Rocking cradle copy lathe

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dog

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Dec 29, 2019
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578
Here is a lathe that was built to turn
a complex non round object from wood.
Also including a pictures of wood from a local saw mill,1x5x12' clear white spruce,$1.20 a bd/ft.
The design of the lathe might be of interest to someone interested in building a prop carving machine and the
picture of the wood is just to say that there is still good wood to be had,and I
pulled both these out of wood for a roof
job.
 

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Aviacs

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Messages
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and I pulled both these out of wood for a roof
Nice save!. What function was the lathe intended for on the roof?

The wood looks good except the grain is in the wrong direction for spar material, e.g.
For capstrips and smaller stock it could be great, depending on grain slope both directions.

smt <-----fondness for weird woodwhacking machinery,"nice" lumber, & pulling both out of job lots and odd places. :)
 

dog

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Nice save!. What function was the lathe intended for on the roof?

The wood looks good except the grain is in the wrong direction for spar material, e.g.
For capstrips and smaller stock it could be great, depending on grain slope both directions.

smt <-----fondness for weird woodwhacking machinery,"nice" lumber, & pulling both out of job lots and odd places. :)
The lathe can turn "any" shape ,so a prop is a possibility,its a copy lathe which holds a pattern in the top spindle and blank in the lower
one.Probably for chair and table legs,tool handles.Will go about 4’.
I have not roof mounted it yet,but I did dissasemble it to get it where it is ,and while carrying it up the stairs,my end brought me to
my knees,got my grip,stood back up and got it
the rest of the way up the stairs.
The joke is you can have it if you can pick it up
and walk away.
The design is interesting in that if it was updated and the patterns were digital,than
a complex shape like a propeller can be carved
useing ONE linear actuator,perhaps this is how it is done now?Dont know.
Also rescued the remains of a steam powered
box making factory.
Pulled another totaly clear 1x5x10' piece and took it home yesterday,and ya not spar material
but strips for anything else.
I will be tempted to test a couple of strips or
a 1x1x24" piece to see how.. it compares to the
published numbers on proper aircraft grade spruce.Stick ,bucket,sand,scale,saw horses,
check,check,yup,got two,lots around,ok change tempted to,gota.
 

Aviacs

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Oct 21, 2019
Messages
271
The joke is you can have it if you can pick it up
and walk away
If i was 40 years younger, would be tempted to try it.
Oh, yeah, that kind of effort is how my back got in the shape it's in now. :(

Given the wood, you are probably in the PNW anyway? Opposite coast from me.
Wish we had that species option growing locally.
I'm butchering a pine tree today.

Gunstock lathes are still used - for gunstocks and for propellers among other stuff. There a young woman that runs one, forget which aftermarket prop manufacturer - she took over her grandather's shop quite a few years ago. He may have built the lathe she uses. There are videos online. At one point, she shows the storage rooms of patterns that are required to run such a machine. As you allude, most of the younger generation is figuring out how to apply that control with silicon bits. Easier to store, and to modify.

You lathe looks more like a relatively light automatic lathe. Also still run in factories that make small complex parts. The tooling for that looks like a reel from a push mower with chunky bits sticking out all around on shear angles. The cost of the tooling will make your head spin faster than the cutter head. (the spindle turns slowly). They will do poly-sided figures based on the cam mounted on one end. Even squares or rectangles. Some have a sliding provision and will do shapes that are angled axially.

Unfortunately, they are not configured to easily make propeller blades and such because there is not a (built in) method to accommodate twist.

A gunstock lathe traces a full pattern (instead of a cam at one end). The cutter (or sometimes sawblade) travels with the stylus that traces the pattern, which rotates in synch with the part. A dedicated person could configure your machine to do such by adding a another spindle to hold/rotate the pattern; and a carriage and feedscrew or feedrod to move it and the tracing stylus, and arranging a means to control (change) the relative distances for size adjustment. A (late) friend of mine, Bob Aymar built one when he designed & was making Aymar propellers. Later Aymar-DeMuth.

Do you have other parts not shown to add to it?
 

dog

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Dec 29, 2019
Messages
578
Just whats pictured,there is a twin a
in water powered mill that is in private hands that has patterns for handles and who knows what.
This machine has the pattern and blank rotating in the rocking cradle and then the cutter is on carriage with a lead screw.
There is a follower on the cutter cariage that
is set to the pattern.
Cutters are just bits of steel,two rakers and two
cup cutters.
And yes there is a gadget or two,one is some
part of a follower and the other has two cone
pulleys for a variable speed flat belt drive for??
And this seems similar to the gunstock lathe.
Sounds like you know way more about it than me.
And no dont live on the left coast,atlantic Canada.
Just spoke for a thousand bd/ft of ? rough sawn boards.There were pine logs in the pile
40" at the but,not much smaller 16'away.
Another mill cutts them 21 or 22 feet though you can order 24.
The fellow at the one mill told me that they still have the original family mill,water powerd,and they want someone to run it but cant find anybody.
 

Bill-Higdon

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Feb 6, 2011
Messages
1,594
Location
Salem, Oregon, USA
Just whats pictured,there is a twin a
in water powered mill that is in private hands that has patterns for handles and who knows what.
This machine has the pattern and blank rotating in the rocking cradle and then the cutter is on carriage with a lead screw.
There is a follower on the cutter cariage that
is set to the pattern.
Cutters are just bits of steel,two rakers and two
cup cutters.
And yes there is a gadget or two,one is some
part of a follower and the other has two cone
pulleys for a variable speed flat belt drive for??
And this seems similar to the gunstock lathe.
Sounds like you know way more about it than me.
And no dont live on the left coast,atlantic Canada.
Just spoke for a thousand bd/ft of ? rough sawn boards.There were pine logs in the pile
40" at the but,not much smaller 16'away.
Another mill cutts them 21 or 22 feet though you can order 24.
The fellow at the one mill told me that they still have the original family mill,water powerd,and they want someone to run it but cant find anybody.
Culver Props Culver Props Page Log In or Sign Up to View
 
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dog

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Dec 29, 2019
Messages
578
The culver prop machine uses the same principals,but the movements are distributed a little differently and optimised for propeller production.Nice shop,everything strait forward,
someone could try and cnc the whole thing but
I think that costs of equipment,set up times,would end up costing more,be no faster,
and the process for balancing would remain
unchanged.
The idea I am promoting is the didgitization of
the prop templates,especialy for someone starting from scratch.
 

Aviacs

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Joined
Oct 21, 2019
Messages
271
Now that is strange.
I replied to this since my last post, noting that with more intent observation i could make out better how your lathe worked.
Must have edited a typo or something, and forgot to save?

Anyway, i was originally taking it that the carriage, with the leadscrew not visible, was merely a pick-n-place option for the cutter.
If it travels with leadscrew actuation, then it certainly could carve props to a pattern! The limit would be whether the other 2 spindles are, or can be arranged, to be far enough apart to clear the work and the pattern as both turn for any given prop.

Also commented that the cutters you describe should be very good for roughing because that style geometry minimizes tear-out. OTOH with only 2 effective teeth (& spurs) on the circumference, it could be slow but effective for finishing at finer feeds, too. Or, bore and fit any cutter head or saw plate to the drive.

The only other (minor) difficulty might be to rig up (make new) a headstock that would accommodate a means to index the propeller between blades.

That is a cool machine to have around. Will you plan to use it to make propeller(s)?

smt
 

dog

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Joined
Dec 29, 2019
Messages
578
The head and tail stock on the culver propeller carving machine could be adapted to the lathe
I have.
The cutter head could be swapped out with a new one with more teeth, or a second finnish sanding head could be added on the back side
of the spindle.
The part of the challenge that interests me most is to digitise the patterns.
Lots of other challenges in becoming a propeller maker.
 
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