A little clarification on something I mentioned in a previous post, and a little humor.

I mentioned that the part numbering on these JS46 mowers was a little bizzare.   Turns out there are two things happening with this model.

First, it is sold as a John Deere, but it appears to be manufactured by Murray.  Probably them's fighting words to people that bleed green, but it doesn't make any sense it would be the other way around.  I'll show why later.

Second, pay attention to the mower serial number.  There is a breakpoint before or after 150K ( 150,000 ).

Early models use the GX22837 blade adapter with a GX23522 blade (one holer).
Later models use the GX24214 blade adapter with a GX24213 blade (three holer).

early:

 

Late:

 

Note that I could not find a picture of the GX24214 anywhere, these are pics I took.  I think this part is top secret or something, very odd it is that hard to find.

Both adapters are about $10 each, and the blades are about $30 online.  Interesting, though, the early blade 23522 is available at Lowes for $19.  No where on the package is indicated it is only for early mowers.  Curious.  Par for the course there.

Back to my second point.  Murray.

The numbers on the blade adapters, early 7101414, late 7104332, and on the blades early 7104179, late 7103288 are Murray numbers.  Strictly they may be AYP or even Briggs, as these parts all came in Briggs boxes.  However, they are made in the USA.  

At any rate, why go to all this trouble?  Like I said before, it is easier to find parts for a model of a mower if you know what you have.  JD has a reputation for maintaining supply and their dealers are quality.  Many home store blades are crappy thin and often bent.  these blades are SERIOUS, almost 1/4 inch thick.  They will be much easier to sharpen.

The lesson for today is - if you are looking to buy a mower or any piece of equipment, get the model and search for the parts you might need in the future.  You may learn something about the unit you intend to buy, or maybe that it isn't exactly what you think it is after all.

Progress at last...

After non-trivial searching for parts, I settled on mower blade, adapter and pulley from the same Deere series mower that the engine came from, a JS46.  I ordered them online as that is way cheaper than visiting the local dealer (sorry).  HOWEVER, what wasn't clear is that there was a serial number breakpoint where the blade & adapter changed designs.  I ordered the correct adapter, but the "cheaper" blade had to be exchanged for the right one.

The earlier blade only had one hole, the newer one has three as shown above.  In the diagram (from partstree.com), I chose the 0050 pulley and the 0110 blade adapter to fit.

This is important as the blade adapter mounting surface is 0.9 inch lower than the end of the shaft, and the blade itself has the cutting edges even lower again.  This results in the cutting plane being 1.65 inches beyond the end of the shaft.  This folds back into the deck design and defines the height of the motor mounting with respect to the lower edge of the sides.  Now that part can progress forward.

Additionally, I acquired a Spektrum DX7S radio and AR8000 receiver.  Local purchase at Performance Hobbies in Webster.

I was going to get relays from the same place I got the motor controller, but I need at least 3 channels ( I ordered 4 ).  They wanted about $25 each, so I looked around a little more.  I found Pololu ( same place that makes all kinds of stuff including some of the original RepRap motion control ) had some nice units for under $10 each.  I also scored some RC servo cable extensions.

These relays will control the engine start and kill switch plus the motor brakes.  These modules interpret the RC servo pulses and turn on the relay at a certain threshold.  At this price, it isn't worth making anything.  A very rough draft schematic is below.

I am looking at circuit breakers and will probably use a Bussmann 70A switchable unit, which will double as an "off" switch.  I may also add some automotive self resetting breakers here and there as I worry about melting things sometimes.

Still working on tooling, the Y axis DRO is getting closer.  The encoder mounting plate is done, and working on the bracket for the read head.  The new vise is installed and trammed in, what a difference that makes in setup and repeatability!

Progress Update

Yesterday, the Briggs engine arrived via a very mixed up FedEx delivery.  Also, I picked up the special order 24 Volt alternator at the local electrical shop.  They installed the bidirectional fan and put the smallest diameter pulley on that they had in stock.  Normal is 2.5 inch diameter, but they had a 2.25 on hand.  They said for best output I should spin it at 4500 RPM, but with a 2.85 drive pulley I should get close to 4000 which is pretty close.  I can change the pulleys later if the load balance doesn't quite work out.

Further progress is temporarily on hold.  Today I installed the X axis DRO on the mill and also received my new used Kurt D675 vise.  I cleaned the machine to install the encoder, and also installed the new vise.  It is much more robust than the older Armstrong that I got with the mill.  I just need to tram it in, maybe tomorrow, then I would like to install the Y axis encoder to complete the DRO.  I also have a Z encoder for the knee, but I'll save that for another day.

These upgrades should allow for easier and more accurate fabrication of remaining parts.

L8R...