log splitter

[bwalker]

gearbox stress

I share the same thoughts on gearboxbox streess as you Steve. I thought about maybe using a cushon drive of off a pressure washer. These are sold by northern tool.

 

[django]

Sweeeet.

 

[django]

Pictures

Here's a couple of shots of what it looks like so far.
Steve

 

[django]

Other side.

 

[Crofter]

Nice looking work DJANGO I like your slide, looks like good anti bind qualities. What size is the roller chain. 60 or 80? How many ft. pounds energe will you have stored in the flywheels when they are wound up. I am just wondering if you stall the ram (and you will for some reason or other like a piece falling in cross grain) will the force be greater than the breaking strength of the chain. I could be all wet here but just check if you can to see what safety factor you have here.

Lik at the split,
Frank

 

[django]

Thanks for the positive comments, Frank. The slide is also self-lubricating. As I have stated before (twice actually) the roller chain is #60. There are a couple of reasons for this: It is readily available to me at low cost. If I were to use #80 the smallest sprocket I could use would make the larger sprocket quite large and expensive. ( and probably unnecessary) I am sure there will be times when I'll run into something that will stall the machine, however I am willing to bet that the Drive Belt will slip before a #60 chain will break. The real test of the chain will be it's shock load, that's what I am curious about. As far as "foot pounds" of energy, I assume you want a torque number, and to be honest, I don't know. And to be really honest I am not sure it would really tell me anything, because I don't know how much torque I "need." Also, That number would only be relative to a "freewheeling" flywheel that wasn't being driven ( except for a "static" system, then the numbers would mean the same thing). To actually decipher the "power" of the system involves the kind of mathematics that I don't care to do, and I don't believe in the reliability of( too many variables.) The real proof is in the real world performance. From what I can tell so far, by how much the engine works to "spool up" the flywheels, I do this s-l-o-w-l-y- or it will just about kill the engine, I have some pretty good energy stored in the wheels.

 

[jokers]

Very interesting design Steve, nice work also. I was wondering how the slide is self lubricating? I can`t get into specifics, or recommend that you try this at home, lol, but I can tell you that #60 chain will withstand enough shockload to stall a 30hp two cylinder diesel engine. Thanks, Russ

 

[django]

You are my kind of people, Russ The slide is self lubricating via plates or if you will, bearings made from a material called Nyloil which is nylon impregnated with oil. It is excellent stuff, dense, hard ( for a plastic) and tough. You can't see this in the pics, but the I beam is fully captured by these plates.
I thought about using UHMW, Which is a polyethaline material that I used on the chain tightener,( it's used in a lot of food service app's,like cutting boards table tops, etc... VERY dense.) it has great wear resistance,and is "slippery", but like I always say, use what you can find.

 

[Crofter]

Jokers:

Question? over what period of time. In how many revolutions would it drag it to a stall. If you have virtually instantaneous stall the forces are much higher than the engines 75 or so foot pounds torque. With Djangos splitter, if the ram jambs, the flywheel must stop also since there is solid mechanical connection through the roller chain. I would guess there would be at least 50 thoousand ft pd energy stored (25 ton) Does that sound right?These are the forces I feel the chain might be subjected to and question its strength. Think of the cross sectional area of the two side links and there is not a lot of area. The pin is only about 3/16" in diameter too, probably weaker than the side links even. We used roller chain to actuate the trombone of delimbers and saw lots of failures when subject to shock loading.
I'm not trying to be smart Joker, I'd like to pick your brain on installation details of boilers and a few other things I've read in your posts.

Frank

 

[bwalker]

At work we have a huge parts washer thats powered by a 60 hp electric motor. It uses#60 chain to rotate the heavy steel cleaning drum. I also might add that it gets next to no maintance and a chain last for about 3 years.

 

[Crofter]

Bwalker.

That roller chain will do well in a slow speed operation like you describe with the parts washer and the torque of a 60 hp motor at 1750 rpm. might be something in the neighbourhood of 100 pounds foot torque. That does not in any way extrapolate into it being similarly stressed in the splitter application. I think you are assuming that because only a 5 or 10 hp motor is being used to wind up this flywheel on the splitter that proportionate torque would come into play here. I am guessing because I can't find a chart which gives foot pounds of energy stored per pound foot per rpm of flywheel. I think something like 50,00 foot pounds of stored energy. Remember Django said it took a long time to spool up. When you have a lock up situation with a flywheel that energy is released instantly. There is no relief valve like in hydraulics. Please at least incorporate some manner of sheer pin.

Frank

 

[bwalker]

Crofter, As django already pointed out the belt would slip before before the chain reached its failure point.

 

[Crofter]

BWalker

The belt is ahead of the flywheel in this system. It is not the torque of the motor that is of significance here, it is the energy stored in the 100 or so pounds of flywheel travelling at perhaps 1,500 feet per minute. This is what is hooked directly to that #60 roller chain and the ram. Ben you mess around with rifles too; we have discussed this in passing, do a calculation on that flywheel as if it were a bullet and what it would take to stop it. It definitely has more ft pds energy than your 460 Weatherby. Think about it.
Im not trying to be difficult and I AM talking about the worst case scenario of an instant and total lockup of the ram. I saw the results of what happened when a truck was towed with the starter drive engaged. When they popped the clutch the 15 or so to one ratio of the flywheel to starer drive spun the windings out of the armature and locked it up taking a chunk off the rear of the engine block and a huge piece out of the bell housing. The fellow actually thought someone had put a car bomb in his truck. Iwould feel better with a shear pin on that flywheel.

 

[django]

For the record, it's 250lbs of flywheel, and 2200 ft/min.@600rpm.
Ever shoot a log with your Weatherby 460 and have complete and total lockup of the bullet?

 

[bwalker]

.

The belt is ahead of the flywheel in this system.

Crofter, I failed to relise this point hence my comments

 

[Crofter]

Django, you are right in suggesting that my example of the bullet into wood wouldn't be total and instant lockup and I don't think you are likely to have it in your splitter either, unless someone feeds it a boulder. I suggest that you should be prepared for the unexpected though. I am probably guilty of a bit of overstatement to illustrate a point. There is much more energy hidden in that flywheel than meets the eye. Unlike in a hydraulic system, there is no safety relief valve. Could you perhaps put a 5/16 or 3/8 bolt throug either one of the roller chain sprockets and leave the key out at least until you try it on wood. The roller chain I spoke of on the the tree delimbers usually got broken by having the head hit the ground when the machine was being moved. The normal mode of being driven by the hydraulic motor caused no problems but the relief valve takes care of any overloads then. Its going to work!

Frank

 

[django]

Flywheel Splitter

Well, It's coming along. The only problem I am having to fight with is keeping the rack engaged in the pinion. There is a serious amount of force acting on that gear. I split some red oak and some smaller dia. elm without any prob. but when I tried an 18" Elm log it sorta blew my cam follower apart. And broke a tooth off my pinoin. And bent the 5/8 dia. shaft the camlock assy. pivots on.
So there is work to do yet. But I'm having fun. I think.
Django

 

[django]

oops I did it again..............

Well, I exploded it again, This doesn't make me look very smart, I know, but trial and error is what it's all about. I thought I had the whole cam follower thing figured out, I didnt. Next up, solid steel wheel with oil-bronze bushing. Good news is it took one NASTY crotch to do this. I split a bunch of oak logs before this, no problem. I wasn't going to split the crotch in the worst possible orientation, but I wanted to see what it would do. It broke. Absolutely shattered the cam follower. Before it broke I made it a good 8 in. into the crotch. My safety overload didn't trip, flywheels never even slowed down, so it may be too tight, but when I get pinion #3 (!) It's back at it.
Just letting those interested know how it's going. I can post pics of the carnage if you want to see what the damage looks like.
Django

 

[kam]

Yes , let's see the pics.

 

[Crofter]

Django: Is the rack and pinion a standard gearform tooth profile or one you milled out using the side of your running shoe. I am exaggerating here as I am known to do, but thinking that there shouldn' be that much thrust on the cam follower. How many teeth on the pinion?

Frank