Farmall Cub

Several months ago I went through the necessary trouble shooting to determine that the cutout relay on my '49 had went out on me. The generator still chraged when I grounded the field. So I set on the quest to get a new cutout relay. If you've priced them, new ones are just south of $100.00. Jim Becker put me on to the concept of a diode in place of the cutout, though he never had actually done it. What I really wanted to do, in my effort to keep my "Blue Ribbon Cub" as close to original as possible, was gut the existing Delco Remy cutout and "hide" the cutout inside it, even though once the hoods on it you can' tell it anyway...it was just a personal thing.

After looking back through my Brillman catalog, I ordered the D100 Cutout relay from Brillman for slightly less than $30, after talking with Jim Brillman on the phone to see if he bought my crazy idea of putting the new cutout relay in the old can. He seemed to think there was more than enough room to make it work and it should work out well. Heck of a ncie guy and I enjoyed talking to him on the phone. I've bought stuff from him before, but never actually spoke with him. Very sharp!

http://brillman.com/store/d100-cutout-relay.html

Last night about 9:10 after finishing my garden chores for the evening I got my second wind so to speak and set in on making the cutout relay swap. First off let me apologize for the crappy pictures. It was dark in my shop, I was tired after working on all day and working the garden and my pictures came out terrible but you should be able to get the idea.

First a picture from several months ago showing what I had originally...


The first picture from last night with the hood off and the lid taken off the cutout...


My idea is really better than I thought, as the feet on the D100 won't line up with the mounting holes in the generator anyway. It's footprint is much smaller...


Using my craftsman dremel tool I cut all the guts out of the cutout. I'll be able to make use of the existing mounting hole for the coil as an opening to get my new wiring into the can...


The D100 has small wiring decal on it, ARM to positive and BAT to negative for positive ground and vice-versa for negative ground...


I did have to cut one foot off the diode and cut the side out of the other. It let me keep it centered up enough in the can to clear the tapped hole in the bottom for the cover screw...


Wiring is really simple. I cut the ends of the existing wiring and added female spade connectors. If I ever need to take generator off I can just unplug everything. The BAT wire connectors to the NEG side of the diode and the ARM lead from the generator connectors to the (+) side of the diode. Conventional "modern" negative ground sytems are the exact opposite.


Didn't show it here for clarity, but I did wrap the terminals of the diode up with insulating tape prior to bolting on the cover. As well as taping up the spade connectors once I put a little heat on them to shrink the insulation...




Completed with the lid back on it...




And the moment of truth, charging on Low...


And charging nicely on High...


Hope this helps someone else along the way. Total cost was a tad over $30.00 and it took longer to remove and reinstall the hood that it did to make the swap...I was on the front porch swing enjoying a nice cigar and cold drink by 10:30 last night

Awesome! Hope it gives you trouble-free service for many, many years!!

This should be saved/locked into the "How-To" section of the forum.

Cool. It never occerred to me that one of Brillman's diodes would fit inside the old cut-out shell. I'd have probably been digging through a Radio Shack catalog looking for something with enough current capacity.

I did hunt through Radio Shacks on-line catalog...and called the local store, which was useless. I figured it was easier to order from Brillman. I needed a bit more cloth wire for somethin I'm adding to my "M" anyway.

Stanton wrote:Awesome! Hope it gives you trouble-free service for many, many years!!

This should be saved/locked into the "How-To" section of the forum.

I really, really like that! One thing I wondered though, would it be possible to solder your wires coming off the diode to the terminals on the old cut out base, so it looks even more original?

PS I love that old, original IH amp gauge! I wish the repro's they do now looked just like that....

Al

Soldering it back in to the old lugs is very doable...and I thought about it. I don't have a soldering iron and talked myself out of spending the extra money on it, since you can't see with the hood on anyway. You would have to maintain insulation and separation between the cutout shell and the old base. The existing lugs are separted from the base by bakelite, assuming it's in good condition I don't see why not.

I like the old ammeter too, brass ring and all!

Very clever indeed! Gotta love it when a plan comes together.

Hey, a great Idea! Also, I like your good installation job complete with a "how to" photo record. I expect John Brillman will soon be having to re-stock his cutout bin .

Super A wrote:...would it be possible to solder your wires coming off the diode to the terminals on the old cut out base, so it looks even more original?

I was just wondering the same thing. That would give the modernized operation while keeping the "correct police" in the dark, if one should be inclined to snoop around under the hood .

Bill

Thank you all for the compliments, and again I apologize for my crappy pictures.

The wiring on my Cub is in pretty bad shape, extremely fragile. The more you mess with it the worse it gets. I've basically re-wrapped everything with friction tape to keep it from just falling apart. You can see some of that in the pictures. Though I have no intentions of painting the tractor, I do intend one of these days to rewire it with cloth wire and loom like I did my Farmall "M". When I do that in a another year of two I may go ahead and go the solder route.

I've got another project floating around in my head to give me some "convenience power" on my restored "M". It is a 12V tractor with Delco alternator under the hood. I'm tinkerin' around with gutting an original Delco-Remy V/R and putting a power outlet in the bottom side of the lid. The gutted V/R would be mounted on the gas tank pedestal and look dead on original. That's why I ordered some more cloth wire from Brillman when I ordered the diode...

I have done similar to two tractors and several generators. I used diodes that sell for a few dollars apiece. If you are going to hide the diode anyway then the few dollar diodes will work as well as the 30 dollar Brillman diode.

One potential problem is a large voltage spike, i.e. 10K volts going into the cutout diode or condenser when used with a battery ignition system if the battery becomes disconnected. Should not be a problem with your magneto system.

I like the modernization of this modification! I have been having an issue with a "sticky" cutout, so I might just have to try this mod myself. One possible issue that I see is with the single-sided mounting of the diode to the base of the original cutout. With that single mount and the other side hanging out there, could vibration cause the one mounting nut to come loose? Could the vibration further cause the side of the diode to become brittle? Perhaps I am just making a mountain out of a mole-hill...

Mike in La Crosse, WI

I like the idea of the diode, but what about the voltage drop across it? Doesn't that affect the charging voltage at the battery? I know the drop is small - either 0.7 or 0.3 volts, but that might be significant…??

Voltage in a cut-out system is limited by the battery. Voltage input to the diode should increase enough to make up the difference without making a noteworthy change in the charging current. If it fails to keep the battery charged, the third brush can be tweaked a bit to boost the charge rate.

Hengy wrote:I like the modernization of this modification! I have been having an issue with a "sticky" cutout, so I might just have to try this mod myself. One possible issue that I see is with the single-sided mounting of the diode to the base of the original cutout. With that single mount and the other side hanging out there, could vibration cause the one mounting nut to come loose? Could the vibration further cause the side of the diode to become brittle? Perhaps I am just making a mountain out of a mole-hill...

Mike in La Crosse, WI

Mike, Thats possible...mounting it on one leg wasn't my preference, I used a No. 10 machine screw, lockwasher and nut. even if it does, it'll just go along for the ride inside the can. I wrapped and insulated the two termianls before I put the lid on it, so even if it does it won't ground the armature lead.

FCubman,
I didn't feel like the voltage drop would be enough to concern me, matter of fact I didn't even try to check it...