Hornby Class 71

[NIK]

More than likely the issue is with top part of the gear tower, not being clipped in place properly - the loco not being level is a dead giveaway for that. You'll need to remove the PCB to gain access to it. 10 minutes to fix tops

 

Does the top part of the gear tower clip into the bottom part?.

 

That would explain why I couldn't work out how to get the whole gear tower out of the chassis.

 

 

Regards

 

Nick

[toboldlygo]

Does the top part of the gear tower clip into the bottom part?.

 

That would explain why I couldn't work out how to get the whole gear tower out of the chassis.

 

 

Regards

 

Nick

 

Yes, it holds all the gears in place.

[NIK]

Yes, it holds all the gears in place.

Many thanks for the info.

 

Unfortunately the top of the tower was firmly clipped in place. I visually checked the gears anyway.

 

I had a few goes trying to get the bottom of the tower to work properly but although I got close it always ended with the gears going out of mesh in one direction.

 

The amount the wheels can be turned by hand before resistance is met on the working bogie of my class 71 is lot more than a Bachmann Class 25 or a Heljan 33.

 

I might try adding a sliver of material (gorilla tape?) to the middle prong of the keeper plate to see if the middle gear that connects the vertical tower to the horizontal was sitting too low to mesh in both directions.

 

Regards

 

Nick

[toboldlygo]

Many thanks for the info.

 

Unfortunately the top of the tower was firmly clipped in place. I visually checked the gears anyway.

 

I had a few goes trying to get the bottom of the tower to work properly but although I got close it always ended with the gears going out of mesh in one direction.

 

The amount the wheels can be turned by hand before resistance is met on the working bogie of my class 71 is lot more than a Bachmann Class 25 or a Heljan 33.

 

I might try adding a sliver of material (gorilla tape?) to the middle prong of the keeper plate to see if the middle gear that connects the vertical tower to the horizontal was sitting too low to mesh in both directions.

 

Regards

 

Nick

 

I wonder whether they've put the wrong diameter gear in or put them in the wrong way round.

Edited September 1, 2016 by toboldlygo

[NIK]

I wonder whether they've put the wrong diameter gear in or put them in the wrong way round.

 

I definitely don't blame Hornby - the problems only started after I forcefully clipped the body over the Zimo MX600R decoder. Luckily there aren't any gradients on the electrified sections of the club layout I'm hoping to run the loco on. So I can probably get away with running it as 4 wheel drive for now until spares become available. I tried adding gorilla tape rectangles to the centre  prongs of the keeper plate and it seemed to help but not enough to stop the gears grinding when running in reverse on the rolling road. I've also drilled out a deeper recess for the middle intermediate gear in case it wasn't close enough to the vertical tower but that only made things worse - I will add material to the keeper plate to make up for making the tower gear recess deeper.

 

Regards

 

Nick

[JSpencer]

It sounds like at least one gear has lost some teeth. You must really have forced it home to stripe them off, in a direction causing the wheels to turn or dislocate.

 

BTW, does it have as much free play as a Dapol class 52 (they are 1/4 turn before resistance sets in)?

Edited September 1, 2016 by JSpencer

[NIK]

It sounds like at least one gear has lost some teeth. You must really have forced it home to stripe them off, in a direction causing the wheels to turn or dislocate.

 

BTW, does it have as much free play as a Dapol class 52 (they are 1/4 turn before resistance sets in)?

 

I don't have a Dapol 52 - it seems like I might have been clutching at straws if the Dapol 52 has similar free play.

 

I haven't found any gears with stripped teeth or even worn teeth. I tried to make sure I pressed the body straight down so the wheels didn't turn.

 

Regards

 

Nick

[luke_stevens]

I definitely don't blame Hornby - the problems only started after I forcefully clipped the body over the Zimo MX600R decoder. Luckily there aren't any gradients on the electrified sections of the club layout I'm hoping to run the loco on. So I can probably get away with running it as 4 wheel drive for now until spares become available. I tried adding gorilla tape rectangles to the centre  prongs of the keeper plate and it seemed to help but not enough to stop the gears grinding when running in reverse on the rolling road. I've also drilled out a deeper recess for the middle intermediate gear in case it wasn't close enough to the vertical tower but that only made things worse - I will add material to the keeper plate to make up for making the tower gear recess deeper.

 

Regards

 

Nick

Hi Nick,

 

Is there any chance of some photos? I'd be interested to see what is going on.

 

I haven't got a Hornby 71 (committed to a DJ one) but I'd like to understand what is going on. A little bit of learning, etc.

 

Yours

 

Luke

[JSpencer]

I don't have a Dapol 52 - it seems like I might have been clutching at straws if the Dapol 52 has similar free play.

 

I haven't found any gears with stripped teeth or even worn teeth. I tried to make sure I pressed the body straight down so the wheels didn't turn.

 

Regards

 

Nick

You can push a Dapol 52 almost 2 cm before it locks up! Their 73 is lot less, nearly half that.

 

Unless Hornby switched to bevel gears (unlikely as both ends would be free running), I cannot imagine any circumstances that will cause a bogie to be free running. One of the gears must be disengaged somewhere, either through being broken, it's shaft being broken, the tower being un clipped or broken above or below. Something broken or unclipped has caused it to disengage some where.

 

Maybe forcing the body back on, caused the bogie under the tower to split leading to gears being disengaged.

[NIK]

I think I've found the problem with my class 71.

 

I ran the loco in reverse for a few seconds then looked at the gears in the tower. The gear that is driven by the worm had worn and bent teeth.

 

Maybe as suggested one of the clips at the top of the gear tower had not held and the worm came out of proper mesh and damaged the next gear.

 

I tried remodelling the top of the gear tower with a fine tipped soldering iron and a file to get the worm shaft to sit a bit lower and mesh with the remains of the gear teeth but it just made things worse.

 

Regards

 

Nick

[JSpencer]

I think I've found the problem with my class 71.

 

I ran the loco in reverse for a few seconds then looked at the gears in the tower. The gear that is driven by the worm had worn and bent teeth.

 

Maybe as suggested one of the clips at the top of the gear tower had not held and the worm came out of proper mesh and damaged the next gear.

 

I tried remodelling the top of the gear tower with a fine tipped soldering iron and a file to get the worm shaft to sit a bit lower and mesh with the remains of the gear teeth but it just made things worse.

 

Regards

 

Nick

Plastic and soldering ions make a bad combination. Your best bet is now to acquire a spare bogie, this is no hope of fixing this unless you have machine tools to make new parts.

[NIK]

Yes,

 

Hornby haven't published a service sheet for the Class 71 yet.

 

I might just be able to make a new housing for the worm gear but I can't make the twin gear that mates with the worm and the gear tower.

 

A member of my club 3D printed a gear for a Dapol N gauge Terrier but I suspect a new Hornby gear tower will be a similar price. Plus the Class 71 motor seems pretty torquey.

 

My 71 now on 4 wheel drive has a drawbar pull of 37g at DCC speed step 126 and wheels slipping. I will put it on my DCC test track and see how many Mk 1 coaches it will pull.

 

Does any one know if the Class 71 ever hauled dead EMUs or DEMUs?.

 

 

Regards

 

Nick

[34theletterbetweenB&D]

...Hornby haven't published a service sheet for the Class 71 yet.

 

I might just be able to make a new housing for the worm gear but I can't make the twin gear that mates with the worm and the gear tower....

 

 In your shoes I'd contact Hornby service, explain that you have managed to damage the mechanism, and can they help?

 

 

...My 71 now on 4 wheel drive has a drawbar pull of 37g at DCC speed step 126 and wheels slipping. I will put it on my DCC test track and see how many Mk 1 coaches it will pull...

 

 If the mk1s are free running, that should  be good for reliably starting 18 coaches on level track. That's the sort of pull that the better RTR steam models exert...

[Ian Hargrave]

I have followed NIK's tribulations with his 71 with much sympathy and note members advice/comments with interest.

It does occur as a strictly dc only operator that maybe his wiser course of action would be to purchase a new model rather than prolong the agony by testing to destruction ? Sorry....

[barison82]

Does any one know if the Class 71 ever hauled dead EMUs or DEMUs?.

 

I recall seeing a photo a good while ago in a book depicting a Class 71 hauling a 4-SUB unit through Thames Ditton station after a derailment at Hampton Court; the loco was utilised to tow the damaged stock clear. So I'm certain that these loco's had hauled dead EMUs/DEMUs.

 

Alex

Edited September 6, 2016 by barison82

[NIK]

I recall seeing a photo a good while ago in a book depicting a Class 71 hauling a 4-SUB unit through Thames Ditton station after a derailment at Hampton Court; the loco was utilised to tow the damaged stock clear. So I'm certain that these loco's had hauled dead EMUs/DEMUs.

 

Alex

 

Dear Alex,

 

Many thanks for the info.  That gives me a better excuse for running my 71 with 4 wheel drive hauling an EMU (driven or motor-less).

 

I have got a 4-SUB kit to build, although I'll practise on some less rare kits first.

 

 

Regards

 

Nick

[royaloak]

I definitely don't blame Hornby - the problems only started after I forcefully clipped the body over the Zimo MX600R decoder. Luckily there aren't any gradients on the electrified sections of the club layout I'm hoping to run the loco on. So I can probably get away with running it as 4 wheel drive for now until spares become available. I tried adding gorilla tape rectangles to the centre  prongs of the keeper plate and it seemed to help but not enough to stop the gears grinding when running in reverse on the rolling road. I've also drilled out a deeper recess for the middle intermediate gear in case it wasn't close enough to the vertical tower but that only made things worse - I will add material to the keeper plate to make up for making the tower gear recess deeper.

 

Regards

 

Nick

Why force it?

If it wont go on then there is something wrong so find out what is preventing the body going on, brute force nearly always ends in tears!

[slilley]

Yes,

 

Hornby haven't published a service sheet for the Class 71 yet.

 

I might just be able to make a new housing for the worm gear but I can't make the twin gear that mates with the worm and the gear tower.

 

A member of my club 3D printed a gear for a Dapol N gauge Terrier but I suspect a new Hornby gear tower will be a similar price. Plus the Class 71 motor seems pretty torquey.

 

My 71 now on 4 wheel drive has a drawbar pull of 37g at DCC speed step 126 and wheels slipping. I will put it on my DCC test track and see how many Mk 1 coaches it will pull.

 

Does any one know if the Class 71 ever hauled dead EMUs or DEMUs?.

 

 

Regards

 

Nick

 

No E5005 hauled a  4TC  421 on the Man of Kent railtour on 11 April 1971

[slilley]

I recall seeing a photo a good while ago in a book depicting a Class 71 hauling a 4-SUB unit through Thames Ditton station after a derailment at Hampton Court; the loco was utilised to tow the damaged stock clear. So I'm certain that these loco's had hauled dead EMUs/DEMUs.

 

Alex

 

Are you sure it was a 71? They rarely left the South Eastern Division and would have had a conductor if on the South Western. Might it have been a 74?

 

Simon

[stovepipe]

I've got a photo of the Man of Kent tour at Sittingbourne, 71 with a TC unit, listed as 427 below.

 

http://www.sixbellsjunction.co.uk/70s/710411se.html

Edited September 17, 2016 by stovepipe

[south]

Hi everyone. Could anyone tell me if a 71 in br blue ever made it onto the southwestern. Really want to buy the Hornby model and need an excuse

[slilley]

Hi everyone. Could anyone tell me if a 71 in br blue ever made it onto the southwestern. Really want to buy the Hornby model and need an excuse

They would have done going to Eastleigh for overhaul.

 

Also, I know E5010 worked a Guildford to Margate charter on 12 June 1968, but not sure if the loco was in blue yet or in green with one of the many variations of small yellow panel. Still doing some digging into that working.

 

The only other working I know of was when E5006 worked a test train of 2 4VEP units from Waterloo to Eastleigh  on 15 June 1969. This was the later E5006 previously E5022. The original E5006 was converted to become 74003.

 

Best wishes

 

Simon

[slilley]

I've got a photo of the Man of Kent tour at Sittingbourne, 71 with a TC unit, listed as 427 below.

 

http://www.sixbellsjunction.co.uk/70s/710411se.html

Thanks for that

 

typo on my part

Edited September 18, 2016 by slilley

[stovepipe]

They would have done going to Eastleigh for overhaul.

 

Also, I know E5010 worked a Guildford to Margate charter on 12 June 1968, but not sure if the loco was in blue yet or in green with one of the many variations of small yellow panel. Still doing some digging into that working.

 

The only other working I know of was when E5006 worked a test train of 2 4VEP units from Waterloo to Eastleigh  on 15 June 1969. This was the later E5006 previously E5022. The original E5006 was converted to become 74003.

 

Best wishes

 

Simon

 

From the info I have E5010 would have been in green with full yellow ends in June 1968, and E5006 (i.e.E5022) was in blue with full yellows by November 1968.

 

It's a shame neither manufacturer are issuing pre-TOPS blue versions - they spent 6 to 7 years in this configuration after all.

 

[south]

Thanks guys. Any more info please put on here. Think i might have to invest anyway. My old area was Woking twin bridges in the 70s and early 80s. Many happy long days spent there