Weed Wacker Revisited.

GoldenMotor.com

deacon

minor bike philosopher
Jan 15, 2008
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Thanks for the info I'll she what I can come up with. Night now I'm trying to decide what to make my roller on the ryobi from.
 

deacon

minor bike philosopher
Jan 15, 2008
8,114
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north carolina
I used to make drive wheels for the short drive shaft week whacker by getting a steel pipe end cap in the plumbing department of home depot and a matching pipe nipple. then I drilled a hole dead center of the end cap and bolted it on, Then i just screwed the pipe nipple into it. Looks like im going to do that again

for the long shaft I have I think I am going to try CB2 laminated roller. I'm going to look around for something to use for the drive part, He once mentioned a cutting board I think that might be worth a look
 
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deacon

minor bike philosopher
Jan 15, 2008
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yeah but i have to mount up something three inches long, onto a three quarter inch long post. If i don't have smomething hollow so that I can use a socket and extension, I have to attach something that I can attach something else to. I used to use those unthreaded bike pegs. But the last one I used was so large it put a strain on the motor.

The 3/4" pipe nipple was the best drive wheel, but the welds I make just aren't strong enough. It has to be a simple fix for me and guys like me. The rubber or some kind of composition would be fine, except that I won't have a way to attach it. I know this worked before so I'm going to go back to what I know. I racked my brain lass night and it's all I could come up with. I try use stuff guys who are not tool junkies can do. It my thing, simple easy to find easy to assemble motors. If you can see an easy adapter please let me know I'm open to anything.

The long shaft blower is perfect for the laminated wheel and I'm going to use it there. I just don't see an easy way to mount it here.
 
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cannonball2

Well-Known Member
Oct 28, 2010
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Colonial Coast USA.
Get a coupling or sleeve nut, they are at the hardware store, used to put threaded rod together. Rethread it to 5/16 fine. Screw it on the WE shaft then get a properly sized Gr 8 bolt and washers, you can then make the rubber roller, just slide the discs on the bolt and tighten until they are compressed. It will take some care sizing the bolt as there wont be a ton of threads left in the sleeve nut when tightened. this is a way you can use on all short shaft WEs, and you can make rollers any size you want and change em quickly!
 

deacon

minor bike philosopher
Jan 15, 2008
8,114
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You know i never heard of a sleeve nut. I will have to take a look around for them. I did get my end cap 3/4 pipe nipple on so the bike is running. I will take a look for the coupling nuts when I get to the hardware store next time.

The motor runs now with very little vibration. The end cap is self centering because it is such a tight fit that It probably has less vibration than it did before. I still have no idea what the crank bearing is going to take before it gives up. I don't think I have lost one of those, just because the motor mounts or drive shafts never lasted long enough for the crank to get wonky.

I also got the frame for the blower motor finished maybe. I might need to add more stabilizers but it might also work the way it is.
 

deacon

minor bike philosopher
Jan 15, 2008
8,114
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north carolina
My smallest hole saw is 1.5 inches. I'm going to have to buy a smaller one at home depot. I'm not ready for the blower motor yet, but it will be ready for me as soon as I get the saw. I rescued a half inch thick self healing cutting board from my stack of unused toys I used it back in the days of my photo studio.

I think it will make a good wheel, and they are easy to find at walmart im sure.
 

rustycase

Gutter Rider
May 26, 2011
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Sure sounds like you're having fun, Deacon! Ha! Ha!

...well, that metal plate on the backside of the motor that covers the crank and stuff must be sealed well, all the time, or you will immediately be too lean to start it, or, if running when it comes loose, it will go way lean and burn up the motor if it runs long enough.

It's additionally a crankcase stuffer, so there is better secondary compression for the fuel charge making it's way up to the combustion chamber.

I can't believe what good luck you are having running these WW motors that have only one bearing supporting the crank! The pressure on the drive roller really should be sending them in Xtreme wear almost immediately, and the crank seal going bad soon as that bearing gets loose... which leads to lean, meaning hard starting and then burning up when you DO get them started...lol

Luck is certainly running with you, Deacon!
Best
rc

hope you post more pics soon!
 

deacon

minor bike philosopher
Jan 15, 2008
8,114
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north carolina
I think they are tougher than we think All my kills so far dating back years seem to be vibration related Really cheap metal in these things.
 

deacon

minor bike philosopher
Jan 15, 2008
8,114
9
0
north carolina
several years ago a lady named comfortable shoes went all over boston with one of these. She only stopped on it because she built a occhopper with a kit engine.
 

cannonball2

Well-Known Member
Oct 28, 2010
3,682
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Colonial Coast USA.
Actually RC the what I call half crank engines like the Ryobi and Homeys have two crank bearings they are just on both sides of the case, they are sized pretty well. If you have an older unit with the good bearings they used back then, its a pretty tough engine. Admittedly a "full" crank engine would be better. But think about it, I doubt unless some one is running a monster pull down spring, that the down/side forces on the bearings exceed 20lbs maybe, not unreasonable. Deek is probably right about vibes and the metal rollers. Metal has very little ability to dampen vibes, in fact it can resonate with disasterious results. Something like wood, rubber etc. will dampen to a degree. Also Its hard to center a metal roller when made with hand tools(not impossible). Pipe is heavy, even slightly off center and its gonna be a vibe maker!
 

rustycase

Gutter Rider
May 26, 2011
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Lol

So you DID notice, CB2!

I have never pulled a crank out of a case. lol

Deacon is really doing well, making the presentation, working through the problems bit by bit.

...seems to me, if the vibration is caused by low grade metal, he's on the right track to try oversized bolts to hold it... grab ahold of it firmer...
the prob is still the metal quality.
it will strip out.
a heli-coil or thread-sert is a fix for that, IF there is room for one.
...I just checked the price of heli-coil kits...
6mm set is $52+
a 'motorcycle heli-coil set' that does 6mm, 8mm, and 10mm is $122+

it just doesn't seem to be worth it, to me.
(I bought the last one, a weedeater branded hedge trimmer for $7 at a thrift store. Bulb was bad, and cord is not retracted, for whatever reason.)

I guess it is best to grasp the engine best as you can, by whatever method can be rigged, with materials on hand ! Lol

...might be fun to go over to a 'home machine shop' forum and see if those guys have found an inexpensive way to dynamically balance the little two cycle cranks. if there is vibration problem, balancing is the fix for it. then you could spin it up like a morini !

Best
rc
 

cannonball2

Well-Known Member
Oct 28, 2010
3,682
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Colonial Coast USA.
Hey RC if you want to see the finer pionts of civilizing one of these engines Go to R/C Universe to the engine section in conversions, its amazing. Balancing and porting specs are there, just about every kind of engine has been tried, interesting stuff. One of the thing most folks forget that to an extent the WE designer probably roughly balanced the unit around its clutch and drive, once something else is attatched the your guess is as good as anyones what its gonna balance like. I doubt they spend a lot of time smoothing up a $79 WE past the point that its sorta comfortable to use. So all that being said, you are starting out with(on the bottom$ end) a cheap throw away unit that probably works better than it should all things considered. Its up to the MBer to make a silk purse out of a sows ear as they say.
 

deacon

minor bike philosopher
Jan 15, 2008
8,114
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north carolina
My thinking is to do a lot now, so that when I get it all interchangeable, it will be a minor setup routine. In a perfect world ,there would only be one kind of engine I used. When it shook itself to death, I would just take everything off it. put it on another 25dollar motor just like it and run it a few hundred miles.

That said, the bike is only good for around town, to the store or just out sight seeing. The advantage to the weedeater is that there are plenty of them around. They are very light weight and 30+ cc does a decent job of pushing even my fat rear around. Once you make the custom bike and the mount, it is all bolt together like an erector set.

Spring tension is like this.

If you lay the motor on the wheel with no spring tension, it will push the bike but mostly it will just slip.

If you put too much tension on the motor you will know it because it bogs down on any incline and even on the flat runs slow. It will hardly slip at all.

When you get it right there is just a little additional tension on the motor. It runs and slips when it gets under a lot of stress. That's a good thing. The motor bogging down wont create a drag on the bike if the wheel is slipping over the tire.

I build a two sided frame over the tire. One side holds the motor the other side now has the scissor hinge with cable pull to lift the motor and this is new the spring tensioner is hooked to the scissors. The default position is a little tension holding the drive wheel down by forcing the scissor more toward the closed position.

I will not be able to make much of the data from this motor. I have abused it way past what a motor should endure to do this job. I ran it with a drive wheel way out of balance but it is still running. I ran it with the flywheel rubbing on the tire in heavy traffic unit it just stopped. But once it cooled off it ran just fine again. I have done the same ride three times since with the flywheel not rubbing and had no problem at all. The new drive wheel with the self centering end cap is a lot better as well..

I haven't really used one yet on a bike but I like the new homelite/ ryobi When used with a clutch, which I would take off, you have a longer drive shave and a beefier one. The non clutch version might have a 5/16 short drive shaft which is not all bad, but the long 3/8' drive shaft would seem better suited to the job at hand.
 
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deacon

minor bike philosopher
Jan 15, 2008
8,114
9
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north carolina
I rode the bike for what it was meant for this morning. I rode it five miles round trip to get biscuits for our breakfast. The bike had a minor problem created by my trying to fix what didn't need fixing. So I had to fix what I fixed yesterday after breakfast.

What I had done was move the spring to make it part of the hinge system. In doing so it rubbed against the side of the mountain bike tread. It slowed the bike some but mostly it made a terrible racket when I lifted the motor. Springs make a noise like nothing else, so it wasn't have to find.

I used part of an old brake caliper to move the spring away from the bike so that it is still connected to the hinge but not rubbing the wheel. It did just fine on my test ride.

The more I ride this bike the more I am thinking about making one really good one and just do the interchangeable engine thing. I am wondering how much of a pain it is to use a full suspension bike and attach the motor mount to the seat post with a ubolt type thing.

I have already used the small connector pipe on top of the bmx type handle bars to hold a 3/8 inch axle. I don't think the motor would be likely to wear out the tube even without bearings so I'm going to pack it with grease and just sue it.

I welded (as best I could) the tube to a piece of angle iron. Then I drilled a hole in it and bolted it onto the bike at the brake holder. It works fine, but I'm thinking,

Buy a dual suspension bike.
take the front shifter cable off (making it a six speed more or less) use the shifter and cable as a throttle
use a ubolt to attach that piece of angle iron, with the 3/8 inch tube welded on, to the seat post.
build my dual rail mount.
get a new weed whacker and retread the mount after I am sure it runs lol.
Use the hinge spring and lift combo system.
 
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rustycase

Gutter Rider
May 26, 2011
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Wow.
Ur doing a lot of work, Deacon.

picked up another two cents i can donate... :)

determine what diameter roller you can live with.
have one made up of steel that will not wear out or self destruct.
...and, will not shred tires!
have it made with a provision for an outboard bearing, like this.
build your frame so it is supported, together with the power unit.
like this...

Best
rc
 

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cannonball2

Well-Known Member
Oct 28, 2010
3,682
221
63
Colonial Coast USA.
Nice job RC! See you are using a blower motor.

Deacon on the dual suspension bike the motor should be mounted to the lower suspension frame(notice I said should). If mounted to the seat post it will travel with it when it deflects, If you hinge it there, it might be ok, but will pull the engine foward on deflection so all the mounts and braces will have to move. Its easier to mount it just above the tire and let it stay with the rear wheel, you have separated them the other way. Look at my Schwinn or Mongoose build.
 

deacon

minor bike philosopher
Jan 15, 2008
8,114
9
0
north carolina
My only attachment points are the eng which would be on the seat post and yes hinged and the scissor hinge which also allows for movement. Everything floats which might be why this motor has stayed tight so well.

RC that is definitely the way it should be done. Truth is I like to keep it simple and do everything myself. But then I don't have to have the bike to get to work or to go to the doctor. I also have lots of time to play with it. If not the bike then what lol.

Please no one take this as gosple but it seems that if the drive is no more than three inches and it is wedged against the flywheel it seems to do pretty well. I haven't really had any problems except my poor welding but now I don't welt that any more. I have no idea how this new (Old) method will hold out over the long haul, but it's working okay right now.
 

deacon

minor bike philosopher
Jan 15, 2008
8,114
9
0
north carolina
My WW bike is running poorly. The motor runs fine, the bike itself took a turn for the worse. I'm not absolutely sure but I think it is the rear wheel adjustment somehow. I'm going to switch it out for a different wheel. If it is that I might not even fix this wheel. When the freewheel catches there is about a quarter turn before it moves the bike forward. When I put on brakes thee is about an inch or two of what feels like slack in the mechanism. Anybody got any ideas.