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View Full Version : Best way to show internal oil passages in a shaft for training aid?



winchman
02-02-2012, 01:32 AM
The AgTech instructor asked me yesterday about machining a transmission shaft to show his students how the five internal oil passages in the shaft transfer oil from the input grooves at one end to the clutch packs and bearings positioned along the shaft.

The shaft is about three feet long and three inches in diameter, so it has the potential to involve a LOT of machining. I'm also concerned (actually pretty sure) that the shaft is hardened on the outer surfaces.

I'm sure there's a good way to make an effective training aid to show this sort of thing without destroying the shaft and using up a bunch of tooling. I'm open to suggestions.

ikdor
02-02-2012, 02:39 AM
Wire EDM if it in a large machine, and bring something to read :p

Igor

Black Forest
02-02-2012, 03:44 AM
Do a 3D model of it in a 3D CAD program including the parts that get the oil. Much better learning tool for the students.

winchman
02-02-2012, 08:01 AM
I like that idea, and the drafting instructor owes me a favor or two.

One thing I've thought about is fishing some wires of different colors through the passages to show how the ports are connected.

Another possibility is to machine a simplified scale model of the shaft out of aluminum bar with cutaways to show the internal passages.

Any thoughts on those ideas?

vpt
02-02-2012, 08:20 AM
Is it possible to just use LED lights in the channels? Every LED a different color for a different channel.

I use a LED light to check channel routes and check for blockages and stuff.

http://img404.imageshack.us/img404/2738/turbopedestalgut014.jpg

http://img220.imageshack.us/img220/153/turbopedestalgut013.jpg

http://img196.imageshack.us/img196/9581/turbopedestalgut006.jpg

http://img843.imageshack.us/img843/8106/turbopedestalgut007.jpg

vpt
02-02-2012, 08:21 AM
http://img265.imageshack.us/img265/6884/turbopedestalgut009.jpg

Rosco-P
02-02-2012, 09:28 AM
One thing I've thought about is fishing some wires of different colors through the passages to show how the ports are connected.

Another possibility is to machine a simplified scale model of the shaft out of aluminum bar with cutaways to show the internal passages.


Both good ideas, something they can touch and examine. Might not be as cool as a CAD drawing, with cutaways and sectional views, but machining is a hands-on effort, not a computer simulation.

Tony
02-02-2012, 09:40 AM
scale part in clear plastic, acrylic maybe. don't know how
complicated the part is but milling away 1/2 of a 3" shaft sounds
like a lot of work (and not as fun)

no cutaways.. you could run some colored paint through the holes
with an air gun maybe. just enough to show where everything is going.
you could slip the clear part into some steel or alum tubing so it
looks the same at first then "unveil" it.

APEowner
02-02-2012, 01:34 PM
I've used the colored wire approach many times.

vpt
02-02-2012, 06:29 PM
The colored wire idea is a good one.

brian Rupnow
02-02-2012, 08:11 PM
Model it in 3D cad and set the color scale to "transparent". This for instance is one of the cylinders being used in my model steam engine thread, with the color scale set to transparent.
http://i307.photobucket.com/albums/nn294/BrianRupnow/transparentcylinder.jpg

Ggerg1186
02-02-2012, 08:32 PM
Can you put the thing in a furnace and let it air cool slowly to soften the hardfacing before machining?

After that I think you would want a dividing head and tailstock.

Void
02-02-2012, 10:00 PM
I have used the colored wire idea, also bright yellow plastic rods. I have also seen the clear plastic model idea. The 3D CAD model is good but it can also be confusing.

One thing to consider is scale (how many students and how far away?) required.

Not only because no one has mentioned it yet... it is also a bit messy (depending how you set it up); but why not inject some water with food coloring or light oil in to the normal "input" side of the series of channels and drillings, then wherever the liquid floods or squirts out is clearly seen. I have used the liquid method on cylinder heads, rocker arm assys, engine blocks, crankshafts, and complex pumps and valve bodies. It should also work well on a transmission shaft.

To get an idea how it will work just take the shaft over to the parts washer/solvent tank an stick the nozzle in the input hole.

-DU-

justanengineer
02-02-2012, 10:10 PM
I think the overall shape of the shaft would dictate much of this work, if you truly are going to machine it to show a cross section. If possible, I would clamp the shaft in a pair of vises (they dont even have to be matched due to lack of precision required) on a horizontal mill table, and simply use carbide to chew right through it. On a standard size turret mill this job would be a PITA IMHO simply due to lack of rigidity and power.

3d models, colored lights, liquids, and string are nice, but to really appreciate the difficulty associated with gun drilling I think you need to cross section the iron.

Circlip
02-03-2012, 06:43 AM
"Model" the oilways from coloured (colored) Acrylic rods and set the ends into a flat clear acrylic plate. Use a piece of clear tube for the "Shaft" O/D and cross drill for the outlets in the tube o/d.

Regards Ian.