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Mcruff
11-15-2009, 06:11 PM
A friend of mine had his Kubota PTO shaft on his lawnmower crap out. The splined shaft sheared off in the coupling. Kubota wanted $833 plus tax. I made him a new shaft and (2) coupling for $260. I have about 14 hours in all the pieces. I will weld the couplings back to the shafts tomorrow at work.
These were 100% made on my South Bend 9" lathe, splines and all. I broached the splines using my carriage with a tool in my QCTP. The fit came out very good, still gotta put zerk fittings back in them.

http://i6.photobucket.com/albums/y233/mcruff/CNC/Splinedshaft.jpg

bborr01
11-15-2009, 06:19 PM
Nice job Mcruff.
Can you post a photo of your spline cutting setup?
Also I was wondering how you indexed the chuck for the spline.
Brian

Mcruff
11-15-2009, 06:28 PM
I use this to index the spindle:
http://i6.photobucket.com/albums/y233/mcruff/Southbend%20lathe/LatheIndexer.jpg
As far as the cutter I have a couple of boring bars that I made that hold square toolbits. I grind them to the form and then use the carriage handwheel to shave off about .002 per pass.

bborr01
11-15-2009, 06:39 PM
Mcruff,
Thanks for the photo of the indexer and the info on the cutters. I will file that away for if I have to do splines.
Brian

deltaenterprizes
11-15-2009, 06:50 PM
Very nice work.

Doozer
11-15-2009, 07:07 PM
What material did you use and did you harden them?
The old ones were most likely hard, and they broke, so chances are they need to be as strong or better.
Nice work indeed. Sweet SB lathe also.

--Doozer

clutch
11-15-2009, 07:17 PM
Ditto on request on how you hardened them.

Did your friend grease the failed ones periodically?

Clutch

Mcruff
11-15-2009, 07:30 PM
The old ones were not hard at all. They weren't even as hard as the 1020 steel I used. The welds on them were even junk. This was on a 3 1/2 year old commerical Kubota mower.
He did not grease them as the leaf vaccum setup was installed by the dealer and he was told it was a permantely greased assembly from the factory, and there was no mention of it in his service manual. When the splines sheared on the shaft he removed the covers for the shaft an pulley and found 2 zerk fittings (at that point he was a little peeved). The splines on the old shaft sheared from the rust that had setup in the coupler until there was no material left to catch the splines. When I pulled the shafts apart all that came out was rust, about 4 tablespoons full. You have to realize this shaft is small (19mm OD), in fact the u-joint on the other end is the smallest I have ever seen. The main thing was to make these last another 3-4 years, as by that time he will have worn the mower out. He mows about 60-100 acres a week with this mower, mainly rich doctors and CEO types. The vacuum system is already obsolete and unavailable from Kubota, the shaft assembly was the only part left available from Kubota, or at least thats what he was told. He said they quit building the unit around 2 1/2 years ago.

MTNGUN
11-15-2009, 07:51 PM
Well done, McGruff. I hope I can learn to do that kind of work someday.

Jim Shaper
11-15-2009, 08:39 PM
14 hours plus materials for $260? Do you take outside work? :D

I charge most of my friends $50 an hour (keeps them from asking me to fix garbage).

Mcruff
11-15-2009, 09:24 PM
14 hours plus materials for $260? Do you take outside work? :D

I charge most of my friends $50 an hour (keeps them from asking me to fix garbage).
I was kind of in need of some money for something I wanted.
If it was for a company instead of a friends lawn service it would have been a whole lot more money. I actually took 3 small jobs this weekend for a total of $385, probably $10 in materials total so I think I did ok for a hobby business. I don't do this to make a living, mainly to give me a challenge, keep me out of trouble on the weekends and make money for my Jeep trail rides and repair parts.;)

Bill in Ky
11-15-2009, 09:52 PM
Very nice work! I really like the indexer.

tattoomike68
11-15-2009, 10:23 PM
Yea give the work away. ;)

I would cheat and use off the shelf PTO parts and shine them up and say I made them.

Iv worked in farm repair type shops and we keep enough PTO stuff on hand to change over metric kabota stuff over to cheaper priced american sized stuff at a fraction of the price. done it dozes of times. just pull the parts off the shelf, machine to length and weld them up.

Farmers are smart they will get things changed over to take a $12 cross kit that they have on thier parts shelves and wont buy the $49 kabota cross kit.
same for yokes.

Jim Shaper
11-16-2009, 12:39 AM
Dang it... so much for my outsourcing idea. lol

I'm in business under the "do what you love and the money will follow" but the money seems to have taken the scenic route. :p

JMS6449
11-16-2009, 07:36 AM
14 hours plus materials for $260? Do you take outside work? :D

I charge most of my friends $50 an hour (keeps them from asking me to fix garbage).


I agree with Jim.

It may only be a hobby, but $18.50 per hour. Have a whole bunch of work for you to bid, and you won't have to cut splines.

snowman
11-16-2009, 08:03 AM
I agree with Jim.

It may only be a hobby, but $18.50 per hour. Have a whole bunch of work for you to bid, and you won't have to cut splines.

Send it on over.

Like he said, it's a hobby that occupies the time. It's not a career.

Right now my machines cost me money. While they have all paid for themselves, it'd be nice to start making money with them again on occasion.

There's a big difference between doing something for 8 hours a day and doing something to keep your wife from nagging you.

PixMan
03-12-2010, 10:13 AM
There's a big difference between doing something for 8 hours a day and doing something to keep your wife from nagging you.

This is the exact same reason my dad has a shop to play in. Keeps mom at bay as she doesn't like the smell in there. Smells heavenly to me. ;)

As for the splined shaft, I'd have both pieces case-hardened to make the assembly stronger and reduce wear.

John Stevenson
03-12-2010, 10:30 AM
I though farm / tractor shops sold lengths of pre done spline and couplings over there ?

Ken_Shea
03-12-2010, 12:55 PM
Very nice Mcruff, not sure how I missed this as I check here several times a day to see what's new and interesting.
Both new and very interesting to me.

Saw it on the email from HSMM as the Project of the month.

RobbieKnobbie
03-12-2010, 01:18 PM
The fine powdery rust that you pulled out of the spline socket is the result of fretting along the contact surfaces of the spline. It's not a function of the hardness of the material, it' s a lack of lubrication. The unlubricated splines roll and slide against each other with every revolution, and that causes the metal parts to wear little pits in each other's surfaces. The material pulled out of the pit corrodes (since there's no lubricant to begin with) and turns into an abrasive that accelerates the wear even further.

They were obviously NOT lubricated for life as the dealer claimed, but if your friend keeps the joint wet, it should last a lot longer.

Beautiful work though!

Chainz
03-12-2010, 01:29 PM
I'm in business under the "do what you love and the money will follow" but the money seems to have taken the scenic route. :p

Thank you. This was good for my morning chuckle. Now I can get to work.

Al Messer
03-12-2010, 06:01 PM
This again demonstrates the universality of a lathe and a guy that knows how to use it. Bravo!!

Weldone
03-12-2010, 10:19 PM
Nice job! I now have a good idea of what else to use those indexing plates that I have kicking around for.:o

Black_Moons
03-12-2010, 11:55 PM
They were obviously NOT lubricated for life as the dealer claimed, but if your friend keeps the joint wet, it should last a lot longer.

Beautiful work though!

Of course they where lubricated for life, the dealer just wanted that life to be really short.. :) Sell ya another $800 one or a new $3000 lawnmower.

Kibby
03-13-2010, 05:48 AM
This is the exact same reason my dad has a shop to play in. Keeps mom at bay as she doesn't like the smell in there. Smells heavenly to me. ;)

I love it when my wife comes into the shop to tell me something, wrinkles her nose and says, "OMG! What have you been eating?" :D

Steve Seebold
03-13-2010, 11:45 AM
I agree with Jim.

It may only be a hobby, but $18.50 per hour. Have a whole bunch of work for you to bid, and you won't have to cut splines.

At $18.50 an hour, that's $260.00 more than you had yesterday. What would you have done if you hadn't done that besides sit on your ass watching TV.

I have 2 Dyna-Mite 2400 NC mills in my garage. They are small (6.2.inches of X travel 5 inches of Y and 4 inches of Z) but they are fun to play with. If I get creative, I can make up to $60.00 an hour on them. If I'm lazy, I might make 5 or 6, but hey, I'm supposed to be retired, so WHO CARES.

JoeCB
03-13-2010, 11:58 AM
Ya' I love "lubed for life" ... that translates to "it's lubed until it breaks"

Go try and find zerks on any new cars???

Joe B