Shortening propshaft

[Lawnmowerboy]

Hi all, Need to shorten a propshaft to fit the gokart. Is there anything in paticular I need to watch out for. Will be doing it on a lathe and can balance it properly, The current idea is to cut nearer to one end to minimise centrifugal force on the join, If it were to cut with the part off and then make a sliding fit sleeve out of solid say en1a or 3b non leaded. then do the fit up and get straight as poss then tig it up and balance? It's not for high speed long term use and I just dont want it breaking and killing me. It'll only be used for hooning round the field. Can antone see any flaws here or offer a better idea?

 

[nickk]

you got the idea,also if u can stick your parting tool thru the original weld where the tube is spigotted onto the uj its one less weld,or did you intend cutting there?

 

[Lawnmowerboy]

Well I was thinking doing it so i could get a good 6 or 8 inches of sleeve in either piece to strengthen before welding, so it can't physically come apart unless the sleeve breaks or the tube breaks elsewhere

 

[Shox Dr]

As nick say grind the weld off one end

 

[Lawnmowerboy]

Okies!

 

[brightspark]

you got the idea,also if u can stick your parting tool thru the original weld where the tube is spigotted onto the uj its one less weld,or did you intend cutting there?

i shortened an atlas propshaft by parting off the the uj cup on the end , took 6inch out refit the end and welded it up . the only balancing was a 1 inch square of 1/16th of an inch plate . clock the tube up after welding in the lathe . if theres a bit of run out tape the weight on to counterbalance the runout and if its ok weld it in position job done . the propshaft had 200 hp going through it flat out with no probs

 

[Lawnmowerboy]

Sounds easy enuff! Will report back!

 

[normspanners]

You must make sure you kee

 

[brightspark]

You must make sure you kee

????? giz a clue

 

[normspanners]

Hi you must make sure the yolks are kept in line before rejoining the shaft!!, I use a piece of angle to scribe a line before cutting that keeps them 'in phase ' other wise it will vibrate and shake because of the action of the uj's fighting each other .
Also the line of the input shaft should be within 1 deg of parrallel of the line of the output flange to keep both uj's running equal.
A way of balancing aprop 'in the field' is to put the vehicles axle on stands
remove the rear wheels but replace the wheel nuts include washers if needed to keep drums /discs tight. Then get someone to run the car in top gear speed up till you feel the vibration then lying under the car look which end the run out is, hold a sharpened chalk stick and lightly touch the prop with the chalk, stop the prop the mark left is the heavy spot . Then fit two identicle 'jubilee clips' opposing each other on the prop so that they are balanced then keep doing prop runs and adjust the jubilees screw bits towards each other but away from the chalk mark until the vibration dissapears. Then mark the position of the screw bits remove the clips cut the screw bits off the clips and weigh them. cut strips of steel to an identicle weight and tack them on inplace of the clips. and you have abalanced prop. This is especially handy when you have a high speed vib because the best prop balancers can only balance to 5000rpm and on rally cars using a 5.1 axle ratio the prop can be spining up to 10000rpm in top !! at 125 mph. I have had to do this a few times to stop cars jumping out of gear as it does the con rods no good at that revs especially if the driver rams it in 3rd in his haste !

 

[normspanners]

????? giz a clue

sorry about that I typed it all out with one finger btw, then moved the key board pressed summat n lost it all bar that bit, I said OH FLICKIN DEAR, I then had to find another key board coz I put my fist through the other n smashed it and now my hand hurts.

 

[Sid]

I put my fist through the other n smashed it and now my hand hurts.

You need to calm down a bit

 

[normspanners]

calm?,calm?,I AM CALM!!!! AND NOW I NEED A NEW LAPTOP

 

[Robotstar5]

Remings me of this scene from American Chopper

 

[pedrobedro]

Remings me of this scene from American Chopper

That's what steroids do for you

 

[normspanners]

I only hit mine once, mind you that was enough most of the keys shot off !! ha it had it coming, I'd been havin problems with my p's for a while, but thats old age for ya !!