Back from the foundry

[kappullen]

I just got these castings back from the foundry yesterday.
It took a long time to make the pattern for the large piece.

Me, being cheapest guy in town, used part of a tree down in the back yard for the pattern.

She's been a warping, and me a straightning, and a warping etc.
Have to put the piece in the lathe to see how good or bad she is.

There is a yoke cast in foam, and a couple of cap squares cast from aluminum patterns in there.




The casable is formed so the tube can be used as a swivel gun, or on a carriage.

The other tube, and bronze axle, will make another howitzer like these.



Those squarish looking brass things are templates for the tracer mill for sights.

Got my work cut out for me!

kap

[Powder keg]

Nice job Kap!!! What's that big one in the back? Could you please post more picts of your patterns? Are thet split or solid? I like that Howitzer. You don't happen to have a drawing of it do you? What will your new guns be bored to? Does the green tape do anything special? How do you plan on getting the barrel into the swivel yoke? I've been thinking of a 2 piece one that is cast.  The hole that it is mounted in will be tappered and hold it togather. What flavor of brass did you use?  Hope I'm not being to nosey :oops: I just love to learn about new things. Again nice work

[kappullen]

PK,

That thing in the back is a soda can mortar from a decade or so ago.

The patterns are split. The green tape covers the screw holes from the machining process. They are filled with modeling clay and taped quick and dirty.

The wooden pattern has oak plugs in the screw holes.

I don't know exactly what I'm going to do with the yoke.
First thoughts were to mill a slot on the front side and bolt in a filler piece.

I think I'll saw the thing off the front side on 45 degrees and bolt the piece back with recessed head screws on prior to boring for trunions.

The back half takes the load.

I'm just learning too. Should have put a fillet around the trunniun/barrel joint as it is recessed in the corner a little from shrinkage.

The foundry guy put clay on the howitzer to make a fillet the first time and I      
                                       ASSumed
 he would do it again.

Those foundry guys always know why your casting is screwed up but didn't bother to do it right.

I hoped I wouldn't have to skim machine the thing but the underside has some marks in it that have to go.

I like a rough cast barrel. They look like they have been out in the weather a hundred or so years.

They are Navy Bronze.

Thanks for the comments.

Kap

[Powder keg]

Thanks Kap, Couple more questions.

Do you know how the barrles were pored? Were they horizontal or verticle?

I've had a couple of bad castings because of no radius in a corner also. Was there a shrink on the bottom of that barrel? The petrobond sand I use picks up lots of detail. Did the tape show up on your casting? I've used wood for a couple of my patterns and had the grain show up on the casting.

I remember seeing a picture of a swivel yoke one time that had a strap that went over the trunions and was held in place by a screw under the trunions. I think I'm going to do one that way.

Thanks,

[Cat Whisperer]

WOW.

Hmmmmm.

WOW.


Hmmmm - what else can one say - doin' it from scratch.  Lots of work, lots of satisfaction!

[Cpt Ed]

Kap,

Triple Wow, really nice stuff, and in your living room?

Understanding wife?  :grin:

Where is the Goex can for size?  :roll:

[kappullen]

pk,

They were cast horizontally.
I think a vertical setup with a curved feeder like a cane would work best.

You would need flasks with holes in the end to achieve this.
Here is a sketch of the theory.



Pouring this way should, from the bottom up, should allow any foreign materials float to the muzzle end, and out the top.
That's my theory anyway.

I don'y know if any foundry is set up to cast this way anymore.
The old cannon were cast this way with a head on the muzzle to catch the crap I believe.

I rough turned the barrel last night till midnight last night.
The crud only took 1/16 to remove.

My steady only held the breach by about 1/8".
I have a larger steady that needs the base modified for future use.

I had at one time 2 steads with a 10" hole that I used to make a couple full sized mortars for some NSSA guys.

I didn't figure I would need them anymore.  They are now now at a place I used to work. He used them for some shaft work, and when I quit, they didn't (quit).

This tube is only a shade over 4" diameter by 24".

I'll put some pictures up later. We have a wedding to go to today (not mine).

See ya.

kap

[Powder keg]

I can't get over how nice those cast barrels look!!! Could you please explain how you held the two halfs of your swivel gun pattern togather while you were machining them? I've tried a couple of different things, and I got the job done, but they didn't seem right. I'm excited to get started on some of my castings now. Are those models of 12 pound Dahlgren light boat howitzers? What scale? Thanks again for sharing your wealth of knowledge. Later,

[Cat Whisperer]

Kap -
Take a look at George's thread on how he setup his vertical casting moulds.

Ceramic filter - neat idea.  I could almost see the ceramic 'cookies' made near here by Corning used in catylitic converters - but they might be a bit fragile to get hit by a stream of molten steel or bronze.

[Powder keg]

Here is the thread. http://www.graybeardoutdoors.com/phpbb2/viewtopic.php?t=58644&start=0&postdays=0&postorder=asc&highlight=

[kappullen]

Pk

I held the pattern halfs togather with deck screws. I also put some hose clamps on for insurance.



This is the trunnion boring operation showing the pipe clamps.

Before dis-assembling the halfs, I drilled thru for dowels as locators.
for the foundry.

CW,

That's a good thread that George did on vertical casting.  Shows that nothing is new under the sun.

Here is a pic with a powder can as requested.
This is the setup for finishing between those dratted trinnions.

Those are indexing head centers that can be found on ebay, or flea markets at steam shows.

The right one is 1/2 " high to give the 1.5+- taper per side.





Here are a couple of shots on the lathe.





That extra band at the muzzle is for the steady rest during drilling and will be skimmed off later.

I'm just learning too. That makes life interesting each day.

Kap

[Cat Whisperer]

The pictures of the setups are PRICELESS!

I have one indexing head center, now I'll have to get another.

Now I know why I've got two 6" vices too!

[kappullen]

cw,

You could use aluminum blockes as well with pointed screws and lock nuts for the centers.

Those oldtime hardened square head set screws would work nicely as would hardened shcs's.

I just do things the lazy way sometimes using the vices.

I took .03 cuts with the 1/4" end mill and held the barrel from rotating with my hand.  Be careful or the endmill could dig in on you.

I do not recomend doing this this way!    It did work out ok for me.

I'll finish off with riffler files.

An indexer would have worked out better but mine is too big for those centers.

A bar of some kind clamped on the tube as a handle would be safer than holding by hand.

Safety first!

Kap

[Powder keg]

Thanks Kap, Why didn't I think of that :oops:  The last one I did I glued the two halfs togather with a piece of paper between the two halfs. It was a bear to get the halfs apart :x  What scale are your boat howitzers? How long are the barrles? I've seen pictures of them on light field carriages before but never a navel style carriage. Anyone have a picture?

Thanks,

[Cat Whisperer]

cw,
 ....

I do not recomend doing this this way!    It did work out ok for me.

....Safety first!

Kap

How well I know the phrase!  

Thanks for all the detail - it puts us 3 giant steps closer to getting it done.

[kappullen]

pk,

Here is a howitzer on a naval carriage.
This piece is in the Navy Museum in Washington.



Those barrels are about 14" long (mine).

I fired one in the back yard with a tablespoon of f and half a Walmart bag as wadding and the wife went beserk!

She "tried" to make me to promise not to EVER do it again in the back yard.

Nothing behind us but a tree farm.


The saga of the swivel gun continues.

Here the trunnions are machined.



I was poking around getting the boring head setup for turning the trunnions and saw the rotary table with chuck already setup on the old Bridgeport.  

 I've have given that one away twice (and paid for it twice).

The trunnions were cut with a hog mill, .02" depth of cut, by 1/2 inch passes.
I'll file them out as a regular mill is gonna chatter and wine with that setup.

Just can't get gready with the cut. I know my limitations.

I've always (usually) been a "LUCKY MACHINIST" in my carreer.
Most my scrap can be indicated and skimmed to make it ok!
Still have all my fingers. Lost my shirt in a lathe once (close call).

Be careful out there!

Course I have a dumpster of scrap somewhere in never never land.

Those that do nothing, never goof up.

Kap

[Powder keg]

Great Pictures Kap!!! I can't believe you'd scare your pore wife like that :shock: Over the fourth I was invited to a friends house to shoot my cannons. There was 40-50 people's there. He lives out in the country. After dark, while the fireworks were about to die down, I snuck off and loaded my 1/3 scale 24 pounder. No one knew what hit'em :-D  :-D  :-D

Thanks for the stories!

[Cat Whisperer]

Good of you to share your pix and experiences.

I really appreciate the details of the machining practices.

I usually fire of ONE round (blank) every year or so on the 4th of July.  Echoes all over (the town is in a valley) - and lots of other folks do much the same.

[Cat Whisperer]

Kap -

Thanks for the pix on the Naval gun - looks like one of the barrels I saw at Petersburg this last weekend.

[Powder keg]

I really appreciate the details of the machining practices.

Me to!!! Thanks!!

[kappullen]

Well, here is another howitzer at the Navy Museum.
I suppose those brackets are for ammo boxes.



I did some drilling tonite on the swivel gun.
The bore is 1.140 diameter by 20.5 deep.

The drilling was done with the same spade drill I used on the howitzers.
The plan is to regrind it to a spherical point and finish all three with the spherical bottom.  

The third howitzer will have a smaller bore.



That is a drill tip avalible at Manhattan Supply Corp. at a reasonable price. Tha shanks are a bit high, but the thing is simple and can be made of crs on the mill and lathe in a couple of hours.

This shank is tackwelded, or fixed somehow (can't remember) in a piece of black water pipe, tacked to a broken reamer shank. It has been holding the corner of the garage up for some years.



I could only drill about 5/16 before clearing chips (pia) but got the job done in two, to three hours.

You have to start the drill dead true so I started the hole with a stubby
1 5/32 twist drill. I put a bar in the tool post against the twist drill while starting to hold it steady.  Sometimes I'll drill and bore a bit to finish bore size to get things going straight.

There's lots of ways to skin a cat. I don't claim to do it the only way.
I just do it the cheap way.

kap

[GGaskill]

How about putting a fitting on the taper end and a hole up front and pumping cutting fluid through to clear the chips?

[kappullen]

GGaskill,

Thanks for the idea.

The pipe section is tapped to 1/8 npt but the lathe coolant
tank is dry right now.

If it was steel, the tank would be full!

kap

[GGaskill]

You probably would need 100-150 psi oil pressure to be able to flush the chips from the hole; some kind of gear pump with a tank to catch the oil as it exits the hole and a couple of stages of settling and/or filtration to minimize the chips flowing through the pump.

How good is the hole surface finish from the spade drill?

[Cat Whisperer]

I'm using a spade drill with two holes for coolant and using a water-base coolant - at the normal pressure of the built-in flood-coolant pump (a few pounds).  Turning at the slow non-back-geared speed of 300 or 400 rpm using a 1" bit the chips are curled very nicely and flushed very well, with a mirror finish.  (Pictures tonight.)  The only drawback is that I now have to shield the spray to keep from putting a gallon or two onto the floor.  

I got the drill for just over $20 on Ebay and the bits for a buck or two (same place).

The key is the shaving function and the quick turn that breaks the chips up.

[kappullen]

Tim,

That's a good deal on spade drills!
I have a couple left over from some machinery auction.

This project is almost done.

The rain let up and I took a couple of shots outside.





I only have a couple of details to take care of.

kap

[Cat Whisperer]

Kap -
 That's one FINE looking shootin' "iron".

What is that on the bottom?  I figure that a an old wheel is way too ugly, but coming up with something that looks good is a problem - your solution is elegant.

[kappullen]

Cw,
That is the umbrella stand from under the patio table!
Quick and dirty.
Thankyou.
Kap

[Cat Whisperer]

Cw,
That is the umbrella stand from under the patio table!
Quick and dirty.
Thankyou.
Kap

Your secret is safe with me - I'll not divulge it!

Where can I get one?

[Powder keg]

Nice looking gun Kap!!! How bouts a closeup of that nice lookin yoke? I hope my castings come out that nice.