Author Topic: an engine repair  (Read 7831 times)

Offline shoey51

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an engine repair
« on: January 25, 2011, 02:49:12 PM »
not sure if this is the right place to post this mods please move if needed.
I have started a thread on a to steam forum of this repair job and a very good friend pmed me and sugested I might get a more informed help
on this forum (thanks David aka Stilldrillin)

My little loco engine was starting to rock and roll badly while being drive so I thought it time I investigated.

I jacked up the rear of the loco and removed the axle I used a small car jack to do this
here is the loco now resting on blocks whith axle removed.


the axle removed I could see the problem


also it looked like the previous owner had tried to weld the wheel to the axle.

so i was pondering what to do next :scratch:
the wheel was loose so i presumed the weld hadnt taken trying to to weld steel to cast isnt easy.
so I took the axle to work as they have a nice press there and managed to remove both wheels
and discovered this


the wheel had been scotchlocked and the thread had been welded :bang:
so im throwing it it out to the experts for help in what they think may be the best solution to fix this.

cheers Graham

Offline Stilldrillin

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Re: an engine repair
« Reply #1 on: January 25, 2011, 03:25:52 PM »
Hi Graham.
Nice to see you've posted. There's more engineering expertise over here...... I hope!  :scratch:

I've noticed several members over there, posting engineering/ machining subjects. Can't understand why they're not 'ere.....  ::)

We're quite a friendly bunch, as you know!  :thumbup:

My only thoughts, so far, are to bore out the wheel and sleeve back to standard. Then the axle looks a relatively simple job to replace the worn section.

Lets see what the others think........  :smart:

David D
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Still modifying bits of metal... Occasionally, making an improvement!

Offline Bogstandard

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Re: an engine repair
« Reply #2 on: January 25, 2011, 03:44:08 PM »
Actually, that is a recognised method of locking two parts together, but usually you would use a couple or three screws, equispaced around the shaft and wheel, not just one.

You will most probably need to make a new axle shaft to sort out your bearing problem first. Then cut a new keyway into it and clean up the keyway slot in the wheel to match.

I personally would then recut the original welded over screwthread and put a grub screw in there. Then drill two more holes, not quite as big as the first one will end up, one either side of the key, making the holes equidistant from each other, and thread and grub screw those as well.

Drill thru the wheel hub into the key, and thread the hole and key, and put another grub screw into that, which will stop the key coming out of it's slot.

By doing it that way, you should easily be able to remove the wheel by taking out the three grub screws around the axle end and sliding it off the axle.


There are many ways to fix things like this together, I have just given you an easy option.


Bogs
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Location - Crewe, Cheshire

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Offline sbwhart

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Re: an engine repair
« Reply #3 on: January 25, 2011, 04:53:46 PM »
Hi Graham sorry to see your engine in dock.

Its good advice from John about how to fix the wheel back on, the other option would be to bore the wheel out and rebush it back to size, the bush can be pressed in with a little high strength loctite but there is a risk of craking the wheel if you get the interfearance wrong, so I'd go with Johns method first.

The wheel problem may be a result of the knackered bearing one leading to the other. Whilst you've got the axle boxes off have you thought of fitting roller bearings you'd have to bore the boxes out to take the bearings and make new axles, a lot of the 5" guys at our club run with roller bearing in their axle boxes.

Stew

A little bit of clearance never got in the road
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Location:- Crewe Cheshire

Offline madjackghengis

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Re: an engine repair
« Reply #4 on: January 27, 2011, 07:55:59 AM »
Hi Graham, in reading all the knowlegable answers, I thought I'd let you have my thoughts, from a purely mechanic's perspective, from here in the colonies.  John has the straight forward repair, and it's nice and solid, I'd add welding up the axle where its buggered up, and turn down the welded section, over replacing the axle, all that assuming the rest of the axle is in good shape and solid.  What John says gives you four separate locks, and substantially more bearing area of the locks, which would make it far more resistant to working loose, and once it works loose to start with, there's only looser, no turning back.  I believe I'd braze up the threaded section in the wheel, assuming its cast, and then bore to get back to round, and put the screws in three virgin places, and clean up the key to at least a tight push fit, when it goes in the wheel and axle together, even if it means a larger key.  That wheel is essentially acting as a flywheel, and driving the axle, so the wheel is going to act and react to the engine directly, leaving all the mass and inertia of the axle to follow, so the key, pun intended, to keeping the two solid, is to work from the wheel to the axle, as far as stresses go, rather than the conventional axle to wheel, which assumes the axle drives the wheel.  I'd also locktite the wheel and axle joint when everything is fitted up for the final assembly, if it can't start working loose, it won't get looser with time.  The idea of adding live bearings is a good one, if you're ready to go all the way with a whole new axle, and then it can be a bit oversized, and allow a better clean up of the hub, and a good chance of finding the opposite wheel starting to work loose, and get it solid and well keyed before any damage is done.  This looks a lot like farm equipment repair, if you don't mind my saying so, similar problems, lots of torque, lots of load, and stop and go making inertia a serious factor.  I'd sure like to lay my own hands on that bit of work, not much rail work unless one is close and part of  a club over here.  Something about steam engines, tied to flanged flywheels, running on tracks, with boilers attached to the engines, in tandem, and frames bolted on to the engines and boilers, and pulling boxes for stuff or people, from the bolted on frames, but brought down to the essence, two tandem steam engines with driving and rolling wheels attached, and a boiler to provide the steam - the most basic engine/drive system starting the steam driving idea from the beginning of the steam age.  It feels subtly primitive and original, and connects with the guys who had to figure all this out from scratch, just using their noggins, and learning from what breaks. :lol:  I've always felt steam engine enthusiasts and motorcyle drivers are of the same breed, just wanting to put wheels on an engine, and drive the engine around, with the necessary equipment attached, and no more.  Some jobs get you paid, other jobs you'd pay just for the privilege of doing it, at least I find that happens, all though even the second kind, the owner wants to pay.  :beer: cheers, I hope you enjoy the repair as much as we enjoy watching it unfold.  :poke: mad jack

Offline shoey51

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Re: an engine repair
« Reply #5 on: February 13, 2011, 05:17:21 PM »
Thanks every one for your kind words. the plans finally turned up from Reeves and after getting them laminated I started to compare the plans to the engine that i have. there are a few changes that had been done mainly in the way the valve linkages were made.
Have decided to make a new axle so will start that as soon as I get some steel

Offline shoey51

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Re: an engine repair
« Reply #6 on: March 25, 2011, 11:34:14 PM »
I have a question I need answering. Ive been working on turning down a new axle and find there is a taper. there is a .2 mm difference in the diameter of the rod from the chuck end and the stock end  is there a way to fix this. sorry for my stupid question but im still learning. the difference is over the 10" length im turning down. Axle will be shorter when finnished but im trying to get a start point to work from.

cheers Graham

Offline sbwhart

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Re: an engine repair
« Reply #7 on: March 26, 2011, 02:59:32 AM »
Hi Graham

I take it over that lenthe that your using a centre if so you should be able to slew your tail stop over to straighten things out, if you look at the base of the tail stop ther should be a screw either side oposit each other, what you do is slaken one side off and tigten the other up this has the effect of slewing the tail stop over.  If the bar is small at the tail stop end then you need to slew it towards you, if its small at the chuck end then slew it away from you.


This is how it looks on my lathe



Hope this helps
A little bit of clearance never got in the road
 :wave:

Location:- Crewe Cheshire

Offline Stilldrillin

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Re: an engine repair
« Reply #8 on: March 26, 2011, 03:02:27 AM »
Just taken the words out of me mouth Stew!  :thumbup:

David D
David.

Still drilling holes... Sometimes, in the right place!

Still modifying bits of metal... Occasionally, making an improvement!

Offline John Stevenson

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Re: an engine repair
« Reply #9 on: March 26, 2011, 05:33:25 AM »
Before you starts alter the tailstock you need to know if the lathe is turning parallel on juts a piece in the chuck.
If it's not correctly levelled this will happen and altering the tailstock will only be good for that length.

First off check with a good level, not a builders level that it is level across the bed at the chuck, across the bed at the tailstock end and along the bed.
Shim or adjust levelling feet to suit.

Then get a steel bar about 1" diameter and with 6" sticking out the chuck centre drill it and support from tailstock.
Then relieve the 4" centre section to about 3/4" diameter leaving 1" untouched at either end.

Move the tailstock out the way and take a light cut along the two raised surfaces without altering any settings and take a measurement. They should be the same. If so move the tailstock back into play and repeat.

You can now see if there is any difference and which way to go.

If the first test shows different readings then it shows the lathe isn't level and you will have to jack it up to correct it. If the outer sticky out end is smaller then pack the rear tailstock end of the bed up and retry.

If the chuck end is larger then adjust the rear of the headstock end.

What ever happens get the unsupported bar cutting correct before you even think about touching the tailstock or else you will be chasing tapers for the whole of the while you have the lathe.

Non of the sizes of bar are critical, use anything you have within reason

John S
John Stevenson

Offline sbwhart

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Re: an engine repair
« Reply #10 on: March 26, 2011, 05:48:55 AM »
Thats a great bit of information John

Thanks for passing on

Stew
A little bit of clearance never got in the road
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Location:- Crewe Cheshire

Offline shoey51

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Re: an engine repair
« Reply #11 on: March 26, 2011, 05:11:47 PM »
Thanks John for the great information and every ones input
now to find a good level
cheers Graham