

mainspringsThe big challenge, other than flying circlips, was cleaning the drive springs. They are cased in barrels and I was advised to be very careful removing them from the barrels. Stories of springs bounding out of control and slashing through various body parts convinced me to heed the advice. The proper tool for the job is a winder. Commercial versions are available for a mere $200 (plus sleeves, plus shipping, plus etc.). The more affordable answer came in the form of a homebuilt design by Joe Collins, one of the NAWCC members. So, there was a detour to to the woodworking (and metal working) shop to build an instance of Joe’s winder.

The winder cost about a tenth of the commercial version and did its job very well. I have no pictures of it in use because controlling the tension of the springs was a lot more important than taking pictures. mainspring winderBasically, the sequence is: Clamp the spring barrel in the v shaped jaws. Oh yeah, this is after removing the gear on the end of the arbor, and removing a cap from the barrel, both with their own forms of entertainment. Attach the crank shaft to the winding stem. Crank the spring up tight enough to allow a sleeve to be shoved into the barrel. Unwind the spring into the sleeve. Pull the sleeve, spring contained, out of the barrel. Capture the outside end of the spring with a hook on an arm at the side of the barrel. Tighten enough to allow the sleeve to be pulled away. Lastly, unwind the spring. You can watch Joe demonstrating the winder in a video here. The spring can then be cleaned, polished, lightly oiled and replaced into the barrel by reversing the removal process. Building the winder took quite a few hours. Using it took about 6 minutes.

movement on the test standReassembly was the simple process of putting all the parts back in their proper places (including multiple hunts for flying circlips) and adding very tiny drops of oil only to the pivot points. It’s really handy to have a test stand, making it much easier to put the movement on the stand rather than back in the case for testing. I can now take the movement off the test stand, remove the pendulum and strike levers (3 circlips), separate the plates, adjust wheel positions in the strike train, and put it all back together in about 10 minutes (excluding circlip search and rescue time). That comes from practice. The time train has the larger number of wheels, but is very straightforward. The strike train is another matter. I learned by trial and trial, and trial, that the strike train can be assembled in such ways that the hours strike but the half hours don’t, the half hours strike and the hours don’t, and clock strikes bam-bim instead of bim-bam.

The case got bit of refinishing with danish oil and, of course, the brass and glass got a good cleaning. It’s all back together now (including all circlips), hanging on the wall again, and keeping good time. It’s good to hear the familiar bim-bam once more.

Yes Heidi, your “claim tag” is still firmly attached.