Extractor issues

[DaveS]

Hi all

Half way through extraction today my manual extractor stopped working - the crank handle goes around but it does not turn the cage. I think it is a Unimel from thrones bought about 5 years ago but hasn't had much use.

I've dismantled the mechanism and the problem seems to be with the cog (?) at the head of the main rod into the extractor - I can spin the cog but it doesn't turn the green bit underneath. when I turn the green bit underneath (2nd photo) i can see the very top bit of the cog going around but it doesn't move the cog. Not sure I am explaining it very well so sorry if it isn't clear!

I don't seem to be able to dismantle the thing further and there are no screws or similar to tighten so not sure if it is repairable - any suggestions? anyone know where I can get a replacement if you think it can't be repaired?

Many thanks

 

[DaveS]

Just tried a video to show..

 

[blackcloud]

Is there a roll pin that has snapped
It would look like a tubular peg that pins the pinion to the shaft.
You tap it out with a thin punch and get a replacement from a metalworking supply or eBay.
Just an idea

 

[blackcloud]

I can't see clearly- is the pinion turning on the shaft ?
Other than a roll pin it might be a grub screw which could have a hexagon shaped socket for an Allen key.
There are a pair of holes on the circular plate that suggest it can be screwed with a peg spanner or at worst a punch this would allow further investigation.

 

[DaveS]

Thanks Blackcloud. As you may have gathered from my post i'm not particularly familiar with the terms so I'm sorry I don't quite understand...

The pair of holes on the circular plate had screws in which I removed but couldn't work out their function - couldn't move or remove anything once they were out.

The green bracket underneath - I assumed this was what the gear moved as the shaft goes into it. However it turns independently of the gear. There are 2 holes in this that I can see all the way through. Looking downwards the green bracket I can see a rusted piece of metal - could this have sheared off the shaft? It must be lower (towards the open end) than the 2 holes.

I can't see a hex socket.

Sorry I should have focussed more in my metal working GCSE class!

Thanks

 

[Anduril]

Thanks Blackcloud. As you may have gathered from my post i'm not particularly familiar with the terms so I'm sorry I don't quite understand...

The pair of holes on the circular plate had screws in which I removed but couldn't work out their function - couldn't move or remove anything once they were out.

The green bracket underneath - I assumed this was what the gear moved as the shaft goes into it. However it turns independently of the gear. There are 2 holes in this that I can see all the way through. Looking downwards the green bracket I can see a rusted piece of metal - could this have sheared off the shaft? It must be lower (towards the open end) than the 2 holes.

I can't see a hex socket.

Sorry I should have focussed more in my metal working GCSE class!

Thanks

Your second picture post 5 of the green shaft looks as though it should have a slotted spring pin Search - Accu

 

[user 20297]

I have a basic, hand-cranked, Thornes extractor. It was a PITA as the drive didn't engage until I was revving it really fast and then if I relaxed my turning it disengaged and had to be started again. I noticed a small adjustment screw on the side and gently turned it in to find that things got better. Too far and it locked up; backed out a little and now it's perfect.

 

[blackcloud]

Anduril is referring to a roll pin too.
Theres the one painted green- it is tapped into a hole that runs right through the green tube and also through the shaft .It's held there by its own 'springyness'
What I'm getting at is the pin may have sheared (snapped) off inside allowing the shaft to turn without the green cranking
tube
Have a look if there's also one pinning the "cog" to the shaft that may have sheared off.
The circular plate is the bearing housing retainer
At this point put the screws back in for now,but if it's not the roll pins you may have to get the shaft out to investigate further.
We' ll get there !

 

[Anduril]

The rod from the extraction basket should have a hole near the top, this should contain the rest of the slotted spring pin. If you are in desperate need of extracting a spring crop while you are ordering a replacement part, then a split pin could be used as a temporary measure.

 

[DaveS]

The rod from the extraction basket should have a hole near the top, this should contain the rest of the slotted spring pin. If you are in desperate need of extracting a spring crop while you are ordering a replacement part, then a split pin could be used as a temporary measure.

Ah the rod on the extractor basket does not have a hole at the top - I suspect that part just have sheared off and be stuck in the green bit. I've tried banging it though and it doesn't come out!

The extractor generally has proved problematic - part of the cage fell off today too.

 

[DaveS]

Anduril is referring to a roll pin too.
Theres the one painted green- it is tapped into a hole that runs right through the green tube and also through the shaft .It's held there by its own 'springyness'
What I'm getting at is the pin may have sheared (snapped) off inside allowing the shaft to turn without the green cranking
tube
Have a look if there's also one pinning the "cog" to the shaft that may have sheared off.
The circular plate is the bearing housing retainer
At this point put the screws back in for now,but if it's not the roll pins you may have to get the shaft out to investigate further.
We' ll get there !

I didn't notice that there is a hole in the cog bit.... When I insert a paperclip the cog spins the green bit so it does look like I'm missing a pin... Where on earth do I get a replacement - how do know what I'm looking for?

Thanks

 

[blackcloud]

Engineering shop,mower repair shop,small car garage ,eBay etc
It's called a roll pin and you will need to know what diameter it is.
EBay will sell you a selection pack no doubt.
You need a pin punch slightly smaller than the hole in the shaft and a hammer to drive out the old one if there's anything left and in with the new.
I love fixing things but I'm aware some folk could do without all the faff and drama,so you might just take it to somewhere like the mower repair shop as its fairly rudimentary engineering.
Let us know!!!

 

[Anduril]

If it isn't a pin, does it contain a thread? If so it might need a grub screw
https://www.thorne.co.uk/extraction/extractor-spares

 

[blackcloud]

Clean it up and see if there's a screw thread
Might be a grub screw -again you need to know what size and get one on eBay.
I would personally have made it with roll pins because they don't unscrew and fall out
EBay link

 

[victor meldrew]

Clean it up and see if there's a screw thread
Might be a grub screw -again you need to know what size and get one on eBay.
I would personally have made it with roll pins because they don't unscrew and fall out
EBay link

Or a Woodruff key even .

 

[DaveS]

Thanks all -there isn't anything there to know if it was a pin or screw... I'll google for a mower repair shop... Didn't know they still existed!

 

[Anduril]

Thorne can service your extractor, they will do any make or model.

 

[Gilberdyke John]

I didn't notice that there is a hole in the cog bit.... When I insert a paperclip the cog spins the green bit so it does look like I'm missing a pin... Where on earth do I get a replacement - how do know what I'm looking for?

Thanks

I couldn't make out the detail but reading the comments and replies I'm thinking there is a missing pin or bolt to secure the gear to the shaft. You don't come across as being likely to have much in the line of engineering tools but can you determine if the hole you mention goes right through the gear and shaft or only part way plus what diameter the hole is? The easy way to determine the diameter of the hole is to try pushing the shank (smooth part) of a drill bit into it. If the hole goes right through a roll pin would be a good solution but it might be just as easy to get a nut & part threaded bolt of correct diameter and adequate length and fix it through the assembly. Once secure I would cut off any excess thread sticking out and bruise the thread tip so it doesn't work loose and drop through inside the extractor. Pity you're not near or I could show you how to deal with it.

 

[Anduril]

I couldn't make out the detail but reading the comments and replies I'm thinking there is a missing pin or bolt to secure the gear to the shaft. You don't come across as being likely to have much in the line of engineering tools but can you determine if the hole you mention goes right through the gear and shaft or only part way plus what diameter the hole is? The easy way to determine the diameter of the hole is to try pushing the shank (smooth part) of a drill bit into it. If the hole goes right through a roll pin would be a good solution but it might be just as easy to get a nut & part threaded bolt of correct diameter and adequate length and fix it through the assembly. Once secure I would cut off any excess thread sticking out and bruise the thread tip so it doesn't work loose and drop through inside the extractor. Pity you're not near or I could show you how to deal with it.

If you look at the second picture in post 5 and enlarge it you can see straight through the hole

 

[Gilberdyke John]

If you look at the second picture in post 5 and enlarge it you can see straight through the hole

Thanks. I'm reading this on a small tablet so it wasn't evident to me. Now that's established it's just a matter of measurement