Murray Widebody build

[jhodgson53]

Steal away! The cover plate took all of an hour to make. After I removed the original slotted plate which held the deck height adjustment lever, I traced around it on a piece of thin cardboard taped to the plate, then transferred that to an old license plate and cut it out with snips and smoothed the sharp edges with sandpaper. The bottom two holes are where the original slotted plate bolted on. I drilled the other two holes in place to hit plenty of "meat" around the edge of the fender cutout. The original slotted plate has a tab that just extends under the fender at the top, but the license plate was just long enough to make it the way I did. I wasn't going for "bling" but it doesn't look bad; sort of like the plates and panels you would fab up in a racing sedan. And no cost other than my time and screws I already had on hand.

I'm trying to find that piece of 4" angle iron that I need to make the bracket for the golf cart front axle, without buying an eight-foot length which I'll probably not use in my lifetime. Everything I've found so far is either too small or way too big. I'm going to check tomorrow with a couple of fabrication firms that are close to my office. Failing that, there's a scrap dealer that picks up stuff from our fleet garage who may be able to help.

No luck with the transaxle pulley today. Heated and cooled, judiciously pecked and pried, all with an eye to not damaging the input shaft bearing, and no movement yet. Next step may be the Dremel with cutoff discs to cut through the pulley hub and get close to the shaft. Seldom have I seen anything so profoundly rusted stuck here outside the salt belt.

Best to all,
-JB
Posted on: July 06, 2010, 10:05:29 PM My new front wheels and new pulleys arrived today:

http://www.offroadmowers.com/uploader/files/56/wheels%20and%20puleys.jpg

The wheels are 8", 7"wide, 4 on 4.  engine pulley is 4.75, trans pulley is 6.25.

My work interfered with my attempts to procure the angle iron today. I hate it when that happens! Maybe better luck tomorrow!
Got home late and found the new stuff waiting on my front porch.
I'll take a few minutes in the morning to apply another PB Blaster dose to the trans pulley before I leave for the office; tomorrow evening will be my last attempt to remove the pulley intact, then I resort to the cutoff wheels.

Still trying to figure the most cost-effective way to mount a substantial brake disk on the 3/4" axle. Suggestions are welcome.


Later,
JB

[Chris]

Those are the same exact wheels I have on the back of my Toro. They still look good after sitting outside in the weather for two years

[jhodgson53]

Here are some Briggs and Stratton decals I ordered from their website; about 6 bucks for the lot.:

http://www.offroadmowers.com/uploader/files/56/BandSdecals.jpg

The big ones are about 18" wide by 8"high, and the small ones about 8" by 3". More bling, I guess?

It's officially 100 degrees here today, so I'm waiting for things to cool down a bit before venturing to the shed and continuing my torture of the transaxle pulley.   Or myself, as the case may be.

Ref the wheels, they seem to be very well made. They're zero offset so the front track won't be waaaay wider than the rear. When I eventually get four-bolt hubs for the rear, I'll get another set and maybe go to a 22" tire vs, the 20" ones I have now.  Surplus Center has some very nice 12" rims that would look so cool with a low profile tire, but for my purposes I prefer the taller tire which when run soft will to some extent compensate for the unsprung chassis.

Anyone ever use any of that rubber fender flare material around the rear fenders to cut down on splatter?
My tires already stick out a bit past the sheet metal, so I was just thinking......

Later,
JB


Posted on: July 08, 2010, 03:59:16 PMAnother thing: Anyone ever see a brake arrangement on a kart that has a "shoe" that actually rubs against the rear tire tread when the brake is applied?  My uncle had a dirt track racing cart when I was a kid, (45 years ago) and IIRC it had this type of brake. The metal shoe was covered with a thick piece of rubber, about 1/2" if memory serves. The rubber looked like and may have been a piece of tire tread. They worked very well as I recall, but of course we're talking about a light vehicle. I was wondering about this as a solution to my split braking system. It could be auxilliary to the disc brake on the axle, and I have a blade engagement lever on the right side of the mower that I could set up to apply the right brake if pulled back, and the left brake if pushed forward, or something like that.

Just thinking out loud again...
JB

[jhodgson53]

  FINALLY! I got the old pulley off the transaxle this afternoon. Had to cut through the pulley around the hub with the Dremel, then cut through the hub lengthwise down to the keyway,  then put a big screwdriver in the cut slot and PRY, creating just enough clearance to loosen the hub on the shaft.

I'm definitely going to put some anti-seize compound on the shaft with the new pulley. I'm anxious to get the drive train back together and see if and how much my clutch and idler pulleys will have to be modified, and what length drive belt I will now need. I have parts ordered for my new rear disc brake (mechanical caliper), but I rebuilt the stock trans brake just for giggles while I already had everything apart. I won't be doing anything adventurous until I get that disc brake installed.

Had to spend time today working on the grasscutter, which decided not to start on Saturday morning.  Finally figured out that it is the starter, go figure!

Later,
JB

[Chris]

I wouldn't mess with the on-tire brake because they're pretty much useless when you get them wet. I had a pedal-cart with one of those when I was was little kid, they were pretty much useless.

As for the transaxle/transmission disc brake. I've found that they work really good as a parking brake. I use to use mine way back in the beginning days of off-roading as the primary brake until I found out what happens when your chain falls off/snaps. Ended up going backwards down a very steep, large hill very fast.

[jhodgson53]

  Yes, come to think of it, we never raced that dirt track kart in the rain!

Im buying a 6.5" sprocket to use as a brake disc. See any problem with that, other than keeping fingers and toes away from the spinning sprocket? I could grind the teeth off, I suppose.

Later,
JB

[Chris]

Are you planning to use it as a sprocket also? You could get a go-cart sprocket for really cheap. I got a nice cross-drilled & slotted one with a hub for like $10 on ebay.

[jhodgson53]

My immediate plans are to use it for a brake disc only. I decided on the sprocket because they were easy to find with a 3/4" bore, like my axles, and without having to bolt them onto a hub they take up less space on the axle between the wheel hub and the trans case. I'll use the Dremel to grind a keyway in the axle where the sprocket will sit. I saw a pic of a gokart recently that used the drive sprocket on the axle for it's brake disc; the caliper was mounted at the three o'clock position with the chain passing above and below it.

I have daydreamed about eventually installing a chain drive to a more substantial live rear axle, using the current transaxle as a transmission only. This would probably require lengthening the frame to relocate the live axle rearward, or relocating the trans forward to preserve the stock wheelbase. Maybe when I get this one up and running as my workhorse, I might find another one to use as a "testbed" for an idea I have for a mower-based UTV of sorts, looking something like a Toro RER with the rear wheelbase extended to make it more "mid-engined" in nature, with a small utility bed or platfrom behind the seat. My purpose wouldn't be to conquer the Kalahari with it, but something handy and fun to use here on the farm, without spending several thousand dollars. Another project for another day!

No progress today on the Murray other than getting the new trans pulley on.  Bad thunderstorms with torrential downpour in the area kept me in the house nearly all evening after work. Ordered a new starter for the grasscutter.

Later,
JB

[jhodgson53]

  I got the steel cut for the piece I'm making to change the geometry of the steering arm on the golf cart spindle I'm using. That's the sketch I took a pic of previously. Hope to get it welded and drilled in the next couple of days. Ordered rod ends for the tie rod and steering linkage. Got my brake caliper today, and the brake disc / sprocket has been shipped. If rain slacks off I may make some progress tomorrow. My mowers are still sitting outside under a tarp while the shed is otherwise occupied.

Got a new starter for the grasscutter too, but the grass has got ahead of me, so it's back to the big tractor and 6' mower as soon as things dry out a bit. 

Later!
-JB
Posted on: July 17, 2010, 12:52:05 AM The mailman brought my sprocket / brake disc today. It's a great fit in the caliper.  I'll have to get set screws and a shaft key for it. Pics to follow.

Later,
JB

Posted on: July 17, 2010, 09:49:21 PMHere's a pic of the Airheart brake caliper I'll be using:

http://www.offroadmowers.com/uploader/files/56/brakecaliper.jpg

Hoping for a couple of dry days so I can begin putting the drivetrain back together. Once that is acccomplished, I can turn my attention to the front axle, steering, etc.

Later,
JB

[Chris]

Nice status updates, seems like you're currently the only active build on the forum

[jhodgson53]

That's a shame. I'm having a blast.

Mocked up the brake disc and caliper and I have clearance issue with the wheel. If I had a slightly smaller sprocket with a smaller diameter hub, It would put the caliper closer to the axle centerline and clear the wheel. If I used a brake disc with an offset hub:

http://www.offroadmowers.com/uploader/files/56/offset%20disc%20brake.JPG

it would move the assembly inboard away from the wheel. An auto disc is the only production piece I'm familiar with in that configuration, and that might fit the bill IF I can find a thin one (3/8" max) for an old, small car.

I'll have to look at the specs on some different sprockets first and see where that leads.

Later,
JB

[Chris]

I guess I don't understand what's going on, do you have a picture of it assembled?

[jhodgson53]

No I don't and I've disassembled it all now. Let me see if I can explain it better. There's not enough room between the disc and the wheel for the caliper to fit over the disc without the caliper rubbing the inside edge of the wheel rim. Either the wheel will have to move outboard (which can't be done with the stock mounting arrangement)  or the disc / caliper will have to move inboard. Or I get bigger diameter wheels. Or a smaller caliper.

I did find a smaller caliper on ebay;
http://www.offroadmowers.com/uploader/files/56/small%20mech%20caliper.JPG
I've messaged the seller to try and get the overall dimensions so I can see if it will solve my problems. It looks promising.

Also, I found out that a solid brake rotor for a Vega, K-car or Isuzu PuP can be bolted to a 4 on 4 hub, ditto for a Chevette or Fiat 850 with minor fitting with a round file. 
http://www.offroadmowers.com/uploader/files/56/fiat%20brake%20disc.JPG
http://www.offroadmowers.com/uploader/files/56/4on4rearhub.JPG

This also bears exploration. Like the sketch in the previous post shows, the auto brake rotor will move the actual disc surface inboard by a few inches, which is plenty. This will be a bit more pricey than the smaller caliper; about $20 for the rotor and $25 for the hub, vs $28 or so for the caliper. Plus, if the brake rotor is too thick for my current caliper, I'll have to get someone with a brake lathe to thin it down for me.

Decisions, decisions!

Later,
JB

[Chris]

Alright, I think I understand what's going on here now. I forgot you were running an transaxle and not a transmission.

What's the problem with moving the wheels outboard? Run out of axletube?


Edit: Check out how George Herrin mounted his brake setup.

More on the build. Here you see I am seting up the brake system. These are not new brakes but some I had and want to try on this build.


here is an overall view of the brakes and rotor. Yup its a big rotor but the bigger it is the less force needed to stop it. It is a motorcycle rotor redrilled to fit the MCP brake hub. Everything is setup so the rotor hub is against the bearing hub and I put a slit collar outside the brake hub to hold it all in place. The caliper is bolted to the frame with a couple shims between it aqnd frame to align it to the rotor.


Here you can see the clearance between caliper and tire. Tire 19 inches from center of frame. Thats the outer sidewall.

http://www.heymow.com/index.php?topic=1613.msg13238#msg13238

[jhodgson53]

  Yes, Mr. Herrin has a nice brake setup. 
In my case, you've got it, there's just not enough axle sticking out of the housing to accommodate all the pieces!
Running an axle like his, with the bearings up flush against the frame, it would be a snap.

I'm leaning toward trying the smaller caliper, if I can confirm that it's small enough to fit.

Went out to mow, and my grasscutter has a flat.   

Later!
JB