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Replacing a cracked universal joint between a Sagami motor and worm gear

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Replacing a cracked universal joint between a Sagami motor and worm gear
Posted by BMMECNYC on Tuesday, June 11, 2019 3:43 PM

Ive got an older DC locomotive that has what I think is a cracked univeral joint.  Whats the best way of going about replacing these?  I think its the universal on the motor side because the worm and univeral stops spinning but the motor makes high rev noises.  Its on a long discontinued brand, and there aren't currently any diecast or plastic models of this locomotive available on the market.  Any suggestions?

Thanks,

Andrew

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Posted by richg1998 on Tuesday, June 11, 2019 3:50 PM

How about a photo? I have used NWSL in the past but he is going out of business in August and might still have parts.

His stuff is excellent.

Get your dial caliper out if not sure.

He use to answer calls. Tough time. Wife passed. Catalog below.

http://www.nwsl.com/nwsl-online-catalog.html

You will need a p[hoto hosting site if you have not post photos before.

Rich

If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.

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Posted by woodone on Tuesday, June 11, 2019 3:51 PM

You can get complete u-joints from North West Short Line.

Measure your shaft sizes and just replace the u-joint assembly .

you need to hurry and get an order in has soon NWSL will close its doors. Then we will all be in a world of hurt!

 

 

 

 

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Posted by gmpullman on Tuesday, June 11, 2019 3:56 PM

BMMECNYC
I think its the universal on the motor side because the worm and univeral stops spinning but the motor makes high rev noises.

I have used this A-Line universal #12031, universal kit. 

https://ppw-aline.com/collections/miscellaneous-re-powering-parts

Yes, NWSL would be my first choice and I have used their parts for some brass rebuilds but you have to be sure of your shaft sizes and order accordingly.

Good Luck, Ed

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Posted by richg1998 on Tuesday, June 11, 2019 4:03 PM

Thanks. I will Bookmark that one.

Rich

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Posted by BMMECNYC on Tuesday, June 11, 2019 4:24 PM

For a photo, click on the Silverton, Lake City and Northern hyperlink at the bottom of this post.

Andrew

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Posted by Renegade1c on Tuesday, June 11, 2019 4:36 PM

A piece of R/C (Radio Contro) car gas line tubing works pretty well. Its flexable and chemical resistant. it might wear out after sitting for long periods of time (10+ years).

It was used pretty commonly in older brass for just such a purpose. 


Colorado Front Range Railroad: 
http://www.coloradofrontrangerr.com/

flag

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Posted by richg1998 on Tuesday, June 11, 2019 4:42 PM

Ok, I can see the black plastic coupling and the brass worm. Cannot see a crack but I am sure you can.

If it is an import, it must be metric and NWSL does sell metric if you looked at the catalog. They do sell SAE/metric adapters as I have used them in the past.

I used Sagami when NWSL parts was in Seattle, WA

Rich

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Posted by BMMECNYC on Tuesday, June 11, 2019 4:46 PM

Rich,

Both were approximately ~.094 (just slightly over that).  So I ordered 2.4mm.

The crack is hard to see, but is definitely there. 

Also took the opportunity to pick up replacement bevel gears for my two truck climax should the worst come to pass..Sad

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Posted by richg1998 on Tuesday, June 11, 2019 6:04 PM

Great planning.

Going to be sad to see this place go away but know the feeling.

Lost my wife in 2001. Almost gave up.

Rich

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Posted by Ronvaaw9c on Monday, August 12, 2019 3:40 PM

After having a very hard time finding gas line tubing I tried screen door spline as recommended somewhere. Works great and I have a hundred year supply for $6.

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Posted by BigDaddy on Monday, August 12, 2019 6:53 PM

Ronvaaw9c
After having a very hard time finding gas line tubing I tried screen door spline as recommended

What I think of screen door spline is solid  most is <1/8" in diameter and holds the screen in.  I see some of it has a center hole, 1/4" in dia. but that hole looks tiny.  https://images.homedepot-static.com/productImages/c9563308-1fb6-43b8-ad01-0d25e8312032/svn/blacks-prime-line-screen-spline-spline-rollers-p-7604-c3_1000.jpg

If that is what you mean, how does it work like tubing?

Hobby shops these days that would have gas powered RC planes would have tubing.  There used to be gas powered cars, but I suspect batteries have taken over that market.

 

Henry

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Posted by rrinker on Monday, August 12, 2019 10:35 PM

 My LHS, which has almost no train stuff, but does have Evergreen and Plastruct, and plenty of music wire, always has the RC car and plane stuff, plenty of fuel line. It isn;t a permanent solution in my loco, it allows the truck to swivel just fine but it binds on rocking motion because there is no fore-aft slack in the fuel line. If it were on the long end, it probbaly would be fine, but there is about as much distance between the motor and worm as in the picture of the OP's loco, and it just doesn't work - the loco runs but it tracks poorly. A real universal is desperately needed. Long end has Athearn 6 axle components in the drive train (loco was remotored before I got it) and works great. Short end was fine, except someone glued the drive shaft to the universal where it was designed to slide freely back and forth. 

                                         --Randy

 


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Posted by gmpullman on Tuesday, August 13, 2019 1:17 AM

There was some discussion here about drive shaft tubing:

http://cs.trains.com/mrr/f/88/p/226643/2533240.aspx

It has to be silicone, well, the silicone works the best anyway, anything else is too stiff.

I don't recall if I found mine here:

https://www.ebay.com/itm/Locomotive-FlexDrive-Shaft-Coupling-U-Joint-Silicone-Tube-12-x-2mm-ID-Clear-/132485750161

or at Greenway Products:

http://greenway-products.com/brass-builders-corner-trackside-specialties/flexdrive-tubing-clone/

Good Luck, Ed

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Posted by rrinker on Tuesday, August 13, 2019 7:10 AM

 I have the silicone stuff, the LHS has both, cheap plastic fuel line and the goood silicone stuff. The cheap plastic stuff isn;t good for the intended use, either - I had at least one gas engine thing that wasn't the typical .049 with built in fual tank, and the plastic fuel line it came with turned to so much mush after long exposure to the nitro and castor oil. 

 One thing I've considered for this loco (Alco models brass RS-3) is moving the motor more to the center to get equal drive lengths on either side. It's kind of silly the replacement motor is shoived all the way to oone end like it is. Wasn;t a fit issue, the replacement round can motor is a fraction of the size of the original Alco Models open frame motor.

                                 --Randy


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Posted by Ronvaaw9c on Tuesday, August 13, 2019 11:34 AM

Course, it’s the inside diameter we’re concerned with. Ace had quite a few sizes and I found the perfect fit. Take a motor down with you and fit it. I’ve done this to 20 brass locos and it works great.

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Posted by doctorwayne on Tuesday, August 13, 2019 3:18 PM

Like some cracked gears, a cracked universal may be repairable.


This Proto USRA 0-8-0 developed a cracked gear quite some time ago...

...but upon disassembling it, I was pleasantly surprised to find that it had a fairly substantial hub on one side of the gear.
I selected a piece of brass tubing with an outside diameter larger than that of the hub.  The inside diameter, however, was smaller than the hub.  After measuring the hub's diameter, I used various drills (fractional, numbered, and letter-types) in a pin vise to gradually enlarge the inside of the tubing.  When it was very close to the size needed, I manually compressed the gear to close the crack, then pressed the re-sized tubing onto the hub, using a small vise. 
The re-assembled loco runs as it did before the crack developed, and has been troublefree since then.
In a similar manner, it may be possible to rescue that cracked universal.

Wayne

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Posted by BMMECNYC on Sunday, November 17, 2019 12:21 PM

doctorwayne

Like some cracked gears, a cracked universal may be repairable.


This Proto USRA 0-8-0 developed a cracked gear quite some time ago...

...but upon disassembling it, I was pleasantly surprised to find that it had a fairly substantial hub on one side of the gear.
I selected a piece of brass tubing with an outside diameter larger than that of the hub.  The inside diameter, however, was smaller than the hub.  After measuring the hub's diameter, I used various drills (fractional, numbered, and letter-types) in a pin vise to gradually enlarge the inside of the tubing.  When it was very close to the size needed, I manually compressed the gear to close the crack, then pressed the re-sized tubing onto the hub, using a small vise. 
The re-assembled loco runs as it did before the crack developed, and has been troublefree since then.
In a similar manner, it may be possible to rescue that cracked universal.

Wayne

 

Thanks Wayne,

I kept the parts, will attempt this repair when the time comes.

Andrew

Rule 108: In case of doubt or uncertainty, the safe course must be taken.

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Posted by SeeYou190 on Sunday, November 17, 2019 4:49 PM

Northwest Short Line is coming back!

.

Their new website is almost functional. Product pictures are being added every day.

.

-Kevin

.

Wink Happily modeling my STRATTON & GILLETTE RAILROAD. A Class A line located in a personal fantasy world of semi-plausible nonsense on Tuesday, August 3rd, 1954.

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