Small cast-iron shaper from Harbor Freight

[Joe Gwinn]

Yeah- but maybe you could just put in a different spacer or two each time you run a batch. Intermittent oscillation.

The groove may form too fast, fast enough to interfere with even one use. I'd try this with an electric drill first.

[R.G.]

The groove may form too fast, fast enough to interfere with even one use. I'd try this with an electric drill first.

Yep. Could be. Might happen. Maybe. Only one way to tell. My first test would be to chuck it up in my drill press first, of course.

For some reason this didn't hit me until this morning. Take a look at :
Rotary-Shaper Drill Attachment

Rotary -Shaper Follower Kit

Something had been bothering me for a while. I grew up butchering wood with a Stanley SurForm rasp of my father's, and it's still one of my favorite tools. The thing is well suited to shaping and forming wood and similar materials as it planes off shavings, not dust. The cylindrical tool with the follower wheel looks like it might be exactly what's needed for shaping a stack of vulcanized fibre blanks; these things can't be much worse than end-grain walnut, which I have butchered at with a Stanley.

They're cheaper than a robo-sander, too. Don't know about accuracy, but the replaceable blades bode well for a sturdier tool if the cheapo from microplanes doesn't give the accuracy.

Looks like a target-rich environment. Most pickup makers have a drill press, so the Lil'Shaver cylinder and follower wheel would chuck right up. After that, it's templates and handles. The cylinder is taller, up to a bit over 3", so you'd have to see how high you wanted to stack blanks.

Even for a custom purpose tool, you could put $20 into the cylinder and $40 into the HF bench drillpress and have a flatwork blanking solution.

The only open question there is the degree to which you need to finish sand. If the finishing is trivial, it could be block-o-wood time, or you might need a sanding drum with a fine grit. Having a blank stack cut to size and only removing tool roughness would cut abrasive wear a lot.

[David Schwab]

Here's the handle I came up with.

That's a good idea. I've seen handles kind of like this for handling small parts on a router table. There are some commercial ones made, but not especially for pickups.

This is one of them MLCS Small Parts Holder

MLCS has a lot of cool router table stuff.

I make pickguards all the time using a laminate trimmer upside-down in a vice, but those are a lot larger than a pickup.

I used to have a jig to make truss rod covers with a router/trimmer. This would work for flatwork as well. Basically you take a piece of plywood or something similar like MDF or even plastic, larger than the part you want to make, and preferably something you can either clamp to a work bench, or otherwise affix in one spot. Let's say it's 12" square. In the middle of that attach your pattern for the flatwork. This would also be made from plywood or MDF or whatever, and it would be in the exact shape of the flatwork, and something like 1/2" thick. You want it thicker than the height of the bearing on a the pattern bit.

In the case of the truss rod covers, the pattern had two holes in the location they would be in on the cover, and I used two pickguard screws to attach the plastic or wood blank to the pattern. You can also screw down your forbon, or use double stick tape. (not the foam tape... the kind woodworkers use).

So take a piece of forbon roughly cut to shape and larger than the finished piece, and attach it on top of the pattern. Now take your laminate trimmer with a pattern bit that has the bearing on the end of the bit, and rout your flatwork to the desired shape.

Some notes. I had made a larger clear acrylic base for the trimmer and had riser blocks attached to keep the trimmer level over the surface. This is not needed, but it does prevent you from tipping the trim router and possibly ruing your cut and or pattern.

This method keeps the bit away from your fingers, especially with the larger base. You could possibly stack up your forbon and cut several at one time. I would try and screw them down for this. An alternative for screwing them down is to make a top pattern the same shape as the bottom pattern, that would have counter sunk holes for screws. If you really want to get fancy, the bottom pattern half could have threaded brass inserts for use with machine screws. This would sandwich the forbon together between the patterns and the bit would follow either the bottom or top pattern depending on which type of pattern bit you use. You would just have to make sure the top and bottom register correctly (i.e. line up).

Also use a HSS spiral bit that pushes the work down toward the table. You will get a better cut. You can get solid carbide spiral bits too, but I think HSS might work better with forbon? I've never routed the stuff myself.

I can draw up an illustration if anyone's having a hard time visualizing it, but just think of an upside-down router table. This way you hold the router, and not the small parts.

[Joe Gwinn]

For some reason this didn't hit me until this morning. Take a look at :
Rotary-Shaper Drill Attachment

Rotary -Shaper Follower Kit

Something had been bothering me for a while. I grew up butchering wood with a Stanley SurForm rasp of my father's, and it's still one of my favorite tools. The thing is well suited to shaping and forming wood and similar materials as it planes off shavings, not dust. The cylindrical tool with the follower wheel looks like it might be exactly what's needed for shaping a stack of vulcanized fibre blanks; these things can't be much worse than end-grain walnut, which I have butchered at with a Stanley.

They're cheaper than a robo-sander, too. Don't know about accuracy, but the replaceable blades bode well for a sturdier tool if the cheapo from microplanes doesn't give the accuracy.

Microplane stuff works pretty well on wood. Never tried it on forbon, but it's certainly worth a try.

It cuts flesh pretty well, much better than a sanding drum, so some kind of jig is needed.

The only open question there is the degree to which you need to finish sand. If the finishing is trivial, it could be block-o-wood time, or you might need a sanding drum with a fine grit. Having a blank stack cut to size and only removing tool roughness would cut abrasive wear a lot.

The real reason to sand is to smooth the edges, so the #43 wire doesn't snag. This cannot be done in the jig with a hard drum so well. A sanding sponge might be the better approach.

[R.G.]

The real reason to sand is to smooth the edges, so the #43 wire doesn't snag. This cannot be done in the jig with a hard drum so well. A sanding sponge might be the better approach.

Yeah... hmm... maybe a few whacks on a sanding sponge all around before using the flatwork would not only smooth edges but apply a bit of chamfer to them in a very smooth way as well.

Good idea. Like flap-wheel sanding the inside of holes in aircraft skin so the rivets can spread into the chamfers on each side.

[Joe Gwinn]

Maybe. The thought occurs to me that one could rewire a series AC/DC to shunt AC/DC, then PWM the now lower-voltage motor for both speed and torque. It's probably worth it.

You could do even better by disconnecting the field coil, running that at a fixed current and then varying the current in the rotor for speed control. It takes making a DC supply up, but you get a DC motor then; the torque is max at stall and goes down with speed. More properly, its torque is linear with current, so you can modulate either the field or rotor current to change speed/torque. Electrons are easy.

The problem is that to run at 1/5 the design speed with anything like full torque will require some kind of closed-loop speed control. I initially went this way when designing a research winder for making pickups, but soon decided that it was far simpler to use a toothed belt and two pulleys to get a 4:1 or 5:1 speed reduction. Then the motor was in its design range, as was the bobbin, and simple voltage control of the power supply driving the motor sufficed.

That said, I also mounted an Agilent 3-channel optical encoder on the bobbin shaft, giving me pretty detailed information on bobbin motion and position. These optical encoders are pretty fussy mechanically, but even so it wasn't that hard. The outputs drive the turns counter, and a shaft-angle triggered xenon strobe.

[R.G.]

Creeping featurism is very difficult to avoid.

When I'm making some techno-widget for myself, I have to have a stern discussion with myself about objectives - minimal/maximal function, min/max cost, specific feature set, and so on. But it's difficult to leave off something like an encoder and flashing strobe... 8-)

I have a PIC counter design going too, not that PIC counters are earth shaking. PIC, 16x2 LCD display, 4x4 phone keyboard. I think I can make it not only do counting but either stop-on-count or at least near-end-of-count warning, count up/down, the usual trivia.

[Joe Gwinn]

That said, I also mounted an Agilent 3-channel optical encoder on the bobbin shaft, giving me pretty detailed information on bobbin motion and position. These optical encoders are pretty fussy mechanically, but even so it wasn't that hard. The outputs drive the turns counter, and a shaft-angle triggered xenon strobe.

Creeping featurism is very difficult to avoid.

When I'm making some techno-widget for myself, I have to have a stern discussion with myself about objectives - minimal/maximal function, min/max cost, specific feature set, and so on. But it's difficult to leave off something like an encoder and flashing strobe... 8-)

My excuse is that it's all for research.

The only problem with the strobe is that commutator noise from the motor (PM DC) gets into the electronics, and causes visible jumps and tics. Will need to add some shielding and bypassing, although the strobe is usable as is.

The larger issue will be if the strobe is useful while winding. The rationale is that having the motion stopped will allow easier diagnosis of winding problems. The pre-story was that I realized that the loose turns I was getting were due to momentary hang-ups of wire on bobbin edge, because I was winding slow enough to see it happen, far too slow to be practical in real use.

[Joe Gwinn]

Grizzly has a similar thing for $89, but in green: http://www.grizzly.com/products/G8693. This is probably why HF dropped the price in the catalog. The material is not specified in the Grizzly item.

I called Harbor Freight. The $89 is correct (if you use the full catalog number), and the weight is 43 pounds, almost the same as the Grizzly unit.

[R.G.]

That's a good idea. I've seen handles kind of like this for handling small parts on a router table. There are some commercial ones made, but not especially for pickups. This is one of them MLCS Small Parts Holder

I like that. How about combining the overhead handle like I drew with the two-handed setup from MLCS? A strip of wood, maybe 10" long, with the forbon stack and template screwed to the center underneath. The template for the stack is furthest from the handle, and engages the bearing on the router bit which sticks up from the table. With two hand-holds, you can do a good job of keeping the template flat and keeping good control. And there's lots of space for dust to get away, so a vacuum inlet near the blade should get most of it.

I make pickguards all the time using a laminate trimmer upside-down in a vice, but those are a lot larger than a pickup.

I used to have a jig to make truss rod covers with a router/trimmer...
I can draw up an illustration if anyone's having a hard time visualizing it, but just think of an upside-down router table. This way you hold the router, and not the small parts.

That's a clear enough description.

I think that the router-table-plus-handle and your jigging approach are just about equivalent; the only difference seems to be whether the router is on top or on bottom. both ought to work.

I think I'm going to try out the microplane drums. Those look really promising as well.

[David Schwab]

I think that the router-table-plus-handle and your jigging approach are just about equivalent; the only difference seems to be whether the router is on top or on bottom. both ought to work.

You can also take the same idea with the router on the bottom, and the template on the top. Just take the large router base idea, and make it a large piece of acrylic, with the pattern in the middle, and with rise blocks on the edges. But a couple of handles on top, and you have a holder like your idea, that you move over the router table. The large acrylic sheet lets you see what's going on and keeps your fingers safe. And also it wont tip over while routing.

[Joe Gwinn]

You can also take the same idea with the router on the bottom, and the template on the top. Just take the large router base idea, and make it a large piece of acrylic, with the pattern in the middle, and with rise blocks on the edges. But a couple of handles on top, and you have a holder like your idea, that you move over the router table. The large acrylic sheet lets you see what's going on and keeps your fingers safe. And also it won't tip over while routing.

The only issue with a router is that it's big and heavy. With a shaper plus jig, there is far less to heave around. Aside from that, both approaches are used, although I would think that the shaper should be less tiring to use and therefore more accurate in practice. But in both cases the jig is key.

[David Schwab]

I would think that the shaper should be less tiring to use and therefore more accurate in practice. But in both cases the jig is key.

It is less tiring. The only thing about router tables/shapers is watching the direction of feed, and getting the cut started.

When using them in wood working, you have a starter pin that you pivot the work on. You probably can't use that with a pattern, so you just have to be careful starting your cut so it doesn't grab.

Laminate trimmers aren't heavy but heavy makes for a cleaner cut.