[FINALIST] - AK's LT-08 Rat Rod Tractor Build [2019 Build-Off Entry]

Yeah it will be. Hopefully it's not too much, thinking about a bigger pulley on the driveshaft just to tame 'er a little bit.

Got my crank adapter welded into the engine pulley again, turned out nice and straight this time. Tried mocking up the smallest belt I could find, just to get a look at things:



Too long obviously, haha. But if I but a bigger pulley on the drive shaft it might take up enough slack for me to make it work. That's probably what I'll end up doing.

I'd get a shorter belt. If this is gonna win, she needs to be fast!

AllisKidD21 wrote:

Yeah it will be. Hopefully it's not too much, thinking about a bigger pulley on the driveshaft just to tame 'er a little bit.

Got my crank adapter welded into the engine pulley again, turned out nice and straight this time. Tried mocking up the smallest belt I could find, just to get a look at things:



Too long obviously, haha. But if I but a bigger pulley on the drive shaft it might take up enough slack for me to make it work. That's probably what I'll end up doing.

I'd almost leave the smaller pulley, it would give you more room to build your clutch.  Maybe a tiller style clutch?  Single pulley pushing into the belt between the drive pulleys?

Yeah well I have a real small flat idler in mind for the clutch, so hopefully I'll have enough room even with a bigger pulley on the shaft.


We'll see anyways, it's all still kinda up in the air. Haha.

Your going to need some really good wrap around on the driveshaft pulley, to keep it from slippin, LOL.

Yeah, haha. I'm sure that would cause some issues. Like I said though I'm most likely gonna put a bigger one on there instead, should make things easier.

I would use a chain drive with a centrifugal clutch, just cuz its way easier to build.... With the small Pulleys U will have belt slip I guess...

Well if you can find a cen. clutch that will fit on a short tapered shaft, send it my way! LOL. While you're at it, send me the chain and sprockets too!

AllisKidD21 wrote:

Well if you can find a cen. clutch that will fit on a short tapered shaft, send it my way! LOL. While you're at it, send me the chain and sprockets too!

If I would be in your Position I would
A: Swap a crank with the correct shaft in
B: Use another Engine
C: Weld the Crank up to 1" to fit the Clutch

Okay..... good to know I guess.

SebastianAlbrecht wrote:

AllisKidD21 wrote:

Well if you can find a cen. clutch that will fit on a short tapered shaft, send it my way! LOL. While you're at it, send me the chain and sprockets too!

If I would be in your Position I would
A: Swap a crank with the correct shaft in
B: Use another Engine
C: Weld the Crank up to 1" to fit the Clutch        

Yeah, it's not like it'd be waaaay simpler to gear it differently or anything.

SebastianAlbrecht wrote:

AllisKidD21 wrote:

Well if you can find a cen. clutch that will fit on a short tapered shaft, send it my way! LOL. While you're at it, send me the chain and sprockets too!

If I would be in your Position I would
A: Swap a crank with the correct shaft in
B: Use another Engine
C: Weld the Crank up to 1" to fit the Clutch        

Weld the crank up to 1" ? it's not that easy, unless you have a metal lathe laying around and i don't.

Got the engine out again tonight to do a little more work:



Finally gutted all the wiring and the solenoid, as none of it will be used:



Probably shoulda done that a while ago but oh well, haha.

Then I took the steering all apart, cleaned up the frame around that area, and cleaned up the steering assembly a bit. Also I got the last hole drilled for the front pillow block bearing. There was only one holding it before because the steering had to be removed to drill the last hole and I hadn't done that yet.

Got it all done and both front bolts in. You can see I had to use a carrige bolt and grind it down to clear the steering sector gear, and cut one side of it for the steering plate thing to clear:





Couple other spots had to be clearanced as well, haha. Kind of a pain but it worked out in the end. I'll get the steering assembly greased up and fully put back together tomorrow if all goes well.

Okay, so I got the steering all lubed up and re-assembled today:



Should be good to go! Then I figured out what pulley to use on the driveshaft:



Using the big end of the double pulley I originally mocked up. Had to do a little notch in the frame for it to sit back far enough, but it worked out perfectly!

I just drilled and tapped a hole for a 1/4-20 NC bolt, to act as a set scew to hold it on.



Then I actually finally got around to starting on the clutch! Found an idler that'd work and made a clutch arm:



Simple piece of angle steel for the pivot/mount:



I just welded the angle steel right to the frame, turned out pretty good!

Disengaged:



Engaged:



Looks pretty good so far. I also added a brace at the other end of the angle steel:





Quite solid now, shouldn't be going anywhere!

Pretty happy to be makin progress on this clutch now, tomorrow I'm gonna work on the linkage setup, we'll see how that goes, haha.

Let me know what ya think!!

Nice job.  Only thing, I think I would have put it on the other side.  That way should it get into pto it would throw it back out instead of trying to jam it between the pulleys? Then again I may not touch the pto pulley?

I suppose, but the other side is the torque side of the belt and I try not to build clutches on that side as it can cause the belt to fight the clutch under tension.

Kinda hard to tell but the idler actually clears the engine pulley when all the way back and will rest right on the drive shaft pulley, so if I add a stop for the arm in the right spot it should be fine.

The clutch pulley looks like it will be sticking out the side when pulling on the belt. That will be neat to see when driving it.

LOL, I thought so too!! It'll look like the fan belt or something, haha.

AllisKidD21 wrote:

I suppose, but the other side is the torque side of the belt and I try not to build clutches on that side as it can cause the belt to fight the clutch under tension.

Kinda hard to tell but the idler actually clears the engine pulley when all the way back and will rest right on the drive shaft pulley, so if I add a stop for the arm in the right spot it should be fine.

Excellent. if it clears fine, then absolutely that side looks good!

Thanks. Hopefully it works good anyways, haha.

Nice job. Looks a lot like a drive belt configuration I see on snowblowers in regards to the distance between everything. Most have a couple belt keepers on the engine pulley and trans pulley and a keeper built into the clutch arm. Space looks tight there but I know you'll make it work great.

Looking Great! That Clutch hopefully puts enough tension on the belt

That's pretty sweet, should fit the rat rod theme very well too!

Can't wait to see how this all pans out, Great Build !

Need some kind of bullet cone for it.. LOL

Thanks a lot fellas!!

I actually managed to work at it and get the clutch pretty much done today.

I didn't take as many pictures as I should've... but basically I used sort of a bell-crank setup to transfer the motion from the clutch pedal rock shaft to the clutch idler arm.

This is the upper portion of it:



The pivot point is an automotive flat idler clamped to the inside of the frame with a U-bolt, so the whole thing pivots on a bearings.

Had to make a special bolt for the upper arm so it would lock in place but still be removable:



Simple clutch spring setup:



And the lower arm and linkage:





Finally, the function!





It works!! Hahaha. Ran out of time to do a test with the engine running, but that should be pretty soon now. The clutch needs a couple things as well like a stronger spring and possibly a lower linkage mount on the idler arm so I get a bit more throw out of it. But as it is now it fully engages and disengages, so I'm happy!

Let me know what ya think!