Spring and Springs in Alaska

So we are a few days away from the vernal equinox, AKA spring. Strangely, I have been working on some projects that involve springs. And we have a surprise ending.

First we have the spiffy new handle on the dividing head.

This is a spring loaded plunger that pushes the prong into the dividing head and holds it steady. The plunger is pulled back to go to the next hole on the plate. It took quite a lot of messing around to get it right. I kept getting the spring backwards! I had to change springs several times; my supply of springs is limited. So that is one spring.

Next idea I had was a vertically adjustable Dremel holder. My first try looked like this:

The Dremel is held in the chainsaw attachment, already described elsewhere. This worked but it was very sloppy, so I spring-loaded the screws.

It works a lot better that way. The Dremel tends to lever it because this stuff is all Aluminum form Lowe's. A casting would be much better but I'm not set up for that. Bit too much slop. Have to think about that. As it is it is a hand-held Dremel router.

Well, that's three springs. While I was at it I clamped the thing to my homemade pantograph.

This worked surprisingly well. I realize now I have a pantograph with adjustable ratios, depending on where I clamp it. Bonus. It is nice to have a vertical adjustment. I hand-made a set of templates, seen at left. I am holding everything down with two-faced tape. Not ideal, but it works. I m encouraged. Springs are  wonderful.

Finally, "spring" also means a season of the year. The Vernal Equinox is March 21 or 22 depending on a lot of things. This is an astronomical datum. Alaska has its own ideas:

About 10 cm or 4" snow yesterday. Biggest snow of the year. Of course we were (still are) in the El Nino hotspot. No snow to speak of, until yesterday. A day late and a dollar short. No skiing. But it was nice to have the snow, and a fire welcome. Observe Miss Mocha curled up on her tuffet at the right of the picture. Right out of Currier and Ives.

And today the temperature went way up, +6C or so I do not expect winter wonderland to last very long. Spring, one way or another, is here.

Life is a grind

Well, the bandsaw vise is working. I still need some blade adjustments to bet the thing to cut perfectly square. But this is for another day.  Today's post is about a grinder. Specifically I have a 4mm carbide end mill to deal with, for my Proxxon mill. The largest size collet I have for that mill is 3.2 mm which is 1/8" in RGU. So I propose to cut the shank down to 3mm to fit my next collet. I tried very hard to cut it down to 3.2 mm and failed. I cut a taper into it. Slipped in the collet.

Now you might say "you have a lathe, dummy! Just turn the shank down! Piece of cake!" Alas, the end mill is carbide. If I tried to cut it with even a carbide tool, I would ruin the shank, certainly the tool, and maybe even the lathe. Not an option!

The only way to do this with my equipment is with a toolpost grinder. But nobody makes one for the Taig. So I improvised one. I started with some 1/4" - 6.3 mm steel square bar from Lowe's. Nice nickel finish on it, too. The Taig toolpost takes this size. Ten second's worth of time with Handy Bandy cut it off. Then I milled the ends square.

 The basis for this gadget is the Dremel chainsaw sharpener. This gadget is lousy for chainsaw sharpening. But the Dremel screws into it. It is amazingly a metric thread, M19x2, which I cannot cut. It's very large and I have no such tap. So I bolted the sharpener bracket on my piece of bar. I put a dial indicator on the Dremel and on the chuck. Chuck ran out (was off center) .06 mm and the Dremel only .03. I was impressed by the Dremel. It took a lot of fiddling to get the holes in the bracket right in line.

In the end, it took a long time. The grinder does not like big cuts. Furthermore if the grinder axis is off-center you will grind a taper on the shaft. So you have to measure the shaft at root, middle, and end and adjust the toolpost accordingly. There is no way I can get a dial indictor into this setup, I sure tried enough, but no room. I practiced on a broken drill bit until I got the angles right. I wore out 3 grinding wheels in the process. Carbide is very hard. Also things tend to move. So it's grind, measure, reset, go again. Took, essentially, a full day.

But it worked. The new shaft fits, just, the 3mm collet, so I have a 4mm endmill at my disposal on Cecil B. de Mille.

Divide and conquer

OK, I confess. What I am really trying to do is build a clock from the ground up. As with anything else, building a clock is no mean feat. It also rapidly becomes an obsession. So I am obsessed. I do not think this is grounds for a lawsuit. Anyway, the big thing about a clock is gear-cutting. There are several requirements for this. You need two perpendicular axes. On one of them a cutter is revolved, preferably by power. On the other, the would-be gear is held. On this latter you must have an indexer of some kind, i.e. a gizmo that will turn the (proto)gear by a precise amount. In a previous post I chronicled the making of the latter gizmo, the dividing plate. The gizmo allows me to divide a circle into 60 parts. By skipping holes I could also do 30 parts. In fact, any of the factors of 60, and now you know why they made you study factoring in school. Clock gears go from 120 or so teeth all the way down to 6. A clock, you see, is just a big gearbox. But you cannot shift the gears, unlike an automobile.

So in our last episode I had made the dividing plate. Had I about $300 to spare I could have bought a spin indexer to do the same job. But no. We did a dividing plate by hand (previous post).  So I turned up an arbor from a piece of scrap steel. An arbor in machinistspeak is simply an axle. There it is on the four-jaw chuck, a pain to set up but it runs really really true.  This held my victim, a failure from the dividing plate episode. Much too small to be a dividing plate. Next, I  arranged my Dremel (knock-off) device on to the vertical slide on the lathe. Major project. Too many things to adjust. I have blogged on this contraption before, so see previous posts.

This needs some overhauling. Once the DSO (Dremel Shaped Object is bolted in I cannot adjust it except with the vertical slide, and it has extremely limited travel, 50 mm or so. Not enough. This is why most people do this on a mill. But a (small) mill is about $500 plus shipping, almost as much as the mill itself. And again, I have no space for a mill. But lashup though it may be, I have the two required perpendicular axes. And it cost much less than the mill, i.e. zero.

I have no cutter yet. This is work in progress. In its stead (thak you Richard, for pointing out my error. I said "staid" before),  I put an abrasive cut-off wheel on the dremel. I also arranged a spring-loaded detent for the divider plate. So I am really not cutting gears yet. But the whole two-axis lashup arrangement is working! I cut some remarkably gear-like slots in the sacrificial victim! I was a bit worried about wobble, but none was perceptible.

The classical material for clock gears is brass, sometimes steel. But brass is like Unobtainium in Alaska. Small pieces, at a hobby store, maybe. Big pieces, no. So I am doing all this in plastic. Plastic is everywhere. On dismantling an expired (battery) clock I found plastic gears everywhere. So if they can do it so can I. My  plastic is found. I think it is a piece of refrigerator. So I can experiment all day long. Just as well. Winter is here. Lots of time to experiment.

Dremel attachment, the sequel

In our last episode we saw how I went about converting a chainsaw sharpening attachment into a vertical spindle for the Taig. But you will remember that the thing fouled the DSO (Dremel Shaped Object)/ What we needed were some spacers. Some careful measurement convinced me that 6.5 mm would be enough. I found a nice piece of scrap rod a little over 13mm long. Great. Now we have to center-drill it so it will act as a spacer. Of course it will need longer screws. Fortunately I save every screw that comes across my path.  But the real problem is center-drilling the spacers. Now the best way to do this is on the Taig, but Mr Taig was busy with other jobs. Furthermore the self-centering three-jaw chuck's jaws are shot. So I did it on the drill press. I made a fixture (a device to hold things down while you work on them). A simple wood block. Drill a hole through it, tight fit on the round piece, and slit the hole with a saw.

  

Clamp it in a vise. The slit makes the wood close around the steel rod and holds it fast.  Then you can e.g. drill it, which I did, all the way through. Fortunalely the hole was started by a previous project so I didn't have to center it. Then I sawed the spacer in half with a hacksaw, a marvellous tool. Use the same block to do the sawing. Guides the saw.  At the end of the day I had to roughly equal pieces. Trim up with a file, still on the block. At the end of the day I had two spacers.For the record the spacers are steel 6.3 mm (1/4") hardware store stuff.

You can just see the spacers. Now I have a spindle at right angles to the lathe axis, marvellous.

What I really want to do is cut clock gears. So for this I need a dividing plate and this is my next project. We will see how it goes.  I will also need gear cutters. I will have to make these. This is Alaska. We do have Home depot, and Lowe's, but we do not have machinist's supply houses. Got to order from afar, and pay shipping costs too. So I will make my own cutters. They must fit a Dremel shaft. I intend to start out with plastic gears.  Dremel will certainly cut plastic! But your high-precision  quartz clock uses plastic (probably lexan) gears so maybe I can cut one too.

I have also, quite accidentally, got the beginning of an ornamental lathe, but that's a separate post. Still need a dividing plate. Stay tuned.

A vertical spindle for the Taig lathe

Ah, what to post. I have been very busy, but as usual at this time of year I can't tell you about it. So let's look at the Dremel atachment for the Taig lathe. Nice and neutral, nobody's getting one of these for Christmas.

Milling on my Taig lathe is a comprehensive nuisance.  I do have the Taig vertical milling attachment.  But the cross-feed screw has a very limited travel. So I have been toying for a long time with adding a vertical milling spindle. A lot of things came together this afternoon. An article in Popular Mechanics, a reprint. A lot of watching videos on watchmaking, a fascinating subject. Need a magnifying glass!  All the reading I have done on ornamental lathes. Lots of stuff.

So a long time ago I bought an attachment for the Dremel. I don't own such a thing but I have a knock-off, made in Asia. Good for them. The attachment purported to let you sharpen chainsaws, a subject of great interest to me. Dull chainsaws are dangerous. Even sharp ones are risky, but less so. This attachment , as far as I am concerned, was a waste of money. It consisted of a bracket and a plastic gizmo that screws on to the nose of your DSO (Dremel-Shaped Object). You held the bracket so's it lined up with the bar, then used rotary grinders to sharpen the teeth. But hand-held. Waste of time. You cannot hand-hold these things worth spit. I have discoursed before on this subject. Get a proper jig, or buy a chain saw grinder. I did both. But the Dremel nose and the bracket I kept.

Today I thought, "hey, if attached this bracket to a piece of 1/4" (6mm) bar with some holes drilled into it, I could mount the whole thing on the Taig milling attachment! So after some work this afternoon, we are here.

Behold the Taig lathe with vertical milling attachment. Behold also the 6mm bar. It sticks up and fouls the DSO. But really the bracket is inadequate. The DSO won't fit.  A matter of about 3mm. So I will have to make some spacers. This will allow the DSO to screw into the plastic fitting at the bottom. This may turn into a major project. But if I can do it, then I have a vertical spindle for the Taig.  Maybe I could even cut gears, at least in Brass or  Aluminum or plastic.  Then I could make a clock. Of course I would need dividing  plates. Next topic, I suppose.