Beefing up an axle- what methods could i use?

That axle ain't near strong enough. BTDT Years ago BIL built a 'buggy' with a 1.125" rear axle, he bent it the on the first drive.
 
little_sparky said:
Sorry Dave i thought i mentioned that, i meant to but left it out, oops! it is a 3/4" axle without a keyway.



This too was a concern in the back of my mind about it breaking or bending at the weld but this just confirms it, thank you :)

and what exactly do you mean by a spool for the hub? will i have to unspoke it to do that? because although that is an option, it is only one i will refer to if the axle bends or something like that because i will have to repaint the hubs, true up the wheels and put the tires on again which i don't even think it is possible to take the tires off now.

I really really wish that i used a bigger axle and painted the rims a different colour right from the start :(

Thanks
Little_sparky
Click to expand...


The front wheel has a spool hub, the axle goes through the hub. and Yes, I'm afraid so.
 
Like he said too much off set axel will bend, won't turn with locked rear end, needs a diff.
Golf cart rear end? Look at a motorcycle wheel, use a narrow hub. Lawn mower rear? Or stub axels and one wheel drive.
 
The rear axel and the wheels are really quite nicely executed, but I fear they will not be up to the task. I think you should take a step back and resolve that you must redo the whole arrangement. Pretty much all of the comments above are relevant. You should definitely go with a differential or arrange things so that only one wheel is driven; otherwise you will not be able to turn. Those big fat tires will overwhelm the cool skinny tire in front and you'll just understeer right into the ditch. While on the topic of the skinny front tire; from looking at the pics it looks like you may have a problem with the caster arrangement. If you project the pivot axis of the forks onto the floor, you need to be sure that the contact patch of the tire is behind the pivot axis. This ensures that, when under way, the front tire trails the pivot axis and things are fairly stable. If the contact patch is in front of the pivot axis, the wheel will work very hard to get itself into a position where it is behind the pivot axis. The faster you go, the harder it tries and you'll crash. I once built something where that was the case and it was more than disconcerting. Good luck with your project, I think you're off to a good start (except for the rear axle arrangement).
 
Did not read what steel you are using but presume it is 1018 or similar.
One way of beefing the axle is to use stronger metal, say 4340, this won't particularly reduce the bending moments but it will take substantially more PSI to permanently yield.

Ken
 
use the nice wheels and make a small trailer to pull behind a trike with a small rear end and beefier components for on the road----------just start over on the trike and build it for the new requirements of using it on the road safely----get a small car rearend and shorten it up if needed----Dave
 
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little_sparky said:
Hello all,

I am halfway through building a tricycle turned trike called a 'Gladiator Chopper Trike' and have come to a bit of an obstacle that wont effect the build immediately, but I'm a bit iffy about it for the future.

I have a split axle (after really researching I probably should have used a differential but I didn't know I was going to put a motor on it straight away), but the size of the axle is what im worried about, each axle has a 15" commodore car wheel on it with the centres cut out and spoked to the axle, so its not exactly easy to take the tire off to use a 1" or 1 1/4" axle instead.

The two separate axles

View attachment 92386

The two rims and axles sanded and grinded down, with a bit of paint

View attachment 92387

The two wheels complete; spoked up with tires on

View attachment 92388

Axles are connected to the frame with pillow block bearings and two in the middle.

View attachment 92389

And finally the bike, near completion.

View attachment 92390
_________________________________________________________________________________________________

So now I ask the question, how can i beef up these axles? with a motor, a heavy rider and speeds around 30km an hour, the last thing you want is for your axle to give way and I'm not going to take the risk unless someone out there is 1000% positive and has proof that this wont break i just cant take the risk.

I will, of course, move the hubs/tires as close to the frame and bearings as I can to reduce that 'leaver' effect. I did think of drilling out a 1 1/4" piece of shaft, drilling from both ends to hollow out as long a piece as I can and then welding it as close to the hub as possible and changing the outside bearing to a 1 1/4" bearing, then drill out another one that would finish flush with the inner bearing and the first piece of drilled out shaft and that would mean that I could either cut a key way or grub screw my sprocket adapter into the 1 1/4" bar without any worries of it breaking on me.

So it would look a little something like this

View attachment 92394

View attachment 92395

Thanks
little_sparky
Click to expand...


Finally found the photos as promised
image3_edited.jpgimage4.jpgimage4_edited.jpg
enjoy, fixit

image3_edited.jpg image4.jpg image4_edited.jpg
 
little_sparky-----don't be discouraged on your project----many of us start out good on our projects and then find we have to back-up and change the plans to allow for new goals----It's a very good project and no matter how old you get you will have a desire for one---I'm 71 now and still have been collecting parts for my powered trike build---start looking for a couple motorcycle spoked wheels and tires to start with---but don't be discouraged---stay challenged---a very neat project-------------Dave
 
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You have a great project going, and it looks like it will be a lot of fun! :thumbzup3:

I agree that the size of the back tires will overwhelm the size of your axles under power. With pedal power going to one wheel I think it would work, but 6.5 hp would break them. Any adjustments or changes you make now will be easier and cost less than making changes later on. You are still at a good point in your project to make changes and adjustments. Like Dave Smith said, this is a normal part of fabricating cool stuff, so don't be discouraged.

For the horsepower range you are thinking about, an old golf cart differential would be a good solid platform, and will do everything you want. You'll be able to drive the heck out of it without having to worry, and then let YOUR kids drive it again in 20 years :biggrin:

GG
 
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