Power Rake build

[Stonehaller]

Is there any reason to choose a Lovejoy setup vs Universal joint?
I can get either setup for about the same cost. The LJ would add a bit of cushioning during startup vs the solid connection of the UJ.

The Lovejoy coupling you picked out will not handle the load. Your tractor has about 18 PTO HP. At 540 RPM, 18 HP is 175 lb-ft of torque. The coupling is only rated 680 in-lbs or about 57 lb-ft.

The universal joint has a high enough rating, but the thing with a universal joint is that you need two joints to handle both axial and angular misalignment. Two joints also maintain constant angular velocity. You would still need a second bearing to support the shaft near the sprocket.

I see Surplus Center has some 60 pitch roller chain couplings that will handle the torque, but are only rated for 500 RPM. Also, I do not see a cover for the 60 pitch chain couplings so you have to ask them as you would need a cover to keep the dirt out.

Are you planning on a slip clutch or shear pin in the PTO shaft?

 

[Zick]

The Lovejoy coupling you picked out will not handle the load. Your tractor has about 18 PTO HP. At 540 RPM, 18 HP is 175 lb-ft of torque. The coupling is only rated 680 in-lbs or about 57 lb-ft.

The universal joint has a high enough rating, but the thing with a universal joint is that you need two joints to handle both axial and angular misalignment. Two joints also maintain constant angular velocity. You would still need a second bearing to support the shaft near the sprocket.

I see Surplus Center has some 60 pitch roller chain couplings that will handle the torque, but are only rated for 500 RPM. Also, I do not see a cover for the 60 pitch chain couplings so you have to ask them as you would need a cover to keep the dirt out.

Are you planning on a slip clutch or shear pin in the PTO shaft?

Thanks

I am not really familiar with those chain couplers, they will be able to handle the varying angles?

I looked at the 60 pitch couplers and it says that they are rated to 3000 RPMs.
1" BORE 60 PITCH 18 TOOTH CHAIN COUPLER HALF
And they do have the covers for them as well.
60 PITCH 18 TOOTH COUPLING COVER


And I have a slip clutch for the PTO shaft.

Thanks for your help. :thumbsup:

 

[PhysAssist]

Thanks

I am not really familiar with those chain couplers, they will be able to handle the varying angles?

I looked at the 60 pitch couplers and it says that they are rated to 3000 RPMs.
1" BORE 60 PITCH 18 TOOTH CHAIN COUPLER HALF
And they do have the covers for them as well.
60 PITCH 18 TOOTH COUPLING COVER


And I have a slip clutch for the PTO shaft.

Thanks for your help. :thumbsup:

Hi Zick,

You are entirely welcome, I meant it.

The other thing is that I am learning as least as much and probably more than you are from the others posting and I really appreciate that as well.

Thomas

 

[PhysAssist]

The Lovejoy coupling you picked out will not handle the load. Your tractor has about 18 PTO HP. At 540 RPM, 18 HP is 175 lb-ft of torque. The coupling is only rated 680 in-lbs or about 57 lb-ft.

The universal joint has a high enough rating, but the thing with a universal joint is that you need two joints to handle both axial and angular misalignment. Two joints also maintain constant angular velocity. You would still need a second bearing to support the shaft near the sprocket.

I see Surplus Center has some 60 pitch roller chain couplings that will handle the torque, but are only rated for 500 RPM. Also, I do not see a cover for the 60 pitch chain couplings so you have to ask them as you would need a cover to keep the dirt out.

Are you planning on a slip clutch or shear pin in the PTO shaft?

Stonehauler,

Please excuse my ignorance, but if the rating listed on Surplus Center states that the max power rating is:
"Power 39.6 Hp max @ 3600 RPM" is it really necessary to look at the max torque too?

It is the start-up toque to get it to that RPM that is the issue?

Thanks, and sorry Zick for the thread co-op, but I didn't understand why there are separate listings for the two ratings, as Stonehaller seemed to be using your HP and RPM's to figure out your torque figure...

Thanks again,
Thomas

 

[Stonehaller]

Thanks

I am not really familiar with those chain couplers, they will be able to handle the varying angles?

I looked at the 60 pitch couplers and it says that they are rated to 3000 RPMs.
1" BORE 60 PITCH 18 TOOTH CHAIN COUPLER HALF
And they do have the covers for them as well.
60 PITCH 18 TOOTH COUPLING COVER


And I have a slip clutch for the PTO shaft.

Thanks for your help. :thumbsup:

Oops, I missed that there were multiple pages. That coupling you picked is plenty big enough. Chain couplings can handle both angular and axial offset (parallelism or eccentricity), but your shafts have to be pretty close. They are not like universal joints. You probably need to get your shafts within about 0.015" and 1 degree angularity.

Lovejoy also makes larger jaw couplings. A Model L110 with a Hydrel spider can handle 189 lb-ft of torque up to 1750 RPM. Their misalignment capability is similar to the chain couplings. I would expect the love joy is more expensive than the chain but you may want to do a search to check it out.

If you have enough room, you could use the universal joints as well. Another thing about universal joints is that you want some off set in your shafts so the bearings in the u-joints will turn. You could just put a spacer under your gear box so that the u-joints run at 1 or 2 degrees. The nice thing about the u-joints is you do not have to mess around trying to get the gear box precision aligned to the shaft.

Stonehauler,

Please excuse my ignorance, but if the rating listed on Surplus Center states that the max power rating is:
"Power 39.6 Hp max @ 3600 RPM" is it really necessary to look at the max torque too?

It is the start-up toque to get it to that RPM that is the issue?

Thanks, and sorry Zick for the thread co-op, but I didn't understand why there are separate listings for the two ratings, as Stonehaller seemed to be using your HP and RPM's to figure out your torque figure...

Thanks again,
Thomas

It is important to consider torque when sizing drive line components. Horsepower alone does not give you enough information. You need horsepower and velocity or torque and velocity. The torque rating for couplings is generally constant over the RPM range. 39.6 HP at 3600 RPM is 57.7 lb-ft of torque. That same torque at 540 RPM is only 5.9 HP - much less than the tractor can do. Here's the formula to calculate torque in lb-ft from HP and RPM: Torque (lb-ft) = (Horsepower x 5252) / RPM.

 

[Zick]

So due to some personal issues and my crappy Clarke welder dying (Think it's just a relay but I can't find anyone that stocks it), I am behind schedule.
Had to take everything out to my father in laws and use his equipment. Though I'm not really complaining since he has much nicer stuff that I have.

Like everyone said it would, this took forever! Probably about 8 hrs worth :grumpy:




Setting up the gauge wheels.




Finishing up on the angle mechanism.




Still need to setup the chain idler gear and figure out a cover for it. Then the fun part, taking it all apart again and painting it. :tired:

 

[Xfaxman]

:thumbsup: looks like a gooder-un.

 

[GolfAddict]

Good progress, thanks for keeping us updated!

 

[Zick]

Big update!
Worked on it slowly over winter but finally got it done enough to try out. Seemed like all those little things took longer to get done than the bigger stuff.

Getting the chain coupler setup and installed. May or may not be the best place to put it but I didn't know any better. :confused3:






Test run inside. Click on pic to play video.



Temp cover to keep an eye on things until I can make up a final cover.




After using for about 3 hours.



Results: It worked excellent and better than I hoped! :hyper:
But there are a few things that I need to address before I can use it again.

The gauge wheels (8" what I had laying around) are probably a too small. They worked OK but bigger and wider wheels would be better. The wheel arm is way too short. I can't put the wheels down far enough to get the wheels to hold the rake because they get too close to the teeth and will actually hit. Plus, at that angle the wheels don't track well. So I'll probably extend the arm out another 1ft and maybe upgrade the wheels.

The gauge wheel c channel bracket that holds the top link to the wheel arm is way too weak, it flexes really bad and I bent it when I tried to back into a hill :ashamed:
So that will probably get boxed in for strength.

And now for the bad part. After about 3 hrs of use, I heard something and found the drum wasn't spinning anymore. I saw the chain had came off so I took over the cover to investigate and found this.


And this, the sprocket took some damage too.


I managed to fix the chain and clean up the sprocket enough to probably re-use. Got plenty of chain so if it messes up the chain I'll replace the sprocket.

I found that the set screws on the pillow blocks holding the drum must have vibrated loose and allowed the drum to shift over which threw of the chain alignment.
I'm going to see about finding some kind of sleeve to fill up the gap between the drum and side pillow blocks so it can't move side to side anymore.

 

[Xfaxman]

Glad it worked well and you can fix the problems. :thumbsup:

On the gauge wheels, casters need to be level, so you could cut where I put the arrows extend slightly and change the angle to make them level when down.

If level they will be farther from the drum.