Author Topic: A Wallaby of my own.  (Read 252172 times)

Offline steamer

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Re: A Wallaby of my own.
« Reply #45 on: August 06, 2012, 11:47:13 AM »
Thanks for that Jerry!   Your Right!

Dave
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline swilliams

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Re: A Wallaby of my own.
« Reply #46 on: August 06, 2012, 02:27:23 PM »
Dave

I've had good success with the ignition system from the Jerry Howell site. I've used the 6V coil
http://www.model-engine-plans.com/partskits/ignitionsystems/coil.htm

and the electronic ignition
http://www.model-engine-plans.com/partskits/ignitionsystems/transistors.htm

Soldering it together is a piece of cake and you can buy an extra magnet for your two cylinder set up.
http://www.model-engine-plans.com/partskits/ignitionsystems/sensorsmagnets.htm

I don't know how well it compares to other stuff out there as it's the only one I've used. Maybe what Steve Hucks recommended would suit you better. Just another option.

Steve

Offline steamer

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Re: A Wallaby of my own.
« Reply #47 on: August 07, 2012, 02:01:31 AM »
Some Pictures from last night.....







I motored it on the lathe and it seems to pump oil OK....though I don't know to what pressure....

I'll put some shellac gasket compound on the mating surfaces....

Dave
« Last Edit: August 07, 2012, 02:21:03 AM by steamer »
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline steamer

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Re: A Wallaby of my own.
« Reply #48 on: August 07, 2012, 02:14:50 AM »
Dave

I've had good success with the ignition system from the Jerry Howell site. I've used the 6V coil
http://www.model-engine-plans.com/partskits/ignitionsystems/coil.htm

and the electronic ignition
http://www.model-engine-plans.com/partskits/ignitionsystems/transistors.htm

Soldering it together is a piece of cake and you can buy an extra magnet for your two cylinder set up.
http://www.model-engine-plans.com/partskits/ignitionsystems/sensorsmagnets.htm

I don't know how well it compares to other stuff out there as it's the only one I've used. Maybe what Steve Hucks recommended would suit you better. Just another option.

Steve


Thanks for the interest and support Steve.....I'll check on those items too!

Dave
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline steamer

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Re: A Wallaby of my own.
« Reply #49 on: August 12, 2012, 12:43:46 AM »
OK....starting in on the gears.

I started with the gear blanks.   The gears are 32 DP 20 deg PA and 40 tooth.   the pinions are 20 tooth.
Starting with the gears
Here's a piece of stock bored to 3/8 and faced.


This is more than enough stock for both gears, so I'll cut them both at the same time.   To cut the gears, I'll need to mount the blank on a arbor, so I turned one up.  Here it is on the arbor and turned to size.



Here it is ready to go into the dividing head.



I've decided to make cutters the GailNM way.   I'll be using his spreadsheet published long ago on the other site.    The biggest issue I ran into with this method was how to put relief on the cutter, preferably form relief.    I did some literary research and came up with a way that E T Westbury used to do the same....though with a more complicated rig I think.....though I am positive...this is not that original!....hell I thought of it so it must be about 100 years old!

If I mount the cutter blank off center from it's arbor....and put the form on the cutter using the button method,  when I mount the cutter in the arbor ON center, I'll have form relief. 

So I worked out how far off center I needed to put the blank cutter to get a 6 degree relief angle, and bored a hole in the arbor for my cutter blank. In this case it's a .1875 diameter oil hardening tool steel.

Now using the button method I can cut the flankes of the tooth cutter.   Using Gail's spreadsheet I computed the button diameter that corresponds to a standard diameter end mill.   I'll use a 3/8 endmill for the big gear.

Here's the cutter in the arbor in the off center position ready to cut the flank radius.

   

At this point....It was 90F+ in the shop and about 90% relative humidity......I had enough...couldn't see out the glasses!

I'll finish the cutter tomorrow.....maybe I can cut the gears then.

Dave

"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline steamer

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Re: A Wallaby of my own.
« Reply #50 on: August 12, 2012, 11:15:50 AM »
From Gails spreadsheet, which is based on "Gears and Gear cutting" by Ivan Law.   The distance between buttons is .394 and the infeed is .154"

I'll go cut that....and report   Additionally I'll be taking .054" off the top to generate the top cutting edge.   When installed in the arbor on center, this edge will be directly on center with the arbor.

Dave

PS   I"ll take pictures!...... ::)
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline ozzie46

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Re: A Wallaby of my own.
« Reply #51 on: August 12, 2012, 12:51:53 PM »
  I"ve been following along for a spell now and the gear cutting is some thing I need to try very soon.

  I'm reading everything I can find on it. Every post even remotely related and articles too.

  Anxiously waiting for more.

  Ron

Offline steamer

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Re: A Wallaby of my own.
« Reply #52 on: August 12, 2012, 01:00:03 PM »
Hi Guys

Boy the shop is way cooler early in the morning!
I cut the cutter and started cutting a gear.  I think I have an index error, but I'm going to finish the gear regardless.

Making the cutter.



Putting the feed on by turning the dividing head into the cutter.



Checking the fit of the cutter to an existing 32 DP gear....seems good!



The cutter was then hardened in the usual manner of heating to cherry red and quenching in oil.   I stoned the top surface to sharpen it.

Cutting the gear blank...


Now it's a 40 tooth gear so the index head is set up for 1 turn/tooth.   The pitch appears off though.

I'll have to investigate that...but the cutter cuts very nicely .....so I'll finish this one off with my Son....and see about getting more stock..... :Doh: :cheers:

Dave

 
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline steamer

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Re: A Wallaby of my own.
« Reply #53 on: August 12, 2012, 02:01:53 PM »
As far as making the cutter is concerned, once you have an arbor to hold it while you cut it, it's very easy.  The arbor in the photo came with my Aciera and has W12 shank, but is machinable.
Additionally, it already had a .1875 diameter hole on center in the end.  I just bored a hole 90 degrees off from this and .054 off center to allow for the relief.   

I think I could crank out another cutter in about 20 minutes once I have the data from the spread sheet.

Additionaly, I think I could benefit from a pair of half pins to get everything lined up with each other.   

Dave

« Last Edit: August 12, 2012, 02:15:40 PM by steamer »
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline mklotz

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Re: A Wallaby of my own.
« Reply #54 on: August 12, 2012, 03:33:30 PM »
Looking good, Dave, but please take that wedding ring off when you're in the shop. 
Regards, Marv
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Offline steamer

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Re: A Wallaby of my own.
« Reply #55 on: August 12, 2012, 03:38:28 PM »
Sir!  yes Sir! ;D

Marv has a point.....I won't go into what a ring does when it gets caught in a machine.

Dave
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline Dan Rowe

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Re: A Wallaby of my own.
« Reply #56 on: August 12, 2012, 03:47:08 PM »
Dave,
I did not notice the ring. I will not wear a ring or a wrist watch. I did not even buy a class ring from the Academy as I did not want to test my memory or luck.

Nice job on the gears. How did you detect the index error?

Dan
ShaylocoDan

Offline steamer

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Re: A Wallaby of my own.
« Reply #57 on: August 12, 2012, 03:50:20 PM »
Hi Dan,
Thank you for the interest!
I checked it my gear gage set.....didn't match,,,,hmmmmm  I have a gear caliper..so I'll measure up and investigate ......I checked the math on the spreadsheet..and it jives, so I suspect I pulled a bone head....that's OK,,,,we all learn something every day.

Dave

"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline steamer

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Re: A Wallaby of my own.
« Reply #58 on: August 12, 2012, 08:14:13 PM »
Well Im officially a grad of bone head U!
One should make sure the part cant rotate before cutting! :slap: :hammerbash:
My son and I cut about twenty more teeth after I tightened it up and it cut very nice!

Took some pictures....ill post later.

Dave
« Last Edit: August 13, 2012, 01:38:23 AM by steamer »
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline zeeprogrammer

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Re: A Wallaby of my own.
« Reply #59 on: August 12, 2012, 08:18:23 PM »
Well Im officially a grad of bone head U!

I'm in a different class. I have a lot of work to do to get admitted to yours.
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

 

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