Re-purposed 1250

[TnPaul]

Hello all,

New member here, but have been lurking for awhile. What a wealth of great info and ideas here, not to mention all the great looking rebuilt Cubs! Very inspiring! I currently have 2 Cubs. A Super LT 1554 I use for mowing about 3 1/2 acres, and on old 1250 carcass, no motor but otherwise intact, that I need help with.

I am in need of a LOT of help and suggestions to re-purpose the old 1250. I am building my retirement, so to speak, and will be building a "trackless train", similar to the pic below, using the 1250 as the locomotive. I bought the 1250 specifically for the hydro trans and cast iron rear end since I will need strong smooth pulling power. I am a carpenter by trade, so I shouldn't need much help with the body or cars, but I definitely need help with the engine and trans.

So for now, I'll start with my first dilemma. I have a 16hp B&S Vanguard I plan on re-powering with, but the drive shaft will be too short. No problem in having a new one made, but can I get rid of the rag joints and use u-joints? I need the 1" shaft on the motor for a pulley to drive an alternator and possibly a compressor, but I don't see a way to use the pulley and rag joint together. Any suggestions appreciated, as well as any other words of wisdom.

Thanks,
Paul

[bkw3614]

Paul,

That looks like a wonderful project. I have a 1250 that I am trying to get back into running condition and I call it a nightmare, but actually, this is pretty fun. I am no mechanic, but have had the pleasure of working with someone who is not stumpable. I kept my mouth shut and learned a lot. I also spent thirty years designing and building stage scenery, so I have a dual interest in your project.

First, you may wish to consider finding a 12 or 14 horsepower Kohler K series AQS engine to go into your 1250. That way, your motor mounts and and drive shaft will line up perfectly, there will be an alternator in place for the starter, and a PTO for any auxiliary accessories you want to add. If you do this, be sure you do the engine cradle modification and use new ISO mounts.

If you are set on using the Briggs and Stratton, that would be okay, I guess. You will have to design a whole new motor mount system, fuel tank support, throttle and choke controls and wire a new electrical system. I think the drive shaft is 5/8" 4140 shaft steel. A good machine shop can make you a shaft any length you need. I would recommend that you use the existing flex joint and flange mounting system for mounting the drive shaft to the hydraulic pump. There is a bushing and a small ball bearing inside the bushing to help center the shaft and help it flex as necessary. BE SURE to install a cooling fan for the hydraulic pump, available from Cub Cadet, at the pump end. For the engine end, you can get a "driver to driven" coupler from a local bearing supply house. Two makers come to mind, Lovejoy and Dodge. Both companies make reputable power transmission products and a person knowledgeable with the product line can design something for your need. They do it all the time.

This sounds like a wonderful project. All the best of luck with it. Please keep us posted on your progress.

[ACecil]

That is neat! Please keep us updated.

[themaddhatter]

You have a few options on the QL to drive aux equipment:

- If you go down the Kohler AQS path, you can use a drive cup pulley. My 1450 has this (some don't though). The coupling between the crankshaft and the front rag joint MAY have a pulley casting into it. They do pop up on ebay from time to time as well
- The front crank connection using a lovejoy has already been mentioned
- The rear output of the hydro unit can also be used (little stubby shaft). You could run an extension out to the rear of the tractor and use it to power something as well (or even put the compressor under the seat and relocate the battery). That is what the SGTs did to run rear PTOs.

Do you need lots of power? The charging system on the AQS is 10-15 amps IIRC, so if you are going to run a radio/bunch of lights/chimes/etc, you may be looking at adapting an automotive alternator using one of these three locations, and a compressor off the other. A one-wire alternator for a GM is probably the simplest setup one can do, and there are a pile of different pulley options available.

For a compressor, a York compressor (used on old volvos, some older fords, etc) works great as a compressor (~ 10 CFM & 100 psi, depending on the specs), and has an integrated electric clutch, so you can turn it on & off, or wire it to a pressure solenoid to turn off the compressor when at pressure (give you more engine power/less fuel burned). I ran one of these to power a semi air horn, air tools, and inflate tires on a couple different vehicles.

You can do U-joints as well. I am putting together a 1450 using u-joints (idea based on Dave Kemp's writeup). Search his name, cub cadet, and u-joints on google and it will pop up. I used a different series/brand joint setup, as his is now price prohibitive (had a few eccentricities with my joints, but figured it out).

[TnPaul]

Thanks bkw & maddhatter for the response & suggestions. I am lucky that my son-in-law is a machinery maintenance tech and has access to lathes, mills, and any machine shop and fabricating eqpt you can imagine. Only problem will be keeping him from taking the project over completely .

I think I'm going to need more hp than a 12 or 14 because of the added accessories on board. The 16hp was on the low end of what I originally wanted, but we'll see how it performs. Cost is definitely a factor, and the B&S was priced right. I think we've got the new motor mount figured out, but will have to alter the frame a little as well. I won't be using the existing fuel tank, battery, or even the hood and fenders.

I'm not familiar with a "driver to driven" coupler. Sounds like a u-joint. Will check it out. SIL will be able to make any length & diameter drive shaft, and will definitely install new fan. Existing one is completely broken. It just seems to me that a significant amount of transferable power would be lost using a flex/rag joint, whereas a u-joint would transfer all the power.

I will be needing significantly more power than the tractor normally supplies, hence the automotive alternator. I haven't measured how many amps will be needed since I'm still not sure what all eqpt will be installed. And I did plan on using an old automotive compressor for the air horn. I like the idea of putting the compressor where the battery was located and driving it off the rear of the hydro. Leaves more room under the hood.

[Methos]

Very cool project! I built a caboose for my son several years ago. Not as sweet as what your planning on doing but we're happy with it.

Here's a idea for the drive line.
http://cubfaq.com/davek.html

[TnPaul]

Thank you Methos! The link you provided is great! I will definitely refer to it when I begin my assembly! I have a feeling your son enjoys/enjoyed the caboose almost as much as you! Can't wait to give my granddaughters a ride around the property!

[Methos]

Originally Posted by TnPaul

Thank you Methos! The link you provided is great! I will definitely refer to it when I begin my assembly! I have a feeling your son enjoys/enjoyed the caboose almost as much as you! Can't wait to give my granddaughters a ride around the property!

Your welcome! My son like to pull me around in it now.

[bkw3614]

I wouldn't underestimate the power of the one lung Kohler K series engines. I do, however, understand your power needs may be a bit greater than these engines can deliver, even the 16 horsepower, which, I understand, are rare.

I concur with Madhatter on the GM Delcotron alternator. There are several styles of that one wire alternator available, and you should look for one with a built-in voltage regulator. I think they were popular in the 1980's cars and trucks. Look for a large ampere capacity. As far as a compressor, it seems that from your posts, that you want a compressor to power an air horn. If that is the case, I would recommend a Bendix air compressor from a medium duty truck that was air brake equipped. These are fairly easy to find in a truck salvage yard, and they will have air reservoir tanks and a place to mount the air governor on the compressor, making it easy to plumb. Problem is with installation, your engine will need a full oil pressure system to provide for the lubrication of the air compressor through the engine oil pressure system. You will also need an air pressure and reservoir gauge, but that is a minor problem to install. Lubrication is a problem with compressors, because most don't have their own lube system. You will find this problem with air conditioning compressors, such as the York, as suggested previously. Perhaps considering an electric air-sounding horn is a better alternative. Just a thought....

I hope you get this project together...It sounds like a fun adventure.

[Sam Mac]

I think you are way over engineering this project. If it was me I’d go with a Delco 1 wire alternator for the 12 volt power and a pickup truck train air horn kit like this one from JC Whitney
http://www.jcwhitney.com/complete-tr...b2619c2553u0j1