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Sunday, July 28, 2013

A Pin Vise Improvement


I brought this over from the garage.



It's quite a nice pin vise, but it has a flaw -- the handle isn't pinned to the chuck's spindle, so the handle will turn on the spindle if it's forced enough. I often use a pin vise as a tap wrench, so that won't do.

Here it is taken apart.


I think I see what happened when my dad was making this.

He'd meant to pin the handle, and began drilling through, but the hardness of the spindle defeated him. (I tried a file on that steel, and the file wouldn't touch it.) He then tried for a shallow, partial pinning, but didn't quite get what he was after.

There's an existing 3/32" hole through the spindle. If I can get that short pin out of the handle's ferrule, there may be a way I can exploit that.

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Progress

I got the 'pinlet' out of the ferrule, and here's where I am with the handle/spindle interface now.


The hole in the ferrule is 1/8". The hole through the spindle is 3/32". I can go either of two ways with this.

a) I have cobalt drills. I can risk a costly cobalt drill in that incredibly hard steel, and maybe drill through 1/8", and then install a 1/8" roll pin or equivalent.

b) I can drill through the other side of the ferrule 3/32", install a 3/32" roll pin or equivalent, and then back fill the remaining oversize hole in the ferrule with epoxy.

I think I'll go with 'b)' -- 'b)' will work well enough, and it can't cost me a drill.

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Here's a view of a pin's trial installation.


I got that pin from the shank of a broken 3/32" twist drill. See this post for my method of cutting very hard steel items like that.

Needless to say, I don't have an interference fit here, so I'll install the pin with CA adhesive.

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A Method For Forming An Epoxy Fill

The pin vise's handle has an 11/64" hole through it for hanging it on a nail. Where the drill emerged, there was some splintering out that I 'd like to correct, so I'm going to try something here that I've been meaning to try out. Here's what I've done.


I smeared the shank of an 11/64" twist drill with WD-40, placed the drill in the hole and laid on the epoxy around it. I'm thinking that once the epoxy has fully cured (overninght, even though it's the five-minute stuff), I should be able to knock the drill out fairly easily, leaving behind a fill that exhibits a nice clean hole. We'll see how this works out.

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It worked.


Now I just have to file away the excess epoxy.

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That turned out remarkably well.


At the ferrule, you can see the back-filled, oversize pin hole.

(I sanded the thing in the lathe a little -- that's why it looks so dull. I mean to paint it dark blue.)

The handle is bored all the way through. I'll fill that bore with dowel, and drill a 5/32" hole in the end. That will be the chuck key's parking spot when the tool is idle, hanging on a toolboard.

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All Done


There we are -- always at the ready, and I know where its chuck key is.

I mentioned earlier that I often use a pin vise as a tap wrench for small taps. If the chuck tends to unscrew when I'm doing that, I'll install the chuck with blue thread-locker.

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Saturday, July 27, 2013

A De-Laminated Pot Handle Insulator


The two insulator halves are undamaged, it's just that the factory's adhesive took early retirement.


I'm tempted to use CA adhesive for this repair, that would be quick and easy, but CA adhesive is not all that heat resistant.

A better choice might be Permatex Ultra Grey gasket maker. That stuff will be up to the job for certain.

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Here are the parts ready for reassembly.


And here's the insulator gently clamped up for the Permatex to cure overnight.


That should be a good, permanent repair.

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Not Quite -- FRIDAY, OCTOBER 10, 2014


The repair lasted for over a year, then gave up the ghost.

What's obvious to me now is that the Permatex gasket maker doesn't truly adhere to the plastic -- it peels away quite readily.


I suspect that the plastic is of the sort that nothing will truly adhere to.

Hmmm.

I'll re-glue the insulator halves using CA adhesive this time, and see how that holds up. If that fails, I'll be left with no choice other than to install through-fasteners. That will give me a permanent, albeit inelegant, repair.

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Here it is glued and clamped up again.


I'll give that twenty-four hours for the glue to cure, then I can return the pot to service and see how long this repair lasts.

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Sunday, July 14, 2013

Swaging A Distorted Hose Fitting Seat


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[An aside -- 'swage'[1] is a slightly problematic word. See the footnote.]

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We have a garden hose nozzle that's a pretty decent unit of its kind, but it has a problem -- the seating flange in its hose fitting is distorted, and it won't seal properly. The likelihood of my succeeding at repairing the thing may be slim-to-nil, but I'll give it a try. Here's a view of the hose fitting end of the nozzle in the vise.


The distortion is by the rear jaw of the vise -- the flange is lifted there; no washer can compensate for a distortion like that. I'll see if a brass punch can have any good effect on it.

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A 7/32" punch, followed by the back end of an 11/16" socket wrench, got me some iffy-looking progress, like so.


The flange is light gauge aluminum, and it tore in three places, but I think I can make this work.

A ball-valve goes with this nozzle, and the ball-valve can be permanently attached. I'll install the ball-valve with a high quality orange rubber washer and Permatex Ultra Grey sealant. That should get the nozzle back to a useable state.


I'll just have to be careful to tighten the fitting with the ball-valve's lever correctly oriented for convenient operation -- the fitting will no longer be readily adjustable with cured sealant in it.

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So far, so good.


Tomorrow, I'll add the quick-disconnect and try it out.

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Working Fine -- MONDAY, JULY 15, 2013

I hooked it up and it's back in good order. Here's what the whole unit looks like.


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Note:

[1] Whenever I write 'swage' on blogger, I get the red, squiggly underscore indicating a misspelled or non-existent word. 'Swage' is a proper word. Here's a tangible example of a 'swaging' tool.


'Swage' is a perfectly good English word. I may tend to use the word a bit loosely, but I don't think I'm guilty of having used it incorrectly here. What I did here was I 'swaged' the hose fitting's seating flange down into place.

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Saturday, July 6, 2013

A Battery Compartment Cover For A Lego R/C Dune Buggy


Pictured below is a garage sale find.


My son picked it up for very little. It's in fine condition and complete, except that it's missing its battery compartment cover underneath. Here's a view of that.


This may be a bit challenging; we'll see how it goes.

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I have some 0.024" thick aluminum that will serve for a cover. The most intricate part of this will be the cover's rear edge, so I'll start with that. Once I have that so it fits, I'll cut a rectangle the correct width from the oversize piece of aluminum stock, and the remainder of the work ought to be fairly straightforward.

Here's a view of the rear edge's layout done on masking tape.


I can cut most of that with a nibbler, then file to the layout lines.

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So Far, So Good


The rear edge fits perfectly.

I'll finish this tomorrow. The union here doesn't like me to work overtime.

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Front And Rear Edges Both Fitted -- SUNDAY, JULY 7, 2013

The front edge turned out to be a bit of an ordeal; it needed two shallow notches to accommodate the two latches. That took a fair amount of trial-and-error filing to get it right. Anyway, it's done now.

The remaining edges are simply a flush fit to the perimeter of the battery compartment, so I just have to trace the outline from above, and cut it with snips.

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All Cut To Shape

It's nearing completion.


I tried it out with the battery inside, and that 0.024" thick aluminum appears to be quite adequate for the job.

I'll laminate fish paper[1] to the cover's upper (inner) surface with double-sided tape, both for the sake of electrical insulation (not that it's really needed), and to lend the cover a little extra strength. The good effect that lamination has on the strength of thin materials is remarkable.

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Fish Paper Lamination Done And Painted -- MONDAY, JULY 8, 2013

I hadn't meant to paint the fish paper side, but my ancient roll of fish paper was badly discoloured, and looked awful, so I painted it 'camouflage khaki'. Here's a view of that.


[It says 'camouflage khaki' on the spray-paint can. It looks like a pretty good facsimile of 'light/medium grey' to me. Whatever.]

I'll let that paint harden for a day or two or three, then I'll do the flat black painting of the underside, and this thing will be well and truly done.

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Fully Painted, But With A Revision -- SATURDAY, JULY 13, 2013

The light colour on the upper surface turned out to have been a mistake -- it showed a little at the sides and didn't look right. So, I made the cover flat black all over, and added an 'UP' label to the insulated side, like so.


And that's as done as it's going to get. Here's a view of the car with the cover in place.


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Another Revision -- TUESDAY, JULY 16, 2013

My son pointed out a potentially misleading characteristic of the 'UP' label I added to the insulated side of the cover. Consider --


To access the battery, one turns the car upside down. It would not be wildly illogical, then, to replace the cover with the word 'UP' facing 'up' -- i.e. ultimately upside down.

I guess the simplest fix for that would be to replace 'UP' with 'IN', like so.


There; that should take care of that.

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Note:

[1] Fish paper is a tough, thin (0.010") elecrical insulating material. I tend to think of it as belonging to the days of vacuum tube electronics, but it's still used and is still available. Why it's called 'fish paper' is a mystery  to me; it neither looks like nor smells like fish. Were I to go fishing, it wouldn't occur to me to take any fish paper with me. Were I the proprietor of a 'fish & chips' establishment, I wouldn't serve fish & chips wrapped in fish paper -- that's what newspapers are for, like so.


If anyone knows why 'fish paper' is called 'fish paper', I wish they'd explain it to me.

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