Wednesday, March 30, 2016

A Little Non-Wood Diversion

Last year I was fortunate enough to acquire a car that I had long aspired to, an early 90's Lancia Delta. I have quickly learned that spare parts are going to be an ongoing problem.

A small plastic cap that was supposed to cover the rear window's wiper shaft / wiper arm connection cracked and fell off recently and thus I began my Quixotic quest to locate a new one of these. It is actually a purely decorative part, as the car works fine without it, and it is worth in my estimate about 17 cents. Not available from the usual (European) Lancia suppliers, I took to eBay and some less well known folks, and discovered it was in fact available. Prices ranged from about 17 euros to 40 euros, plus shipping of course.

Well these egregious prices really annoyed me, so I decided to instead 3D print a replacement.  I have never done 3D printing so this was to be a learning exercise as well as a process to get a usable part.

My son is attending university and has access to and is familiar with CAD software as part of one of his engineering courses, so he was to be my partner in crime on this. Without him helping me it is doubtful I would be able to get this done. I have no desire to learn CAD software myself, and paying someone to do it, or having a 3D scan of it made seemed totally uneconomical.

So after measuring up the original somewhat carefully with my calipers, I sent him the dimensions, he CAD'ed it up and subsequently sent me back a drawing.

After a couple back and forths it was good to go. I located a nearby 3D printer and $9 later I had my first prototype.

Original on left and first prototype on right

No surprise the fit was not quite right, so a bit more measuring and back and forthing we had a second drawing ready to print. The printer was also very helpful and provided some suggestions for improvement. However, for the second prototype they also increased their price to $13 for some unknown reason.
From Left: Original (now falling apart again), first prototype, second prototype

The second prototype is not quite right, but we are getting closer. Hopefully the next version will be on the money. Otherwise the exercise will turn out to have cost more than what I could have paid for one of the egregiously priced parts from Europe! In that case I may have to print off a few spares and attempt to undercut the European suppliers by offering them up on eBay etc.

Sunday, March 13, 2016

Plane Bottoms

I have a variety of planes, and which one I use for a particular task depends mostly on the material to be worked. The type/hardness/grain of material, how wide it is, how long it is, what quality of finish is needed, and so on. I have several planes in different sizes that I have made myself, following the designs of James Krenov. I also have a couple styles of asian planes, antique Stanley planes in multiple sizes, a modern low angle plane, curved bottom planes, block planes, etc.

Probably my top 3 go-to planes are a Veritas low angle smoother, a Stanley/Bailey #3, and a Krenov-sytle smoother.

The Veritas and the Stanley are easy to set for a consistent thickness shaving, but both are a pain to sharpen. The Veritas because the blade is wide and made of a particularly hard steel, the Stanley because the blade is thin (although it is a thicker replacement blade) and tends to rock on the stone if I am not careful. Frankly both of these sharpen better with a jig. The Krenov-style plane is very fussy to setup, but when done so correctly offers the thinest shavings, And it is much easier to sharpen.

Anyways since we all know you can never have too many planes, I thought it would be fun to try an English smoothing plane. So I picked up an old Norris from Patrick Leach, author of the famous plane treatise "Patrick's Blood and Gore".

Although it is a bit shorter than the other planes, it is also has a 2 1/4" wide blade. Versus the 1 3/4" blade on the Stanley. It is also heavier by far than any of the other planes

Patrick claimed the Norris was a 'decent user' when he sold it to me, and it was as he described. The opening was tight, the blade had lots of life in it still, there were no cracks in the plane anywhere. It was well patinated, in fact it look like it had rolled around in a tool kit for a long time and was covered in tiny dents! But they were just superficial. A quick sharpening had it spitting out shavings, but the adjustment mechanism was pretty stiff, and it was apparent that the bottom of the plane was not flat.

So I decided to work on the flatness by scraping it with a carbide scraping tool, an old-school technique I learned 10+ years ago at a seminar down in Seattle. Most people (myself included) will use a piece of sandpaper on a flat surface, like a jointer's outfeed table, to flatten the bottom of a plane. This technique is fine, but scraping will provide a far more uniformly flat surface, to within a fraction of a thousanth of an inch.

In fact, the Stanley/Bailey was my first experiment in scraping, It was in really bad shape initially, so I took it with me to that scraping class just for a lark, and had good success in making in extremely flat.
Bottom of the Stanley plane's scrape marks

So I hoped to replicate that success on the Norris. In a nutshell, the process involves rolling out ink to a very thin layer on a granite surface plate, then setting down the plane on the surface plate. When the plane is lifted up, all the high spots will have ink on them and the low spots will not. Then, using a carbide tipped tool, all the inked spots are scraped off. The process is repeated as many times as required to get the surface flat. Since scraping only removes a tiny bit of material, it could take 50 or more passes to get the surface properly flat.

Here is the Norris part way through the process. I think the ink on the surface plate was too thick, it should have been more like a series of spots than a continuous area.

I worked on scraping it over two days and lost count of the number of passes I took. Because it is quite messy I was doing it outside. It finally started to rain on the second day so I had to call it done. It definitely cuts better than it did before being scraped, but is still not what I hoped. I think I need to give the blade a proper sharpening, and loosen up the adjustment mechanism before I pass judgment on it.

Saturday, March 5, 2016

Boxes Round 2 - The One Day Box Challenge

After the middling success of my finger jointed boxes, I still had a bunch of dimensioned material lying around suitable for a couple of larger boxes. So I decided to abandon the finger jointed technique, and instead challenged myself to use whatever technique I wanted, but to take no more than one day to do each box.

Aaaaand we're off on the One Day Box Challenge!

First up was some beech, I had three pieces about 10" long each. I decided to use the Golden Ratio to set the dimensions of the box, so I cut one piece in half for 5", and then trimmed the other two pieces to about 8". I decided to use an overlapping butt joint, similar to some boxes I had built last Christmas.

After gluing them up (OK that was overnight) I decided the butt joint was not durable enough, so I wound up pinning the corners. For that I used bamboo skewers. It turns out though that bamboo skewers' diameters are wildly inconsistent, so I drove them through a series of smaller and smaller holes in a drill gage, until I got them to where I wanted.

I tried the same trick on some ebony, thinking that contrasting pins would be cool, but it was impossible to keep the ebony 'dowel' straight especially as the diameter got smaller.

I routed a groove on the insides of the pieces for the bottom to fit into. Amazingly, I had a piece of catalpa kicking around that was almost the perfect size for the bottom.

So once the pins were glued in place, I sanded the sides of the box down to make the pins' surface match the box surface perfectly.

The next box was similar, but was of plum with a spalted elm bottom. I decided to have the joints stick out a bit in a kind of salute to the Craftsman style of yore.

Anyways I think they turned out alright. My wife was impressed enough with this recent flurry of boxes that she asked me to make her a jewelry box.

I have also done some work on the cherry table, will show more on it next time.