Author Topic: Galloway Castings  (Read 20607 times)

PatJ

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Galloway Castings
« on: December 04, 2013, 01:44:15 PM »
I started making a bar-stock Galloway, not to any particular scale, but with flywheels about 10" dia.
As I recall, the 1/4 scale was smaller than I wanted, and the 1/3 scale was too big, so I think I was between those sizes.

This was a few years back, and just learning 3D.

I have since got into backyard castings, and so I will revisit this engine and try to cast a one-piece frame and cylinder from cast iron.
I don't really care for the bolted frame/cylinder kit designs since that is not how the originals were made.

I think I have enough photos to go by, and my dad had two that were 7.5 hp, one being a round rod.
I remember the simplicity of this engine, and how well it ran.

Here is a piston I made from gray iron bar stock, but I need to cast this to make it lighter.
And my first attempt at a 3D flywheel, which is only partially correct.
« Last Edit: December 24, 2013, 07:05:26 AM by PatJ »

PatJ

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Re: Galloway Castings
« Reply #1 on: December 04, 2013, 01:45:35 PM »
My dad's forged-rod Galloway.
« Last Edit: December 24, 2013, 07:06:23 AM by PatJ »

Offline Jasonb

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Re: Galloway Castings
« Reply #2 on: December 04, 2013, 04:41:56 PM »
Pat the 10" flywheel is about right for a 1/3scale 5HP engine but if you are going for your Dads engine then as you say something like 3/10 scale. You will have some fun with the cores if you do a single casting to get the water jacket around the cylinder.

Here is a challenge for you, cast wheels for a Hand portable cart :LittleDevil: Those 5/32" dia spokes won't be easy to get the iron to flow down. Should be able to post my finished wheels next week. ;)

J

PatJ

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Re: Galloway Castings
« Reply #3 on: December 04, 2013, 06:56:42 PM »
I am not really trying to match a particular engine, just trying to find a convenient size that will fit the lathe and not have fiddly sized parts.

I noticed that the galloway has a bolt-on water hopper, and I would make mine that way.

Many of the hit-and-miss engines did have the water hopper cast as an integral part of the cylinder and frame, but I would have to think about that core.  Obvioiusly if they use to make them that way, then they can once again be made that way.

For those wheels, I would use steel rods, and cast the hub and rim around the rods, as was done on some of the old John Deere tractor wheels.

PatJ

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Re: Galloway Castings
« Reply #4 on: December 04, 2013, 10:29:20 PM »
Hey Jason, I found your Galloway thread:
http://www.modelenginemaker.com/index.php/topic,2160.0.html

Great work as usual.

PatJ

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Re: Galloway Castings
« Reply #5 on: December 05, 2013, 01:54:18 AM »
It looks like the horsepower ratings were 2.5, 5, 7.5, 10 and 15.

My dad's was a 7.5 hp if I recall correctly.

And the flywheels for that engine were about 36" dia.
Bore was perhaps 6.5" with a 12' stroke, to give a compression ration of about 5.25:1.

So while I don't like the flywheels to get too big, I also don't like trying to handle and machine small parts, so my leaning is a 1/3 scale of the 7.5 hp engine, which would give a 2.17" bore, a 4" stroke, and a 12" dia. flywheel.

A bit on the big side, but probably castable/machinable with the equipment I have.
« Last Edit: December 05, 2013, 02:12:37 AM by PatJ »

PatJ

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Re: Galloway Castings
« Reply #6 on: December 05, 2013, 07:31:02 AM »
Here is where I got with the cylinder/frame model tonight.

More work to do on this, but getting it roughed out enough to be able to make patterns.

Water drain hole is on the bottom of the cylinder jacket.
The compression release is on the side of the cylinder, down the stroke a bit.

Still need some bearing flanges, and miscellaneous bosses.

I will probaby have to make the curved parts of the frame using sheet metal, and then glue some foam or thin plywood layers to the inside to get the correct wall thickness.
The shape of the interior of the frame will be defined by the frame walls.

This is a 3D PDF, so you can click on it, and pan/tilt/zoom it.

Now I need to determine cores and parting line.
I guess parting line vertically down the long axis.

The bottom of the frame will be open, and there will be a core print extending down from that opening.
Another core print will go upwards out the top of the water hopper opening.
A core print out the bore where the cylinder head goes, and one more print at the ignitor hole.

The water holes in the end of the cylinder would probably be best machined after casting to simplify the water jacket core.
« Last Edit: December 05, 2013, 08:01:37 AM by PatJ »

Offline Jasonb

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Re: Galloway Castings
« Reply #7 on: December 05, 2013, 07:41:43 AM »
Looking good Pat, the base is open at the bottom which should make it a lot easier to put a core in.

PM sent


PatJ

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Re: Galloway Castings
« Reply #8 on: December 05, 2013, 07:43:07 AM »
Here is today's progress on the 7.5 hp Galloway.

This frame and cylinder are very tricky to model.

I don't have a way to add the compound curves at the back of the cylinder and at the back of the base yet, but don't really need those to make the pattern, since those can be manually added.

« Last Edit: December 07, 2013, 08:12:47 AM by PatJ »

PatJ

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Re: Galloway Castings
« Reply #9 on: December 07, 2013, 08:14:14 AM »
And the 3D PDF file.

You can pan/tilt/zoom with this file.

PatJ

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Re: Galloway Castings
« Reply #10 on: December 09, 2013, 06:49:51 AM »
The large parts of the engine have been modeled, including the gears, and the engine operates well in simulation so far.

Now on to the small parts, then it will be 2D drawings, and then the pattern making can begin.

This engine is about 20% larger than a 1/3 scale 5 hp Galloway, with flywheels just under 12" dia.

PatJ

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Re: Galloway Castings
« Reply #11 on: December 09, 2013, 06:52:55 AM »
And a video of the first simulation run.

PatJ

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Re: Galloway Castings
« Reply #12 on: December 09, 2013, 06:55:50 AM »
And we got gears !!!!     :cartwheel:

PatJ

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Re: Galloway Castings
« Reply #13 on: December 09, 2013, 08:46:11 PM »
I drew the gears for this engine with the correct number of teeth, and the correct approximate tooth shape, but the small gear got a bit thin at the keyway.

I need to draw the gears accurately so I can cut them, and I remember that in the past there has been a great deal of discussion about gear cutting.

Seems like you start with a chart for number of teeth, and then get the blank dimensions, and then select a cutter type, and go from there.

Anybody got a quick synopsis on making gears?

I have the standard cutters and an indexing head, I just need to dial in the correct geometry for the blanks and cutting setup.

Offline Jasonb

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Re: Galloway Castings
« Reply #14 on: December 09, 2013, 08:52:36 PM »
Whats the centre distance between the two gears? then its easy enough to work out but if you have just plotted it without a specific PCD it may need tweaking to suit standard gear pitch

PatJ

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Re: Galloway Castings
« Reply #15 on: December 09, 2013, 09:31:18 PM »
The gears were drawn from an old engraving, and so while the relative size of them is correct as far as the proportions to the other engine parts, there has to be a conversion to a standard tooth/gear size, which is what I can't remember how to do.

I guess I could look up some typical gear/tooth sizes for approximately the same size gears online at McMaster-Carr, and then go from there.

Offline Jasonb

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Re: Galloway Castings
« Reply #16 on: December 09, 2013, 09:54:06 PM »
The basic rule is if you half the size of the gear the DP double, third the size the DP goes up 3 times.

for example if your full size had 4" gear with 48 teeth at 12DP, a half scale model would have a 2" dia gear with the same number of teeth but they would need to be 24DP

So if you can say what the diameters scaled or what the distance between the two gear centres scaled it will allow us to suggest some likely candidates. As you are not scaling to an easy ratio it my be you need to adjust the tooth number to allow a standard DP  cutter to be used rather than sticking to 48:24 which may result in say 26DP profile which would need custom cutters.

J

PatJ

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Re: Galloway Castings
« Reply #17 on: December 09, 2013, 10:07:47 PM »
Thanks Jason, it seems to be a knotty problem, but definitely solvable.

I dug out some of the notes I made a few years ago, just before I stopped working on this engine design.
They are as follows:
(Note, I have no idea if the following information is correct or not, these are just my best understanding of it a few years ago.  Worse yet, I don't even recall the source of this info).

And I seem to recall a gear blank chart in the Machinists Handbook, I will look for that.

For an internal combustion engine, the gear ratio needs to be 1:2, ie: the smaller gear on the crankshaft turns twice for every revolution of the larger gear which contains the cam, unless you have a pivoting cam like the Wright Brother's engine, in which case the cam rotates at crankshaft speed.

Obviously, as the gear gets larger, then in general, the teeth get proportionally larger.

Spur Gears: Spur gears are cylindrical and have teeth which are parallel with the axis of the gear. The are designed for use on shafts whose axes are parallel with each other. A spur rack has teeth at right angles to the axis of motion. Spur gears are the most commonly used used type of gear, and are normally used with moderate speed and moderate tooth load. Spur gears can be used on pairs of shafts requiring varitations in speed ratios.

Diametral pitch defines the size of the gear tooth.

The defiinition of Diametral pitch (P) is:  A ratio equal to the number of teeth on the gear per inch of pitch diameter.  P=N / D

where: N = The number of teeth on a gear or pinion, and D = the Pitch Diameter, which is the diameter of the pitch circle of a gear or pinion.

The Pitch Circle is an imaginary circle that rolls without slipping with a pitch circle of a mating gear.  (In rough terms, it is a circle with a radius located about half the way up the height of the gear tooth.)

The term "Involute profile" refers to the shape of the gear tooth.  There are a number of gear tooth shapes with varying functions, but the involute profile is in common use for many general purpose gears today.  The idea behind the gear profile is to be able to transfer power from one gear to another with a minimum of slippage and friction.

Below is a chart of "Involute Gear Teeth", and the "P" number refers to the teeth per inch.

So for a given tooth size, and a given number of teeth, you generally know the size of the gear.

Gears have to transmit power, so the size of the teeth used and the strength of the material used to make the gear, as well as the velocity of the gear determine which pitch to use.  Generally, the more power that is required to be transmitted, the larger the teeth need to be, and probably the wider the teeth need to be.

To mesh two gears together, they have to have the same tooth size.

Standard gear cutters will cut a range of gear teeth quantities, with the lower number meshing more efficiently that a higher number.

Cutter No.   Cutting Capacity (Quan. of teeth)
1      135
2      55 to 134
3      35 to 54
4      26 to 34
5      21 to 35
6      17 to 20
7      14 to 16
8      12 to 13


Ok, like I said, don't assume any of the above infomation is correct.
I have no gear experience, but rather I am trying to learn how to make some gears.

PatJ

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Re: Galloway Castings
« Reply #18 on: December 09, 2013, 10:50:31 PM »
I found a spreadsheet for gears.
That seems like the way to go.

Gear design can be a can of worms I guess, there is a lot too it.

I just need some simple straight cut gears though using standard gear cutters, so I guess I will go the spreadsheet route.

I don't want to re-invent gear theory, I just want to make a couple.

It looks like the rough diameters of the gears I need are 2.27" and 1.135".
It woud be nice to keep the 48:24 tooth ratio to match the original engine, if that is feasable.

I will try and figure out blank sizes and tool bit feed-ins, and tooth size.

And I found the chart below, that will be helpful (if it is the rigth chart for the cutters I have).
« Last Edit: December 09, 2013, 10:53:41 PM by PatJ »

PatJ

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Re: Galloway Castings
« Reply #19 on: December 09, 2013, 10:58:07 PM »
From McMaster-Carr:

To work together, gears must have the same pitch and pressure angle (the angle between contact points of meshing teeth). A gear's pitch is its number of teeth divided by its pitch diameter. For example, a gear with 16 teeth and a pitch diameter of 1/2" will have a pitch of 32. For higher load capacities, choose 20 pressure angle gears over 14 1/2 gears.

Use gauges to measure gear pitch and pressure angle.

Offline swilliams

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Re: Galloway Castings
« Reply #20 on: December 10, 2013, 07:19:10 AM »
The calculation you need is pretty straight forward Pat

If you take the distance between the two gears, lets call it x
Then you want a 48 and 24 tooth gear

so take (48 + 24) / 2 / x = 36 / x
This will give you the DP of the gear

The diameters you gave are 2.27" and 1.135", I assume they are the outside diameters of the gears??
To get the outside diameter you add 2 teeth. So (48 + 2) / 2.27 = 22.02DP

On the other hand if it's the pitch circle diameter (that corresponds to x above), then 48 / 2.27 = 21.14DP

We can convert this to metric which gives more options 25.4 / 21.14 = M1.201
The nearest standard metric size is M1.25 which corresponds to 20.32DP

Obviously you've got some playing around to do. Anyway hope that makes sense

Steve

Offline Jasonb

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Re: Galloway Castings
« Reply #21 on: December 10, 2013, 07:51:06 AM »
As your large dia is exactly twice the small dia I have to assume this is the PCD of the gears as the OD will not be exactly twice.

As I mentioned above by using a odd scale you are unlikely to be able to use standard cutters and keep the same number of teeth so unless you want to get into making your own 21.14DP cutters you would be best to choose the nearest standard DP and adjust the tooth count.

24DP would be close with 54T @ 2.250PCD and 27T @ 1.125PCD which only moves your centre to centre distance 0.012"

I don't know if the 7.5HP used a a larger gear but the 5HP had a 6" PCD 8DP 48T large gear and 24T small and I doubt they used an odd DP which means the next size up 6DP would put the gear at 8"PCD (8.333" OD ) which would scale to approx 2.4PCD which is too large for what you want

Online Jo

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Re: Galloway Castings
« Reply #22 on: December 10, 2013, 07:58:08 AM »
Personally with designing spur gears I cheat and use Shopcalc: http://home.scarlet.be/mini-draaien-frezen/engels/program-01.html It is so quick and easy to have a fiddle with the numbers and find what numbers of teeth/DP will give you what you need.

Sadly I couldn't find a similair dodge for spur gears and had to create my own spread sheet.

Jo
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PatJ

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Re: Galloway Castings
« Reply #23 on: December 10, 2013, 08:38:04 AM »
Thanks for the info Steve, Jason & Jo.

I am going to have to study gears a bit more to get more familiar with the terms.

I am a bit slow when it comes to learning, so I try and make up for it with extra effort.

Offline swilliams

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Re: Galloway Castings
« Reply #24 on: December 10, 2013, 08:58:44 AM »
I am a bit slow when it comes to learning, so I try and make up for it with extra effort.

Sounds good Pat. Don't matter how you get there, so long as you arrive  ;)

Steve

PatJ

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Re: Galloway Castings
« Reply #25 on: December 22, 2013, 08:47:22 AM »
I started working on the valve gear for this engine, and traced the shape of the cam from a photo that was found online.

I modeled the various parts; cam, pushrod, pushrod end, and rocker arm and support, and then assembled everything for a simulation.

The factory cam was symmetrical so that the engine could run either forward or backward depending on where the timing gears were set.

My cam shape was off, and so I did not get the factory settings of exhaust valve opening at 35 degrees before BDC and opening at 5 degrees after TDC.

I reshaped the cam to the the correct valve timing, and then raised the top of the lobe to get slightly more lift.

I noticed from the brochures that the older engines used a single flyball, and the later models used twin flyballs.
I will go with the single flyball with the forked arm that hinges from the front.

The most recent effort on this design is to determine the surfaces that require machining allowances, draft, etc. so that pattern drawings can be generated.  I am marking the machined surfaces in red, and will extend those bosses probably about 0.1" outward.

PatJ

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Re: Galloway Castings
« Reply #26 on: December 22, 2013, 08:53:47 AM »
I have tried to accurately model the flywheel spokes for this engine from the very beginning, and I think I finally have a layout I can live with on the 4th attempt.

I used a lofted ellipse that tapers in both directions, but not linearly; there is a slight break about 1/3 of the way out from the hub.

Lofted shapes wreak havoc on fillets, and so the fillets I had to use are fudged in place, but they can be hand sanded on the pattern.


PatJ

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Re: Galloway Castings
« Reply #27 on: December 22, 2013, 08:57:40 AM »
Here are the beginnings of some core prints that I will need to add to the patterns.

The cylinder and frame will be cast as one piece, but so far it has been easier to model these two parts separately.

PatJ

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Re: Galloway Castings
« Reply #28 on: December 22, 2013, 09:00:38 AM »
And the non-draft-angle machining allowances on the flywheel (in blue), and machining allowances with draft angle at the outside of the rim (in orange).

Online Jo

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Re: Galloway Castings
« Reply #29 on: December 22, 2013, 09:05:15 AM »
Welcome back Pat  :ThumbsUp: you have been busy.

What wood are you planning to use to make the patterns?

Jo
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Offline metalmad

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Re: Galloway Castings
« Reply #30 on: December 22, 2013, 09:46:39 AM »
Hi Pat
Have you started the patterns yet?
I'm looking forward to see this one come together  :ThumbsUp:
Pete
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PatJ

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Re: Galloway Castings
« Reply #31 on: December 22, 2013, 09:55:10 AM »
Thanks Jo, Metalmad-

At this point, I am trying to enlist my buddy in CA (the country) to make the patterns for this engine on his new large-format CNC machine.

I could hand-make the patterns and core boxes, but it would certainly expedite things if I had some help.

I don't really have a schedule for this engine.
I work on it in my spare time.

Once I get all the machining allowances added to the model, and define the core prints and core boxes, then the pattern making can begin.
I am using resin-bound sand, and so the fact that the sand sets and hardens should aleviate most of the sand problems that one would normally run into with complex cores and patterns.  I plan on casting the water jacket/passages in the cylinder and head like the factory did it.

Offline steamer

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Re: Galloway Castings
« Reply #32 on: December 22, 2013, 10:25:46 AM »
THAT's the way to make a pattern!....

If you're going to machine a pattern, you might want to consider aluminum.   It isn't really anymore difficult to machine than MDF, ect, and is far more durable should you want to make more that a few castings.....especially patterns in the small sizes that are easy to damage during ramming if made of wood.

Dave
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Damned ijjit!

Offline gbritnell

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Re: Galloway Castings
« Reply #33 on: December 22, 2013, 04:44:08 PM »
Hi Pat,
In regard to your flywheel spoke construction here's a way you can get the shape you need.
1. Create your rim and hub
2. create a workplane through the axis of spoke.
3. draw the profile, taper part way up then the remaining taper I presume at a different angle.
4. do a revolve on the profile and you will get your spoke.
5. fillet the spoke into the hub and rim.
gbritnell
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PatJ

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Re: Galloway Castings
« Reply #34 on: December 22, 2013, 05:34:06 PM »
THAT's the way to make a pattern!....

If you're going to machine a pattern, you might want to consider aluminum.   It isn't really anymore difficult to machine than MDF, ect, and is far more durable should you want to make more that a few castings.....especially patterns in the small sizes that are easy to damage during ramming if made of wood.

Dave

I have considered using aluminum for patterns, but in larger sizes, the cost can get prohibitive, and I think bit wear would be greater.
I have had trouble with both wood and plastic patterns breaking due to ramming, handling, and mainly pulling the pattern from the sand.

One idea I am going to try is to make temporary patterns in wood with double shrinkage, and then cast those in zamak-27, which has a low melting point, good fluidity and is very strong metal for applications that don't require operation at elevated temperatures.

I think zamak-27 is as strong as cold-rolled steel, although not as hard, and it machines and finishes very well.
It does not drill very well, but I don't need to drill it for patterns.

And with self-hardening fine sand, I can make a pretty clean copy of the master pattern, since the sand sets before the pattern is pulled, thus no distortion is added by having to tap on the pattern to release it from the sand, and no distortion from having to ram the cope up against the drag, since the drag sand is set (hardened).

I could use aluminum for casting metal patterns, but zamak is not as gummy as AL356, it saws easier and machines cleaner than 356, melts at a lower temperature, is much stronger than AL, and pours with much more fluidity than AL.

The photo below shows an ingot of zamak-27 with a single pass of a fly cutter, which feels very smooth to the touch, and then on the lower right sanding lightly with fine sandpaper, and upper right with a wire brush.  The light sanding is a good method.
The wire brushing tends to melt the metal, so that is not good, but I don't need to wire brush a pattern.
« Last Edit: December 22, 2013, 05:38:56 PM by PatJ »

PatJ

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Re: Galloway Castings
« Reply #35 on: December 22, 2013, 05:43:31 PM »
Hi Pat,
In regard to your flywheel spoke construction here's a way you can get the shape you need.
1. Create your rim and hub
2. create a workplane through the axis of spoke.
3. draw the profile, taper part way up then the remaining taper I presume at a different angle.
4. do a revolve on the profile and you will get your spoke.
5. fillet the spoke into the hub and rim.
gbritnell

George-
I am not sure why my lofted spoke won't fillet, but I did try extruding an ellipse while using a taper, and the result is not usable, and not the same as lofting through two or more ellipses.

I need to experiment with the filleting to figure out how to fillet a lofted shape without having to fudge it.

I don't know how to draw a profile and then revolve it into an ellipsoidal shape, I would think the spoke would come out circular in section?

Offline steamer

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Re: Galloway Castings
« Reply #36 on: December 22, 2013, 06:12:11 PM »
I think the biggest expense with a CNC is going to be the cycle time....and any futzing around with the part....if they can load it and go, it will get done faster....

If they have to mess with chipped MDF...or whatever, it will take longer...and time is money.....

Just sayin.

Dave
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Damned ijjit!

PatJ

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Re: Galloway Castings
« Reply #37 on: December 22, 2013, 06:34:55 PM »
Dave-

Yep, I hear what you are saying.
I guess if I were going to make commercial kits available I would certainly use aluminum in a CNC for patterns.

I was thinking along the lines of plywood that does not have many or any knots in it, if there is such a thing, and glued up in layers if necessary.  Plywood has pretty good dimensional stability, but does break out sometimes.

Plywood avoids the fuzzy finish, and holes in the plywood can be filled easily enough.

The guy with the CNC is retired, so not really a time is money thing, but even he does not want to have to repeat a run.

It is something to think about.
I guess I will get whatever he decides to use, if he decides to make these patterns.

I can make patterns manually in wood, but for things like tapered ellipsoidal spokes, CNC or 3D printing is nice, and for tight tolerances where you are trying to maintain a uniform wall section like in the cylinder/water jacket area, you need all the accuracy you can get.

Online Jo

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Re: Galloway Castings
« Reply #38 on: December 22, 2013, 06:42:10 PM »
I guess if I were going to make commercial kits available

Is the Galloway market not already saturated? George B did a wonderful job in sorting out the original model design and they are already available in four different scales.... I am not sure how big the fine scale market might be  :shrug:.

Jo
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Offline steamer

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Re: Galloway Castings
« Reply #39 on: December 22, 2013, 06:47:57 PM »
Dave-

Yep, I hear what you are saying.
I guess if I were going to make commercial kits available I would certainly use aluminum in a CNC for patterns.

I was thinking along the lines of plywood that does not have many or any knots in it, if there is such a thing, and glued up in layers if necessary.  Plywood has pretty good dimensional stability, but does break out sometimes.

Plywood avoids the fuzzy finish, and holes in the plywood can be filled easily enough.

The guy with the CNC is retired, so not really a time is money thing, but even he does not want to have to repeat a run.

It is something to think about.
I guess I will get whatever he decides to use, if he decides to make these patterns.

I can make patterns manually in wood, but for things like tapered ellipsoidal spokes, CNC or 3D printing is nice, and for tight tolerances where you are trying to maintain a uniform wall section like in the cylinder/water jacket area, you need all the accuracy you can get.


If you go the plywood route.....stick with BS 1088 marine plywood, or Birch Aircraft plywood.    BS1088 guarantees there are no knots or voids...

But both are pricey....MDF would be the next choice I think....


Dave
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Damned ijjit!

Offline Jasonb

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Re: Galloway Castings
« Reply #40 on: December 22, 2013, 06:49:33 PM »
I did not read it that way Jo, "if I were" suggests that Pat would use aluminium if that were the case but he is using ply and likely to cast one or two parts from the pattern.

Also no one makes a kit of a 7.5HP at the moment which is what Pat is modeling

J

PatJ

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Re: Galloway Castings
« Reply #41 on: December 22, 2013, 07:18:41 PM »
Dave-

Thanks for the tips, I have not tried to get any patterns CNC'ed yet, and so am new to that.

Jo-

I would say that the market is saturated, and the market is small too in my opinion to support someone anyway; two good reasons not to offer a casting kits for sale.

But my idea was to make 1/3 scale castings of my dad's 7.5 hp round rod, and those kits don't exist.
And I am not aware of any kits having a one-piece frame and cylinder casting with water jackets like the original engine, or water jackets in the head, or tapered ellipsoidal spokes shaped like the original engines, etc.

So the argument can be made "Would anybody notice that sort of thing, would anybody care, and would anybody pay extra for these features"? and the answer is "probably not".

But since I remember my dad's engine well, remember how it was built, and have photos of it, then it seems logical to make the castings exactly like that.

Some casting kits these days have superb quality, and some are lumps of metal that only vaguely resemble the part to be made.

It is pretty easy to make better castings yourself than some of the kits that are available, but not necessarily all the kits; some kits have superb quality and are very difficult to match in quality.

I am no casting expert, lets make that clear.
I am a casting expert wannabe, but my progress so far is very exciting, especially in cast iron, and cast iron parts with cast passages.

I guess everyone has a level of accuracy that they want to work towards.
« Last Edit: December 24, 2013, 07:13:29 AM by PatJ »

Online Jo

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Re: Galloway Castings
« Reply #42 on: December 22, 2013, 07:23:04 PM »
I can understand the need to make a model of your Dad's engine and to make that an accurate model 8).

Like I have had a number of "offers" to make my 1/6th S&P commercial.. that is not the point of why I am doing it, its personal  ;)

Jo
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PatJ

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Re: Galloway Castings
« Reply #43 on: December 22, 2013, 07:25:52 PM »
Yep, that pretty much sums it up, "its personal".

And there is the chance that I will fail miserably, but I would rather try and fail then not try.

PatJ

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Re: Galloway Castings
« Reply #44 on: December 24, 2013, 06:40:14 AM »
I was thinking about why I design and cast engines, and about all I can come up with is that scene in the movie "Forrest Gump", where he keeps running and running, and finally the newscasters start running along side him, and they ask him "Why are you running....it this for world peace, the homeless, women's rights, the environment, animals....?".

And Forrest replies "I just felt like.......running......."

And so that is how it is with me and designing/casting engines.
My motivations are not exactly what you would consider complex.


Here is a core box for the cylinder, and also the core that this core box will produce (with the bore core shown inside of it).

Edit:
The tabs extending up towards the water hopper should not go all the way up.
And the cylinder and frame will be cast in a single piece, but I modeled them seperately because I was having shell issues with the frame when I combined them.
« Last Edit: December 24, 2013, 07:16:43 AM by PatJ »

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Re: Galloway Castings
« Reply #45 on: December 24, 2013, 06:43:52 AM »
And here is the water hopper core.
The gray part on the bottom actually needs to be a rectangle, but you get the idea.

Offline swilliams

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Re: Galloway Castings
« Reply #46 on: December 24, 2013, 09:09:47 AM »
Some nice progress Pat, you've been busy

Steve

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Re: Galloway Castings
« Reply #47 on: December 24, 2013, 10:40:30 AM »
Thanks Steve, insomnia works wonders for modeling.

Here are the piston and cylinder head cores.

It is difficult to get a clear idea of how to make the core box without looking at the core first.
And if you had asked me what the cores would have looked like beforehand, I would generally not could have guessed some of these shapes, although I have seen a piston core, which looks like one of the old pole line insulators.

Core prints for the cylinder head core are in purple.
« Last Edit: December 24, 2013, 10:44:44 AM by PatJ »

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Re: Galloway Castings
« Reply #48 on: December 24, 2013, 10:46:35 AM »
And here is the piston again for comparison with the above core.
The Galloway piston has a rib across the top on the inside.

Offline gbritnell

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Re: Galloway Castings
« Reply #49 on: December 28, 2013, 01:15:55 AM »
Hi Jason,
I was intrigued with your flywheel construction problems so this evening I had a little bit of time to play with it in my Cad program. I drew the hub, extruded it,  then the spoke profile as an ellipse and extruded it but only halfway to the rim with one draft angle. I then extruded from the end of the spoke ellipse to the rim with another draft angle. I then did an array of the spokes. Now I tried to fillet it, I tried edges, I tried faces, I changed radius sizes but with no luck. What I ended up doing was putting a fillet between each of the spokes first. Once this was done I could lay a fillet all the way around the edges. I'll try and post a picture of my screen shot but I'm not sure how it will come out.
gbritnell
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PatJ

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Re: Galloway Castings
« Reply #50 on: December 28, 2013, 05:18:15 AM »
Here are the intake and exhaust springs, and the forked arm for the old style single-weight governor system with the arm hinged at the front towards the cylinder head.

I drew the arm twice, and got the axis mixed up the first time.
Jason pointed out that I neglected to thin out the fork, but I can do that easily enough.

That forked arm is sort of a dyslexic's nightmare, but I think I got it.

Offline Jasonb

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Re: Galloway Castings
« Reply #51 on: December 28, 2013, 07:37:21 AM »
You also need a slot for the pivot not a hole.

PatJ

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Re: Galloway Castings
« Reply #52 on: December 28, 2013, 08:24:12 AM »
Thanks Jason, I could not see that in the old Galloway parts list, or the photos I have, but you are right, looking down on that forked arm, it will need to get slightly longer as it changes planes.

I did notice it on the rocker arm for the exhaust valve, and could see it in the motion study of that part, and noticed that the slot can only go one way.

PatJ

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Re: Galloway Castings
« Reply #53 on: December 28, 2013, 09:45:44 AM »
Hi Jason,
I was intrigued with your flywheel construction problems so this evening I had a little bit of time to play with it in my Cad program. I drew the hub, extruded it,  then the spoke profile as an ellipse and extruded it but only halfway to the rim with one draft angle. I then extruded from the end of the spoke ellipse to the rim with another draft angle. I then did an array of the spokes. Now I tried to fillet it, I tried edges, I tried faces, I changed radius sizes but with no luck. What I ended up doing was putting a fillet between each of the spokes first. Once this was done I could lay a fillet all the way around the edges. I'll try and post a picture of my screen shot but I'm not sure how it will come out.
gbritnell

That looks pretty nice to me, and authentic too.

PatJ

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Re: Galloway Castings
« Reply #54 on: December 28, 2013, 09:47:52 AM »
Jason-

Are you using the little spring shown in the photo, at the red arrow?

PatJ

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Re: Galloway Castings
« Reply #55 on: December 28, 2013, 09:49:21 AM »
And a revised forked governor arm.
I will add the slot when I can size it exactly.

PatJ

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Re: Galloway Castings
« Reply #56 on: December 28, 2013, 10:01:38 AM »
The beginning of an exploded view, and the latest assembly.

I would like to have an exploded view for each sub-assembly such as fuel system, valve gear, governor system, etc.

Offline Jasonb

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Re: Galloway Castings
« Reply #57 on: December 28, 2013, 01:24:56 PM »
Yes Pat the spring will go in once I gave established the exact position of things then I can drill the small pocket in the rod to suit