Wednesday, October 16, 2024

Wooden Wheel Barrow


 Making a Wooden Wheel Barrow


Completed Wheel Barrow.

This is going to be a long-term project as I intend to use greenwood for the wheel. A good book giving some details of an early wheel barrow design written in 1917: "The Complete Woodworker" edited by Bernard E. Jones on pages:349-352. Interestingly he starts by saying that "the greatest drawback to the ordinary wheel barrow is that more than half the weight of the load and barrow are borne by the arms and shoulders of the user." The design he illustrates allows the greater part of the load over the wheel and "is much easier to handle, and therefore more suitable for female farm-workers and gardeners and amateurs generally, the greater part of the load being carried over the wheel, thus taking much weight off the arms. In fact in some Chinese wheel barrows, the wheel is placed in the centre so that the load is directly over the wheel. The barrow illustrated in Bernard Jones's book, is also shorter than modern versions, and narrow enough to pass through a 2 ft 6 in. doorway with deep sides, being desirable features for stable use. Unfortunately, he does not give much information about the construction of the wheel (the author advises to get the wheel from a wheelwright) but does give some dimensions and that it is constructed as four spokes (or two straight through spokes) one rectangular and the other square rather than round.

I chose to adopt the design illustrated by Bernard Jones with some modifications in construction and materials. As the wheel components dried over the summer, I purchased kiln-dried ash for the chassis elements (excluding the main barrow). The design intent for the wheel barrow was to enable easy disassembly for storage purposes when not in use. The materials used in the construction are listed at the end of this section.

Making the Felloes and Spokes.

The felloes are the pieces that make up the rim of the wheel. The four felloes were crafted from green ash that was felled in January 2024. The trunks of the ash, approximately 16 cm in diameter, were split  and then fashioned into rectangular slabs, roughly 9 cm wide, 5 cm thick, and 33 cm long, using a carving axe and a froe before being set aside to dry.

The green wood for the felloes left to dry.

I had originally planned to use eight spokes to connect the felloes and the hub but after reading the account by Jack Hill ( The Complete Practical Book of Country Crafts, David & Charles, Newton Abbot, UK, p 133.) about traditional wooden wheel barrows in England made with four spokes, I decided to follow that design. Although there are four spokes, they are really two pieces of wood that pass through the centre of the hub to connect to the four felloes. These two pieces are quite different. One is rectangular in the centre (3 inches by 1 inch) passing through the hub and then tapered at both ends to cylindrical spokes that pass through the felloes. The other is one spindle that passes through the hub and the rectangle section of the spoke to fix into the rim. 

I made the rectangular-sectioned spoke from a single piece of ash, split from a trunk and roughly shaped with a drawknife and axe. I levelled one wider face with a roughing plane and a smoothing plane. The opposite face was reduced to a thickness of 30 mm using a kerfing plane and a rip-frame saw, then finished with a smoothing plane. The narrower faces were planed to achieve a final size of 60 mm in width, 26 mm in thickness, and 450 mm in length. The final shaping will occur after the ash has dried. Although narrower than the 3 inches (75 mm) specified in Jack Hill's book, I believe this variance is not critical. The spoke ends will be trimmed to 25 mm on the pole lathe once the wood is dry.

Rectangular spoke left to dry. The two ends will be shaped to cylinders after is has dried.

The other spoke was prepared from a section of cleaved ash by cutting and shaping on the spindle lathe. This was about 30 mm diameter and will be adjusted to 25 mm after it has dried.

The spokes were made from the air dried ash that had previously been  roughly shaped. The rectangular cross-sectioned spoke was shaped at each end ready for mounting on the pole lathe. The ends were turned down to 7/8 inch diameter for the first 3 inches and then shaped using a spokeshave being careful to keep the rectangular section in the middle that will go through the hub mortice.

Shaping the ends of the rectangular spoke.

Spoke when near completion. The ends are 7/8 inch diameter.

When dry, the felloes were cut to shape. This was aided using a piece of underlaid plywood with a drawing of the wheel and 1/4 segments. Another piece of plywood was cut to the shape of a felloe and was used to mark the shape onto the ash dried sections. One face of each felloe was chosen to make flat and planed and checked with a ruler and winding sticks. The shape of the felloe was then drawn onto the flat face and then the outside edge was sawn leaving a little waste to plane to the exact shape needed. The outside edge was then planed to the line making sure it was perpendicular to the other edge. After this the inside edge was drawn, sawn and planed as needed. Finally the width of the felloe was marked to 40 mm and sawn to the line and then planed smooth.

A felloe clamped for sawing.



Sawing a felloe, hard work with a lot of further planing to get the right shape.


A felloe prepared and compared with the plywood underlay to check the shape. The underlay will also be used to mark the centres of the felloes and the positions of the axle through the hub.

The rim of four felloes braced to check the size before marking the spoke positions.

 

Drilling a felloe for a spoke tang to fit. 

Construction of the Wheel : Making the Hub and Connecting the Spokes and Felloes.

Ash trunk used to make the hub.

The hub was made from a trunk of ash using a draw-knife and axe in preparation for mounting on the pole lathe. Traditionally, the hubs were made using elm but this is now hard to come-by. The size was adjusted so that the central part of the hub was 77 mm in diameter and the ends were 58 mm in diameter. Final refinements will be made after the wood has dried.

Hub after initial lathing. The cylinder on the left is just surplus wood (later used to make a mallet). The central cylinder is 77 mm in diameter for a length of about 80 mm. The ends are 58 mm in diameter and the total width of the hub is 300 mm.

The hub was left to dry in the workshop and the mass measured at intervals over the summer of 2024. All greenwood parts had their end-grain sealed with wax before storage to reduce the chance of splitting and to minimise distortion. 

3 rd May: 1425g and 4 th June: 1290 g indicating a loss of 1350 g, i.e. 9% of original mass. On 8 July it weighed 1230 g and 1234 on 23 July indicating about 13 % loss in mass. It weighed 1236 g on 15 th August indicating it had equilibrated with the atmosphere and was ready for further work. For this purpose, the piece was returned to the lathe and the diameter was reduced to accommodate the fitting of the steel rims as shown below. I attempted to heat them before installation but discovered that it made very little difference to the fitting. This is probably because of the small diameters of the rim and so their expansion on heating was small.

Hub with the steel rims fitted and ready for the axle stubs to be fitted. The piece of wood on the right is the wood that will be shaped for the first through spoke.

The positions of the spokes through the hub were marked by drilling a hole in the underlaid plywood (see the description of making the wheel felloes below) and setting the hub upright through the hole so that the spoke positions were diametrically opposite and at right angles to each other.

Marking the hub for drilling and morticing for the spokes.

The hub through-mortice was started by carefully marking the rectangles on both faces of the hub and then drilling 1/2 inch auger hole through the centre, starting from each side and meeting in the middle. Further smaller holes were drilled to roughly define the mortice. The rest of the mortice was chiselled from each side and then the spoke inserted in stages to get a close fit.

The second ash spoke was finished on the pole lathe and adjusted to 7/8 th inch diameter. The mortice for the spoke was drilled using a number 13 (13/16 th inch diameter) auger being careful to meet in the centre of the hub. The spoke diameter was trimmed to get a close fit in the mortice. It is very important to get the spokes in the correct alignments with each other.


Having drilled the hub for the spokes, the felloes were drilled for the tangs. The rectangular spoke was fitted into the hub and the felloes laid in position for the tang positions to be marked and then drilled as shown above. Once the rectangular spoke was fitted, the cylindrical spokes were marked with the felloes in place. Great care is needed in getting the correct angles, positions and level of the drill holes. The wheel was then assembled, tightened and planed to its final shape ready  fitting the steel rim.


Finished wheel without the steel rim fitted.

The iron rim for the wheel was cold bent to a circle of approximately 400 mm diameter. To do this I made a semi-circular former of thick pine and using clamps bent the rim around the former as shown:

Forming the mild steel rim using a former and clamps.

The traditional method of making the rim would probably involved steel rollers or the Blacksmith's smithy and would have made a more perfect circle in circumference than I was able to by cold working. 

The next step was to complete the tyre by joining the two ends with a butt weld. The circumference measurement is important as the tyre is fitted when it is heated to several hundred degrees on a fire and then hammered onto the wheel. I calculated, using the linear expansion of mild steel, that the expansion at 400 C would be around 8 mm so that the inner circumference of the tyre had to be 8 mm shorter so that when expanded it would closely fit the wheel. I measured the relevant distances using a "traveller", a circular disc about 5 cm in diameter mounted on a handle, and then cut the tyre 8 mm short. I no longer have my MIG welder equipment, so got a local engineering firm to make the butt weld. I checked the size after welding by trying to mount the tyre when cold (about 10 C at the moment) but as expected the tyre was too small. 

The next task is I think difficult and one that wheelwrights would have had great experience, that is mounting the tyre on the wheel to get a tight fit and force the wheel components together. Remember that at his stage the wheel is not glued  at all and it will depend on the tyre to hold the components rigid. The tyre was bedded in a wood fire set in a large barbeque stand and heated for over one hour. The steel should reach at least 400 C and maybe as high as 1000 C before it was removed for mounting on the wheel. I think it is important to fix the wheel horizontally so that it cannot move  to enable the tyre to be hammered into position. Wheelwrights had a special metal jig for two people to do this and metal tongs to hold the rim and also prise it into position. 

The tyre embedded in the fire with the wheel clamped in position.

My first attempt was not successful, partly because I was not holding the tyre well enough, and also because the tyre deviated in places from a circular shape. In my second attempt, I was aided by my daughter, Emily, who was able to hammer and hold the tyre on the opposite side from me hammering it into position. Once it was engaged with the wheel all around it, it was just a matter of hammering into position and so tightening the wheel and pulling the felloes together. It certainly seems like a two person job especially with the high temperatures involved. The rig was then doused with water to cool the wheel. Much to my relief, the tyre did fit tightly. 

The wheel after mounting the tyre and during the cooling stage.

Construction of the chassis.

The plan for the chassis was drawn from the information given in "The Complete Woodworker". The angle of the strines (the two arms of the wheelbarrow) was calculated as 5 degrees from horizontal. 


Sketch of chassis of the wheel barrow. Dimensions in mm.


 Although it was tempting to make the chassis before the hub and felloes were dry, I decided to wait as the dimensions of the frame and axle mounting blocks depended on the width of the hub. 

Sketch of the mounting blocks showing the position of the steel tube for the axle and also the position of the hub. The height and width of the block is 50 mm and will be attached to the frame by bolts. The hub will run parallel to the frame and mounting blocks.

The ash mounting blocks were 250 mm long and 50 mm in cross section. A section was chiselled out to make the block flush with the hub and so allow the strines to diverge at an angle of 10 degrees, i.e. 5 degrees on each side. Holes were drilled 65 mm from the front for the stainless steel tubes where the axle will pass ensuring the correct angle. Holes were also drilled for the 10 mm galvanised bolts that will secure the blocks to the end of the strines. Finally, the blocks were shaped as shown. 

Axle trunnion  block showing the hole for the axle and the holes to attach it to the underside of the strine. Note that the axle hole is 5 degrees off normal to compensate for the divergence of the wheelbarrow arms.

The next job was to mount the wheel on the trunnions. This involved drilling holes in the hub to screw in the 20 mm stainless steel bolts. It is crucial that these holes are drilled in line so that the bolts pass through the trunnions and allow the wheel to spin. I don't know how the Wheelwrights did this ( I cannot find any written records of this) but after much thought I decided to clamp the trunnions in place and with the correct strine alignment, pass the auger through the tube in the trunnion and drill into the centre  of the hub with the wheel correctly mounted between the strines. In his way the trunnions guided  the auger. As the auger was going into the end-grain  of the hub, I used a bull-nosed auger (I had a no 8 or 4/8 inch auger available) to get to a depth of 10 cm and then opened this out with s normal no 9 auger to allow the bolt to thread into the hole in the hub. 

The underside of the mounted wheel with the stainless steel bolts (axle) in place passing through the trunnion steel sleeve into the hub. The mounting blocks were attached using two 6 inch 10 mm galvanised bolts.

The last stage with the no 9 auger and screwing the axle bolt, were done with the wheel mounted in a vice.
The trunnions (now attached to the wheel) were then attached to the underside of the strines using 6 inch length and 10 mm diameter bolts.
The next stage was to connect the two sloats in place and hence fix the geometry of the base of the wheel barrow. By doing this after mounting the wheel, allowed some slight adjustment in the strine alignment so that the wheel rotated freely.

The legs were made from 50 x 50 mm ash. From the ground to the bottom of the strine was 380 mm and from the top of the strine to the top of the leg was 380 mm. The bottom of the leg was tapered to 44 x 44 mm and the top to 44 mm x 25 mm. The leg was made if two pieces set at an angle of 16 degrees. This was calculated from the dimensions given in "The Complete Woodworker". The pieces were joined by a scarf joint. I found the best way to cut these was by making a kerf cut along the long side of the joint on both sides and then sawing down being guided by the kerf channels. The joint was glued and the legs fixed to the strines using 8 mm stainless steel bolts.

A leg fixed in position by a bolt to the strine. The top piece was scarfed to the bottom and diverged 16 degrees from vertical 

I am not sure how the legs were originally made. It is possible that wood grown with a curve was used so that the grain followed the bend. Otherwise the legs could have been cut from a wide board but this meant some possible wastage and a weakness in the grain at the bend. I decided to keep straight grain in the two pieces and use bolts to strengthen the scarf joints,

The ash standards were cut from 520 x 45 x 32 mm stock and tapered to a thickness of 22 mm (7/8 th inch) at the top. The standards needed to be at the same divergent angle from the strines as the top of the legs and to do this the standards were housed into the strines at an angle of 10 degrees and also tapered just at the joint by another 10 degrees. The alignment of the standards and top of the legs was checked using an adjustable bevel and also by sight. They were attached to the strine with a M8 stainless steel bolts; the housing joint also stopped the standard rotating on the strine and so improved the overall strength.

A standard mounted in a housing joint in the strine and shaped to an angle to match the leg top.

The main frame was treated with natural linseed oil and then three coats of yacht varnish. Further coats of varnish will be applied later. 
Some kiln dried redwood planks  ( 212 x 22 x 1000 mm) were purchased  for the wheel Barrow sides and bottom. My idea was to make the wheel barrow top so that it could be dismantled easily in order to carry different shapes and for ease of maintenance. The shape and size of the  sides and top on general was taken from "The Complete Woodworker". The bottom and two sides were first constructed. 
The bottom was made with the grain running length-wise to aid moving the contents in and out of the barrow. Using a jointing plane, the three sections were aligned and then glued and clamped. After finishing, the bottom was treated with linseed oil and the underside with varnish.
The sides were about a metre and their profile sketched with pencil before the first side was sawn and shaped with a spoke shave. The second side was copied from this and then the two clamped together for minor adjustments.
The next task was to make the sloping end-board near the handles. This is to be removable and so a groove on both sides was cut with a 1/2 inch dado plane (made in Glasgow by Carrick and Craig I think sometimes called a trenching plane or housing plane) and backed with a 20 x15 mm strip. As my dado plane is narrower than the required groove width, two passes of the plane were needed. Before using the dado plane, the edges were scribed and chiselled to facilitate cutting. The edges of the board were angled to lie flush in the groove. The height meant that two boards were glued together and a hand grip drilled and sawn.

Progress in making the bottom and sides. The first groove for the sliding end-board can be seen. Also note that the base board does not cover the entire front sloate but leaves space for the front board to be fitted so that it rests on the sloate and faces the edge of the bottom board. The same geometry was used for supporting the rear board.

Rear board placed in side grooves. Support strips will be added later.

The front boards are more complex as the aim is to get as much of the load of the wheelbarrow over the wheels. The lowest one meeting the bottom board is narrow (13 cm) and rises at a steep angle (about 60 degrees).The grooves on each side were cut to 7 mm depth using a plough plane and chisel. The edges of the grooves have to be angled (not the normal 90 degrees) to compensate for the slope of the two side boards) The front boards are difficult to shape and it did take time to get them right. I did this by removing the side boards on one side and then shaping the bottom of the board to fit the base. This meant planing at two angles as shown below. 

The shape of the edges on the bottom of the first front board. The bottom rests of the front sloate and faces the bottom board, The sides were also planed to fit the angle of the two strines. 

Then one end of the board was marked from a measurement with an angle bevel. Another bevel was used to measure the angle on the sides and then sawn to that angle and the mark already made across the grain. Final adjustments to this side were made after fitting the board to the base and into the groove. The other side was made in a similar way by marking the position of the groove on the side to match the other side and then making the housing as before. However, the tricky part is to make the final saw cut so that the board is the right length and fit tightly between the sides. The angle of the cut was taken using the angle bevel (basically the same angle as the first side) and the length was measured at the widest points between the grooves using two adjustable 6 mm dowels passing through a block, a simple internal measuring  stick. This was checked at the extremities of the housing at the widest points. This measurement should of course include the depth of the housing joints. The board was then sawn on the waste side following the marking across the grain and also at the correct angle to take account of the converging strines.

First front board set to raise the wheel barrow load above the wheel. The board meets the front sloate and base board and is housed in grooves ploughed into the sides. Marking for the middle front board are also seen on the righthand side. 

The next front board rises at a lower angle (about 25 degrees) and is 24 cm wide. Again, the shaping of the housing joint and edges of this board are challenging. The angle bevel and internal measuring sticks proved essential when combined with some trial and error making small adjustments to get a good fit. The edge joining to the first board was planed to give a close fit.

The second front board mounted in their housings (these are 7 mm deep on either side).

The third and final board was mounted in a similar way and matched with the second board  by carefully planning the edges.
A 8 mm galvanised threaded tie was set on the outside of the top board to prevent the top side boards bending under load. This is shown in the design in "The Complete Woodworker". The tie was placed in a narrow channel made with the dago plane and so prevented movement of the top board on both directions.

The third front board set in its housing and tied with a 8 mm  threaded screw set in a channel


The barrow top was then treated with several coats of linseed oil and further treatments later in the year.

Side view after the first treatment. The ash frame had already been treated three times with yacht varnish.
 
The barrow can be easily dismantled by releasing the steel tie at the front and then removing the rear panel (also easily removed for unloading if required), top front board and the top side boards. This allows the barrow to be used with smaller loads. The barrow can then be dismantled to the basic frame by removing the two front boards and the two lower side boards. Hopefully this will help in the longer term maintenance of the wheel barrow.

Wheel barrow with the top removed.

Materials.

Kiln dried ash was purchased as follows:

Strines: 50 x 70 x 1200 mm @2

Sloates: 34 x 67 x1200 mm @1 (these are the two bars on the bed between the strines).

Legs: 50 x 50 x1200 mm @2

Standards: 34 x 45 x 1200 @1 (two standards to support sides at the front sloat).

In addition the following ironware was purchased:

Bolts for hub/wheel: 2@ M16 by 150 mm long, stainless steel.

Bolts for legs and standards:4@ M8 by 110 mm, stainless steel.

Tube for trunnion block (block below strine that carries the axle): 20 mm OD and 16 mm ID, 100 mm long and stainless steel. The M16 bolts fit through comfortably).

Mild steel tubes for hub: 76.2 mm OD, 3.2 mm wall thickness, 50 mm length. These were cut in half to provide rings for each side of the hub.

57.2 mm OD, 1.6 mm wall thickness, 50 mm length (www.metals4u.co.uk).

Black mild steel flat bar for wheel tyre: 40 mm width, 3 mm thickness and 1300 mm length (www.metals4u.co.uk). This mild steel has a black scale formed by oxidation during hot rolling. It bends well when cold.

Book References for design features:

"The Complete Woodworker ", Cassell's Handcraft Library, General Editor:  Bernard E. Jones, 5th edition 1926.

The Complete Practical Book of Country Crafts" Jack Hill, David and Charles, Newton Abbot, 1980.

Friday, July 12, 2024

Coffee Table or Side Table

 This is a project that will take a little time as I am using freshly felled ash for the legs that will be shaped from about 15 cm diameter ash trunks collected locally. These were free from any noticeable ash dieback that has affected many of the local trees in the woodlands in Devon and also in many other parts of the UK. 

Making the table legs using green ash

I have a slab of waney sweet chestnut (Teale & Sons Timber Ltd.) about  1180 mm long by 280 mm wide and 27 mm thick that should make two coffee or side tables with a little to spare. I plan to make the legs from green ash.

The ash was about 15 cm diameter and about 45 cm in length enabling me to split into four billets. The grain was reasonable straight and so cleaving with a froe was easy. The original log and three of the billets are shown above together with a rounded leg. Once cleaved the corners were removed using the froe and then chopped into shape using a carving axe. The final shaping of the billet for the pole lathe was done with a draw knife and large spoke shave. This was then mounted on the pole lathe (for spindle turning), and both ends were worked to produce a regular cylinder. The billet was then removed from the lathe and the wood between the ends removed with a large draw knife. This made the rough shaping on the lathe much easier. Once the spindle was turned (about 40 mm in diameter), the ends were sealed with oil/molten wax and then left to dry over several months. Several of these were made and stored.

 After air drying in the workshop, the legs were shaped on the pole lathe as shown below. The total length is 42 cm. The top 5 cm was made 1+ inch diameter for the first 5 cm and then widened to 39 mm over a length of 17 cm. The diameter of 39 mm was continued for a further 5 cm and decreased to 30 mm over a length of 10 cm. The final 5 cm was turned to 30 mm for the bottom of the legs. The part of the leg to be inserted into the top was left slightly greater in diameter then 1 inch and was finally adjusted on the lathe after the holes in the top were drilled. This insured a tight fit was achieved.

Ash table leg turned to size.

A piece of sweet chestnut was chosen with a shape that looked like a surf-board together with the obvious figuration resembling a wave pattern. My artistic talents are limited so I was helped by my daughter Bex to design the top. The shape was adjusted by sawing with a key-hole saw (to get a curved shape) and then planing with spokeshaves. The edge and rim of the board displayed spalting which was preserved to add some features. The surfaces had been rough cut so needed careful planing, scraping and finally sanding to 320 grit size.

Sweet chestnut top planed and sanded ready for drilling the 1 inch holes for the legs.

The positions of the legs were marked on the top. This was decided by calculating the distance of the top of the legs from the outside edge of the top so that the bottoms of the legs were not protruding. The angle of the legs was set at 12 degrees from vertical as this had proved good for previous tables and I had a jig to aid drilling at this this angle. This distance was 8.1 cm so this decided the approximate hole positions from the edges. The exact positions were made symmetrical along the length of the board and to give a good balance for the table.

Set-up using a rig to drill the 1 inch holes at 12 degrees from vertical.

The top after one treatment with danish oil and the legs ready for final adjustment and mounting. The oil brought-out the rich brown colour of the wood and the wave figuration.

Once the legs were dry (checked by weighing over 3 weeks), they were finished on the pole lathe by sanding and adjusting the top diameter to fit tightly into the pre-drilled holes. The tops were then sawn to length allowing about 2 mm of the legs to protrude. The legs were fitted by using glue and hardwood wedges with slits sawn in the leg tops. Care was taken to saw across the grain and fit with the wedges hammered in across the grain of the table top to avoid the risk of splitting with the grain. Once dry, the protruding leg tops were sawn off and finished with a chisel and sandpaper. 

The lengths of the legs were adjusted by placing the table on a flat surface, levelling the table as necessary by propping up the legs with cardboard. Then, a thin wooden slab was used to hold a pencil while it was rotated around each leg. This technique guarantees that the table is level and the legs are parallel to the ground.

The finished table after treatment with danish oil, Notice the wave pattern of the top and also the spalting of the sweet chestnut. The ash legs also show some grain patterns.

My artistic daughters design imitating a surf board!

The table was finished with three coats of danish oil and sanding between coats with 320 grit sand paper. Hopefully the table will last many years. 

Sycamore top and ash legs.

Watney edge sycamore top and ash legs.


Thursday, June 13, 2024

Chip Carving, my experiences.

 In the past I have done some relief carving but haven't tried chip carving and in particular the Swiss method of chip carving described by Wayne Barton in his book "Chip Carving. Techniques and Patterns". In chip carving, wood is removed in pieces (i.e. chips) from the wood to make a design directly rather than shaving or sculpturing the wood to form a design as in carving or relief carving. In this method you only need two tools, a cutting knife and a stab knife. The cutting knife or Kerbschnitzen is named after chip carving or "engraving carving" used in Switzerland and Germany.

Cutting Knife made by Pfeil purchased from Classic Hand Tools, UK

My first attempts at chip carving were on the base of a display-stand made from green ash. The 1 1/2 inch hole is for the pedestal of the stand. I used the Pfeil cutting knife by holding it as shown in the diagrams in Wayne Barton's book. I found this a good natural hold and had no difficulty making the cuts although I did wonder about wearing a glove but I will see how I progress.

This is the tulip design shown in Wayne Barton's book with a 4 x 4 mm triangular border. 

I continued learning the techniques by following the designs and notes in Daniel Clay's book, "Chip Carving. Techniques for Carving Beautiful Patterns by Hand". This uses the methods described in Wayne Barton's book but with more information on particular designs and holding the knife. I used limewood for this and followed the layout given in the book. I did not use a stab knife at all and couldn't see a need. Also I found no need for gloves following the techniques described by these authors. 

Each of the faces has a design, in fact the ones illustrated on the front of Daniel Clay's book that are based on the "Seed of Life".

Rather than waste the test boards, I made two boxes. The first pictured above was made with rebate corners with strips of sapele and a yellow poplar top, just waste wood I had at hand. I found that the poplar was also easy to chip carve.
The practice boards, one and two, featured in the book, were carved from larger pieces of limewood and subsequently assembled into a larger box, this time incorporating beech pieces for the rebated corners.

The limewood practise boards made into a storage box. This time the corners are beech and the bottom was 5 mm plywood. The wood was finished with danish oil.

Working with larger chips can be challenging as it requires the knife to penetrate deeper, which sometimes makes the top of the blade uncomfortable. It's crucial to keep your thumb close to the knife blade, rest your knuckle on the workpiece, and adjust the blade's angle at intersections, all of which are detailed in the books. Among my preferred designs are the "Tulip Pot" featured on one side of the box and the "Seed of Life."

Monday, March 11, 2024

Reamer for Conical Dowels

 This is my experience on making a wooden reamer suitable for making mortices for chair legs etc. The advantages of this joint, in comparison to a straight cylindrical mortice, is that the leg cannot push through the joint because of its conical shape, the joint does not need gluing and can be dismantled for transporting. Also the joint does not need a wedge hammered across the tenon to tighten the joint. They were used routinely by Windsor chairmakers.

I made one by following some of the instructions on the "South Fork Timber" internet site with a few modifications. I started with an old keyhole saw blade and filed the teeth off using a hand file to give a metal blade about 24.3 mm wide at one end and sloping to 12 mm at the other. The length of the blade was 15 cm and gave an included angle of 5 degrees (i.e. the internal angle at the tip if originally pointed and hence a slope of 3 degrees off vertical). This will allow holes to be shaped to a maximum of near an inch at the wide part and 1 cm at the narrow. The choice of the included angle was determined by the blade available and how much filing I wanted to do. If the angle is too steep, e.g. 12 degrees, the surface contact area is reduced making it easier to rotate the tenon and making a less snug fit. If the angle is very small, e.g. 2 degrees, there will be greater contact area and hence force to break the tenon open especially if making a tenon in soft wood with a hard wood reamer. Six degrees seems to be a popular angle used in the past by chairmakers. There are more explanations on reamers on the blog of Tim Manney and also Elia Bizzarri, including some videos.

Having prepared the shape of the blade, making sure the sides were straight, I filed a 70-degree angle to each edge of the blade with the high points on opposite sides of the blade. The choice of sides will determine in which direction of rotation the reamer will cut. I hadn't realised this so my reamer cuts on a anticlockwise rotation. I honed the edge to 1200-grit at 70-degrees. (some advice the same angle as card scrapers, i.e.45 degrees). A cutting edge will be applied later using a hard chisel steel using the same technique used for card scrapers. 

The wooden part of the reamer was made from a piece of  oven dried beech dowel about 35 cm long and 2 inches diameter (I could have used a narrower dowel but this is what I had available). This was mounted on the pole lathe and the top handle area shaped as shown. The exact dimensions are not important the only criteria is that the handle must be of sufficient diameter to mount a cross-bar and the blade area must match the profile of the blade.

The reamer being shaped on the pole lathe. Note that the "pointed end" ,on the right, has a cylinder left on to aid later adjustments after the slot for the blade has been cut. This allows the reamer to be mounted on the lathe after cutting. The reamer blade is also shown,

 The profile of the blade portion was guided by using the blade itself with many minor alterations using the skew-edged chisel and finally coarse sandpaper. I found this difficult to get exactly right and so erred on the side of leaving a little too much wood on the sides.

A tricky part of the job is to mark the centre line on the blade portion and also where the handle holes need to be bored for the "T" bar. To do this I used the pole lathe bed with the reamer mounted. My attachment points on the lathe are exactly parallel to the bed. I place a board across the bed and with callipers measured the distance from the bed to the attachment points. I then attached the reamer tightly to the lathe and marked dots along the reamer blade portion of the wood using the pre-set calliper. It is important to get the calliper tips vertical. The other side of the reamer was also marked in the same way ensuring that the lather was not turned. The handle holes were marked in a similar way.

Marking the saw-cut line using the lathe bed and callipers

Maybe marking the saw-cut line is tricky but not as challenging as making the saw-cut itself. I checked my tenon saw and small panel saw for the width or kerf and checked this by sawing some waste wood and inserting the blade of the reamer. Both were fine making a tight fit for the reamer blade. I found the best method of sawing was to have the reamer at about 30-degrees from the horizontal and cutting short sections from each side and then mounting it vertically and cutting down. I did as much as possible with the tenon saw and finished with a panel saw. The pole lathe mounting cylinder was cut through but otherwise left intact so that the sawn reamer could be shut with a small cable tie and remounted on the lathe. The kerf of the saw-cut was cleaned-up using some 120-grit sandpaper backed with a thin card scraper. After checking the fit of the blade, the reamer was mounted on the lathe and fine adjustments made by sanding. The skew-chisel was not used. This was repeated a few times so that the blade protruded a fraction, less then 0.5 mm, from the reamer body. Finally, a narrow channel was carved with a chisel to accommodate waste wood cut in the tenon. This was about 1/8-inch wide cut on the high side of the blade edges.

A "T" bar was shaped from some dry hazel and gauged on the pole lathe to 5/8 inch diameter. A mounting hole was drilled through the reamer using the marks previously made using the lathe bed. After finishing the blade, the reamer was successfully tested and as expected, does need to be removed often from the tenon to release waste dust. 

Finished beech reamer with blade mounted and ready for use. The tool will be treated with linseed oil.

  An adjustment screw was added to aid the positioning of the blade. I used a short M5 bolt and drilled a hole 4.2 mm diameter and threaded this. Drilling the hole was tricky, so I used a small drill and made the hole from the bottom within the saw-slot upwards and at an angle of about 60-degrees. I then enlarged this to 4.2 mm diameter, drilled from the top, and gouged out space for the bolt head. The screw must be adjusted with the blade out to reduce stress on the beech threads.

Adjuster screw in position. 

I thought I'd add a few words on the geometry of the tenon. The shape is determined by the larger diameter of the mortice and the length of the hole i.e., if a through tenon, thickness of the wood. For mine, with an included angle of 5 degrees, this leads to a formula:
 
Small diameter side of tenon = Large diameter side of tenon - length of tenon (i.e. wood thickness) x 0.088

So if the wood is 30 mm thick and the maximum diameter is 15 mm, the smaller diameter will be 12.4 mm. The tenon could then be cut on the pole lathe or alternatively, you could make a rounding plane to match the profile of the reamer.