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View Full Version : A bit of patternmaking trivia.



PeterSibley
03-10-2012, 09:51 PM
This may be of interest to those with an interest in metal casting, it's a useful idea but not something I've seen mentioned in books on the subject.

I made this a few years ago, it's a core box for a toothed wheel with slightly under undercut teeth which made a normal pattern unworkable. Unfortunately I don't have a photo of the finished casting but it was quite successful and cast in manganese bronze .

http://pic40.picturetrail.com/VOL282/9443996/17245530/401628105.jpg



http://pic40.picturetrail.com/VOL282/9443996/17245530/401628106.jpg



http://pic40.picturetrail.com/VOL282/9443996/17245530/401628148.jpg


The central plug is removable and tapered and the blue silicon is indexed to the plug. I use sodium silicate bonded sand as a core material and it serves well .The sand is packed in the mold, gassed with CO2 then the central plug is removed then the blue silicon is peeled out . The bottom photo shows the finished core .

Jay Greer
03-10-2012, 10:12 PM
Certainly a nicely done bit of work! I for one would enjoy reading an account of how you formed the teeth so accuratly.
Jay

Gold Rock
03-10-2012, 10:23 PM
Yeah, I'll second that!

Woxbox
03-10-2012, 10:25 PM
Slick

PeterSibley
03-10-2012, 10:28 PM
Certainly a nicely done bit of work! I for one would enjoy reading an account of how you formed the teeth so accurately.
Jay

I cheat Jay ! A 42 tooth circular saw blade gives the division .

Gold Rock
03-10-2012, 10:40 PM
That's not cheating, that's just being clever.

jsjpd1
03-10-2012, 11:21 PM
That's really neat Peter, what was the gear for?

Jim

PeterSibley
03-10-2012, 11:49 PM
The internals of this windlass I built Jim, a project I completed a few years ago.

http://pic40.picturetrail.com/VOL282/9443996/17245530/401522568.jpg


http://pic40.picturetrail.com/VOL282/9443996/17245530/401522567.jpg

jsjpd1
03-11-2012, 12:05 AM
Wow! That is seriously cool!

P.L.Lenihan
03-11-2012, 12:30 AM
You actually built that windlass Mr.Sibley? Holy son of a gun!! I'm impressed beyond comprehension Sir! The level of skill involved escapes me entirely but a multi-part article in WOODENBOAT on your foundry work would be a real learning experience, to say the least!!

Ego sum ​​formica inter gigantes!!



Cheers!


Peter

RFNK
03-11-2012, 04:43 AM
Lemonhead has a good idea there Peter. I'm sure it'd be very well received.

Rick

Larks
03-11-2012, 04:44 AM
But would you believe that he sold it recently? I seriously hope the guy who bought it appreciates what he has Peter!!!!

PeterSibley
03-11-2012, 04:57 AM
But would you believe that he sold it recently? I seriously hope the guy who bought it appreciates what he has Peter!!!!

I hope he can produce and sell a few .

With a bit of luck the world needs a double acting manual bronze windlass with chain gypsies in 4 different pitches, 10mm shortlink, 13mm shortlink, US 5/16" and 3/8"BBB.Y>

m2c1Iw
03-11-2012, 05:09 AM
I second and third Mr Lenihans words and as to who needs one well I was tempted to suggest anyone building a schooner but seriously talk about wow factor on any sizable boat and a lot more reliable and easier to use manualy than the electric versions.

PeterSibley
03-11-2012, 05:25 AM
It's an idea but seriously I think I have pushed the limits of hobby bronze casting a bit beyond WB's normal limits.

RFNK
03-11-2012, 05:40 AM
I don't agree Peter. The magazine is read by a lot of people who like to make things and like to read about others making things. There was an article about making knives in it not long ago. There are plenty of people who don't have the foggiest idea about casting and the various considerations in choosing the right sand, metal etc. (e.g., me). If you want a hand with photos or anything except the actual casting (I'll be the one hiding behind a tree), I'd be happy to help. I think it's a really interesting aspect of boatbuilding that very few people ever learn much about but many would be very interested in. The article wouldn't have to be about something as complicated as that windlass, although I reckon people would love to see what went into that, it could start with something quite simple, like some mushroom vents!!! or cleats etc. You could make it a two or three part article.

Lemonhead might even sponsor you if you put one of those bloody hats on for the pics!

Rick

PeterSibley
03-11-2012, 06:26 AM
Ah ! Mushroom vents! There might be an article in that ! :D

Larks
03-11-2012, 06:44 AM
Ah ! Mushroom vents! There might be an article in that ! :D

or/and chain stoppers perhaps?

Skegemog
03-11-2012, 07:58 AM
I don't agree Peter. The magazine is read by a lot of people who like to make things and like to read about others making things. There was an article about making knives in it not long ago. There are plenty of people who don't have the foggiest idea about casting and the various considerations in choosing the right sand, metal etc. (e.g., me). If you want a hand with photos or anything except the actual casting (I'll be the one hiding behind a tree), I'd be happy to help. I think it's a really interesting aspect of boatbuilding that very few people ever learn much about but many would be very interested in. The article wouldn't have to be about something as complicated as that windlass, although I reckon people would love to see what went into that, it could start with something quite simple, like some mushroom vents!!! or cleats etc. You could make it a two or three part article.

Lemonhead might even sponsor you if you put one of those bloody hats on for the pics!

Rick

+1 would love to see this.

David G
03-11-2012, 08:06 AM
Peter - I too would like to see a further detailed foto-essay on the process.

Gerarddm
03-11-2012, 11:28 AM
Copy this thread up to the Woodenboat section, or PM one of the WB honchos. I think it has general interest.

St.J
03-11-2012, 12:57 PM
Peter,
This is astonishing.
Even if performing such feats is beyond the reach of us mortals it would be great to read about.
St.John

Sailor
03-11-2012, 01:39 PM
I'd be interested, there were a few bronze casting articles over the years but it's been a while and this one is really SUPER COOL. I'd love to see more about that windlass.

Jay Greer
03-11-2012, 03:08 PM
I am pleased to see the statement, "The computer age is killing personal creativity." proven false!
Bravo!
Jay

PeterSibley
03-11-2012, 03:58 PM
OK, I've copied the thread across so the WB gentlepeoples will notice it and perhaps read it. A short article might be a good idea as I gained my original casting information from those old articles in our magazine, they were a useful input but there hasn't been much since.

WX
03-11-2012, 04:06 PM
All of the above have a good point Peter. Having seen the windlass and had a play with it I can say I was seriously impressed with it. Not to mention the skill and work that went into it, including building a foundry.

Hal Forsen
03-11-2012, 06:52 PM
In the word(s) of my old pal Doc Fleming,
ACES!

RFNK
03-11-2012, 08:46 PM
OK, I've copied the thread across so the WB gentlepeoples will notice it and perhaps read it. A short article might be a good idea as I gained my original casting information from those old articles in our magazine, they were a useful input but there hasn't been much since.

I'll get started on making the pattern then! To make the pattern for bronze mushroom vents, what thickness should I make the sides? The vent I have in mind is about 100mm dia x 70mm h.

As you know, I'm coming up next weekend but I intend to come up again in a few weeks time. If you'd like to put together some sort of photo essay then, with the windlass, the vents or whatever suits you, then I'd be happy to help with that.

Rick

PeterSibley
03-11-2012, 09:44 PM
Rick... perhaps we should talk about it at the EBS with a few accompanying sketches (and ales )? It can be complicated if not organised properly .

RFNK
03-11-2012, 10:41 PM
Done.

Rick

Wooden Boat Fittings
03-11-2012, 10:49 PM
Well, I knew you did a bit of casting Peter, but not like this. This is something else. You should definitely be writing a picture series of How-Tos for WB in my view.

Also, please check your PMs. (They tell me you will need to empty some out before you can receive any more.)

Mike

PeterSibley
03-12-2012, 01:57 AM
PMs cleared .

MPM
03-16-2012, 09:15 AM
Wow! We focus on a WB deadline for a few days, and look what you guys come up with! Peter: We'd be quite interested in an article. Would you e-mail me to discuss it--and whether it's feasible? ([my first name, as written below]@[the magazine's name].com).
Matt Murphy

P.L.Lenihan
03-16-2012, 01:17 PM
(knock,knock,knock)

Mr.Sibley?!,Sir...Are you still on the loo? There's someone very important wants to have a word with you Sir!

(Knock,knock,knock) Did you get that Mr.Sibley?, The boss man ,he's at the door Sir!

PeterSibley
03-16-2012, 03:57 PM
Ah yes ! Thank you Peter, I was down the workshop and didn't hear the door bell.:d

RFNK
03-16-2012, 04:57 PM
Door bell! See what a sfisticated lot they are up in them these hills!

Rick

WX
03-16-2012, 05:25 PM
Door bell! See what a sfisticated lot they are up in them these hills!

Rick
Yeah, normally we just shout knock knock as we approach the house. If you need any computer help with this Peter let me. know

Chip-skiff
03-16-2012, 09:28 PM
Fine work, Peter, with no sign of carelessness or inattention anywhere.

When I was researching a novel, I found that the large shipmakers on the Clyde used to import tons of NZ kauri for use in patternmaking. Evidently it's beautiful to carve and will take intricate shapes without problems owing to unevenness in structure.