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Sunday, May 22, 2016

How to buy a vintage wood lathe

Itching for a new pastime and think woodturning might be your thing but don't want to spend a lot of money on an unproven hobby. So you troll Craigslist but lathes in your price range were hot stuff during the Eisenhower administration. Then you spy this little beauty with some scratches and patina and it calls to you. For the price of date night you could be a woodturner; but should you buy it? What are you getting in to? Let me help.

1920's-30's Goodell Pratt, not recommended for a first lathe.

Let's narrow this down quickly -- my recommendation is limit your search to Delta or Sears Craftsman lathes that were manufactured after 1950. Why? Over time certain features became more desirable until they are now somewhat standardized making it easier to reuse chucks, centers, tooling etc. as you upgrade lathes. But prior to about 1950, oddball choices for thread sizes or tapers were more common and some of those choices fell by the wayside meaning they are largely unused (or unusable) today. Ball bearings also became more common after 1950. There are good choices besides Delta or Craftsman but those two are the most common and both standardized early. Post 1950 should keep you away from oddball stuff; late 50's is even better. In fact, the newer the better but this article is focused on lathes from 1950-1980.

What is this talk of standardization? Modern wood lathes have two ways to attach accessories, 1) threaded spindles and 2) machine tapers. The spindle is the shaft to which your work attaches on one end and power attaches on the other end. The case that holds the spindle is called the headstock. Modern lathes have threading on the outside of the spindle so that faceplates or scroll chucks like the Nova G3 can thread on. The spindle is hollow, and the working end will have a machine taper into which accessories like drive centers, drill chucks or drill bits can fit. But lathes didn't always have both threads and tapers, and it's possible for the headstock to have a taper but not the tailstock. If the lathe you are considering doesn't have both a threaded spindle on the headstock and a machine taper on head and tailstock, I would pass on it.

This lathe has a spindle threaded on both ends so you can attach accessories to the outboard side. The silver pin is for indexing.

Lathe with a threaded spindle and Morse taper

Threaded spindles come in several sizes, the three most common in order are 1"-8 tpi (1" spindle with 8 threads per inch), 3/4"-16 tpi, and 1-1/4"-8 tpi. Lathes eventually standardized on Morse taper inside the spindle but very old lathes may have other tapers. Vintage Delta lathes are almost always 1-8 thread and #2 Morse taper in headstock and tailstock. Vintage Craftsman lathes are almost always 3/4-16 threads and #1 Morse taper in headstock and tailstock. There are exceptions, but they are rare.

What about the motor? Most old lathes will come with a 110V motor between 1/4 - 1 HP and will have 4 pulleys on the headstock giving you 4 possible speeds. These are enough for basic turning but eventually you can add variable speed to get much more utility from your lathe.

A "4 speed" lathe, note the step pulley with 4 grooves. Speeds are changed by moving the v-belt. 
Swing is the distance between the center of the spindle and the bed of the lathe, doubled. So if that distance is 4.5", it is a 9" swing lathe. The greater the swing the larger the items you can turn. Craftsman sold bajillions of 9x30 lathes, 9" swing and 30" max capacity between centers. If you want to make table legs, these 9x30 lathes are ideal. They are also useful for other spindle work like tool handles, honey dippers, spoons, cups, and small bowls. Delta lathes are more commonly 12" swing and allow you a little more room for bowls and platters. Delta also sold gap bed lathes, like this 46-111, that have more swing near the headstock.

1958 Craftsman 9x30 bench lathe modified with variable speed
1970's Rockwell Delta 46-111 gap bed lathe



So what to buy? I recommend buying a Delta or Craftsman lathe made in the 50's or later that has a threaded headstock spindle (sizes 1-8 or 3/4-16) and Morse taper in both head and tail stock. Look for a manual on vintagemachinery.org. Sometimes the manual will not tell you the tapers or thread sizes but it will be good information regardless. If the taper size isn't listed anywhere, they are easy to measure. A #1MT (Morse taper) is a little less than 1/2" across on the spindle. A #2MT is a tad over 11/16" diameter on the spindle. Before buying, have the lathe running and listen for any screeching, scratching, or grinding that may indicate bearings need replacement. Make sure the tailstock turns in and out freely and that the centers are removable from both head and tailstock. With centers in place, slide the tailstock to the headstock and check that the center points touch. A tiny amount of misalignment is not a deal killer but a big misalignment may indicate a Frankenlathe (a lathe assembled from parts of other lathes), mismatched parts, or other problems.

Tool Caddies for the Tablesaw and Lathe

Long time in coming: simple tool caddies to collect my most commonly used tools in a designated place. Construction is super simple, butt joints, glue, and brad nails. Bottom of both is 1/8" oak/poplar ply. The TS caddy bottom fits into a dado. The lathe caddy bottom fits into a rabbet and is tacked with glue and 5/8" brads. Why are they different? Because I wanted to see if one way would be more durable than the other.

Caddy holds a Nova G3, Nova Midi & tommy bars, Delta centers, Nova centers, PSI centers, Bondhus 4mm hex wrench, knockout bar, and extra jaws.

I have two lathes so a caddy is more convenient than a fixed location like a drawer, a cabinet, or on the wall. Now I can bring my chucks and centers to whichever lathe I'm using in one easy to carry box. I may add holders that will attach to the backside of the caddy for a few lathe chisels.


The TS caddy was badly needed. These are tools I use constantly, like tape measures, a marking knife, pencils, a 6" combo square, pocket calipers, center punch, scribe, Wixey, 12" rule and 6" rule. In the past these tools wanted to clutter my tablesaw and end up on the fence. Since my TS is in the center of the shop, this caddy is within a step or two of any other tool. 

  

The Tools

Why do I have 3 tape measures? Good question, guess I have tape measure fetish. The yellow Stanley is both inch and metric. Once upon a time I planned to convert entirely to metric but it isn't very practical as American woodworking is still inch centric. The green tape is my newest and is a center finding tape measure, regular inches on top and half scale inches on bottom, I like it. The black and chrome center tape is a Lufkin engineer scale (tenths of inches). Some other tools of note are a BluePoint 12" combo square, a Lufkin 6" combo square, a Bluepoint automatic center punch, a Stanley scribe, a General pocket caliper, an iGaging digital caliper, a 6" Craftsman rule, a 12" rule (can't remember the brand).

Friday, April 29, 2016

Folded Cube Table / Stool / Bench


Around 1pm Thursday my oldest daughter tells me she has a project due 9am Friday for her design class. Okay, sure I'm happy to help. Turns out it is THE project, which they had the entire semester to do and is 1/3 their grade. I leave the room and stew for a few minutes because I'm very angry, get over it, fetch my daughter and we go to work. We take care of the paperwork portion, then the prototype requirement, and by 4pm-ish we are in the shop starting work on the actual build. We discuss lots of options but realistically we only have time for plywood. The idea is a cube table/bench/stool made of 8 triangles (legs) and 1 square (the top). Everything is mitered. It was tempting to say, 'It will be butt joints, glued and brad nailed,' and we would have been done in half the time but this is a design project, not a: make Dad's life easy project.

We cut squares, then bisected the squares to make 45/45/90 triangles for the legs. I hot glued plywood scraps to the sled for registering the squares. The hypotenuse doesn't need to be precise, just cleanly cut. To prevent splintering, we set the blade about 1/8" above the sled and ran the squares backward over it. After scoring all the pieces, we raised the blade and cut through.


Miters were cut by burying the blade into a sacrificial fence and sliding the edge to be mitered along the fence. The benefit is you can cut your pieces to finished size before mitering. I recommend running each piece through twice, first with the miter gauge to remove some waste then a second time against the fence to cut your final miter. That reduces the cut off and prevents it being trapped under the blade.


What luck. Two nasty storms, with hail, came through a few hours apart and both knocked out the power. At one point we busted out my Goodell miter saw from the early 1900's and using a battery powered light, kept working. Here she is making a test cut to make sure we are at exactly 45°, the old miter box was dead nuts.



Here are pictures of the glue up, which was tricky because everything is mitered and wanted to slip around. We considered biscuits or splines but with all the glue surfaces they weren't necessary for strength and we were against a deadline.


There wasn't time for a finish but that's how it goes when you procrastinate. We worked until around 2:00 am -ish; 4am now and I'm still wired from too many cups of coffee. I'll get more pictures when she brings it home again. [update; finished picture at top] Considering it was last minute, I'm proud of the result and proud of her work ethic today. (Not proud of her putting it off until today, we are going to have a talk about that.) I don't think it would have been much better if we had more time. The miters came together extremely well considering how many there are. Four of the triangles are mitered on three sides. The top is mitered on four sides. The remaining four triangles are mitered on two sides. And lord help me, she wants to build another one from solid wood.

Friday, April 8, 2016

Upgraded Dust Collector Filter

Upgraded my Delta AP400 dust collector to a Delta 1 micron bag. The original was 30 micron. The new bag is much thicker, so much that it stands up on it's own. The 30 micron bag snapped up when inflated and was as taught as a balloon. Despite being thicker, the new one is pretty much the same with the collector running or off so I guess that means the new bag has less resistance; a lot less resistance.

 

Thursday, March 17, 2016

Will Home Made Spindle Washers Cause Run Out?

If you've been woodturning for awhile and use scroll chucks then you've probably had a chuck that seized on the threads and is difficult to remove. Grease or oil will not prevent stuck chuck but there are anti-seize compounds based on copper or graphite that can help. Another way is a plastic washer, called a spindle washer, that prevents the chuck from getting super tight. These washers can be purchased commercially or made in the shop.

I tend to pack rat jars and containers for various uses. One day a plastic jar lid caught my eye and I decided to make a spindle washer. After some experimentation I found that larger, thicker, lids like those from peanut butter, peanuts, mayonnaise, etc. made better washers. Pass on any lids with writing or other decoration. My method is simple, drill a 1" hole in the center of the lid (use whatever size matches your spindle), mount it on the lathe held in place with a faceplate or chuck and use a parting tool to remove the outside rim. It doesn't have to be perfect. You can make them any size you want. Most of the time I can remove a chuck using only my hand, occasionally after a long turning session I need a little leverage but the washer still prevents the chuck from seizing up tight.




A common concern is that plastic lids are not made with any precision and will cause excessive run-out which expresses itself as vibration. I decided to test a homemade spindle washer and find out how much runout it introduced.

First I measured a washer using an iGaging digital caliper accurate to 0.001" and with a resolution of 0.0005". Now I don't remember from what kind of lid this washer was made, I've had it for more than a year. But measuring various points around the washer, the deviation was never more than 0.0005" so the total variation is withing 0.001" which I found quite impressive.


Next I chucked the largest Forstner bit I own into my Nova G3 and tested runout using a dial indicator against the shank. The results were surprising. The very first test was after turning a handle for a beater chisel and I did not clean the threads beforehand, consequently it had the greatest runout of any test. Really, that test should be thrown out but I included it. The three remaining tests were done with clean threads.



The runout will be magnified as you move away from the center so if my test piece were 2" in diameter, the measured runout would be approximately doubled. Testing shows the washers introduce some runout but less than what the chuck itself introduces. So claims they introduce wobble are valid, however; the chuck introduces even more wobble so how much is acceptable to you. At the end of the day these are wood lathes and I'm not attempting to make precision parts so for me the washer is an acceptable trade off.

Monday, February 22, 2016

Restoring an old Superior buffer/grinder head part1

No idea of the age but it's in good condition. Marked Superior, Made in USA. If anyone has information about these I'd love to know.

 



I ground down the casting seams and defects, filed, wire brushed, then sanded before shooting a primer coat of machine gray. My plan is a two tone paint job in turquoise and off white.


Friday, December 4, 2015

Experiments with acoustic horns as mobile device amplifiers

Before jumping in I have to make it clear that horns are not amplifiers. If I don't, I'll get a bunch of messages enlightening me. But horns do make sound louder and when paired with cell phones are commonly called "passive amps", and even though that is a misnomer what else should we call them? "Phone horn" doesn't have a nice ring. "Impedance matching device for mobile audio electronics" sounds like the title of a patent application. What's the big deal and what's the difference between an amplifier and a horn? An amplifier adds energy to the system, it makes the speaker vibrate harder, moving more air, and increases sound output. Horns are different, they make speakers louder by making transfer from the relatively dense speaker to the relatively rare atmosphere more efficient. Sound travels easier through dense substances like water and less easy through gasses like air. The horn helps the sound energy transfer from one to the other and the result is louder music. If you'd like to hear a smart person explain it, click HERE.



My first ever "horn" was a piece of PVC pipe with a slot in the middle for my phone and the ends cut at an angle toward the listener. It sat on two feet to prevent it from rolling around. It worked "okay". I don't own it anymore and can't find a picture but you may have seen similar speaker stands, maybe with bamboo.

My second (and real) horn which I'm calling 1.0 is based on a design by Dustin Penner. What Dustin brought to the table is a easy to make flat horn from 3 pieces of wood. I made it smaller and changed the curves slightly but overall the result is impressive.


Horn 1.0

Horn 2.0 is based on a folded horn design by MXX on Instructables. This style of horn is usually seen on bass heavy concert speakers and definitely has a warmer but slightly muddier, sound. The downside is this speaker is much more difficult to build than Penner's. 


Horn 2.0

Horn 3.0 is a folded version of v. 1.0. (Probably should be called 1.5) If you are unfamiliar with folded horns, just imagine a trumpet with all it's turns. A horn doesn't need to be straight. 3.0 is much louder than the two previous versions. In my test, it was 12-14 decibels louder than the previous horn designs but the sound is also a bit harsh. To me it sounds like the small transistor radios that were popular in the 60's and 70's. 






Horn 3.0