Vertical shaft to horizontal shaft conversion

[Doc Hickory]

Hi guys!

Got me a question- I have a good 2 cylinder Briggs engine off of a riding mower, about 21 HP.  It's a vertical shaft engine.  Is there a reasonably simple way of converting it  to horizontal shaft use to drive a sawmill?  I'm considering doing this for a saw mill project.  Is it worth the effort or am I just investing in a hatful of headaches? Any ideas or personal experiences with a similar situation would be useful, besides I always like a good yarn!  Thanks and gracias aplenty!

[hackberry jake]

You could hook it up to a split gearbox. Run the drive wheel off one side and a hydraulic pump off the other.

[Dave VH]

I was looking into that when I was thinking about building my own mill.  It was recomended to me that the smaller horsepower would loose too much horsepower in a gear box.  I was told to try and trade my vertical shaft for a horizontal shaft on craigslist.
  That's just what I was told, I don't really know any better

[Herb Brooks]

It can be done with a belt and transition shaft with two pulleys. Try to get a look at an older Cub Cadet or a Cub tractor with a belly mower to get the picture.  I have no clue as to HP loss on a rig like this but do know that if you try to load these mowers to heavy they will bog down.  You do have 21 ponies though.  lots of mills out there running half that. Second thought would be a 1:1 right angle drive from an out fit like https://www.surpluscenter.com/home.asp could be made to work with some creative welding of mounts and such.  Whats this talk of HP loss anyway.  I aint no engineer but seems to me if you put 21hp into a gearbox you should get 21 out.  I spose there is some loss due to friction and the like but in my opinion you won't miss it.

[leroy in kansas]

Another option may be to use hydraulic which will transfer the hp without any belts, bells or whistles. ?

[pineywoods]

It can be done, but it's just not practical. The internal lubrication system would have to be re-worked and the carburator mount and connections modified. Even with that done, the mounting points would be a real hassle. A right angle gearbox would be the most practical way...

[Herb Brooks]

Here's a picture of what i was talking about.

[Herb Brooks]

Guess not.

[Herb Brooks]

https://forestryforum.com/gallery/albums/userpics/29718/thumb_transition_shaft~0.jpg

[Herb Brooks]

I can't work it check it in my gallery. Sorry not too savy.

[Herb Brooks]

 

 
Thanks to shotgun for teaching me to put up pics!

[steamsawyer]

It can be done with a belt and transition shaft with two pulleys. Try to get a look at an older Cub Cadet or a Cub tractor with a belly mower to get the picture.  I have no clue as to HP loss on a rig like this but do know that if you try to load these mowers to heavy they will bog down.  You do have 21 ponies though.  lots of mills out there running half that. Second thought would be a 1:1 right angle drive from an out fit like https://www.surpluscenter.com/home.asp could be made to work with some creative welding of mounts and such.  Whats this talk of HP loss anyway.  I aint no engineer but seems to me if you put 21hp into a gearbox you should get 21 out.  I spose there is some loss due to friction and the like but in my opinion you won't miss it.

Thanks Herb. What you are talking about is called a mule drive. The old Cub Cadet blade deck belt is a good example for the mule drive. I have a 1947 Farmall Cub with a belly mower that uses a similar arrangement from the rear mounted PTO pulley. In my opinion I can't see where you would loose any more than just a small fraction of your HP through the extra idlers. I am not really that familiar with the construction of band mills so I guess the main obstacle might be whether or not you would have enough room for the unorthodox mounting brackets and extra baggage.... I think it's a good idea though.

Alan

[sawguy21]

IMHO, by the time you couple a mule drive or right angle gear box with all the fabrication necessary a horizontal shaft engine would look pretty good. Of course that depends on how much your time is worth to you. Converting your engine to run the crank in a horizontal position is not feasible.

[mikeb1079]

i understand why you want to do this:  vert shaft engines are all over craigslist for dirt cheap.  that said, i have to agree with the advice to just get a horizontal shaft engine.  you'll have enough fab challenges without having to jerry rig a vert shaft engine.  good luck

[Doc Hickory]

Thanks for all the input, guys.  I'll cogitate on all this for a while and make up me mind.  The idea of swapping it for a horizontal shaft engine is kind of appealing, so that's the front runner at the moment.  I appreciate you all taking time to answer.

[Al_Smith]

Old mowers ,old cars ,old combines you can get real creative with a pile of parts .You could get a 90 degree turn using the rear end of a mower with one side lock down .Now weather or not the drive gears are tough enough to last for any length of time under the stress of a sawmill is questionable .

For that matter you can make the turn with Vee belts but you'd need some room to do it not to mention it would take at least a double belt to handle 21 HP plus it would wear the belts fast .

There's always way but the simplest is just scrounging up a horizontal shaft engine .You can usually buy the whole mower for a fraction of what the engine would cost .Plus you have all those good parts in addition to trip and stumble over and hide in the back yard under a blue tarp so the wife is proud of you .:D

[schmism]

I have a good 2 cylinder Briggs engine off of a riding mower, about 21 HP. 

2 questions i think you need to answer before you invest a lot of time and effort into this.

1) what are you replacing
2) what vintage is the  BnS?

If your replaceing something like a 10hp you'll likely see an improvement.   but if your replaceing an existing 18hp you may not.  why?  because remember like 3 years ago Brigs was sued for false advertising because it was takeing the EXACT same engine and printing like 5 diffrent HP numbers on it.  it wasnt uncommon for the same bore/stroke engine to get 15-21hp rateing.  This is why you see all new small engines list displacement and tq numbers instead of "HP" numbers.

But consider by the time you spend the money to convert the vertical, you may have been able to just sell the vertical and take that money (plus the money you would have spent in the conversion) and just bolt on a horzontal shaft and be done.

[Al_Smith]

That is a fact .As a matter of fact coincidently I have two identical Briggs pancake flatheads on riders .One is rated 18,the other 19.5 .Maybe the green paint on the 19.5 made it more powerfull or something . :