home stretch on the new metal shop

 when last we visited this project back in september, the carpenters had just finished getting the slate on the roof ... after that it was on to the siding and window trim outside, and the insulation, second floor radiant heat,and sheetrock inside.  click the photos to enlarge them ..

it was kind of a thrill when the lights went on and siding was mostly finished ...

we still had to have the concrete professionals back to pour the slab for the 

steel/blower/compressor shed .. 

 and we had to build the rather elaborate 20 long rack to store all the small in size, but 20 to 24 long raw materials ... fortunately, the carpenters were called away on another job for a day, which gave us time to figure out the rack before the roof went on .. mucho easier that way ..

the shed is fitted here with a bronze color standing seam roof by donnie dorrs metal shop ..

 and inside, we did some painting, and reconfigured the chop saw tables into a mockup work table so we could figure out where to hang up the welding fume extractor.  we ran the pipes to the blower thursday ..

 boilers these days are amazing ... this little guy puts out 80,000 btus, enough to heat both floors, (+/- 1500 square feet in a vemont winter), and provide domestic hot water for the sink and bathroom.  exhaust out in pvc pipe.  no chimney ...

 ahhh, the doors .. nobody made a cheap standard unit three doors wide, so we had to cobble these together with parts from a company whose name escapes me now .. we made up some quicky transoms from 8/4 pine and ordered up some custom thermopane to fill them.

 there were a couple reasons for that configuration .. #1, you can open the doors totally in the summer like below, and should we move on at some point, the openings are framed to accept regular 9 x 7 commercial overhead doors .. presto, a heated, two car garage with a mother in law apartment above  ... the plumbing and radiant for the second floor was roughed in before the sheetrock went up ..

 

 a few notes below on the quicky transoms ...

 9 3" x 16" plus the frames

 essentially, the frames are butt jointed, timberlock construction, with applied moldings to accept the glass .. framed in the shop and screwed in over the door units .. cheap, easy, and fast ... you dont get that combo often enough ...

all for now ... sam is moving in this week

the steels there waiting for him

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Vacuum Chuck!

Ive finally gotten back around to working with my vacuum system to hold bowls and small children to the lathe.  Just kidding, I dont turn kids...  In this post, Ill describe my process for making a vacuum chuck for my lathe.  The fun part is that this was done without buying a faceplate!

If you recall, I had a few issues getting my system to pull down to adequate vacuum and changed my design a bit to achieve better performance.  Now that Ive gotten all of the kinks worked out of that, lets see if I can make a chuck work on the first pass...

I set out on this project planning to use two sheets of plywood I had laminated to make the base flange.  I have a Ø 9" cardboard tube that I was planning to use as my cylinder.  Well...after I trued up the plywood disc, I cut a tennon in the bottom to hold in my chuck.  The plywood was looking a little weak, so I gave it a test "jiggle" before turning the lathe on.  Boy, am I glad I did that.  The piece immediately delaminated, leaving the tennon in the chuck and the rest in my hand.  

So much for making this work on the first try.  Now what?

Lucky I had recently gone with a friend to pickup a CNC and manual mill.  This was at a local factory that had closed and we were told "if you see anything in this room you want, its yours."  Sweet!!!  I stocked up on all kinds of goodies, including lots of delrin and acrylic.

Plan B (not the morning after pill) is to use a piece of delrin as the base flange for my chuck.  Now, this is not the Ø 9" chuck I originally set out to make, but it will certainly work for my application.  So lets get to it!

Maybe this is repetitive, but I started by laying out my materials for the chuck body.  A disc of delrin ~ Ø 4" and a PVC coupling of similar size.

I started the piece between centers and turned a tennon which I will hold on to in the next step.  Turning plastic between centers can be interesting because a spur drive will not bite into the piece very deep.  I drilled a small pilot hole for the spur drive to center in.  I then used a mallet (off the lathe of course) to make an indention of the spur drive on the piece of delrin.  Gentle cuts are in order during this stage.  If you get a catch, the spur drive will just spin on the back of the blank.  This did happen, but it wasnt too bad.  

For my chuck, I want to have an o-ring sit on the base of the spindle to seal up the system as well as I can.  To do this, I need an o-ring groove to be cut into the chuck body.  I foolishly spent the time making such a feature now...   It occurred to me not too much later that this end of the piece would not be sitting against the base of the spindle...  Oh, well.  Ill just call that wasted time practice.

Ive now put the blank into the chuck and will do the majority of the work from this end.  I start by truing up the face and diameter.  

Next, I form the shoulder that will sit against the base of the spindle.  I actually didnt have to cut a shoulder here, I could have left this surface flat across its diameter and the base flange would have worked just fine.  I also make the o-ring groove that will actually be used now.

Now I move on to drilling out the center to begin the hollowing process.  You dont have to drill out the center, but it does speed up the process a little.  

I used my 1/4 bowl gouge to remove the majority of the material.  Once this tool began chattering too much, I switched to the scorpion hollowing tool to finish removing the majority of material.  I trued up the walls with a scraper.  This was a bit time consuming as the plastic likes to slowly push your tool off of its intended course and forms a taper instead of a straight walled hole.

The spindle on my lathe is 1 1/2 x 8.  A new tap in this size is quite expensive so I looked around on ebay until I found a good one what was used.  I dont recall the brand of this tap, but it was about $25 instead of $100 for a new one.  

Just like anything else, there are lots of ways to tap parts on the lathe.  Most taps have a little hole in the top that is used with a nifty little device called a tap follower.  A tap follower has a spring loaded pin that compresses against the top of a tap and provides downward force so that you can focus on turning the tap handle instead of having a buddy push against the quill while youre working.  I dont have a tap follower so I did the following:

1. Lock the spindle
2. Put live center with center point in tailstock
3. Slide tailstock in place and lock (proper placement is length of tap + a little...  very scientific I know)
4. Hold tap in place with left hand
5. Slowly advance quill with right hand until live center contacts top of tap
6. Maintain pressure on quill and switch hands so that the left hand is on quill advance handle/wheel
7. Use combination wrench (or adjustable wrench) to turn tap
8. Maintain pressure on quill to keep tap centered
9. Retract tap every so often to clear chips and repeat steps 7-9 until tapped to desired depth

Sounds like fun, doesnt it?  Yeah, tapping is kind of boring, but its cheaper than buying a bunch of faceplates!  One last thing before you are finished with this set up is to cut a relief in the threads to match your spindle.  On my lathe, the threads stop about 1/4" before the base of my spindle.  If you dont remove these threads, the chuck will not fully seat on the spindle.

At this point I took the piece out of the chuck and threaded it onto the spindle.  It fit!!!  Ok, were done, go have a beer... I mean lemonade.  

Were actually not done, but the majority of the "hard" work is behind us.  I decided to drill a hole for a Tommy bar to help with removing the chuck.  This is pretty much and optional step, but the added utility could come in handy.  I drilled this hole to correspond with the Tommy bar that came with my chuck.  Now I have one less tool to get lost around the lathe.  I just used a cordless drill and eye balled with location making sure not to drill too close to the tapped hole.  

Next Ill remove the tenon.  I dont have to, but you can probably tell by now that I dont like stuff just left behind.

Now we need to reduce the OD so that the PVC coupling will fit.  I want this to be a rather snug fit so I stop and check my progress often when Im getting close to my final dimension.  Also, the more of the PVC couple that is in contact with the base flange, the stronger your chuck will be.  I cut the shoulder to be about 3/4" deep.

I used liberal amounts of marine grade epoxy to join to two pieces.  Look...the original attempt at making a vacuum chuck came in handy!  I used the tailstock to put equal clamping force on the assembly as the epoxy cured.

Now I reduced my spindle speed and turned on the lathe to see how true the assembly ran.  To my surprise, it was pretty good!  I did still want to clean up the PVC coupling just a little, but it was pretty quick work.

Wow, Mike, when did you get granite work benches?  So, its winter...  And I just didnt feel like freezing while I put the o-ring in place.  For this I used o-ring cord stock and the marine grade epoxy.  A flat gasket would also work well to seal between the chuck body and spindle, but I had o-ring stock so here goes.  I start by laying the stock into the o-ring groove and cutting off the appropriate amount.  I also tore off two pieces of tap to hold the o-ring in place while the epoxy cured.  

I then mix up the epoxy and spread it into the groove using the center of a toothpick that I broke in half.  Next, I lay to o-ring in place, getting as much epoxy on my hands as possible and lay down the tap to hold it in place while the epoxy cures.

The last step is to make a sealing surface on the business end of the vacuum chuck.  For this I used sticky backed foam weather striping that can be found at most home improvement store.  I had no idea just how sticky this stuff is.  WOW!!!  Be prepared to destroy the first strip you try to use.  I wrapped one layer on the inside of the drum and another on top of the first layer. 

Well, theres it is!  Thanks for reading and as always if you made one, have suggestions or questions just let me know!  

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Progress on the Thomasteppich June July 2013

We have taken one photograph each day when Anne did something with her part of the Thomasteppich and turned these into a small video. Anne first outlined the scene in black and then started filling the parts with the coloured wool.

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a claro walnut dining table for sale

ive got this claro walnut table ready to ship.  it could be at your house in time for the holidays.

polished rebar and walnut base ... +/- 44 x 88 x 19.5

$6500. plus shipping

802-867-5541

dan@dorsetcustomfurniture.com

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The medieval toolchest woodcarving knives

I have been busy with chip-carving a sella curulis lately and this is done with one tool. the (wood) carving knife. We know this tool was used in medieval times (and even up till now) based on the furniture and other wooden utensils that are left from this period. There is not much archeological   evidence or illustrations (e.g. in miniatures) of medieval knives that can be directly correlated to woodcarving. Knives that are found can be used for many reasons and many trades. 

In Novgorod, Russia, however, some medieval knives of the 12th and 13th century could be linked to woodcarving and whittling of carpenters and coopers. They had a curved blade and a down-turned tip lower than the axis of the handle carving. 

 

Woodworking knives from Novgorod: (a) and (b) 13th century, (c) 12th century. (d) drawing of the blades with the axis 

of the handle. Images from Wood use in medieval Novgorod by M. Brisbane and J. Hather.

Our woodcarving knife also has such a curved and downturned blade. The design resembles modern woodcarving knives. The blade of our knife was forged by the German mastersmith David Schütze (Wollschmiede). He is specialised in reconstructions of archaeological finds. The knife was especially hardened and whetted to perfection by him for hard woods like oak. I have added a handle of apple wood to it.

Another use of a knife (or an awl) in medieval woodworking is for marking lines and geometric designs. Many of such marks have been found on wooden objects (furniture, houses, etc.) dating from the middle ages. See the photos below for examples of knife marks on the medieval chests from the Luneburger cloisters (Germany).
 

(above) Knife marks providing guides for carving on chest TR-NR-400 from cloister Wienhausen, dating 1320. (right) Knife marks on the inside of the chest for the groove of the small tray. Photos from the book Die Gotischen Truhen der Luneburger Heidekloster, from K.H. von Stulpnagel.

A third type of knife for (late) medieval woodworking, which was still used in the last century by carpenters is the so-called shoulder knife (it even can be bought today at specialist tool shops). This knife has a very long handle which rests against the shoulder providing a stable hold. This stability feature makes the shoulder knife very useful for the very precise construction of intarsia, like the (intarsia) self portrait of Antonio Barili clearly shows.

Image of Antonio Barili (1453-1516) from Sienna, Italy. The artist carves the letters: HOC EGO ANTONIUS BARILIS OPVS COELO - NON PENICELLO EXCVSSI. AN.DN. MCCCCCII. (This work have I Antonio Barili  made with the carving knife, not with a brush. In the year 1502.). Other tools shown are a gouge, a folding knife and a pencil. The woods used for the intarsia are pear, beech, walnut, maple and palisander. The intarsia sadly has been destroyed during the second world war.

The last knife used by medieval woodworkers discussed here is the spoon-carving or hollowing knife. This knife was exclusively used for carving the hollows of spoons and bowls. Again, they have been found in medieval Novgorod, Russia (11-14th century - along with more than 650 spoons), but also at Arhus and Trelleborg in Denmark (10-13th century).

11th-14th century spoon carving knives from Novgorod. Image from the cd of the book: Wood use in medieval Novgorod.

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Progress on the Thomasteppich August 2013 May 2014

 Anne and Katinka at work on the Thomasteppich in April 2014.

Like the previous progress report on the Thomasteppich embroidery project, I have made a photo for most of the days during August 2013 till May 2014 when Anne did something with her part of the Thomasteppich, and turned these into another small video.

Of course not only Anne worked on the tapestry. Also Katinka made an enormous progress...

 Left: Katinkas part of the tapestry in 2013, and right in April 2014.

Also interesting to see is the back of the tapestry. Only tiny stitches appear at the back of the frame, most of the wool is present at the front of the tapestry. The medieval klosterstitch used has two purposes: it saves weight and expensive wool.

 The front and back of the tapestry in August 2013.

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Progress on the Thomasteppich May July 2014

Like the previous progress report on the Thomasteppich embroidery project, I have made a photo for most of the days from May till July 2014 when Anne did something with her part of the Thomasteppich, and turned these into another small video.

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St Thomas on holiday

A few months and it already time for this years summer holidays. Last year we (both Thomasguild families) went to northern Germany, but to separate locations. Marijn and Anne stayed around the hanseatic city of Lübeck, while Bram and Katinka went further north to the Gothic brick cities of Wismar, Greifswald and Stralsund. During our holidays we (of course) visited some musea, old churches and buildings, etc. and did find some medieval images and statues of our patron saint, St. Thomas.

 The altarpiece of the Thomasbruderschaft der brauerknechte.
From the Burgkiche in Lübeck, now in the St. Annenmuseum.

In Lübeck in the St. Annenmuseum Marijn and Anne encountered many Thomasses. The museum houses a large medieval collection, mainly religiously based, and mostly retrieved from the bombed churches in the second world war. One of the finest pieces was a special altar dedicated to him, although our saint had to share it with the two other Thomas saints, Aquino and Beckett. This altarpiece of the Thomasbruderschaft der Brauerknechte (the Thomas brotherhood of the brewers) from the Burgkirche in Lübeck dates from around 1520. It consists of a gilded shrine with sculptures by the Master of the Burgkirchealtars, and painted panels by Erhart Altdorfer and the Master of the Thomasaltar. The shrine is 2.32 metre high and 1.3 m wide, with a depth of 26 cm. The altar wings are 62 cm wide and 17.5 cm deep. The predella (the lower part of the altar) has a height of 94 cm height, a width of 2.84 metre and a depth of 49 cm. There are some marks of the makers of the shrine left on the backside of the altar piece, but unfortunately not visible for us.

The lower middle part of the altar piece with from left to right: Thomas of Aquino, Apostle Thomas and Thomas Beckett.

Part of the predella, with the unbelieving St. Thomas and Christ in the middle.

The backside of the right group of apostles from the predella.

 You can see that the backside of the sculpture is roughly hollowed out.

An old black and white image of the complete altarpiece, but with the parts mixed up.

A part of the high altar from the Marienkirche has a painting on an oak panel of two apostles, of which one is St. Thomas and the other St. Paul or St. Matthias. The painting dates from around 1420 and was made by Conrad von Soest or a successor.

The Apostle on the right is St. Thomas.

Another painting from an altar piece of the Valentinsbruderschaft shows another part of the legend of St. Thomas. He was absent during the death of Maria, and therefore was witness to her ascendency to heaven. Maria did give him her belt (with help of an angel) to show as proof. The painting was made between 1490-1500 by Wilm Dedeke on the wings of the predella.

An angel gives the belt of Maria to Apostle Thomas. Altar piece of the Valentinsbruderschaft.

The following are some remarkable oak statues from an altar from Molln. The statues were made in Lübeck around 1395-1400 and now reside in the St. Annenmuseum. Thomas has a spear in his hand. The two other statues are of St. Simon. He has a saw as an attribute, because he was martyred by being sawn in half lengthwise. One Simon carries an M-toothed cross-cut saw. This is (sofar) the earliest image of such an M-toothed saw, and decades earlier than the saws mentioned in the blogpost on two man cross-cut saws (1450-1475). The other one is more like the two-handed push saw. The back of the statues are hollowed out. The original colour of the statues has been gone, although some traces of bolus remain.

St. Thomas (left) and St. Simon (middle and right) from the altarpiece from Molln.

  

The hollow backside of St. Simon.

In nearby Ratzeburg, Marijn and Anne visited the Dom, in which an altar resides from the end of the 15th century. One of the apostles on the wings of the altar was Thomas. The Thomasses met by Bram and Katinka will likely be presented by them in a blogpost.

St. Thomas with spear (left photo) and St. Simon with saw (right photo) from the altar piece of the Ratzeburger Dom. 

Source

The St. Annenmuseum does not allow photography, but a catalogue of the medieval wooden pieces is available. The images were scanned from this book: Corpus des Mittelalterlichen Holzsculptur and Tafelmalerei in Schleswig-Holstein. Band I. Hansestadt Lübeck, St. Annen-Museum. edited by U. Albrecht. Verlag Ludwig. ISBN 978-3-933598-75-2.

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