Need math help , for my firewood winch build

[zack8.1]

Like stated earlier in the thread, it is important to have a secondary clutch to engage the winch with. Early Scandinavian logging winches used a wheelbarrow wheel as a clutch (easy to build). Bulldog vinsj and Tunby vinsj are two examples. Logging winches evolved from the wheelbarrow style and to the ones that are used now with a inboard drum clutch. Igland, Farmi and Fransegaard to mention 3 modern logging winch brands.

Bulldog vinsj/winch (wheelbarrow wheel clutch):

https://www.google.no/search?q=bulldog+vinsj&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiB3bzFmNnJAhVBOywKHeu-AJMQ_AUIBygB&biw=1056&bih=537#imgdii=ZN2Xdq06v5LgAM:;ZN2Xdq06v5LgAM:;VBhh8ClQE8EOeM:&imgrc=ZN2Xdq06v5LgAM:

The PTO speed of 540 is most times at 2100 RPMs engine speed and as there is a clutch on the PTO side now, you will need a brake on the pinon or on the winch side to stop the winch from unwinding when pulling.

 

[czar800]

I have and use this type of winch. I don't feel the need for a clutch, the brake will act as a slip clutch. dave_dj1 I'm assuming your going to build it similar to mine? Wish I had better video of it pulling logs and tops.

 

[Marshy]

http://web.mit.edu/2.972/www/reports/differential/differential.html
This is about as good of an explanation as I could find however it appears that the other side will actually speed up!
But what do I know? It may slow down when held. I will have to test it and see.

That doesn't explain it that I can see... The outter wheel might speed up but the inner wheel is going to be the driver and turn at the ratio that the gearing has (3.73 or what ever). Fix one wheel and the other will receive 100% power at the rear end ratio. I'm prepared to eat my foot if someone can explain the lower ratio.

 

[czar800]

That doesn't explain it that I can see... The outter wheel might speed up but the inner wheel is going to be the driver and turn at the ratio that the gearing has (3.73 or what ever). Fix one wheel and the other will receive 100% power at the rear end ratio. I'm prepared to eat my foot if someone can explain the lower ratio.

 

[zack8.1]

Just weld the spiders and have a closed diff and then it stays the same and need one brake and the tractor clutch

 

[brenndatomu]

it appears that the other side will actually speed up!

Yes, the gear ratio is effectively cut in half. So 3.73:1 becomes 186.5:1...highway gears!
Here is a quote from Wiki that explains it pretty well
"In automobiles and other wheeled vehicles, the differential allows the outer drive wheel to rotate faster than the inner drive wheel during a turn. This is necessary when the vehicle turns, making the wheel that is traveling around the outside of the turning curve roll farther and faster than the other. The average of the rotational speed of the two driving wheels equals the input rotational speed of the drive shaft. An increase in the speed of one wheel is balanced by a decrease in the speed of the other."

 

[Marshy]

That still doesn't explain why someone said you will get half the ratio. if you lock one side... I believe that statement is false. The whole premis of limited slip is to allow one tire to rotate faster (outside) than the other when turning. The slower tire (inside) will still rotate proportional to the overall ratio of the input (3.73:1).

 

[Ferguson system]

That still doesn't explain why someone said you will get half the ratio. if you lock one side... I believe that statement is false. The whole premis of limited slip is to allow one tire to rotate faster (outside) than the other when turning. The slower tire (inside) will still rotate proportional to the overall ratio of the input (3.73:1).

Yes,
the gear ratio stays the same, but the rpm changes.

 

[kevin j]

The ring gear ratio and the pins that drive the spider gears is 3.73, but the inside wheelturns slower and the outyside wheel turns faster, to average 3.73. Inside wheel does not hold a conmstant speed.
Look at a differential cutaway or schematic. spider pins are constant speed, but any reduction on one side of spdier gear adds to the other side. So stopping one side of the spider means the far side of spider will move at twice the speed of the pins and ring gear, thus the 3.73 reduction is actually 3.73/2 or the 1.8 reduction from input shaft.

 

[czar800]

The ring gear ratio and the pins that drive the spider gears is 3.73, but the inside wheelturns slower and the outyside wheel turns faster, to average 3.73. Inside wheel does not hold a conmstant speed.
Look at a differential cutaway or schematic. spider pins are constant speed, but any reduction on one side of spdier gear adds to the other side. So stopping one side of the spider means the far side of spider will move at twice the speed of the pins and ring gear, thus the 3.73 reduction is actually 3.73/2 or the 1.8 reduction from input shaft.

Thank you!!

 

[czar800]

That still doesn't explain why someone said you will get half the ratio. if you lock one side... I believe that statement is false. The whole premis of limited slip is to allow one tire to rotate faster (outside) than the other when turning. The slower tire (inside) will still rotate proportional to the overall ratio of the input (3.73:1).

I said it, because I have built this type of winch and have used it several years.

 

[czar800]

 

[dave_dj1]

I have and use this type of winch. I don't feel the need for a clutch, the brake will act as a slip clutch. dave_dj1 I'm assuming your going to build it similar to mine? Wish I had better video of it pulling logs and tops.

Yes, that is the type I plan on building only in a more compact version (I hope).
What are your thoughts on the disk brake compared to the drum? My thinking is the disk will be easier for me to adapt. Do you think there will be too much drag on the pads so that the cable side won't be able to be pulled out freely? If that is the case I guess I just won't engage the PTO until I have the log hitched.
My tractor has a soft start button for the PTO and it's a shuttle shift tractor if that makes any difference.

 

[dave_dj1]

Here's a cut and paste from the Farmi website in regards to their line speed
"Winching Speed: 1 to 5 ft. per second."
Am I reading that as 60 -300 ft per min? If so then I think I will be in the ball park at the 145 f/min
This is for the next smaller size Farmi winch
Winching Speed: 40-200 ft. per minute

While we're on the tractor subject, what category TPH do I have?
Thanks,
Dave

 

[czar800]

I would build it with whatever's the easiest possible. If that is a disc brake then do that. As long as the calibers functioning properly shouldn't be real heavy drag.

 

[czar800]

Just a guess but I would say you have a category one.

 

[brenndatomu]

While we're on the tractor subject, what category TPH do I have?

What model is it exactly?
40HP could be a Cat 1 or 2 really...

 

[dave_dj1]

It's a Massey Furgeson 1540 with shuttle shift, 07 , 4 wd

 

[brenndatomu]

Yeah I think MF 1540 would be a Cat 1 TPH

 

[Ferguson system]

Mf 1540 and 1547 has cat 1.