Li'l Brudder (¼-scale Coehorn)

[Cat Whisperer]

Well it certainly is the season!

The ribbon is narrow compared to the projo - making it harder to see.  Great length is the only thing it offers.

[Terry C.]

The ribbon is narrow compared to the projo

In my case, maybe not. These balls are only 1⅛" in diameter, most of the colored ribbon I've seen is at least that wide if not wider.

Any little bit will help.


One of the things I'd had trouble with was sanding the round beads on the bed. I shaped them with a 60-grit blender pad on my angle grinder. They looked good from a distance, but up close you could see a lot of swirls and flat spots. I tried wrapping sandpaper around small pieces of wood, but that didn't work as well as I'd hoped.

The I saw one of my wife's emery boards in the bathroom.

I rode out and bought a pack of cheap emery boards for a buck.
[edit: I checked my receipt and they were only 50¢]

(Visualize if you will, an old fat bearded guy dressed in a black leather jacket, worn-out blue jeans, bandanna and ponytail, and steel-toed boots, perusing the women's makeup aisle at the Dollar General.)

The emery boards did the trick. They are about ½" wide, and flat and stiff enough not to need any backing other than my fingertips. I worked them back-and-forth as I rolled them around the bead.

There were ten boards in the pack, so far I've used six of them and the surface on the rounds is looking 100% better. I'll save the rest for the finish sanding. I still have some holes to drill and some tweaking on the inletting. There will be some smudges and handling marks to remove before I can apply the oil.

[lance]

 i'm wondering about the whistle part, could a small projectile be drilled with two holes that intersect at say a 45. would that keep pressure from escaping while firing? and still make a whistle? Terry C, lot's of bikers around here, some not nice as others, have some pagans, hells angels, they mostly fight among theirselves anyway so nothing for me to worry about. anyway, picture this! a big bad biker stopped by my shop one day to borrow a drill and bits. all i could find for him to carry them in on his bike was a bright pink purse, that i hung from his license plate............ and NO! the purse ain't mine

[Terry C.]

It takes a real man to wear pink!


Whistling balls?

The only thing worse than my eyes, are my ears!

[Victor3]

I've done yellow CRIME SCENE (or CAUTION) tape streamers on the 4.5" before (about 3' long).

Most get ripped off.  Those that stay don't really help visiblity that much.

But, what about something that whistles?

 I've been wanting to try a wire attached between the ball and caution tape. Drilling a hole in the ball would no doubt make it whistle.

[Double D]

Keep in mind if you are using streamers for ranging they won't go as far a ball without a streamer.

The other thing, condition your eye to follow the ball by reducing the charge until you can see the ball go.  That way you will no where to look as you slow increase the charge to increase you range. 

This is also safer because you will know the ball is landing in a safe impact zone.  If you can see where the ball is landing you can be more sure you are not going injure some one or damage something.

[Cat Whisperer]

...
This is also safer because you will know the ball is landing in a safe impact zone.  If you can see where the ball is landing you can be more sure you are not going injure some one or damage something.

Ahhh.  Like when the ball goes out of sight when it clears the top of the mountain/ridge and lands SOMEWHERE out there in the National Forrest?   Don't ask.

[Terry C.]

The Thanksgiving holiday, and other commitments, had kept me from working on the bed. Then a drilling mishap had to be repaired. One of the holes for the trunnion strap stove bolts drifted badly and was off-center on the top side. These holes were marked and drilled from the top and bottom to meet in the center of the block, so not only was it noticeably off-center, it didn't meet up properly and the bolt would not fit through.

I opened up the top of the hole with my tapered reamer and cut a plug from a dowel with a matching taper. This plug was glued into the hole and sanded flush, it extends about an inch below the top. A new hole was drilled and everything was back on track.

The inletting was finished and everything was test-fitted. Then all the hardware was removed and the bed was given a final sanding with 100, then 150 grit sandpaper. The Watco Danish Oil was applied to the oak bed yesterday afternoon.

After letting it cure overnight, it was reassembled this morning.




The trunnion straps are made from .088"  stainless steel and are secured with ¼" SS stove bolts and SS acorn nuts. The trunnion straps will contrast nicely with the barrel after it's blued.

The tiebolts are ¼" SS threaded rod, with SS washers and acorn nuts on each end. The reason there are lock washers on the lower rods and not the upper ones is that those rods were cut slightly longer to accommodate the handles when they are made. They won't tighten up without the extra washer.

Here you can see the end grain:






Here you can see the inletting, and the counterbores for the stove bolt heads






The barrel has developed a little freckling around the muzzle from all the handling, so the next step will be to get it clean and blued.

The handles, when they're added, will be made of bronze. I'd wanted stainless steel handles, but they're just going to be too difficult to make at this scale from the materials that I have. I have some bronze that will make a nice set of handles. I'd like to get these made before Christmas but it's not looking good. We'll have to see how much shop time I can finagle.

At least with the mortar completed to this point, it will be ready for Christmas and New Years salutes.

[Tropico]

Wow !  Thats sure clean Terry  ., beautiful., then  inletting looks really great too .

[lance]

NICE!!! can't hardly wait to see pics when it's all done. have a blast with your Christmas and New Years salutes

[Ex 49'er]

Before you shoot it, don't forget to put something across the back so the finish isn't marred
by the bits of burned fuse blowing back when the charge goes off. Be a shame to have
black scars on that pretty wood.

[Tropico]

Oh ! ! !  You Dirty Dawg    I was just enjoying looking this this wonderful desktop mortar again ., because it is a good-looking project ., and I noticed.........,  You book-matched your wood on your carriage .,the center oak is a mirror match and then your outer grains match each other as well.  Way to go Terry C. Thats awesome ! A subtle mark of a great craftman and a keen eye for detail   ., Did you get that trick from Lendi or Les Paul ...., Either way the carriage now looks even better ! 

[Cat Whisperer]

Great pix of great work.

You've set a standard - and given us the details of doing it!

[Terry C.]

Did you get that trick from Lendi or Les Paul ....

Actually, C.F. Martin 


CW, good workmanship is the result of well-concealed mistakes.

[Terry C.]

Well. as usual my posted schedule didn't survive very long. When I got ready to blue the barrel, I had no swabs. I went to Wal-Mart to get some of the bluing swabs, and they were out.

So the bluing is not done yet. I'll stop by a hardware store tomorrow afternoon and see if they have any soft cotton swabs.


On the other hand, I had some downtime today (a scheduled job was a no-show), so I made the parts for the handles.



The flanges were cut from a CAT D-8N idler shaft thrust washer. That's a lot of technospeak to say they were made from a piece of scrap bronze. The thrust washers are flat rings that are 3/16" thick. Since this is a used part, I took about .010"-.015" off the thickness polishing out the wear marks. The thickness is not critical, but I tried to keep it as uniform as I could.

The handles are made from 1/8" bronze brazing rod. In the photo they still have some of the black Sharpie ink that I applied to show the marks for bending, and they haven't been trimmed to length yet.

I'll make a jig to hold them for soldering, then cut them to length as I set them up in the jig.

[Terry C.]

I didn't get any swabs, but I did find some small round cotton applicators that worked fine.

The bluing has been applied. It looks streaky, but that's because it's still coated in oil. I took this photo just as soon as I got through putting all of the bluing stuff away. I've since wiped it fairly dry and mounted back into the bed, it looks much better than the photo.

I always have a hard time getting decent indoor closeup photos of blued finishes, oily or otherwise. I think it's because my camera focuses on the lighter background instead of the dark finish.

I'll try to get a better photo tomorrow, while I still have natural light.




Unless something comes up, I plan to build the jig for the handles tomorrow evening. If it goes quickly enough, I may even get them soldered.

The plan is to have the mortar completed sometime this weekend.

But you've seen how my plans go...

[Terry C.]

Here is a better photo of the blued barrel (along with the requisite powder can):




Now on to work on the handle jig. This requires some metal cutting that has to be done outside, so I need to get to work while I still have plenty of daylight.

[Terry C.]

I was loosing light quickly, but I got the jig for soldering the handles made.

It's as simple as I could make it: a piece of 2" x 2" aluminum tubing (3/16" wall) with a step cut into it, drilled and tapped in three places.

The step on the side positions the brazing rod handle, it is held in place by a bolt and washer. The flanges are secured on the top with bolts.

The only modification I made after this photo was to bend a 'hook' in the brass washer. The washer is springy and wasn't putting enough tension on the handle to prevent it from from drawing under heat. The bend in the washer 'grabs' the rod and holds in down against the step.




I went ahead and prepped the parts that I had set up in the jig for the photo, and assembled one handle. I taper-reamed the holes so that they are larger at the top, so that the solder could flow down around the rods, and trimmed the handles to a length that put the ends slightly below the surface.  I used a propane torch and low-grade sliver solder (96% tin, 4% silver) and the handle appears plenty strong.


This is not a very clear photo (bad lighting), but here it is.
My very first bronze mortar bed handle:




It still needs to be cleaned and polished, I'll do after the other three are assembled.

That's all for tonight. I'm filthy, hungry, tired, and grouchy. I need (in order) a bath, a meal, and some rest.

There's no cure for the last part...

[Double D]

Wow look like all that's left to do is paint.

[Terry C.]

Paint? What is this 'paint' of which you speak? 


I got handles!

This morning I prepped the rest of the parts, set up the jig, and soldered the other three handles together.




After I sanded the excess solder (there wasn't much) off the backs of the flanges, I removed the handle I made last night and gave all four of them a good cleaning with brake cleaner and a stiff brass brush. They still need some polishing, but I probably won't have time for that until late this evening.






They aren't perfect, but given my methods I think they came out pretty good.  The flanges were printed at full size on sticker paper, these were cut out and arranged on the bronze thrust washer. All of the holes were drilled first, then each piece was roughed out with a cutoff wheel. The eight individual parts were stacked and bolted together with a ¼" bolt, a piece of the brazing rod was passed through the small hole to keep the stack from twisting. Then all of the parts were sanded to their finished shape as a single unit. This made shaping them faster and easier, but it also meant that any defects in the shape would appear in ALL of the pieces.

The rods were shaped using a makeshift bender that I built out of a worn-out pair of Vise-Grip pliers and a couple of HHS tool bits that had been ground down too short to use. There were several rejects, as I tweaked the spacing of my marks to get them to come out the right dimensions. I was finally able to get four that were within about 1/32" of each other. The rejects won't go to waste, I'll use them for something.

The bearing bronze and the brazing rod took the solder well. They were strong enough to survive my oafish handling when I was brushing them, so they should take a stand up well in normal use.

It's raining now, and it's supposed to get heavier this afternoon and continue into the night. It should be over tomorrow so I plan to get the mortar, complete with shiny new bronze handles, outside for some good photos.

[lance]

 Terry, if you want those cool looking bronze handles to really stand out........maybe a nice John Deere green paint job on the base would do it       yeah, it's raining up here too, but freezing rain. I also like the handle jig you made, and promise ya that's an ideal that will get used!

[Terry C.]

It's been in the high 70°s and lower 80°s here all week, but the rain is bringing in a cold front. By Monday morning it will be about 29°, with the high in the 50°s.


I had several pieces of aluminum scrap and a couple of different ideas on the jig. The original plan called for two different sizes of square tubing fastened together to create the ½" step. That got the axe when I saw that it would be difficult to get the flame underneath the solder joint.

Then it was changed to a square tube with a flat strip fastened to the side. All of these designs were based on 1/8" wall tubing.

When I found the section of 2" square with a 3/16" wall, the light went on. With this piece, I could cut the step directly into the tubing without cutting all the way through.

I have a carbide-tipped blade in my table saw that does a very good job on soft aluminum, as long as the cuts are made in several light passes. I rolled the blade up to ½" above the table, and slowly worked the fence over until I had cut the step to my desired depth. I was shooting for .120", to give the washer .005" of bite, but the last pass measured .122". That still should have been enough, but after the rod wanted to slip on the first handle, I measured the rod and it was only .123".

I should have measured it beforehand. Remember what I said about mistakes? It was this error that led me to bend the washer so that it hooked over the rod, instead of just pressing down on it. That turned out to be a much better arrangement.

The reason I chose a hollow aluminum tube for the jig was that it would act as a heat sink and draw the heat off the bronze, making the solder joint set quickly. It worked great, almost too well. I had to preheat the jig for about 30 seconds before I could start soldering. Once I removed the heat, in less than a minute the jig would still be scorching hot and had to be held with a welding glove, but I could remove the screws and lift the handle off with my bare fingers.

[Cat Whisperer]

Thanks for the pix of the FIXTURE -  there is an elegance in it's simplicity.

Not perfect.  SO?  Not perfect is reality.  It is that touch that signifys hand work vs. refined manufacturing process.

[Terry C.]

Camera malfunction!

I set up the mortar and the 10-ball rack outside this morning, and took some photos.

When I opened them on the computer, the color was all screwed up! Not just one, all of them.

The camera has done this before, I removed the batteries and let it sit for awhile and it went back to working correctly. So now the camera is sitting on the desk sans batteries and hopefully when it powers up all will be well again.


I almost deleted all of the photos, but then I had second thoughts. This, despite my camera worries, is a cool effect. So I saved this photo. Kind'a has an 'old' look to it:




Hopefully the camera will be working later and I can get the photo I wanted.

[GGaskill]

To each, his own, but I gotta say that those acorn nuts bug me.

Nice job anyway.

[Terry C.]

Yes, to each his own.


As I had hoped, the camera started working again after sitting without batteries for awhile. So if you'll suffer me one more photo, then this will be done.

[lance]

 Great looking photo! i don't like to steal, but i will borrow the handle jig and that neat ball rack. now that this one is done, what's next? if ya don't mind me asking.

[Double D]

Put me in the column who doesn't like the Acorn nuts.  It never hit me until the handle were added.  They are  to big and over power the handles.

What's left to finish it?