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I Forge Iron

Making a hand-cranked blower


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Getting closer! I cast a set of gears the other day, I tried for a full set but settled for a partial :rolleyes:
The compound gear for the center gear in the train didn't come out, I was experimenting with some local sand and it had way too much clay in it so it held too much moisture and ruined the cast. I also cast an impeller and that came out very nicely. I'm quite happy with that one. here's the ones that came out, Photobucket was giving me fits so I only have a few pics.
1stgearcastings.jpg
And here's the one that didn't come out;
failedgear.jpg
failedgear2.jpg
I started to clean up the good gears today, and they are going to work pretty well, I think. I will be re-casting the compound gear in the next day or so and I will post some more pics.

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Thomas, the gearbox and gears were laid out with the same rule, so shrinkage shouldn't be an issue. I did put a riser on top of the larger gear to help control in-mold shrinkage. Serendipidously, the gear patterns were a bit oversized, but that will allow some meat for whoever builds one to clean'em up. I took a file and some sandpaper to the ones that came out and here's a pic
firstgears.jpg
I think they are still a bit rough, but for hand power they should be fine.

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Looking good Odd Duck. I am suprised I didn't see this thread before.

Sweeps can be really useful they are still often used for the top of a corebox often rotating on a dowel or guided by rails. They can be used with a "skeleton" pattern or corebox to make complex shapes. Skeleton patterns are pretty rare these days but if you are willing to take the time in moulding they make the pattenmaking much less time and material intensive. Most foundries do not want to spend the time needed for this type of work. I have made a skeleton corebox one time in 18 years of patternmaking, it was for a large water meter.

They had a pattern but needed 1 shorter casting with a different inside. The pattern was about 4' dia and about 9' long, so making a new one for 1 casting would have been VERY expensive which made using a skeleton corebox worthwhile. The skeleton box was a large box with a plywood rib everywhere where there was a transition in shape some of the transitions had wood to make more complex shapes. To use the skeleton box it had sand rammed up in it and then sweeps were used to strickle the sand forming the corebox. Parting powder was then applied to this corebox that was mostly made of sand and the core was then made normally out of the corebox. A skeleton pattern is made the same way, ribs and then sand swept between the ribs. This corebox was done using airset sand, but you could use plaster on smaller patterns. Plaster used to but used a lot for sweeping or casting patterns out of but has almost entirely been replaced with Bondo, casting urethanes and epoxies. To shorten the pattern I made a new end flange and coreprint that fit over the existing pattern and a corebox that went into that coreprint to stop off the end. After they made the one casting the flange and soreprint were removed taking the pattern back to normal

Sweeps can also be used with bondo to create shapes especially if you do not have a lathe you can use a sweep with a center dowel.

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Thanks, JNewman, I have seen the skeleton patterns like you spoke of in some of the older pattern books. This one was small and simple enough that a simple strickle worked, I used that casting to make the master pattern. I have more time than I do equipment, so some of the old school methods apply to my needs.

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That sure is an iteresting project you got going there. I wonder if you pulled a silicon mold off of a good set of gears if you could just do a shell lost wax casting in bronze of the gears and not need to do much clean up on them. I have only done "fine art"(?) casting, never anything for machinery so I don't know how the shrinkage of metal would add up to or is it subtract for the gears. Maybe make them too tight to function. However if they were cast out of silicon bronze they would wear for a very long time. <_<

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I've given that a thought, Bentiron, but I'm not set up for/ have any experience with lost wax or investment. They turned out a little oversized as-cast, so there will be lots of meat for fine tuning by the builder/s. I got a good cast of the compound gear this weekend, no pics yet. I also cast the handle, first casting always comes out a bit rough until I figure the gating out. It's a direct copy off of an antique handle off of an apple grinder or something. I bought the handle at a yard sale a few years ago because I liked the shape of it. I'll post some more pics when I get the compound gear cleaned up. The toughest part of this whole project is going to be writing the instructions.

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Just for Grant, he said that he wants a 3 speed:
http://www.sturmey-archer.com/products/hubs
http://bowerylanebicycles.com/bicycles.html

I ran across it on another forum and have been entertaining the idea as well since many 3-speeds were built to handle broken pavement, unlike my road bike that doesn't get used anymore. The price tag in these links is a different story.

Phil

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Here's a pic of the compound gear and the crank handle, I haven't had a chance to work on the gear yet but I cleaned up the handle a bit. I used a steel core to make the d-hole in the square end of the handle but I think I am going to switch to using a sand core to save time. I've got to modify the original handle a bit to make the coreprint but that's going to be pretty simple. I should get the gear done in the next few days, almost ready to take orders! B)
handleandcompound.jpg

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Just for Grant, he said that he wants a 3 speed:
http://www.sturmey-a...m/products/hubs
http://bowerylanebic...m/bicycles.html

I ran across it on another forum and have been entertaining the idea as well since many 3-speeds were built to handle broken pavement, unlike my road bike that doesn't get used anymore. The price tag in these links is a different story.

Phil

Now you're puttin' words in my mouth. I was just talking about easily available gears and how a planetary gear train might work good.
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OddDuck

I have been watching this thread with interest. Now that your at a stage close to mass production, have you worked out a costing? for a mould kit and a finished product?
Well done on your efforts so far. Now all you need is to make portable rivet forges and stands for both, and you have covered the market! :D

Adam

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Now you're puttin' words in my mouth. I was just talking about easily available gears and how a planetary gear train might work good.


There are a number of 3-speed bikes listed on Craigslist, but they are being priced high lately (since it is spring possibly)

The hubs are planetary, and can often be had cheap so it may be and option.

For cast to shape with nothing special going on OddDuck is getting results!

Phil
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Adam2519, I am not going to sell completed units, this is going to be strictly a casting kit thing, I don't have the facilities or equipment to build them consistently or cost effectively. As far as pricing goes, I am thinking $175US + shipping for the full kit, with lesser part-count kits cheaper. I may add mounts or hose adapters eventually, if these go well. I've thought about doing a rivet forge kind of thing, I actually have access to one I could basically copy piece for piece, but the pan itself is a pretty big casting for a small setup like mine. I've been trying to think of workarounds, and I may have one, but I am going to finish this up first.

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I drove while a friend of mine who is unemployed threw up scrap metal from stuff put out for bulk trash pickup this past week, I should have been on the look out for three speed bikes. He threw in about a dozen old bikes, ten speeds mostly but the trouble with those is that all your gearing and chain would be on the outside and exposed, still if you had a nice fan like yours you could still drive it nicely with that gear train. The stuff people throw away, what a waste, he paid me for the tank of gas and still made over a hundred dollars what with all the brass, copper, steel and aluminum. Folk are so wasteful :blink:

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  • 2 weeks later...

Hi Odd Duck,

Let me know when you start selling these kits. They will certainly fill a niche in the hand crank blower that's been needed for a long time. I cannot wait. Say good bye to over-priced antiques on ebay,here comes a new alternative. B) As one who is beginning on this path I await your kit with great anticipation! :)

Ken

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Ken, My plan (and we all know how those usually end up...having teenage kids is rough on the ol'schedule) is to have A kit of some sort or other available within the next two weeks. I am going to do a little more patternwork this weekend on a simple version for those who want a simple belt drive unit. I'll post pics as soon as I have sonmething to show.

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Ken, My plan (and we all know how those usually end up...having teenage kids is rough on the ol'schedule) is to have A kit of some sort or other available within the next two weeks. I am going to do a little more patternwork this weekend on a simple version for those who want a simple belt drive unit. I'll post pics as soon as I have sonmething to show.


Hi Odd Duck,

I can only imagine.My sister has two teenage boys and they keep her plenty busy.:D Wow,you're making a belt drive unit? It sounds like you're going to have a few models available. I think that what you're doing is wonderful and very ambitious. Now that I've been bit by the forging bug, your work and creativity serve to inspire me even more. :D I look forward to seeing your pics. Have a great week.

Ken
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  • 3 weeks later...

Update # I lost count... Latest pattern in the series! This will be the less expensive alternative to the full kit. This is the bit I told Ken Jersey that I was working on, it's a bracket and pulley for a flat belt setup. The neat thing about it will be that it will come as a solid casting, with the pulley and bracket cast together. It will also have the through hole already cast in place, sized so that all you have to do is add a set screw to the pulley, cut it off, clean it up, and add your bushings and 1/2" drive shaft. The bushings I designed it around are common ones that can be found at nearly any hardware outlet, 5/8"OD, 1/2"ID, and about 1 1/8" long. You will also have to file where the bracket and blower meet to align the impeller with the inside of the shell.
pulleybracket1.jpg
pulleybracket2.jpg
And, for those interested, here is a pic of the corebox in progress.
coreforPB6.jpg
coreforPB7.jpg
This kit will consist of a pair of shells, an impeller, and a bracket. Eventually I will be adding a large pulley and support bracket, but I wanted to keep the cost down.
I am going to start taking orders for either set on June 1st. I have to help my son finish his Eagle scout project and I will be able to concentrate on these. The price for the full kit will be $175 and the flat belt kit will be $100. I'm working on getting the gearbox that I have already cast together, should have it ready by the first part of next week. I will of course post pics when it's done.

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Thanks, Iron Clad, no website (yet, I may do that after a while), it will be signifigantly lower tech than that, more of you shoot me an email or pm and we swap all pertinent info, I can invoice thru paypal so there will be a secure payment method and records. Checks and money orders also gladly accepted :) .

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It would, Andrew, provided that the customer had a metal lathe. I've thought of several things like that, perhaps a future version if someone wanted to convert to an electric motor. I want to put out kits that are buildable with simple hand tools (okay, I'm including a drill press in my list of hand tools, but what basic shop doesn't have a cheap one? :) ) I talked to a friend of mine over the weekend, he's a curator at a middle sized museum and has a whole bunch of hand blowers from the early 1800's on up, and said I could either copy them or at least use them for ideas. The only problem is that the museum is in New York state and I'm in Maine. :rolleyes: Might have to take a road trip this summer.

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  • 1 month later...

Hey Odd Duck,
Just thought i would drop a line to see how things are going. I have about scrounged all the things for a forge except for a brake drum or a fire pot of some sorts. Mostly curious of your progress,

any way Thanks Chad J

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