I figured I may open myself to comments like that Frank, But arent you the guy who was so worried about how "powerful" this thing would be? And where exactly would you think all the reactive forces would go? I'm thinking you don't fully understand what is taking place at the union of the rack/pinion. The only way there wouldn't be a force trying to seperate the gears is if the mating surfaces were parallel to each other throughout their rotation, or "dovetailed". Not possible. There is a percentage of the in/out force if you will, that translates into an "up" or uncoupling force acting on the pressure angles. Imagine how much force is being exerted on the log.( before the follower shatters.) I've messed with spurs and racks for some time now, but haven't come across these types of forces. I am as surprised as the next guy.( hence the "learning curve") And what are you calling a "standard gearform" profile? 14 1/2 P.A. or 20 P.A.? There is enough uncoupling force to bend a 5/8 shaft that is only unsupported for 3/8 of an inch. That is some force. The pinion is an 8p 14T. P.D. of 1.75. It's not my first day.
log splitter
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Crofter
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Pressure angles.
I can see you know what a standard gearform is. There is slightly more separation force with the one than the other but still much less than the longitudinal force on the rack. I do believe there is a sharp rise though below a certain number of teeth on the pinion. Don't be defensive, I,m not trying to tear it apart. I know what kind of forces are involved. Obviously you have lots of energy in the flywheel system. What was behind my question was the thought that a larger pinion even a couple of teeth might make a difference.
Frank
I can see you know what a standard gearform is. There is slightly more separation force with the one than the other but still much less than the longitudinal force on the rack. I do believe there is a sharp rise though below a certain number of teeth on the pinion. Don't be defensive, I,m not trying to tear it apart. I know what kind of forces are involved. Obviously you have lots of energy in the flywheel system. What was behind my question was the thought that a larger pinion even a couple of teeth might make a difference.
Frank
I'm not defensive, just responding in kind. There is most definitely a sharp rise with fewer teeth. Smaller radius etc.... The more teeth, the lower the "gear ratio, the faster it moves, the less torque it has, "(flywheel to pinion sfpm.), the less mechanical advantage. ...With a P.D. of 1.75 @ 200 rpm
( flywheel@600) the rack is moving fwd at 18 3/8 inches a second.Thats plenty fast. 2 more teeth is a P.D. of 2.00 = 21 inches a sec. or about 16% faster. I am trying to stay away from too fast, at the pinion. I started out with 12 teeth.
It is my guess that the comm. models have a special pinion shaft with a P.D. of 1" inch or so, gear teeth cut right in the "axle" this is the only way I see them being able to move at 1 foot a sec, and atill have the flywheels and pinion on the same shaft, and be able to spin the flywheels fast enough to make any power. That would be some pretty extreme seperation force. I could have made one of these, but the cost of the gear cutter was prohibitive, and I hate cutting gears, once you've seen a gear hob at work, all that time and effort seems kinda silly. I tried in vain to find one as a stock item with anybody. I am limited to the sprockets I have, unless I spend $100 or so for an even larger one. Really ,the thing works excellent. The way I broke it was to essentially try to break it. But I'm funny that way, gotta see what she'll do. Amazing power. Probably I could take 20lbs. or so off each flywheel and everything would be fine. But what fun would that be?
( flywheel@600) the rack is moving fwd at 18 3/8 inches a second.Thats plenty fast. 2 more teeth is a P.D. of 2.00 = 21 inches a sec. or about 16% faster. I am trying to stay away from too fast, at the pinion. I started out with 12 teeth.
It is my guess that the comm. models have a special pinion shaft with a P.D. of 1" inch or so, gear teeth cut right in the "axle" this is the only way I see them being able to move at 1 foot a sec, and atill have the flywheels and pinion on the same shaft, and be able to spin the flywheels fast enough to make any power. That would be some pretty extreme seperation force. I could have made one of these, but the cost of the gear cutter was prohibitive, and I hate cutting gears, once you've seen a gear hob at work, all that time and effort seems kinda silly. I tried in vain to find one as a stock item with anybody. I am limited to the sprockets I have, unless I spend $100 or so for an even larger one. Really ,the thing works excellent. The way I broke it was to essentially try to break it. But I'm funny that way, gotta see what she'll do. Amazing power. Probably I could take 20lbs. or so off each flywheel and everything would be fine. But what fun would that be?
Crofter
Addicted to ArboristSite
Lol! Django, the reference to " traced out with the side of your running shoe" appies to a joke about a non standard wing chord. I was only wanting to eliminate possible mismatched tooth profiles causing excessive side thrust.
I was not suggesting to speed up the lineal speed of the rack but to increase the size of the driven sprocket and rack pinion. When you are working at close to minimum theoretical tooth count for a given pitch, they get very inefficient. Any springing that allows the pitch lines to separate at all, then skew the 14 or 20 degree pressure angles greatly. The ratio of side thrust to tangental force is no longer 1:5 or 1:7. The same separation from ideal has little effect when more teeth are in contact. The old lickety splitter that I did some repairs on had problems in the same area if I remember correctly. I didn't work on the whole, only some of the loose components. Django you have a difficult position to defend if it doesnt fly, since you are engineer, mechanic, and operator. Lol!
Frank
I was not suggesting to speed up the lineal speed of the rack but to increase the size of the driven sprocket and rack pinion. When you are working at close to minimum theoretical tooth count for a given pitch, they get very inefficient. Any springing that allows the pitch lines to separate at all, then skew the 14 or 20 degree pressure angles greatly. The ratio of side thrust to tangental force is no longer 1:5 or 1:7. The same separation from ideal has little effect when more teeth are in contact. The old lickety splitter that I did some repairs on had problems in the same area if I remember correctly. I didn't work on the whole, only some of the loose components. Django you have a difficult position to defend if it doesnt fly, since you are engineer, mechanic, and operator. Lol!
Frank
Ratio's etc...
Trust me ,if it doesn't work, you'll never know!!
I understand what you are saying, just trying to make sure you understand what I'm saying. Let me re-state my goal for this bad boy, I want to build it as cheap as possible, from materials I can scrounge up. Otherwise I 'd just go buy one. I also understand that the laws of Physics couldn't care less. When you say to "increase the pinion by a couple of teeth" yeah, it would be nice to have a nice, large pinion, however to keep the fpm of the rack at anything close to sanity, you would need a sprocket the size of a garbage can lid. Or enormous flywheels spinning slowly. A sprocket like that new is hunderds of dollars, and I don't want 1000lbs of flywheel.You are right, the teeth must be kept in the proper mesh, at all times. Especailly with fewer teeth. I know this. They just have to be locked together with a little more authority. That's all. It does work.
Trust me ,if it doesn't work, you'll never know!!
I understand what you are saying, just trying to make sure you understand what I'm saying. Let me re-state my goal for this bad boy, I want to build it as cheap as possible, from materials I can scrounge up. Otherwise I 'd just go buy one. I also understand that the laws of Physics couldn't care less. When you say to "increase the pinion by a couple of teeth" yeah, it would be nice to have a nice, large pinion, however to keep the fpm of the rack at anything close to sanity, you would need a sprocket the size of a garbage can lid. Or enormous flywheels spinning slowly. A sprocket like that new is hunderds of dollars, and I don't want 1000lbs of flywheel.You are right, the teeth must be kept in the proper mesh, at all times. Especailly with fewer teeth. I know this. They just have to be locked together with a little more authority. That's all. It does work.
Ouch!
Crofter
Addicted to ArboristSite
Re Stripped Pinion
Django: is that pinion cast iron? I cant see enoug of the grain structure in the photo, but am guessing that it is. I somehow had in my mind that you were only running about 8 teeth but see that this is not the case, so a larger pinion wouldnt gain that much. Are the teeth machined out of the steel shaft on the factory job? If it was something like Superior shafting and heat treated it would have many times the strength of cast iron. Which failed first, the teeth or the engaging mechanism? Only questions not answers.
Frank
Django: is that pinion cast iron? I cant see enoug of the grain structure in the photo, but am guessing that it is. I somehow had in my mind that you were only running about 8 teeth but see that this is not the case, so a larger pinion wouldnt gain that much. Are the teeth machined out of the steel shaft on the factory job? If it was something like Superior shafting and heat treated it would have many times the strength of cast iron. Which failed first, the teeth or the engaging mechanism? Only questions not answers.
Frank
Well Hello there, Frank.
Steel gear. Martin brand. #S814. The engaging mech. failed first, allowing the rack/pinion to disengage enough for the pinion teeth to contact the rack on their tips, knocked 'em right off. What I am going to do after I rebuild things, is just run 1 flywheel and see what happens. Mine are much heavier than the commercial models, one may be enough.
Steel gear. Martin brand. #S814. The engaging mech. failed first, allowing the rack/pinion to disengage enough for the pinion teeth to contact the rack on their tips, knocked 'em right off. What I am going to do after I rebuild things, is just run 1 flywheel and see what happens. Mine are much heavier than the commercial models, one may be enough.
Crofter
Addicted to ArboristSite
Nice looking Job
All spit and polish now. We are waiting for a blow by blow description of how it works. How fast is the cycle time. If you split a really tough block do you have to wait at all for it to recover rpm. Can you abort under load. When is it going to be on the market. Do AS forum members get a discount?
Frank
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All spit and polish now. We are waiting for a blow by blow description of how it works. How fast is the cycle time. If you split a really tough block do you have to wait at all for it to recover rpm. Can you abort under load. When is it going to be on the market. Do AS forum members get a discount?
Frank
/
One and only
Cycle time is 2 seconds. Haven't found any wood yet to stall it significantly, and I've split up to 24" dia. I've split Hickory, Oak,Elm,etc... Ash and the like, I just use a maul. You can stop the cycle at any time. If it was commercialized, it wouldn't be by me, If I start another large project anytime soon, I fear all the money I saved by doing this stuff myself would go to a divorce lawyer.
Cycle time is 2 seconds. Haven't found any wood yet to stall it significantly, and I've split up to 24" dia. I've split Hickory, Oak,Elm,etc... Ash and the like, I just use a maul. You can stop the cycle at any time. If it was commercialized, it wouldn't be by me, If I start another large project anytime soon, I fear all the money I saved by doing this stuff myself would go to a divorce lawyer.
Crofter
Addicted to ArboristSite
Some things we do for love eh?
Glad it came together so well!
Frank
Glad it came together so well!
Frank
DUSTYCEDAR
ArboristSite Lurker
Nice Job
A. Stanton
Addicted to ArboristSite
Knowing that this thread was started some time ago, I have to say this. Last night, 5/28/08, I visited a local Tractor Supply dealer. One of the workers there told me that he can't keep a log splitter in stock due to the high price of oil. So my advice to anyone considering buying a splitter is get one as soon as you can. You might miss out.
DUSTYCEDAR
ArboristSite Lurker
ITS kinda funny u can only find a troy built at most of the mower shops and they have to order it the the box stores have yard machine cub and such.
was looking at a super splitter but i had the same experience with the shop no customer service so i dont want to deal with that.
not sure what to buy at this point i had an iron and oak splitter years ago it was nice for what i paid never failed me wish i did not sell it.
so i am still searching for a splitter.
nice job with the machine you made can i get one?
was looking at a super splitter but i had the same experience with the shop no customer service so i dont want to deal with that.
not sure what to buy at this point i had an iron and oak splitter years ago it was nice for what i paid never failed me wish i did not sell it.
so i am still searching for a splitter.
nice job with the machine you made can i get one?
cornraker
ArboristSite Member
buy a Timberwolf if you can afford it. Production is unmatched especially with the Tw-7
