Converting a Hornby K1 to P4

User avatar
barrowroad
Posts: 251
Joined: Sun Jul 20, 2008 5:28 pm

Converting a Hornby K1 to P4

Postby barrowroad » Tue Nov 23, 2021 11:11 am

I have photographs of two K1's on Barrow Road Shed in the early 1960's, 62057 and 62060 both allocated to York 50A at the time. They add a bit of variety so I obtained a secondhand one on Ebay 62015.
IMG_20211030_153142294.jpg

Having made the purchase I discussed all things K1 with my friend Morgan only to discover that I would need to modify the plate on the top of the boiler in order to model one of the two above engines. At this point I noticed a body of 62024, again on Ebay, and made another purchase subsequently selling the body of 62015.Moral check before you make a purchase.

So what is required for a conversion to P4. Alan Gibson does a conversion pack for this model listed on page 27 of his catalogue.
4800/19 Hornby LNER K1 3 Axles 5' 2" 16 spoke - 3mm Axles Price AU 1 x 4838, 3 x 4844B, 4M42B & 4800
You will also need washers for spacing the wheels from the Hornby chassis. I have used the following from the Alan Gibson range.
4M67/2 30 x brass shim washers with 2mm bore Price O
4M67/3 30 x brass shim washers with 1/8“ bore Price O
Each pack of brass shim washers contains 10 of each width; 1mm;0.5mm and 0.25mm. Each driver will need 2 x 1mm of the 1/8in each side ie 4 or 12 for the three axles. The front bogie and the tender axles will need the 2mm version, a total of 16 1mm washers.
I will leave you to decide if you want to use all 1mm width washers or make up using the narrower ones. If the former you will obviously need more than one pack of each.

You do not need the crankpins 4800 as I will be reusing the Hornby set.

You will also need one 1/8in axle but more of this later.

First task is to separate the tender from the loco by inverting the whole model and carefully disconnecting the plug from the socket in the tender.
The unscrew the loco/tender connection and place the tender to one side.
Next remove the screw at the front of the body which is under the front bogie. You can now carefully remove the body taking particular care at all times with the plastic lampholders on the front of the frontplate as they are very fragile - don't ask.

You should now have this. Note I have temporarily refixed the front screw.
I recommend having small containers to safely store any screws washers etc during the conversion, marking what they are for the rebuild.

IMG_20211116_122805513 - Copy.jpg


IMG_20211116_122830866 - Copy.jpg

Note I have removed the front bogie.

Next we now need to remove the driving wheels and their axles. This requires removal of the valve gear and the coupling rods.
IMG_20211116_124107284 - Copy.jpg

The Hornby screws are removed using a useful tool obtained from Markits which comes with a set of sockets. For this job I have used a number 12 socket. The screws can be removed using pliers if you are very careful. I have used tape to hold the valve gear and connecting rod out of the way.

However the bottom link to piston rod fractured on mine so I decided to remove the cylinders and valve gear from the chassis and store them safely for reassembly.

Undo the 4 Philips screws and lift off the keeper plate to reveal the three driving wheel axles. Hornby have re-designed and improved their keeper plate electrical connection as shown on the left of the photo. I say improved because the old arrangement had two wires soldered to the keeper plate. The new design enables the keeper plate to be lifted off and placed aside without unsoldering the wires.

IMG_20211116_124230764.jpg


Note the inboard brass bearings on the axles especially the orientation of the centre axle. The bearing on the short side of the gear wheel is narrower. I made a quick drawing for reference during reassembly.

Next instalment will deal with the new wheels.

DougN
Posts: 1117
Joined: Wed Sep 01, 2010 9:57 am

Re: Converting a Hornby K1 to P4

Postby DougN » Tue Nov 23, 2021 11:27 am

My K1 is one of my favourite locos. It has done a large number of circuits of the OO layout. I am very interested how this is all going to work out as I suspect it is very similar to converting the B1 which is also one of my favourites. From your videos and Morgans it suggests RTR conversations are quite appropriate for P4...
Doug
Still not doing enough modelling

David Knight
Posts: 713
Joined: Sun Jul 20, 2008 6:02 pm

Re: Converting a Hornby K1 to P4

Postby David Knight » Tue Nov 23, 2021 3:08 pm

I’m not sure of the age of the K1 but have noticed that recent models by Hornby have a bad reputation for fragile pickups. I found out the hard way when doing a B2 Peckett. Something made me offer the pickup strip to a magnet and it stuck so I suspect tinplate is involved.

HTH

David

User avatar
zebedeesknees
Posts: 156
Joined: Mon Jul 12, 2010 5:15 pm

Re: Converting a Hornby K1 to P4

Postby zebedeesknees » Tue Nov 23, 2021 5:10 pm

David Knight wrote:I’m not sure of the age of the K1 but have noticed that recent models by Hornby have a bad reputation for fragile pickups. I found out the hard way when doing a B2 Peckett. Something made me offer the pickup strip to a magnet and it stuck so I suspect tinplate is involved.

HTH

David

It could be David, but tin is quite pricey these days. My guess is that they are steel strip with a thin coat of nickel, replacing the copper alloy(s) that were used. This strip is used in Li-Po battery manufacture particularly for connecting cells, and is what I used in m pic to connect the vaping cells recently. https://www.ebay.co.uk/itm/313084792300

It is cheap and solders well, and comes in thicknesses from 0.1mm, or 0.004". Being ferrous, magnets stick to it, allowing for quick connections for things like charging batteries in locomotives... but more of that later...

Ted.

User avatar
barrowroad
Posts: 251
Joined: Sun Jul 20, 2008 5:28 pm

Re: Converting a Hornby K1 to P4

Postby barrowroad » Tue Nov 23, 2021 6:28 pm

David the pickups on the K1 are fine, easy to bend outwards to reach the wider gauge of P4.

Robin

User avatar
barrowroad
Posts: 251
Joined: Sun Jul 20, 2008 5:28 pm

Re: Converting a Hornby K1 to P4

Postby barrowroad » Wed Nov 24, 2021 12:00 pm

Having removed the keeper plate now lift out the three sets of wheels and axles.
IMG_20211115_115002685.jpg

The Hornby wheels have plastic centres. The front and rear sets have threaded metal inserts in the centre boss to take the crankpin screws which have been removed already. The centre set of drivers have a similar, but longer insert for the connecting rod with the outer end shaped to take the return crank.
The object of this conversion is to remove and reuse these inserts so that all the original Hornby fittings - connecting rods and valve gear - can be used.
I selected the centre drivers and removed one of the wheels by placing the set in a vice with the wheel lying horizontal across the jaws and tapped out the axle using a punch and hammer.
IMG_20211115_115107097.jpg

This is the front after removal of the insert
IMG_20211115_115116261.jpg

and this is the rear. Note the recess for the insert.
IMG_20211115_115128528.jpg


The Alan Gibson wheels now need drilling to accept the Hornby crankpin inserts. This must be carried out very carefully to ensure the size of the hole is the correct diameter to push fit the splined inserts which are 2.2mm in diameter. I used a series of drill bits and a taper to achieve this. I used the drills in a pin chuck and ensured the drill was vertical at all times.
IMG_20211115_122126835.jpg

This is a photo of one of the Gibson wheels that I have drilled to accept the Hornby insert from the centre wheelset. The insert is also shown.
IMG_20211115_115201252.jpg


Insert fitted front view. It is essential that you note the orientation of the centre crankpin inserts to ensure the return crank is in the correct position when refitting takes place.
IMG_20211115_115432027.jpg

Rear view. Note:- you will need to cut a small amount of plastic from the rear boss to allow the insert to sit flat.
IMG_20211115_115451279.jpg

I then placed the wheel on the vice jaws and filed the rear of the insert so that it was level with the rear boss.
IMG_20211115_120130556.jpg


Returning to the centre axle. Remove the second wheel and you are left with the gear wheel and axle. Remove the bushes and store for reuse.
I then measure and note the position of the gear on the axle to ensure it is positioned correctly when refitting to the longer P4 axle.
IMG_20211115_121042968.jpg

Tap out the axle from the gear.

At this point I offered up the gear to the 3mm Gibson axle and found it to be too loose a fit. I have not had this problem with any of the Bachmann or other Hornby steam locos I have converted.

My solution was to use an 1/8in P4 axle I had spare. I opened out the gear slightly with a reamer so that the axle was a very tight fit on the gear wheel adjusting the position on the axle to sit correctly in the Hornby chassis - see measurement note earlier.

The 3mm bushes and the centre drivers then needed the same treatment in order to accept the 1/8in axle.

Assembly of the three axles is the next task and each axle needs fitting with 2 x 1mm spacer washers each side together with a Hornby spacer bush.
The three new sets of P4 wheels assembled and ready for fitting into the Hornby chassis.
IMG_20211116_122715503.jpg


Fit the new set of P4 wheels into the Hornby chassis and reassemble the keeper plate , connecting rods and valve gear.

I found that there were clearance issues on the front axle - a common problem when converting OO models to P4 - and resolved this by thinning down the leading crankpin screws and also thinning the metal on the rear of the piston rod - the large casting that fits over the slide bar.

The added benefit of reusing the Hornby components is it is easy to remove and refit components if you get things wrong.

62057 on shed.
IMG_20211123_144636925.jpg


Feel free to ask questions.

User avatar
johndarch
Posts: 112
Joined: Tue Jan 29, 2019 11:24 am

Re: Converting a Hornby K1 to P4

Postby johndarch » Wed Nov 24, 2021 12:43 pm

Very nice work Robin and well illustrated.

User avatar
barrowroad
Posts: 251
Joined: Sun Jul 20, 2008 5:28 pm

Re: Converting a Hornby K1 to P4

Postby barrowroad » Wed Nov 24, 2021 1:52 pm

Thank you John.

Philip Hall
Posts: 1678
Joined: Mon Aug 10, 2009 7:49 pm

Re: Converting a Hornby K1 to P4

Postby Philip Hall » Wed Nov 24, 2021 5:53 pm

Very nice job, Robin. An interesting method reusing all the Hornby crankpins. I have a few more Hornby engines to convert and I will give your ideas a go.

Philip

DougN
Posts: 1117
Joined: Wed Sep 01, 2010 9:57 am

Re: Converting a Hornby K1 to P4

Postby DougN » Thu Nov 25, 2021 4:02 am

Thanks, very concise explanation as to how and what you need. I am slightly amazed that all that was really needed was the wheels and time. :thumb
Doug
Still not doing enough modelling

User avatar
barrowroad
Posts: 251
Joined: Sun Jul 20, 2008 5:28 pm

Re: Converting a Hornby K1 to P4

Postby barrowroad » Thu Nov 25, 2021 4:59 pm

Doug, The Bachmann steam locos I have converted follow the same principle. The difference is Bachmann use all metal wheels and therefore you cannot reuse the crankpin inserts. My method is to use Markits 10BA crankpins by drilling and tapping the Gibson wheels. I use Gibson insert washers on the coupling rods - solder them in place - and modified crankpin/cranks on the centre axle. The most difficult part of this exercise is this modification to take the original crank. I won't repeat the method here but refer you to an earlier post on my blog about the conversion of a Bachmann Jubilee.

Robin

triumph3
Posts: 52
Joined: Mon Jul 18, 2011 12:52 pm

Re: Converting a Hornby K1 to P4

Postby triumph3 » Thu Nov 25, 2021 6:24 pm

Robin, looking really good.
How did the 2 observed K1s arrive at Barrow Rd in real life?
I know that there were sightings in S Wales with trains on steel traffic from the North East.

Your conversions show just how good modern RTR locos are with bearings on the axles and sometimes separate axle boxes and well cast chassis blocks. If wanting lots of locomotives for a large layout then RTR conversions are the way to go, followed by re numbering.

David

User avatar
barrowroad
Posts: 251
Joined: Sun Jul 20, 2008 5:28 pm

Re: Converting a Hornby K1 to P4

Postby barrowroad » Thu Nov 25, 2021 8:18 pm

Thank you David. Bachmann and Hornby models have so good over the past 15+ years.
I have two photos, one Colourail, of a K1 on shed but I've no idea of the workings. As they were both York shedded I can only assume they worked in from there unless anyone has any other information.

Robin

Albert Hall
Posts: 263
Joined: Mon Nov 23, 2009 9:22 pm

Re: Converting a Hornby K1 to P4

Postby Albert Hall » Thu Nov 25, 2021 8:53 pm

All my spotting records are long gone but 62057 was the sort of cop in the Bristol area not easily forgotten. She drifted down through Lawrence Hill on the GWR route at the head of a mixed freight one evening but no idea where from. Earliest I started spotting in that location would be 1963. It was still light in the evening so must have been during British Summer Time.

Roy

User avatar
barrowroad
Posts: 251
Joined: Sun Jul 20, 2008 5:28 pm

Re: Converting a Hornby K1 to P4

Postby barrowroad » Fri Nov 26, 2021 5:32 pm

Interesting information Roy so thanks.
The photo of it on shed, in a relatively clean condition, is available on the Colourail website. It is alongside the ash plant with a 4F 44269.

Robin


Return to “barrowroad”

Who is online

Users browsing this forum: No registered users and 2 guests