Bricolage - Torno De Madera
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Building a Woodturning Lathe by George F. Farrell, Dollmaker Page 1
The woodturning lathe described here and pictured above is the 4th homemade lathe that I will have built. The frame should be constructed of hardwood (maple is excellent but expensive). In the southeastern states of the US, southern yellow pine is an excellent substitute. Pressure treated lumber is usually southern yellow pine, but is not recommended unless it is carefully chosen to be clear and knot free, quarter-sawn and with no heartwood. The primary reason for choosing something else is that when purchased it is usually saturated with water, so if you decide to use it, it should be stored in a warm dry place long enough to dry out. It is the cheapest solution, and the drying time can be substantially reduced if you use one inch boards. Birch plywood is an expensive alternative but has the advantage of being very stable and already dry, and certainly much easier to use than solid timber of the required size with respect to the mortise and tenon joints.
Compiled by webtoad
The pedestals P1, P2 & P3 in the construction diagram above are all the same physical size. The construction details differ only with the height of the upright and with the brace of P3. The braces, as drawn, are made with two 2X6's (or four 1X6's) notched on the faces as shown in detail "A" to accept the tenon of the feet. The upright for P3 is shorter than the others and has a triangular mortise (detail "C") formed just under the ways to the brace "d". The upright pieces can then be glued together. The edges should be planed to true and square with the sides, notched for the ways at the top ("a" in the diagram showing the construction of the frame). The feet are made of two 2X6's (or four 1X6's). The foot for P3 has a triangular mortise for the brace as shown in detail "B". The triangular mortises of P3 in the upright and its foot are intended to take a brace which will be at an angle of 45 degrees to the upright and to its foot. All of the feet can be glued up and a tenon formed on one end to fit the mortise of the legs. Glue each upright and its foot together making sure the upright and foot are square. Note that the brace of P3 must be inserted during the glue up process (it cannot be left till later). After glue up, bore two 3/8D holes in each joint and drive in a dowel with glue. The brace for the headstock pair P1 & P2 is a 4X4 mounted at a 45 degree angle and below the bottom of the ways just as for P3. It is important that this brace and the one for P3 be aligned even if it becomes necessary to make this brace over long so that the excess can be cut off later. The braces will support a 2X4 running from P1 & P2 to P3 to provide longitudinal support and which will also double as a support for a hinged motor mount. Another longitudinal member (also a 2X4) should be mounted on top of the feet immediately behind the uprights. Compiled by webtoad
When the glue has dried, the ways can be cut to length and fitted into the notches at "a". They should be a snug fit. They should be lag bolted into place without glue. The second of the two longitudinal members mentioned above should now be lag-bolted in place (also without glue). The longitudinal member which will be the motor mount should be deferred until later.
Building a Woodturning Lathe by George F. Farrell, Dollmaker Page 2 Once the frame has been assembled, it is time to mount the headstock spindle:
For the headstock spindle I chose a one-foot length of 3/4D cold rolled steel. It was taken to a local machine shop and threaded for 1.5 inches along one end to 3/4X16 National Fine. This was chosen because a search of the mail order catalogs gave (still does) the following information: 1. Self-centering chucks -- AMT, Woodcraft and Penn State Industries. 2. Headstock drill chuck to take 1/2D drills -- Penn State Ind. 3. Face Plates -- AMT, Penn State Ind. 4. Screw chucks -- Penn State Ind. 5. I could not find a commercially made spur drive center. The Luna chuck (Woodcraft and Penn State Ind.) has a wide range of accessories, one of which is a spur drive center to fit their chuck. The alternative is having one made by a local machine shop. 6. A 3/4X16 National Fine thread nut will also be required to assist in getting the tools on and off. This item can be found at local hardware outlets. 7. Pillow blocks for 3/4D -- Woodworker's Supply The axis of this spindle must be parallel with the ways -- not only vertically but horizontally as well. Failure in this respect will cause whatever is turned to come out elliptical instead of round. The mounting tabs of the pillow blocks have slotted holes allowing lateral adjustment. Vertical adjustment can be accomplished with fender washers under the appropriate pillow block. This works for a coarse adjustment. Finer adjustment means using a thinner material as a shim. Tin-can material, precut to size and stacked between boards, will allow drilling the mounting holes without tearing. Tin-can metal is about 0.012 inches thick; bear and soda pop cans are about 0.005 inches thick; household aluminum foil is about 0.001 inches thick. These should be enough thicknesses of shim to test the patience of even the most persistent and diligent. The best way to test and adjust for runout is to mount the pillow blocks using hanger bolts. Hanger bolts are threaded on one end like lag bolts and threaded on the other end like machine bolts. When buying the 3/4D cold rolled steel shafting for the headstock spindle, it would be best to buy an additional 3 foot length of it. When mounted in the pillow blocks in place of the spindle, it will project out over the ways by about 2 feet. This fact multiplies alignment errors by about 3 making it easier to find a runout error. A Compiled by webtoad
dial indicator set against the side of this extended spindle and run along the ways on a clip that keeps the instrument along the inside of the ways will give a measure of horizontal runout. Vertical runout is measured with the dial indicator set against the underside of the extended spindle and run along the ways. Once the headstock spindle is aligned with the ways, it is time to make the tail stock and tool rest:
Compiled by webtoad
Building a Woodturning Lathe by George F. Farrell, Dollmaker Page 3 Having done this, set the tool rest aside in order to mark the position of and then bore the holes for the tailstock ram. This is done by running the tailstock up to meet the extended headstock spindle, marking around it with a pencil and boring a slightly oversized hole ( big enough to give plenty of clearance but too small to let a 3/4X10 NC nut through). Run the extended headstock spindle through this hole and mark and bore a hole in the other face of the tailstock. Now make two pads 3 inches square and 1 inch thick. Bore a 3/4D hole through each pad at its center. This 3/4D hole should have just enough clearance on the 3/4X10 threaded of the tailstock ram to support the ram without binding. On one of the pads mortise in a 3/4X10 NC nut. The mortise must be deep enough that the nut comes flush with the face of the pad. This pad does double duty. It is a keeper for the nut because the nut is captured between the pad and tailstock vertical face nearest the headstock. Both pads should have holes drilled in all four corners that are slightly oversize for the bolts that will be used to mount the pad. This allows for horizontal and vertical movement of the pad for further alignment.
For the tailstock ram I chose a one-foot length of 3/4x10 National Coarse threaded rod. It was taken to a local machine shop to be turned down for a 1-inch length of 1/2D which was then threaded to 1/2x24. This allows the working end to accept a standard Jacobs-type drill chuck. A ball bearing live center is available from AMT which will thread onto this 1/2x24 stub. Three 3/4x10 nuts are also required as shown above. Tailstock alignment is done as follows. It assumes that you have a drill chuck that will thread onto the 1/2X24 stub on the tailstock ram. Crank the ram all the way in and center a very short drill to the center of the headstock spindle by moving the near pad. When good centering is arrived at, firmly bolt the pad in place. Now pull the tailstock back and crank the ram out as far as it will go. Mount a very long drill in the chuck and center it to the center of the headstock spindle by moving the pad at the crank. It too is then firmly bolted in place. The lathe is now ready to go.
Compiled by webtoad
George added the following notes to his original article, to go with the two photographs: There are a few differences between what was written and what was built. The brace at the tailstock end in the photo on page 1 is a 2X2, because I ran out of the right kind of materials. Also shown in the photo is a something not mentioned in the directions. That is a piece of 2X10 running from the foot of one pedestal to the foot of the other on which there are 2 cement blocks. These are not absolutely necessary but provide a little more stability. This machine is easy to disassemble into its component parts and certainly a lot lighter to move than a cast iron commercial unit. The photo on this page shows the business part of the machine. Here again there is a discrepancy between what I built and what I described. The spacer block between the upright faces of the tailstock was detailed as a rectangular block with rectangular tenons on each end. What I built was a 3-1/4 inch diameter cylinder with 2 inch diameter cylindrical tenons on the ends. And here's a brief bio from George: After college I took up the clarinet as an anti-stress therapy, in spite of having been told that a man of my age (at that time) could never learn it -- I was about 30. I also got interested in woodworking, also for stress relief. Some time during the 70's I bought Robinson's "The Amateur Wind Instrument Maker" -- this combined my two passions. In his Bibliography he mentioned articles written by Peter Tomlin in the magazine Woodworker (a British magazine). I attempted to make some of Tomlin's instruments but was frustrated by my lathe, which was very bad. At that time I did not have the money to Compiled by webtoad
"squander" (my wife's term) on non-essentials and so attempted to make my first woodworking lathe so that I could try making a clarinet (I actually did learn to play -more enthusiasm than skill but I did it). Twenty years ago the internet was not available to search for the kinds of information that I needed, so I unfortunately spent a lot of time reinventing all sorts of things. I am now fully retired, and being exceptionally healthy, I can do whatever I want whenever I want -- within limits (mostly as established by my wife).
Compiled by webtoad
Building a Woodturning Lathe by George F. Farrell, Dollmaker Page 1
The woodturning lathe described here and pictured above is the 4th homemade lathe that I will have built. The frame should be constructed of hardwood (maple is excellent but expensive). In the southeastern states of the US, southern yellow pine is an excellent substitute. Pressure treated lumber is usually southern yellow pine, but is not recommended unless it is carefully chosen to be clear and knot free, quarter-sawn and with no heartwood. The primary reason for choosing something else is that when purchased it is usually saturated with water, so if you decide to use it, it should be stored in a warm dry place long enough to dry out. It is the cheapest solution, and the drying time can be substantially reduced if you use one inch boards. Birch plywood is an expensive alternative but has the advantage of being very stable and already dry, and certainly much easier to use than solid timber of the required size with respect to the mortise and tenon joints.
Compiled by webtoad
The pedestals P1, P2 & P3 in the construction diagram above are all the same physical size. The construction details differ only with the height of the upright and with the brace of P3. The braces, as drawn, are made with two 2X6's (or four 1X6's) notched on the faces as shown in detail "A" to accept the tenon of the feet. The upright for P3 is shorter than the others and has a triangular mortise (detail "C") formed just under the ways to the brace "d". The upright pieces can then be glued together. The edges should be planed to true and square with the sides, notched for the ways at the top ("a" in the diagram showing the construction of the frame). The feet are made of two 2X6's (or four 1X6's). The foot for P3 has a triangular mortise for the brace as shown in detail "B". The triangular mortises of P3 in the upright and its foot are intended to take a brace which will be at an angle of 45 degrees to the upright and to its foot. All of the feet can be glued up and a tenon formed on one end to fit the mortise of the legs. Glue each upright and its foot together making sure the upright and foot are square. Note that the brace of P3 must be inserted during the glue up process (it cannot be left till later). After glue up, bore two 3/8D holes in each joint and drive in a dowel with glue. The brace for the headstock pair P1 & P2 is a 4X4 mounted at a 45 degree angle and below the bottom of the ways just as for P3. It is important that this brace and the one for P3 be aligned even if it becomes necessary to make this brace over long so that the excess can be cut off later. The braces will support a 2X4 running from P1 & P2 to P3 to provide longitudinal support and which will also double as a support for a hinged motor mount. Another longitudinal member (also a 2X4) should be mounted on top of the feet immediately behind the uprights. Compiled by webtoad
When the glue has dried, the ways can be cut to length and fitted into the notches at "a". They should be a snug fit. They should be lag bolted into place without glue. The second of the two longitudinal members mentioned above should now be lag-bolted in place (also without glue). The longitudinal member which will be the motor mount should be deferred until later.
Building a Woodturning Lathe by George F. Farrell, Dollmaker Page 2 Once the frame has been assembled, it is time to mount the headstock spindle:
For the headstock spindle I chose a one-foot length of 3/4D cold rolled steel. It was taken to a local machine shop and threaded for 1.5 inches along one end to 3/4X16 National Fine. This was chosen because a search of the mail order catalogs gave (still does) the following information: 1. Self-centering chucks -- AMT, Woodcraft and Penn State Industries. 2. Headstock drill chuck to take 1/2D drills -- Penn State Ind. 3. Face Plates -- AMT, Penn State Ind. 4. Screw chucks -- Penn State Ind. 5. I could not find a commercially made spur drive center. The Luna chuck (Woodcraft and Penn State Ind.) has a wide range of accessories, one of which is a spur drive center to fit their chuck. The alternative is having one made by a local machine shop. 6. A 3/4X16 National Fine thread nut will also be required to assist in getting the tools on and off. This item can be found at local hardware outlets. 7. Pillow blocks for 3/4D -- Woodworker's Supply The axis of this spindle must be parallel with the ways -- not only vertically but horizontally as well. Failure in this respect will cause whatever is turned to come out elliptical instead of round. The mounting tabs of the pillow blocks have slotted holes allowing lateral adjustment. Vertical adjustment can be accomplished with fender washers under the appropriate pillow block. This works for a coarse adjustment. Finer adjustment means using a thinner material as a shim. Tin-can material, precut to size and stacked between boards, will allow drilling the mounting holes without tearing. Tin-can metal is about 0.012 inches thick; bear and soda pop cans are about 0.005 inches thick; household aluminum foil is about 0.001 inches thick. These should be enough thicknesses of shim to test the patience of even the most persistent and diligent. The best way to test and adjust for runout is to mount the pillow blocks using hanger bolts. Hanger bolts are threaded on one end like lag bolts and threaded on the other end like machine bolts. When buying the 3/4D cold rolled steel shafting for the headstock spindle, it would be best to buy an additional 3 foot length of it. When mounted in the pillow blocks in place of the spindle, it will project out over the ways by about 2 feet. This fact multiplies alignment errors by about 3 making it easier to find a runout error. A Compiled by webtoad
dial indicator set against the side of this extended spindle and run along the ways on a clip that keeps the instrument along the inside of the ways will give a measure of horizontal runout. Vertical runout is measured with the dial indicator set against the underside of the extended spindle and run along the ways. Once the headstock spindle is aligned with the ways, it is time to make the tail stock and tool rest:
Compiled by webtoad
Building a Woodturning Lathe by George F. Farrell, Dollmaker Page 3 Having done this, set the tool rest aside in order to mark the position of and then bore the holes for the tailstock ram. This is done by running the tailstock up to meet the extended headstock spindle, marking around it with a pencil and boring a slightly oversized hole ( big enough to give plenty of clearance but too small to let a 3/4X10 NC nut through). Run the extended headstock spindle through this hole and mark and bore a hole in the other face of the tailstock. Now make two pads 3 inches square and 1 inch thick. Bore a 3/4D hole through each pad at its center. This 3/4D hole should have just enough clearance on the 3/4X10 threaded of the tailstock ram to support the ram without binding. On one of the pads mortise in a 3/4X10 NC nut. The mortise must be deep enough that the nut comes flush with the face of the pad. This pad does double duty. It is a keeper for the nut because the nut is captured between the pad and tailstock vertical face nearest the headstock. Both pads should have holes drilled in all four corners that are slightly oversize for the bolts that will be used to mount the pad. This allows for horizontal and vertical movement of the pad for further alignment.
For the tailstock ram I chose a one-foot length of 3/4x10 National Coarse threaded rod. It was taken to a local machine shop to be turned down for a 1-inch length of 1/2D which was then threaded to 1/2x24. This allows the working end to accept a standard Jacobs-type drill chuck. A ball bearing live center is available from AMT which will thread onto this 1/2x24 stub. Three 3/4x10 nuts are also required as shown above. Tailstock alignment is done as follows. It assumes that you have a drill chuck that will thread onto the 1/2X24 stub on the tailstock ram. Crank the ram all the way in and center a very short drill to the center of the headstock spindle by moving the near pad. When good centering is arrived at, firmly bolt the pad in place. Now pull the tailstock back and crank the ram out as far as it will go. Mount a very long drill in the chuck and center it to the center of the headstock spindle by moving the pad at the crank. It too is then firmly bolted in place. The lathe is now ready to go.
Compiled by webtoad
George added the following notes to his original article, to go with the two photographs: There are a few differences between what was written and what was built. The brace at the tailstock end in the photo on page 1 is a 2X2, because I ran out of the right kind of materials. Also shown in the photo is a something not mentioned in the directions. That is a piece of 2X10 running from the foot of one pedestal to the foot of the other on which there are 2 cement blocks. These are not absolutely necessary but provide a little more stability. This machine is easy to disassemble into its component parts and certainly a lot lighter to move than a cast iron commercial unit. The photo on this page shows the business part of the machine. Here again there is a discrepancy between what I built and what I described. The spacer block between the upright faces of the tailstock was detailed as a rectangular block with rectangular tenons on each end. What I built was a 3-1/4 inch diameter cylinder with 2 inch diameter cylindrical tenons on the ends. And here's a brief bio from George: After college I took up the clarinet as an anti-stress therapy, in spite of having been told that a man of my age (at that time) could never learn it -- I was about 30. I also got interested in woodworking, also for stress relief. Some time during the 70's I bought Robinson's "The Amateur Wind Instrument Maker" -- this combined my two passions. In his Bibliography he mentioned articles written by Peter Tomlin in the magazine Woodworker (a British magazine). I attempted to make some of Tomlin's instruments but was frustrated by my lathe, which was very bad. At that time I did not have the money to Compiled by webtoad
"squander" (my wife's term) on non-essentials and so attempted to make my first woodworking lathe so that I could try making a clarinet (I actually did learn to play -more enthusiasm than skill but I did it). Twenty years ago the internet was not available to search for the kinds of information that I needed, so I unfortunately spent a lot of time reinventing all sorts of things. I am now fully retired, and being exceptionally healthy, I can do whatever I want whenever I want -- within limits (mostly as established by my wife).
Compiled by webtoad
