Tuesday, August 23, 2016

Doug Jones’s Taig Lathe


“I'm making progress on the fan hub for my motor, and in the process, I found another use for the pins I made that fit the holes in the soft jaws.  After boring the rough blank and making the necessary cuts on the face of the hub, I clamped it to a piece of 1/2 inch bar that serves as a mandrel to hold the hub.  Turning off the roughly hacksawed circumfrence produced lots of impact loadings on the much smaller diameter mandrel, loads that would easily cause it to slip in the chuck, so I stuffed one of the pins back into the hole in the chuck jaw to serve as a dog.  This worked quite well.
I took the photo just prior to the final clean-up cuts on the exterior of the hub.  Most of the hacksawed perimeter of the hub has been converted to swarf -- and if you look at the tool, it's a 3/16" square shank boring bar, shimmed to fit the tool holder.  It has cutting edges in the right places, so I used it.  The carriage depth stop is really handy when you're cutting right up to the jaws as I am in this case.


When I got my lathe off E-bay last year, I mounted it temporarily on a chunk of scrap wood.  This spring, I started to build a nice base for the lathe.  It's not quite operational yet (I need to do the fine adjustment on the belt alignment and then connect the motor wiring) but it's finished enough to show off in some photos (attached).
The baseboard is made of MDF (a leftover cabinet door cut down to size) with an aluminum plate (the lid of a surplus bit of electronics junk) epoxied to the MDF as a work surface.  I used about 300 pounds of sand bags to clamp the assembly, and then I used a router to carve off the final 1/8 of an inch all around to square up the edges.  Routing aluminum, you get a lot of chip welding unless you scrape beeswax onto the edge you're going to cut.  That completely solves the problem.  After cutting, I painted all the cut edges.
The on-off switch, circuit breaker and reverse switch are built into the pedestal, along with a microswitch that currently powers everything down if the top cover is opened, but will eventually interlock with a belt guard.  The motor is a salvaged GE 1/4 horse capacitor-run motor, so it is easy to reverse, but it takes a fairly large capacitor.  That fills a good chunk of the pedestal and sits in a well routed into the base.


The pedestal is made of scrap 1 inch wide by 2 inch deep extruded architectural aluminum channel, with some smaller chunks of 3/4 by 3/4 inch channel for bracing.
The motor mount is calculated to put 12.5 pounds of weight on the belt, based on a 10 pound motor (I weighed it first, then did the motor mount calculations).  That's based on the Gates recommendations for the tension on their series 3M belts -- they suggest a minimum tension per strand of 5 pounds, and a maximum of 7.5 pounds.  For two strands (a full loop of belt), that's a total tension of 10 to 15 pounds, so I aimed for the middle.


The motor mount allows the motor to flip inward to make a small package for storage, or to hang out of the way in back to run the lathe.  Working out the details of that led me to buy a Gates 3M650 belt.  This is actually shorter than the 5M800 belt that came with the lathe when I bought it from E-bay.  I have no clue how its original owner mounted it.  Perhaps it was a below-the-bench motor mount.


The on-off switch in the base is a pull-on, push-off switch.  Inside the base, you can see that it's just a plain toggle switch, with a knob that pushes and pulls the toggle.  The knob has hard stops in both directions, so you never put stress on the switch handle no matter how hard you bang the knob to turn off the lathe.  There's a grip turned on the aluminum knob for pulling, and the front has a red PVC insert (convention says that pushing a red switch ought to turn things off).  I knew that I wanted a red insert, but how to make it?  The answer turned out to be polymer clay.  I used Sculpy Primo, but I suspect that Fimo or regular Sculpy would work about as well.  I turned a tapered hollow in the front of the knob, and then cut grooves into the taper so that when I pressed in the polymer clay, it would lock in place.  Then I baked the entire knob to turn the clay into hard PVC.  The finish on the front face of the PVC was achieved by pressing the soft clay in place against a sheet of saran wrap against a clean countertop, and then carefully peeling off the saran wrap and blotting up the thin layer of clay that remained on the aluminum edge of the front face.


Trevor Robson’s Glass Lathe

Trevor Robson made a glass lathe with Taig parts.


Peter Zicha’s Latest Taig Mill Mods

“My latest mods to the mill – As it is a lengthy pain in the ass lining up the 4th axis with a opposite support I came up with this . The track system I machines as the pool cue  site were way to expensive for a track extension. All parts are in getting Anodized right now .”

Monty Remon’s 4 Jaw Chuck Grinding, LP Record Cleaner and Taig Lathe Power Cross Feed.


“I happened to mount a length of ground bar in one of my second hand 4J chucks and noticed daylight at the front of one of the jaws! Dismantling cleaning and swapping jaws over did not improve the situation. I scanned the all the normal websites for a method of preloading the jaws that would allow a full length grind. Drilling the jaws and fitting bolts, wire tensioning were some of the methods I came across, but one involved a machined plate ( "Daisy"?) that all the jaws locked onto. A lot of work- time for a cup of tea and an alternative solution.


Not sugar lumps but 1/2" brass blocks.


One jaw at a time, set to protrude into the centre. Each block is set halfway up the angled jaw face and the adjacent jaw is wound in to nip it. When both blocks are in position the selected jaw is clamped down against the blocks ready to grind. A cleaning session after each jaw grind is required.


A diamond wheel in the Flexi grind chuck wound in and out does the job. DTI checks after proved satisfactory.


No lathe mods., this time, just a couple of projects.
Having recently upgrade my Hifi system and acquired a box of LPs from a friend it seemed from a trawl of the internet that it was imperative that I clean my vinyl before proceeding. Methods were analysed and expensive equipment for cleaning the grooves was studied and of course I did what I do best, have a cup of tea and get the pencil and paper out, this resulted in two gadgets that can be used on existing turntables or mounted on a dedicated cleaning rig with a vacuum pump installed.


The first gadget is for cleaning the grooves using the appropriate  cleaning fluid, it comprises piece of paint pad measuring 1"x4" bonded to a piece of acrylic sheet. Adaptors turned out of acetal for alternate mountings fit in either end, the brush has to be reversed because the bristles have a definite lie.
Once the grooves have been scrubbed 3 or 4 times each way they need vacuuming. I managed to come up with a simple device combining the vac., connection and unipivot in one unit, a sort of inverted roller ball applicator that seals instead of leaking.
The vacuum arm is fabricated from 12mm acrylic tube, the end bar has a 4" slot in its lower surface. The self adhesive pads were cut from the spares of a $500 machine.


A 20mm delrin ball is located 6" 'ish from the vacuum bar and this has an 8mm hole drilled through from the bottom.
The 20mm ball sits on a 20mm diam., acetal pedestal, in a 14 mm diam., seating, this provides the seal and permits adequate movement. The seating is drilled down to the output coupling (length of pen case). The ball seating permits arm elevation and axial movement to cope with mat thickness and warped records (I have many of those) and if a cleaning head is attached to the arm and the' turntable direction reversed then the arm can be moved 90 degs., to the other side of of the record, the captive sleeve that locates the ball pivot on top of the pedestal controls the arm position.
The only other component is the scrubbing brush, fabricated from a piece of "U" channel plastic that clips on the arm.


The unit can be mounted in the corners of the plinth using double sided tape, but I can foresee a through mounted arrangement directly coupled to a vac., pumpnot on my new deck though.


The other little job was a pair of Hifi speaker cavity phase plugs, these replace the centre dust cap on the drive unit. More internet research on the theory behind the design and the improved performance claimed sent me to the work shop, I turned some 1" lengths of acetal bar stock and made two hollow plugs with a hole in the base as in the photos.


I pressed a steel washer in the open end that would stick to the speaker pole piece. The whole assy.,  is turned down to a clearance fit inside the speaker coil. Testing was an eye opener (should be ear opener), the performance in the treble range was astonishing, so much do that I am going to make a few more for my other drive units. I recommend this gizmo to all Hifi nuts.


One day last week when I was checking the latest on the airgun side of you blog, a picture of my lathe carriage showing the hand wheel and x-feed dial and lead screw popped up.
No sippin' whiskey or cup of tea  involved this time but I suddenly realised that if the powered drive was turning with the carriage locked on the lathe bed then the hand wheel rotates! Why not couple the hand wheel to the X-feed  dial and have that powered? How come I never made this connection (groan) before?


Experimental bits.
The layout lent itself to some sort of belt pulley arrangement so I dismantled my zero-able dial and turned and fitted a pulley to the X-feed. I turned a new hand-wheel pulley and mounted it on a shaft extension so that a belt would line up. I fabricated a suitable belt and powered up the arrangement. Well it worked but with a lot of slip, so I have opted for positive drive from toothed belt and pulleys.


A selection was ordered and slimmed down to 4mm. For now I have a small fixed toothed pulley screwed to the inside face of the X-feed dial and a large pulley that is free to rotate on the hand-wheel shaft extension. The pulley/hand-wheel coupling is made by a 1/8" pin that slips through the wheel knob into one of the holes drilled in the pulley, this is to be replaced by the pen ratchet system as on my indexing attachment. A belt tensioning fitting clamps on the apron dove tails.


To use, set the tool on X, LOCK the carriage, wind in on Y to engage the hand wheel drive pin, couple the power-feed elastic band, switch on, the hand wheel will now drive the X-feed via the belt. To stop, switch off, decouple power feed band and hand wheel, then the carriage clamp, do things in the wrong order and all the good work gets ruined as the tool keeps advancing towards the chuck. You can of course make cuts from the centre by crossing the power-feed elastic band.
The cut is very fine at 2:1, I am going to try 4:1 next week, but if I find myself with a hand full of gears, then I might try 10:1. Normal drive from the gearbox will feed the X-slide in, reverse the elastic band and of course the power feed reverses and that drives the X-slide back out.”

Wednesday, August 17, 2016

Peter Zicha’s ER32 Lathe Headstock Conversion

“Some eye candy for you I did a ER32 conversion”


Bob Eckstein’s Toolpost

“I wanted to send a few pictures of a toolpost I made which offsets the tool to the right edge of the carriage to compensate for the location of the T-slots. “


Wayne Furrie’s Model Ordinance

Am attaching a few shots of my latest projects.
The only large tools I have are a drill press and a band saw. I did about 65% of the work on the Taig lathe, about 30% on a small MicroMark mill that was discontinued and 5% on my 45 year old Unimat. The first picture was my last project, finished 2 weeks ago after 4 months. I have MS and do not have use of my left leg and only the thumb and index finger on my left hand so work is slow. However life is good and I get to spend a lot of time in my miniature shop.