"...the stench of that soured burned buttermilk..."
As I mentioned in post #2, oil of wintergreen smells really good, though I never got it hot.
Originally Posted by gwilson
For non critical items I cast them.
As a former gunsmith I encountered all the metals mentioned and weird alloys as well.
I am curious as to ALL this effort one little job?
It is clear you don't know what you are doing and why not "farm" it out and get it done? The client wouldn't know you did....
As for silver, copper and other of a similar types they can be machined, BUT one screw up and the piece will bite into the tool with all the really nasty results that entails...
For parts that have to precise I made very very lite cuts and used cutting oil.
For your project as an ornamental piece dimensional specs isn't that critical except where your joining it to the trophy.
From your posting and I think others missed it; there is no master to cast this piece from?
Go to some "Third" World countries and you will find cottage industries that they don't have much in the way of machine tools. A majority of their "machining" is done by hand and by file.
Don't believe me as to what is done this way? Look up the cottage industries in the Philippines in regards to the manufacturer of firearms; it will blow your mind.
I have fired exact duplicates of the colt assault rifle and ones with "improvements" as well, semi automatic handguns and magnum revolvers as well there.
Frames and receivers as well as many other parts cast then turned and filed BY HAND..
The quality in some is incredible and some you will literally take your own life in your hands...
I have seen pictures taken many years ago of Arabs sitting on the dirt floors of caves,filing out copies of British Webley revolvers. They were made from stolen railroad rails. I thought that was pretty amazing. I'd like to have seen pictures of their entire processes.
In Williamsburg,though,except for a primitive boring machine made of wood,using twisted square files as reamers,and a wooden rifling machine,the gunsmiths make flintlocks from scratch. The barrels are welded up from flat bars of wrought iron.
A small,rough little hole is left through the inside of the welded tube(I won't call it the CENTER of the tube!) Just so you can see light clear through it. The smallest reamer is used to begin reaming the hole. Larger ones are used till the hole is of the correct caliber. These are turned by hand. The holes are straightened by eye by sighting down them. Rays of light will appear to have breaks in them until the tubes are very straight. Then,the rays of light reflected on the insides of the hole will be continuous all the way down the barrels. These same methods are still employed in factories,except they have nice barrel bending presses instead of hammers.
Rifling takes about 600 passes to complete.
I guess I started out maching not knowing what I am doing. Gradually I have learned a few things. The purpose of my original question was to learn something. The generous folks in the thread above have all contributed something to help me out on this project. I am hopefull there will be other jobs to follow this one.
Originally Posted by Bullwhacker
I have been amazed at how long this thread has stayed on track and how useful it has been. I am hopeful it will not switch subjects now to a discussion of primitive gunsmithing.... There is another subforum for that.
Originally Posted by gwilson
Added later: If anyone has a bone to pick with me on this particular post, it would probably be best to just PM me. No need to entertain everyone with some sort of non-thread-ralated debate.
Last edited by dgfoster; 09-30-2011 at 09:01 PM.
Reason: Added later comment
Back on TRACK (I hope)
Thanks for clarifying this
Originally Posted by L Vanice
Interesting. Would try it as a last resort given the smell---yuck!
Originally Posted by buckwill
Ah! Springtime in the shop! Sounds good. Thx.
Originally Posted by L Vanice
Having done at least a bit of all the methods involved, I personally agree with the prior poster who suggested:
1) cast the part
2) chuck in lathe on "slow" and finish with files, then polish
this method has served me well in the past, especially where dimensions are not critical and using silver or other wonky metals - that is, wonky wrt machining :-)
I would also add this for further thought - have you ever cast metals before?
If so, I'll shut up :-)
If not I would suggest you do a trial using aluminum (low melt compared to silver) or low-melt red brass. This will give you some learning experience at melt, pour, preheating the mold, sprues, vents, etc ... all on cheap metal. Learning new methods on silver at $7.50 an ounce was bad - at $30 or more per once a screw up could ruin your day.
toddling off back into the shadows to continue to lurk and learn
Good points all. I do indeed plan to practice on aluminum for this part and for future reference as I am sure I will want to be casting aluminum items here and there.
Originally Posted by shunka
No need to be lurking. Sounds like you have some good information to share.
This is a very SMALL problem,really. Just keep your tools sharp and no acute angles. Keep the tool rest close to the silver and you'll be fine. I was never trained to turn silver. Just did it when helping to make many PGA trophies and retirement gifts. No biggie. Copper is MUCH worse to turn. Practice on COPPER,nothing else,if you want to practice.
I warned you most to keep your HAND HELD turning tool from getting grabbed and sucked UNDER the silver. Just keeping the tool rest very close to the silver will prevent that.
Sounds like excellent advice based on much experience. Thanks, George.
Originally Posted by gwilson
It is solid sterling silver, from Cookson Gold.
Originally Posted by dgfoster
Sterling Silver Rod 16.0mm Diameter, Hard, Straight Lengths 600mm - cooksongold.com
BTW, sorry I failed to mention that I used a Sandvik CD10 insert (diamond) to turn the piece for the final pass.
I've worked with a bit of silver in the lathe.. It can be tricky as it tends to "grab" and is somewhat soft.. If you really need something to practice on get your self some copper ( ground rods from lowes are cheap enough) and when you can turn that successfully and repeatedly then hop over to the silver and it will seem simple.. Tool geometry will be the same.. ( assuming sharp hss )
Let us know how it turns out.
This isn't much help to you but it's an inspiring video. Martin Matthews is I believe the last traditional watch case maker in England, here he's showing the making of a silver pair case for an antique watch. Video is short and has no sound, but you get a good idea of his skill. Only person I've seen actually using a bow powered lathe.
V&A Jewellery Gallery - Making a Watchcase - YouTube
Thanks and some homework done.
Originally Posted by Screwmachine
That was a great video. The coordination of his hand holding the lathe tool and the movement of the bow was the result of a lifetime of practice.... His work was exquisite.
This may be the simplest way to go. I will PM you. Thanks.
Originally Posted by oeo2oo
OK, I got a chunk of copper 3/8” ground rod and gave it a go . Seemed to turn pretty straightforwardly. A few pics of results attached. I used a HSS cutter that was good and sharp. The copper seemed not to misbehave at all. It parted off fine too. I just used some standard “heavy dark” cutting oil. It cut pretty well dry but seemed a little better finish resulted with the oil.
Originally Posted by calvin b
Turning silver is a crime. You should spin it. Haven't you heard of Paul Revere?
IF you would end up with some file work - for whatever reason - you may consider chalking the file to improve finish and keep it from loading up.
Originally Posted by HoosierBoy
Thanks for the reminder about using chalk to reduce pinning when filing , especially when filling soft metals.* I use this pretty routinely if I am filing a finished surface.* I think that using soapstone might even work better than chalk.* For a while I had a hard time finding soapstone to use on the file until it finally dawned on me that the refills for the markers commonly used by welders are very convenient sources of soapstone.* Either way chalk or soapstone does really reduce pinning.* Using a piece of aluminum or brass to clean out the teeth on the file by using the alu or brass like a comb also helps…
BTW, the silver is orderred....
Silver Trophy Nose Cone (Finial) Done
Well, thanks to the generosity of a member, oeo200, I was able to buy a short length of Sterling round .62" bar stock. It was in "hardened" condition--perfect for turning.
It did turn very easily with a sharp HSS tool. I was expecting some drama based on various bits of advice I received but there was no drama. That may have been because of the advice received as I was very careful to use a really sharp tool and to make sure my setup was ideal.
I was careful to save the shavings which came off in long curls. To avoid birds’ nests I just cut for a 3 inch curl, stopped advancing the cutter momentarily, rinse, wash, repeat.....
The cuts were made at closely spaced tangents to the desired shape resulting in a fairly good approximation of the desired curve. Then I started with 220 carbide paper on a flexible plastic backing and progressed to 400, 600, 1000, and 1500. At 1500 it was shining pretty well and then I used some red rouge and put the final shine on it.
The whole thing was pretty easy, really.
See photos of the result below. The overall length is about 1.625” and the diameter is .615”
Thanks to all who helped out.
On the file pinning removal...
On a topic discussing files, Frank Ford showed a beautifully made tool specifically for this use, but using a piece of hard wood. Got me to thinking (dangerous, I know).
What Frank had made was a nice handle to hold a piece of flat hard wood. I had recently found a broken hickory hammer handle at work with the usual failure, right where the head ends (bet you guys have one laying round somewhere). Well, there's a nice handle made out of hardwood, just need to slice off the frayed end and cut the end down flat on the bandsaw. My version is not nearly as fancy as Franks, but it does the job and it was going in the garbage, otherwise.
I told you it was no big deal,and 58 posts!!