Raglan Lathe Gear Issues

[M@tt]

Today i was having the first tinker with my raglan lathe since i bought it a good while ago now!

i was having a fiddle with the various knobs an levers to work out what everything did.

during my tinkering i came across a bit of a problem. i noticed that there is a lever which engages/disengages the gear box. I has 3 positions forward/reverse /disengaged

i found when the lever was put in the revere position it was making a horrible clunking/banging noise, however when in either neutral or forward it was fine.

on closer inspection i think it was because of a poor replacement idler gear which wasn't meshing properly. I've taken a little video to highlight the problem

and also a pic which hopefully shows that the teeth seem to be of varying thicknesses

i'm pretty sure the gear is the problem

does anyone know anywhere apart from lathes.co.uk to get new gears from or anyone able to make one? Its has 26 teeth and i could get some more measurements if someone could knock one up

Cheers

Matt

 

[GeorgiePorgie]

I would'nt suspect the gears just yet,have you tried stripping the gears cam lock and see if its seating properly and aligned and tight?

 

[GeorgiePorgie]

By the way....the cameraman wants shooting.

 

[M@tt]

sorry i'm a bit of a lathe ludite

what's the gears cam lock?

the problem definitely seems to be when the 2nd idler gear is engaged and it's the one that appears to have been made, as the teeth vary in thickness's and you can see it hitting the sides of the other gears at the point where its very difficult to engage

 

[GeorgiePorgie]

what's the gears cam lock?

That arm that you're adjusting to change from forward to reverse.

Any slack and it fails to engage the teeth properly which will cause a metalic rumble noise.

When I got my mini lathe this same occurance was due to slackness in the cam locking levers pivot bolt it was loose and when I tightened it up the knocking noise disappeard

 

[GeorgiePorgie]

Can you take a GOOD pic of the gears in reverse without starting the lathe

 

[FranV8]

If the thickness of the teeth is not consistent, you've got no chance. Replace that gear ASAP, all it's doing now is damaging the healthy gear it meshes with.

 

[scott0031]

It will be a gear problem of some sort. Most likely an individual gear or that and the mating gear. First thing you should do is take them off clean them thoroughly, look at each tooth very carefully for damage.

The problem can be caused by something as simple as swarf that has been embedded into the gear causing a lump. It can also be caused by hard old grease that has been there for donkeys years, that needs digging out, it can get rock hard and causes a deflection of the gear, that can be heard with a clunk you described, same applies to embedded swarf.


The best way to find the faulty gear/ gears is to remove one by one from the lead screw end, then do a rotation until the bump disappears, that tells you the gear you have removed is at fault. Re-assemble the said gear, then do another rotation until you hit the bump, mark with marker pen where it meshes, remove and inspect the area.

It can be something as simple as the train being to tight. Sometimes giving a little more clearance between the gears can cure the problem.



Kind regards,


Scott (ward engineering)

 

[Engineer]

Unless you are screw-cutting there is no need to use reverse gear. Getting spare parts might be difficult, but it would be worth having a good look at the rest of the machine, as it might be quite badly worn in other areas.

 

[Pete.]

All of the gears in the tumbler reverse mechanism are in mesh with at least one gear all of the time, so if the reverse idler was that poorly made that it doesn't mesh with the spindle stub gear, how is it that it will mesh with the forward idler?

 

[M@tt]

i've actually got a manual somewhere its just i didn't have it to hand

i realise that gear is only for reverse but i thought it would be nice to fix it o the machine works as intended

i removed both those 26T idler gears and inspected them. There wasn't any lodged crap which i thought it might have been initially but looking at the teeth they definitely aren't uniform which i think will be the problem

 

[Pete.]

Could be the poorly-made gear is meshing more closely with the spindle than the other idler. Does the knocking stop if you hold it in a slightly looser engagement rather than the tumbler pin?

Dunno what DP your gears are but for example a 26-tooth 16DP steel gear from HPC gears is only £16.41 & vat. Might be just as easy to buy a replacement.

 

[GeorgiePorgie]

This group is based on the raglan tools and machines,see if they can link you to vuying a new gear?

http://groups.yahoo.com/group/RaglanMachineTools/

 

[FranV8]

All of the gears in the tumbler reverse mechanism are in mesh with at least one gear all of the time, so if the reverse idler was that poorly made that it doesn't mesh with the spindle stub gear, how is it that it will mesh with the forward idler?

It may be the issue only truly reveals itself with the gear under load, or perhaps when load is being transmitted in the opposite rotation - if the teeth thicknesses vary, either the pitch of the teeth is totally wrong, or could be right for one direction, but not right for both directions.