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MuellerNick
3rd August 2012, 07:09 PM
Hi!

That's what we did last Saturday:
A day at the backyard foundry - YouTube

I'd like to have that every weekend, minus the work before and after.


Nick

cava
3rd August 2012, 08:46 PM
Fantastic Nick. Thanks for posting. :2tsup:

nearnexus
3rd August 2012, 10:06 PM
Wow, you guys are set up big time.

Glad to see you poured it before you had the barby and a few beers.

Interesting stuff casting alloy.

I cast my own gear blanks but you are way ahead of my beginner efforts.

Rob

MuellerNick
3rd August 2012, 10:36 PM
Glad to see you poured it before you had the barby and a few beers.


We quickly realized, that this is the right sequence. :D
At our first G&G ("Grillen und Giessen"; thats "Casting and BBQ") last year, we first had the BBQ. With the result that we had our last pour at 2 in the morning.

Unfortunately, I have very little takes of the finished parts (I found the missing clips, iMovie didn't like them). Next time, I'll ask the camera man to put more focus on the castings.

Before someone asks: The bubbling aluminium is from degassing tablets.


Nick

tea lady
3rd August 2012, 11:09 PM
:o Wow! That looks fantastic. And I thought raku firing was fun.

MuellerNick
4th August 2012, 12:04 AM
And I thought raku firing was fun.

The furnace as seen here is only in idle. :D

I broke my lid on the top. When I have casted a new one out of refractory concrete, I'll make a video about the furnace.
At full throttle, it has 200 kW. :2tsup:


Nick

Stustoys
4th August 2012, 12:10 AM
Hi Nick,
Great setup you have there.

Is that an oil burning furnace?

Stuart

MuellerNick
4th August 2012, 12:14 AM
Is that an oil burning furnace?


Yep!
I'm still working at the temperature. I can melt CI, but it's not hot enough for pouring. I'll find that out ...


Nick

Ropetangler
4th August 2012, 12:28 AM
Well done Nick and friends, you are obviously well versed in many of the different aspects of casting metal. The support infrastructure , like the muller and were they 3D printed cores in the base? in any case it was most impressive, especially with the large number of your friends involved too. Good to see the high standard of protective clothing too.
Anyone else looking to emulate Nick, but not yet with his knowledge and experience, would learn plenty from watching the many youtube videos uploaded by myfordboy. He covers pretty well everything from building the furnace, making patterns, cores, molding, casting and machining. He has lots of good stuff, and explains why he does it as well as showing what he does. For some reason a google search for myfordboy throws up a lot of other stuff, but this link should get you on to myfordboys stuff on YouTube.
myfordboy - YouTube (http://www.youtube.com/channel/UCNC9gjgYrzLfyMQmp31DnjA)


Our own forum member RayG also has some excellent material with in depth explanations. Here are links to the first 3 parts to get you started, and just use the search function on this forum to get the rest of them.

http://www.woodworkforums.com/f65/casting-tools-part-1-a-143167/
http://www.woodworkforums.com/f65/casting-tools-part-2-burners- (http://www.woodworkforums.com/f65/casting-tools-part-2-burners-143176/)143176/ (http://www.woodworkforums.com/f65/casting-tools-part-2-burners-143176/)
http://www.woodworkforums.com/f65/casting-tools-part-3-furnace-design-construction-143298/
Rob.

Stustoys
4th August 2012, 12:30 AM
Have you thought about preheating the air? I've been tossing around ideas, nothing I like yet. I think with propane you could go as high as 400C. That would have to help things along wouldnt it?(not sure about oil burners though)

Stuart

MuellerNick
4th August 2012, 12:49 AM
Yes, MyfordBoy is very informative to watch!

Re protective gear:
I started in pants, but it got hotter and hotter the bigger the crucible got. This is my thir furnace. The other smaller ones worked with charcoal. But that got too expensive when you get the oil for free.

Re preheating the air:
Yes, I thought about that. With 200 kW, 70 kW are spent on heating up the air. But if I use preheated air, my A/C blower from the VW Passat no longer works. There's also the question where to take off the hot air. If I take it off from the outside of the furnace, I pay with higher heat losses. Also, IIRC, I'm losing less than 20 kW through the walls. So, that only would be 20 kW, that's only 10%. Not a big step forward. The right place would be the exhaust, but then the furnace gets really clumsy and hard to handle. At least with this design. A long exhaust pipe (with a heat exchanger) also is a bit risky. The exhaust might contain CO and that explodes from time to time. :oo:

I'm trying to improve the setup in little steps. Initially, I didn't get aluminium to melt (well, it took forever). But now I have to pay attention that I'm not melting my crucible. I do have SiC and carbon crucibles too, but this one is the most convenient.


Nick

MuellerNick
4th August 2012, 06:19 AM
and were they 3D printed cores in the base?

Forgot to answer that:
There were cores, but they are resin bound sand cores (cold box). Thankfully, I get the chemicals from a friend.

The patterns and core boxes all are CNC-milled with Renshape material.

The one on the muller (with the big belly :U) was a pattern maker. He prefers the hand made ones made from wood.


Nick

Anorak Bob
4th August 2012, 10:30 AM
Thank you for posting the video Nick.:2tsup:

It brings back fond memories of watching foundrymen from the West Australian Government Railways demonstrating casting at the Perth Royal Agricultural Show. I can still smell the dark brown sand and the molten aluminium. That would have been in 1962.:U

Bob.

tea lady
4th August 2012, 12:16 PM
:C I think I dreamed about this last night. :doh:

4-6-4
4th August 2012, 11:33 PM
Greetings chaps Watching the vid brought back Memories. I had my own non ferocious foundry a few years back. To add a few comments I would have weighted the top box ( the cope) but this is a layover from pouring Iron. The Muller the thing with the rollers in it is essential for sand preparation in green sand. I only had steel boxes I found that the wood ones caught fire too often. What is the lining of the furnace. I used a space age stuff called ( damn I can,t remember the name,) it comes in blanket or board form and was excellent for keeping risers molten while the main casting could draw on them. This stuff makes the furnace light and is an excellent reflector of heat. ie it takes less time to melt. My furnace melted 15 Kilos of Aluminum and the same of gun metal or silicon bronze it was fired by LPG gas with a vacuum cleaner for pressure. But you can get normally aspirated burners no that do not require the Vac. I did all my iron at the RMIT Foundry School. I am only too glad to help the amateur. Yours 4-6-4

Stustoys
5th August 2012, 01:56 AM
Hi Nick,
Thanks for your comments, I'd come to the same conclusions as far as pre heat... though I didn't know of the CO issues(do you happen to know if they apply to propane burners?)




I used a space age stuff called ( damn I can,t remember the name,)

ISOLITE ISOWOOL? Hope so because I've bought a box as I collect bits and pieces for my furnace.

Stuart

MuellerNick
5th August 2012, 02:19 AM
though I didn't know of the CO issues(do you happen to know if they apply to propane burners?)

I *think* that's the same.
We had been discussing about a heat-exchanger in the exhaust. But I was warned by someone who was a service man at Voest Alpine (I think), doing steel mills setups abroad and getting them to run. CO is a big issue with burners/furnaces. They frighten it a lot, it is constantly monitored. So I kept away from that idea.
Also, the oil is cheap enough. :D

The furnace liner is 3 cm of refractory concrete (1700°C) and at the outside a layer of 3 cm ceramic fibers. I made the observation, that the concrete helps in combustion with oil. As it helps to evaporate it more quickly. At full throttle, it is glowing orange. Above 500° C, you get spontaneous ignition of the oil (depending of what oil it is, but 500 is the upper limit). Diesel fuel is 280° C IIRC.

eskimo
5th August 2012, 10:42 AM
cant wait for swmbo to leave so I can set myself up like you Nick:D

but I love her and i guess she will never go ...not while i love her anyway

wow...great video

have a beer for me at the next Giessen und Grillen

tea lady
5th August 2012, 11:43 AM
I did all my iron at the RMIT Foundry School. I am only too glad to help the amateur. Yours 4-6-4Oooh! A local type person. :D:cool: Do you still do metal casting?

Stustoys
5th August 2012, 12:58 PM
Thanks Nick,
Based on what you've said I'm now thinking about a spiral of steel tube above the furnace exhaust. I can see three problems as I haven't bothered with the math yet. I am likely over guessing(I cant even use the word estimating) the amount of heat the will flow though the pipe wall, under guessing that amount of air flowing through the pipe and have no idea how long the pipe would last.

I can get oil "cheap" also....maybe a hybrid burner............. or maybe I should stop thinking so much and start building?

Do you coat the inside of you steel "melting pot"(the word escapes me atm) with anything?

Stuart

MuellerNick
5th August 2012, 05:53 PM
Well, the heat regenerator at the exhaust side:
It is very attractive from the energy POV. You have about 80% of the energy going out there. And it is completely wasted.
You have two advantages from hot air on the intake:
Less losses by heating up the air from 20° C to say 1500° C. And the flame will burn faster. The later is an advantage when burning oil, as the flame gets quite long.
I do have a 60 mm tube on the intake.
I you wind a spiral that takes heat from the exhaust, you'll have to find a practical setup that you quickly can remove to have access to the crucible. (A quick reminder: I broke the lid on my furnace, normally I do have one). That sprial has to be long enough to have enough time for the heat to be transferred to the intake air. I didn't calculate the length. Also, you have to consider what type of blower you use. Maybe it won't work with hot air.
The setup of ArtfulBudger where he takes of a bit of hot air from the combustion chamber to heat up the intake air doesn't work. The contact time is way too short. It was something around 2 ms. Roughly, it takes 1 m^3 of air for every liter of fuel you burn. And every liter of fuel has around 10 kWh. With that, you can calculate the air speed in the intake and thus the contact time. ArtfulBudger's setup only helps in pre-heating the oil (that's an advantage, I'll implement that too).
I wouldn't worry too much of the heat on the heat exchanger being too high. The air rushing through really cools it down. With my setup, that are 200 kg of air per hour!


I can get oil "cheap" also....maybe a hybrid burner............. or maybe I should stop thinking so much and start building?


The propane burner is easier to handle I think. But it gets a bit expensive over time. At least with the prices here.


Do you coat the inside of you steel "melting pot"(the word escapes me atm) with anything?

Yes, I do cover the crucible with something I don't know the English word for. Steel crucibles won't last forever. Al dissolves in steel, so it is eating it from the inside. And on the outside, it corrodes from the heat. But they are easy to handle (with the two hooks you can see on my video).

Nick

4-6-4
5th August 2012, 06:28 PM
Dear Tea Lady, I was not far from you when I was casting. The factory was behind Fountain Gate in Lower Gully. I don,t cast any more but I am will to advise about foundry's. of the backyard type. The furnace lining that I forgot the name of is Kao Wool. I had a cast-able refractory base in a drum the size was about 2.6 inches high by about 2 ft in Dia. The Kao Wool was wrapped around the inside of the drum and was about 1 inch thick.. I think it was wound around twice. You could touch the outside of the drum even after three melts. The lid was the top of the drum lined with Kao Wool and had a 4 inch dia hole in the middle. Heat was LPG I got mine from the local servo. This was put in at the bottom of the furnace on an angle to create the swirling of the heat around then crucible. The method was a large gas-air torch. When I first started the furnace was located in Richmond inner Melbourne and did not make much noise in fact the Vac was the nosiest piece,
Now fior the crunch. The furnace is the easy part it is the re working of the sand which is the drama. In green sand moulding The sand has to be mulled to restore it to a useable state. After use it is dry and the muller squeezes the sand and get rid of all the lumps. Some Bentonite is added this is clay which binds the sand together. Finally water is added. If I remember it is about 3 or 4 percent. More than this and the sand is too wet and results in a volcanic effect from the steam created.
So if you are going to play in the foundry the sand is the drama.
But as I have said I will give all the advice necessary
Yours 4--6-4.

tea lady
5th August 2012, 06:37 PM
Dear Tea Lady, ......
So if you are going to play in the foundry the sand is the drama.
But as I have said I will give all the advice necessary
Yours 4--6-4.I have built pottery kilns and mucked about with clay and glazes for 25 years. Metal just kind of intrigues me. I wonder if it is something you could do in a raku kiln? :think: Probably. :cool: One day. In my spare time. :doh: :U

4-6-4
5th August 2012, 11:27 PM
G,day Nick, I have watched the vid again and I liked the rapping tool. I would like to have a closer look at the muller. Does the rollers in it rise and fall. and lastly what was the mould with the cores in it. I liked the method of pouring with the lug on the bottom . I used graphite crucibles and lifted them a large pair of tongs on to a firebrick pedestal and then a ring to pour. Is the sand you use green sand or an oil based sand. Yours 4-6-4

jhovel
5th August 2012, 11:50 PM
Nick,

Yes, I do cover the crucible with something I don't know the English word for. Steel crucibles won't last forever. Al dissolves in steel, so it is eating it from the inside. And on the outside, it corrodes from the heat.
what's the German word for your coating of the steel crucible? I might know the English word for it - and I'd like to know too :)
Joe

MuellerNick
6th August 2012, 01:05 AM
what's the German word for your coating of the steel crucible?

It is "Tiegelschlichte" or "Pfannenschlichte".


The muller's wheels do move up and down (by own weight).
The casting with the core is an A-frame of a diesel engine (scale 1:10). It didn't work this time. But for sure the next time. :rolleyes:
I also have those plier for and a ring for carbon crucibles.
The sand I'm using is oil-bound sand. I'm buying it ready-made and then regenerate it in that muller. I'm slowly getting better at that art.

The sand-rammer, I got for 25 Euros off fleeBay.


Nick

jhovel
6th August 2012, 01:19 AM
Ah, thanks Nick.
The English equivalent is 'Crucible wash' and 'ladle wash' sometimes called crucible or ladle 'slip'.
This is one brand: http://www.refractories.com/pdf_products/MILBRO%20LADLE%20WASH.pdf
What do you use?
Cheers,
Joe

MuellerNick
6th August 2012, 01:33 AM
The English equivalent is 'Crucible wash'

Ah, now I remeber that I have forgotten that word. :D
I don't know what brand I have. I got it from my secret agent, my mystery source.


Nick

4-6-4
6th August 2012, 01:09 PM
Dear Nick, Thanks for the info. We have an oil based sand in Melbourne called Petro Bond. I had small quantities and used it as a facing sand backed up with green sand. I know some small foundries used it exclusively. The muller I had was 1.2 meters and the bowl was falling to bits but it worked. I loaded drums of sand into it with an electric hoist. Did you build yours. Our full time foundries are getting thin on the ground and only use chemically bonded sands. They also do not like the small one offs. Please do another vid the next time you cast. Yours 4-6-4

Stustoys
6th August 2012, 02:17 PM
One of my books calls it a "refactory wash"

My thinking behind preheating is that it would increase the flame temp so things would get hotter faster. I'm not sure this is strictly correct.

Stuart

MuellerNick
6th August 2012, 05:53 PM
Yes, this is a DIY-muller. The first one didn't survive too long. Then I built this one from an warped drum I got. But the gear didn't make it too long. It was a worm gear from a beer-lift and the motor had only 400 W. It went up in smoke. So I fitted a 2 kW motor. But then, the gearbox itself seized. Then I found a more substantial gear. Added two pulleys to reduce speed on the input shaft. Still, it is going quite fast. :D
I need to fix it, as all the bearings supporting the drum seized. Now, I need ear-muffs to operate it.

IIRC, you don't get more temperature by preheating the input air. But you get a faster burn. And the available energy in the combustion chamber increases.

The problem with chemically bound sand is regenerating. It has to be heated up and kept at temperature. Mine (PU bound cold box) needs 480 °C for at least 4 hours to burn. So this takes some energy (and stinks).

I'm quite happy with the oil bound sand. I think it is more expensive over time. You have to throw away part of the sand that is completely burnt, so you have losses. But it is quite stiff. The pattern you see in the very beginning has a core too (black core prints). I can make that core out of fresh oil sand, it doesn't break. You can see when I make one of them at 0:47.
This is a HF-spindle holder I make in "volumes". So I'm using a match-board (that's what I think it is called). If I would use resin bound cores, I'd have to put the parts in the oven to get the core out.


Nick

4-6-4
6th August 2012, 06:45 PM
Dear Nick that is one name for a pattern plate. They can be single or double sided. The chemically bonded sands should be OK for core and used as is. I had access to linseed oil based core sand which had to be cooked and this was smelly This was made and used at the RMIT foundry school. I also purchased ready made stock core in different diameters One thing I could not see is are you venting the cope before separating the boxes. I used a 1 mm wire with a wooden handle and stabbed the cope numerous times down to the pattern. This helps with getting the gas out of the mould. Also a 2mm wire to vent cope and drag sides of any core prints after the the mould is separated
My muller had a gear box drive coupled direct to a motor. and would drive a thirty gallon drum of wet sand. The rollers went up and down acording to how much sand was in the drum and there was a stop to prevent the rollers from running on the bottom of the drum also there were two ploughs one pushed the sand away from the center and the other towards it. I am really enjoying this thread I wish you were not so far away.
Yours 4-6-4

MuellerNick
6th August 2012, 07:00 PM
Initially, I made venting holes. But they turned out to be unnecessary. The sand lets pass air through it good enough.
I have moulds out of core sand that are as "big" as a matchbox. You really can blow through them. I'm using them for very small parts with thin walls. The one that made the biggest problems has a wall thickness of 2 mm. To get that working, I'm casting it with vacuum. Now it works, but there's room left for a better finish. I need to experiment on that with different temperatures, smaller gate and different vacuum.

That's the part I'm talking about:
218502
The surface is too rough for me. Maybe the vacuum was too high.
The vacuum pump is from a milking installation. :D


Nick

RayG
7th August 2012, 09:15 AM
Hi Nick,

Thanks for a great thread, now I can't wait to get back home and do a bit of casting, I'm still in Linz for a while yet, but you've now got me thinking a saturday afternoon barbeque and casting day in Shepparton might be fun.

As far as petrobond goes, I don't worry so much about the burnt bits anymore, maybe just get out the worst black bits, and I just mix it in and sometimes a bit of a squirt of iso-propanol seems to work.

Regards
Ray

MuellerNick
9th August 2012, 02:14 AM
and I just mix it in and sometimes a bit of a squirt of iso-propanol seems to work.

I didn't believe that, but I tried it today.
And, it seems to work. :2tsup:
The sand I had, only had little burnt content. I'll keep observing wether that works. I'll cast tomorrow, so I'll have enough sand to experiment with.

I had phoned the manufacturer of my sand some months ago, because I was completely lost how much to add of what. The answer I got wasn't too helpful: Try 0.5% of oil. And then maybe 0.5% of bentonite.


Thanks!
Nick

RayG
9th August 2012, 09:12 PM
Hi Nick,

I think I read somewhere that you can use methanol instead of iso-propanol, the oil I think synthetic two-stroke oil is what we use, I'm away from the workshop at present, so I can't check. (Actually, I think I'm only 2 1/2 hours from Munich by train.. OBB Railjet :) )

I'm curious as to how you have setup for vacuum casting, do you have a diagram?

Regards
Ray

MuellerNick
10th August 2012, 01:56 AM
I'm curious as to how you have setup for vacuum casting, do you have a diagram?


I'll have a posting and a video as soon as that works the way I want.
I'll make further tests this Saturday (I hope).
Basically, it's a box with a pouring hole out of steel. Inside the box, behind the hole is the mould (made out of core sand). Attached to that box is a vacuum pump. You switch on the pump, grab the small pot with molten aluminium and quickly dump it into the hole on top of the box.
Then wait a few seconds, remove the mold and cast the next part.

One mould already bursted. Well, I had to expect that (unsuited shape). But as it is within a containment, nothing happened.

BTW:
I found the receipe of the homemade Petro-Bond. It's called K-Bond (http://www.foundry.ray-vin.com/k-bond/k-bond.htm).


Nick

fubar
10th August 2012, 09:17 AM
einfach wunderbar

eskimo
10th August 2012, 09:37 AM
einfach wunderbar

your not using profanities are you?:D

Big Shed
10th August 2012, 09:39 AM
BTW:
I found the receipe of the homemade Petro-Bond. It's called K-Bond (http://www.foundry.ray-vin.com/k-bond/k-bond.htm).



I notice in this recipe for for K-Bond they use isopropanol or methanol to gel the Bentone 34.

We used Bentone 34 extensively in the paint industry as an anti-settling agent and frequently made an intermediate Bentone 34 gel before adding it to the mill. The gelling agent we used was just plain methylated spirits, or standard industrial ethanol, ie the stuff you get off the shelf in the hardware store, ie Diggers brand.

This would be much easier to get and certainly a lot cheaper than isopropanol/iso-propyl alcohol.

MuellerNick
10th August 2012, 06:44 PM
(Actually, I think I'm only 2 1/2 hours from Munich by train.. OBB Railjet )

If that was a disguised question wether you can come by at a G&G: Yes. :)
The next one will be on Saturday in a week (18. August).
I'm a bit hard to reach by public transports ...
You could sleep in the shop.

If you are interested, PN me.


Nick

RayG
18th August 2012, 06:35 AM
If that was a disguised question wether you can come by at a G&G: Yes. :)
The next one will be on Saturday in a week (18. August).
I'm a bit hard to reach by public transports ...
You could sleep in the shop.

If you are interested, PN me.


Nick

Just an update, Josh and I are off to Munich in the morning (OBB Railjet train does up to 200kph), and we are looking forward to a hot Munich summer's day (forecast is 29 C) and doing what we like best, melting bits of metal and talking with some like minded people over a barbeque and a few beers....

Should be a good day... :2tsup:

Regards
Ray


PS.. I'll take a few pictures if I remember the camera..

Steamwhisperer
18th August 2012, 07:43 AM
Just a reminder Ray, "don't forget the camera":D

Phil

MuellerNick
18th August 2012, 08:40 AM
"don't forget the camera"

This is a restricted area. Photography absolutely forbidden. :wink:

I talked to the camera man from the last video and instructed him what takes to put a focus on. Unless he has no time, there will be an other video. This time with Ray an Josh. :2tsup:


Nick

Steamwhisperer
18th August 2012, 08:47 AM
This is a restricted area. Photography absolutely forbidden. :wink:

I talked to the camera man from the last video and instructed him what takes to put a focus on. Unless he has no time, there will be an other video. This time with Ray an Josh. :2tsup:


Nick

Hi Nick,
I have the popcorn ready to go. Looking forward to the movie (loved the book).:D

Phil

MuellerNick
18th August 2012, 09:04 AM
I have the popcorn ready to go.

Sorry, no popcorn. Only Beer. Augustiner (http://www.augustiner-braeu.de/augustiners/html/en/index.html), founded 1328 (the beer is not that old).
After the last pour. :no:


Nick

Ropetangler
18th August 2012, 11:19 AM
Just an update, Josh and I are off to Munich in the morning (OBB Railjet train does up to 200kph), and we are looking forward to a hot Munich summer's day (forecast is 29 C) and doing what we like best, melting bits of metal and talking with some like minded people over a barbeque and a few beers....

Should be a good day... :2tsup:

Regards
Ray


PS.. I'll take a few pictures if I remember the camera..
It sounds great Ray, back in Australia we are all envious on several counts. The opportunity to meet with Nick and his mates, messing around in the foundry, and while I have no experience with the Augustiner that Nick has mentioned, while in Ireland I did try some of another German brew, Erdinger, and that was a very nice drop. My recommendation would be to try them both.:D I'm sure you and Josh will have a great afternoon and we look forward to the pictures and the stories:wink:

RayG
20th August 2012, 02:06 AM
Well, we are now back in Linz, thanks again to Nick and friends for his hospitality and warm welcome, and of course not forgetting the workshop's chief engineer (the cat).

It was a perfect day, good weather, good company, good barbeque, good beer, and good casting results.

Nick's workshop is full of really nice machines and very interesting projects.
His diesel engine project is quite complex with lots of very fine beautiful castings. He does amazing work with resin-bonded cores. I also have some pictures of the motor mount casting for mounting high speed spindles.

I'll sort out some pictures of the various castings to post in the next few days, meantime I think Nick is editing the official video.

Regards
Ray

PS..Rob, I've tried Erdinder and it's pretty good but that Augustiner (http://www.augustiner-braeu.de/augustiners/html/en/index.html)(Augustiner Brau Lagerbier Hell) Beer is a real winner. :2tsup:

MuellerNick
20th August 2012, 02:23 AM
thanks again to Nick and friends for his hospitality and warm welcome,

The pleasure was on our side!
Josh and Roy are what I liked so much when I once was in Australia. The best compliment I can make: I'd like them as my neighbors. :2tsup:

I haven't taken any photos and any video. But I do have 150 video takes I'm editing right now. It will be late at night when I'm finished.

I've stolen this picture from one of my guests:
220061
This is right after the last pour (maybe at midnight) and the furnace at full throttle just for the fun of it.


Nick

MuellerNick
20th August 2012, 02:25 AM
Uploaded the thumpnail in the previous post ...

220062

Nick

Ropetangler
20th August 2012, 05:18 PM
I'm glad that wasn't the barbecue Nick, - the snags certainly would have been well done!:D.
On another note, your iPhone app illustrating the bluing process is most impressive. I'm not sure that everybody here will have seen it, so here is the link.
Metal scraping: How to read the spotting - YouTube (http://www.youtube.com/watch?v=y2AUew5Evxc&list=UU4h0VCL37WHGGzp8gwY1fow&index=9&feature=plcp)
All the best Nick, and thank you so much for all the input you provide, I and many others find it most interesting and informative, and the fact that you post the videos in both your native tongue of German and also again in English brings great credit to you. I wonder how you find the time to fit it all in, Thanks again.:2tsup:
Regards,
Rob

MuellerNick
20th August 2012, 05:43 PM
And here is the video from the past Saturday.

YouTube (www.youtube.com/watch?v=o-Sfc1_1cmI)

Nick

shedhappens
20th August 2012, 06:06 PM
Great stuff Nick, and I see that Ray was doing a fantastic job with his taste bud's on the local brew :U

G/day Ray.

Ueee
20th August 2012, 07:42 PM
Looks like fun times Nick! I'm glad Ray and Josh could enjoy the casting and beer with you. However you have got me in trouble, my wife saw most of the video and said, oh it looks like our driveway, only neater......

One question, is that a compressed air line i see providing air for the WMO burner, rather than a blower?

MuellerNick
20th August 2012, 07:56 PM
oh it looks like our driveway, only neater......

Tell her, that she needs new glasses*). Or that her vision capabilities are very selective. :D


One question, is that a compressed air line i see providing air for the WMO burner, rather than a blower?


The compressed air is for Preszilla, the oil tank. The oil is pressure feed (about 2 bar) to the burner. Also, the atomizer for the fuel needs a bit of air. Combustion air comes from a blower.

*)
I strongly suggest welding glasses in your case.


Nick

RayG
20th August 2012, 08:22 PM
Hi Nick, Thanks for the video. good stuff :2tsup:

Here are some of the castings from yesterday, these are by Stefan, he is making a nice tapping guide. You can see some of the parts, and the casting process in the video.

http://www.backsaw.net/pics/Munich/DSCN2133.JPG


The other part Stefan was doing was a Motor Mounting Flange for his friends circular saw, so he could fit a SEW variable speed drive..
http://www.backsaw.net/pics/Munich/DSCN2156.JPG

After a few false starts getting the pattern out of the sand, it came out nicely.

Nick is making a motor mount for mounting those chinese high speed spindles.

I'll sort out some more pictures and post some more in this thread.

Regards
Ray

Machtool
20th August 2012, 08:44 PM
Wow! I’m officially jealous. I’ve been so busy the past few months, I wasn’t aware this was taking place. Had I known, I’d have gotten Ray or Josh to shake Nick’s hand on my behalf. What a great event.

I’ve had the pleasure of Ray and Josh in my shop a few times, glad they kept up their end for the Austrians. (I saw the joke at the start of the video). :D

Nick, if you ever want a holiday down under, I’ll volunteer to look after the Barbeque at the re-union and catch up with the other like minded people.

Best Regards Phil.

Stustoys
20th August 2012, 11:25 PM
Looks like we missed a great day.

To back up a little, Whats the idea behind the vacuum pouring?


Stuart

MuellerNick
21st August 2012, 12:43 AM
Whats the idea behind the vacuum pouring?


To get thin walls with a relatively big surface.
At my previous attempts to cast the protective cover shown above, the melt simply froze half way before the mold was filled. If you suck in the molten metal, it will move quicker and won't have enough time to chill.

Unfortunately, I had no time for further trials. I repeatedly had to repair the muller last week. Makes no sense to have a casting party without sand.

I fear it will take 'till September to start the vacuum-test again. :((
Also, I have to make 4 small patterns, get them working and send cast samples until Friday.


Nick

Anorak Bob
21st August 2012, 08:40 AM
Thank you Nick,

What a fantastic video! The efforts of those involved in its making are greatly appreciated. All we needed was the smell and it would have been like being there.:2tsup:

I'd love to hear more about the high speed spindle, its mount and what you use it for.
I 'd also love to have that Maho parked in my shed.:D

Bob.

MuellerNick
21st August 2012, 09:08 AM
I'd love to hear more about the high speed spindle, its mount and what you use it for.


I only have a small 800 W (or what) 55 mm ER11 air cooled spindle with 24 kRPM. I use that for patterns milling. Or maybe a bit of aluminium or engraving. You don't need more power with a 6 mm mill, they will already be broken at 300 W.
The spindle mount from the video is for 80 mm spindles. I'll sell these mounts.

BTW spindle:
I did not buy mine at eBay, but at a local seller with a clear increase in the price. But he guarantees a maximum runout. Mine only slightly moves the indicator of a Mahr Millmess with 0.5 µm resolution. Also, this spindle has PE, most of those sold on eBay lack that. :o
I'm getting bashed quite often why I spent so much. Bashed by people that have look-alikes with 0.1 mm runout.


Nick

RayG
21st August 2012, 07:04 PM
Hi BT,

You can join the queue for the MAHO, it's running a retrofit EMC2, and with the high speed spindle, it's a perfect machine for pattern making.. ( as well everything else.. :) )

The high speed spindle motor mount that Nick is manufacturing would be perfect for a CNC router.. (I'd suggest send him a PM if you want to buy one :) ) , is some very clever casting and well thought out design.

Half the pattern looks like this. It's done with a match plate with a core through the middle..

http://www.backsaw.net/pics/Munich/DSCN2136.JPG

If you notice the reservoir opposite the mounting plate, that part of the casting stays in place and balances the motor mounting plate while boring the inside.. Then gets cut off later.

This picture I had to get from the video, my picture didn't come out as I would have liked.
http://www.backsaw.net/pics/Munich/HS_Spindle_Mount.JPG

There is a video with more on the Maho making the pattern..

Backyard casting: A HF-spindle-mount + "exhaust" - YouTube (http://www.youtube.com/watch?v=3tAyqxw_pak)


To back up a little, Whats the idea behind the vacuum pouring?




Hi Stuart, check out the wall thickness in that video! getting the wall thickness of the exhaust part, as thin as Nick is getting, is why vacuum casting.

Hi Nick, What was the material being used for the pattern.. I remember it being mentioned, but with my memory I've forgotten already..

Still amazed by the stuff you are making... :2tsup:

Regards
Ray

MuellerNick
21st August 2012, 08:12 PM
Hi Stuart, check out the wall thickness in that video! getting the wall thickness of the exhaust part, as thin as Nick is getting, is why vacuum casting.


The exhaust wasn't vacuum cast. Plain vanilla sand casting. But it took some trials to get the in-gates right.

For the counter weight on the spindle mount:
I do bore it in the lathe with a purpose made jig. I didn't want to do that in the mill with a Wohlhaupter. Feeding is time consuming and a boring bar with 175 mm length and 18 mm shaft ... oh well!
In the lathe, I do it with a boring bar with 40 mm diameter. 800 RPM is no problem with the counter weight. And I just have to hit the start button. :2tsup:

The material is Renshape BM$whatever. They do have hard to remember numbers. It is similar to Ureol 700. That's for the "brown" (how they call it) stuff. The green one is a denser variety. The green one needs no sealing/painting. The beige one likes a cover of pattern paint.
If used for the core boxes (beige one), I brush on a release agent, no paint. Paint together with my core sand binder is a bad idea, the binder likes to stick to it.


Nick

RayG
21st August 2012, 09:08 PM
Hi Nick,

This stuff? FMSC - RenShape BM-70 (http://www.freemansupply.com/RenShapeBM70.htm)



Wow! I’m officially jealous.

Sorry, I wish you were there too, you have a lot in common, and I think you'd have had a good time discussing scraping and metrology stuff..



Nick, if you ever want a holiday down under, I’ll volunteer to look after the Barbeque at the re-union and catch up with the other like minded people.


I'll second that idea!

Regards
Ray

MuellerNick
21st August 2012, 09:54 PM
This stuff? FMSC - RenShape BM-70

Yes. I looked it up, I use RenShape BM 5460. But in the datasheet of the link you gave, it says BM 5460 at the bottom.


I'll second that idea!


Thank you guys! But I fear that won't happen. Unless I win in the lottery (that I don't play at).


Nick