Beefing up an axle- what methods could i use?

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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 custom rims and custom axles/hubs that have been sanded and prepped and now hit with a hint of paintThe two wheels complete; spoked up with tires on Axles are connected to the frame with pillow block bearings and two in the middle. And finally the bike, near completion. __________________________________________________  _______________________________________________can only post 4 pics so post will continue Attached Images
Reply:__________________________________________________  _____________________________________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;Thanks little_sparky
Reply:Unless you have a big engine and are planning to do burnouts, I would expect those axles to bend before they actually break......  but I do expect a lot of bending unless they are a lot stouter than they look.Miller Syncrowave 350Millermatic 252/ 30A spoolgunMiller Bobcat 225g w/ 3545 spoolgunLincoln PowerArc4000Lincoln 175 Mig  Lincoln 135 Mig Everlast 250EX TigCentury ac/dc 230 amp stickVictor O/AHypertherm 1000 plasma
Reply:.....I would expect those axles to bend before they actually break...... but I do expect a lot of bending unless they are a lot stouter than they look.
Reply:Originally Posted by mrmikeyDitto, as much as it sucks I think in this case bigger is better. I'd bite the bullet an go up to 1 1/4" shaft....Mike
Reply:I would build a truss across the bearings because I think the weak point right now is the the outboard tubes. I'd run it with the axles you have now and just keep an eye on them because I think they'd bend long before they'd break if you did a proper job welding the spoke flanges on them.Millermatic 200Hobart Handler 120Victor O/A & Ramco BandsawLincoln 225 ACSnapOn AD HoodMiller XMT304/22AHypertherm Powermax 1650 G3Lincoln Idealarc DC600 w/Extreme 12 VSMiller Digital Elite "Joker"
Reply:Here is a CAD drawing of what the rear motor mount will hopefully look like. plus it will be adjustable.little_sparky
Reply:Remake your bearing mounts. Get rid of the castings and get 3 bolt steel bearing flanges, your bearings will fit so all you need are the flanges. Then get a pipe or tube the size that fits over the center part of the flange and weld one flange to each end of the tube. You can then make that pipe or tube long enough so the bearing is right at the hub. If you do that your axles are good. You will need to remake your center mount so you can put the drive in the middle.Yeah, I know, but it'll be ok!Lincoln Square wave 255Miller Vintage mig30a spoolgunThermal Dynamics Pacmaster 100xl plasmaSmith mc torchEllis 1600 band saw
Reply:Originally Posted by little_sparkyThe only problem  is that i cant get the tyres off the rims now because it wont fit in the machine and i really don't want to spend hours cutting out new rims, drilling holes in them, spoking them up,  truing them and getting paint done again.Although i really really wish i used a thicker axle and painted the rims a different colour, i just really really want to avoid doing thisThankslittle_sparky
Reply:like this typeOf all the things I lost I miss my mind the most...I know just enough about everything to be dangerous......You cant cure stupid..only kill it...
Reply:Originally Posted by roadkillbobbthey make tire machines that grip the inside of the rim so it wont interfere with the spokes, mabe easier to locate that type of machine than cut new rims..
Reply:YW..or you can cut the axle at the spokes, weld a flange on the spoke tube( spool) and then bolt a matching flange to that and weld a heavier axle to the flange, this way if you get a flat tire you dont have to tear down the complete assembly, this way you dont have to respoke the wheel on to a larger spool...Of all the things I lost I miss my mind the most...I know just enough about everything to be dangerous......You cant cure stupid..only kill it...
Reply:Sounds sketchy using regular old mild steel for the axles. You could experience vibrations by only using 2 bearings (which could possibly grow enough to completely bend the axle if not strong enough for the rpm). You'll get a standing wave in the axle between these 2 points. The solution is 3 points of contact. And as far as strength goes, you want a point of contact as far outward as possible (and inward). Remember, any tire/wheel vibration is going to get exponentially worse with rpm and that all needs to be taken into account.Last edited by MikeGyver; 01-13-2015 at 07:18 PM.Welding/Fab Pics: www.UtahWeld.com
Reply:Originally Posted by roadkillbobbYW..or you can cut the axle at the spokes, weld a flange on the spoke tube( spool) and then bolt a matching flange to that and weld a heavier axle to the flange, this way if you get a flat tire you dont have to tear down the complete assembly, this way you dont have to respoke the wheel on to a larger spool...
Reply:Why not skip the motor on this one and do the next one right with real hubs and a keyed axle?  Once you get it done, you'll find a dozen things you'd do differently anyway.My name's not Jim....
Reply:After much pondering about all this......I would not worry all that much about the axles at this point...Look at it this way...The bike looks to be about the same width in the rear as a typical lawn tractor.Granted a tractor won't go as fast but they are basically the same thing.My axles are nothing special either and are just mild steel with a key and I pull 800 lbs of wood pellets around in my trailer and they don't bend.This will be a lot less resistance to move in your deal so that's why I would not worry about it.Just as long as you don't tie them together and only run one wheel drive go for it.And yeah tie the rear frame assy. together like stated earlier....zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:Originally Posted by BoostinjdmWhy not skip the motor on this one and do the next one right with real hubs and a keyed axle?  Once you get it done, you'll find a dozen things you'd do differently anyway.
Reply:Zap is right on ,just run it, strong enough. Nice job too!
Reply:Originally Posted by PavinsteelmanZap is right on ,just run it, strong enough. Nice job too!
Reply:One more thing to do if you did not do it already...To aid in disassembling the axles from the bearings  put small flats on the axles where the set screws go so you don't mark up the shafts from tightening...Save a lot of headaches that way.......zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:Originally Posted by little_sparkyI understand what your saying here, but surely it wouldn't be strong enough would it?it would look something like this yeah?thankslittle_sparky
Reply:Has the diameter of the axle-shaft been mentioned yet?Less than an inch, okay, but how much less?Is it "only" 3/4" or so?But yes, the overhung load has to be reduced.
Reply:Originally Posted by denrep Less than an inch, okay, but how much less?Is it "only" 3/4" or so?
Reply:If you are worried about it use better steel.  1040 is common for shafting.  It is roughly 3x stronger than typical A36 round bar.  Don't try to weld anything to it, though.  I see you have already made flanges for spokes.  Since a set screw is not possible you can simply siv-braze the flanges to the shaft.Last edited by 76GMC1500; 01-15-2015 at 11:44 AM.