Conversion kit for Airfix 4F to Maunsell Q

[Steamport Southport]

Hi again and thanks for all the comments.

 

To date I have managed to get hold of photocopies of the Roche series of loco drawings for both the 4F and Q and their tenders. There are obviously some differences between locos and tenders but not enough to put me off having a go at a basic conversion. David has summarised these differences in his post above but I will still have a try.

I intend to model the result as 30541, not because it is preserved but because it seems to be the only one of the class which is recorded as running on the S&D, I think on a goods train to Blandford Forum. There may have been others but no-one bothered about them, possibly thinking that they were 4Fs.

 

Unfortunately nothing will be happening soon as we are going on holiday tomorrow so work will be put on hold until we get back but I will try to keep anyone who is still interested informed of progress.

 

Thanks again

 

Jim

 

The problem is they are Roche drawings.

 

Roche and accuracy are not always compatible. Some of his drawings have very obvious errors.

 

 

It might be worth looking at a few of these links for the general opinion.

 

https://www.google.co.uk/search?biw=1366&bih=651&ei=zRe-W4X-KIvYaYHTk_gM&q=rmweb+roche+drawing+accuracy&oq=rmweb+roche+drawing+accuracy&gs_l=psy-ab.12...8269.9955.0.11960.6.6.0.0.0.0.93.495.6.6.0....0...1c.1.64.psy-ab..0.0.0....0.7o1DHzEGbs8

 

 

 

Jason

[devonseasider]

If you use the Airfix as a starting point you are still stuck with the Airfix Tender drive

 

 

Not necessarily.  Very easy to replace with etched 4F chassis - Kemilway/Comet/whatever - with decent motor/gearbox as in #21 above.

 

 

 

 The only drawing I have access to at present is very wrong about the shape of the frames at the front 

 

The front frames on 530 were a very different shape to the rest of the class.  Perhaps that's what your drawing shows.

Frame shape from buffer beam to valve chest/smokebox front on 530 was a convex curve, that on the rest of the class (I think all of the rest  .  .  .) was concave.

 

 

 

 Running plate.  The Q has almost no "lip" at the top, very straight sided 

 

 I may have misunderstood what you're saying here, but the running plate is anything but straight sided.  There's a very noticeable narrowing of the running plate forwards from approx. the front edge of the middle splasher.  This is visible in the photos in both #7 & #21 above.

I do agree, though, that there could well be too much front overhang on my attempt in #21.  A bit of careful filing needed, I think.

[Jim49]

Hi Jason and thanks for your comments about the accuracy (or not) of Roche drawings. I have read previously that they should be treated with caution by anyone wanting 100% accuracy but that's not what I am after. 

All I am looking for is something to compare the 2 engines and highlight the major differences. Near enough will be good enough for me.

 

Thanks again,

 

Jim

[hayfield]

Jim

 

I think you have hit the nail on the head for most of us, in that we are not looking for a dead scale replica, however something that looks extremely close to the original. Where we might disagree is what the definition of extremely close is, or what compromises we are happy to live with.

 

There also comes a point in how much we are prepared to pay to convert a loco against how much a new kit is. For me the former should be something where we use parts from the spares box, or able to scratch build. I am a bit lucky in that I am building up quite a stock of spares all on the cheap. You have made a commendable list of parts required, but what  will it cost ?

 

The PDK kit is at £93.50 and no doubt will be far more detailed than an old RTR conversion. On the other hand the company may consider supplying a set of castings at a reasonable, if so may well be far more cost effective than buying the items individually. But this route takes away all the fun of doing the conversion 

[Steve Smith]

On 11/10/2018 at 12:03, devonseasider said:

 

I may have misunderstood what you're saying here, but the running plate is anything but straight sided.  There's a very noticeable narrowing of the running plate forwards from approx. the front edge of the middle splasher.  This is visible in the photos in both #7 & #21 above.

I do agree, though, that there could well be too much front overhang on my attempt in #21.  A bit of careful filing needed, I think.

 

Hello Graham,

Hope it's OK to resurrect this thread, but I was so impressed with your Crownline conversion of the 4F that I have opted to take a similar route for my own Q Class.  My Crownline conversion kit is in the post, but I know that it has a running plate that does not have that distinctive narrowing, which seems to be the most obvious error in the Roche drawing which has the same width dimension of 8'4" shown for the buffer beam and what I'll call the drawbar beam.  As a matter of interest did your kit come like that, and am I right in thinking that the buffer beam will be too wide rather than the rear end too narrow?  I have the GW Models riveter so can fairly easily knock up a narrower buffer beam.   I'll be using the SE Finecast chassis kit and a Perseverance tender chassis.

Thanks,

Steve

[cypherman]

Hi all,

Would you also be able to do this with Triang Deeley 4F. I have several knocking about in boxes.

[MR Chuffer]

14 minutes ago, cypherman said:

Deeley 4F

Don't think Deeley did a 4F, you mean 3F? Quite a few differences with the Fowler 4F.

[hayfield]

Why not but one of the Wills/Wills Finecast whitemetal locos which sell quite cheaply, these are designed for and may well have the Triang/Hornby Jinty chassis, especially if you buy a ready built version.

 

For those wanting to go the extra mile then there are two versions of Wills etch replacement chassis along with the current Southeastern Finecast etched chassis, all of which can be built to remove the motor from the can so it can be built fully detailed

[Steve Smith]

Fair point - I have good experiences of SE Finecast and Crownline kits.  This loco will be to EM Gauge and fully compensated, so I'll need plenty of clearance under the splashers which can be a problem in EM (fat wheels+big flanges).  For the SEF kit I'd follow the methods of Iain Rice so would want to thin visible whitemetal edges and add detail along the lines of DLT's splendid Q.  If I'm honest though this seemed like an economical way to obtain a Crownline/PDK Q Class body with what I felt would be the benefit of the SE Finecast chassis.  Having received the kit I'm surprised that the instructions tell me to glue the many etched brass bits together for the loco body, but to solder the tender body together if I'm up to it.   The only parts of the 4F loco body retained are the running plate (thinned), smokebox, boiler and backhead, with the smokebox receiving an etched overlay with rivet detail.  The kit gets a demerit for the straight sided running plate, but I had to fabricate a complete new running plate and cab for my Rebuilt River U Class, so I'm sure I can fix that if I try.   There's no hopper in the tender, but I've already made those for the U and a Bachmann N Class.  The steam reverser is provided, but not the valves/controls above it.  I could blog the build if there's any interest out there... 

Steve

[Steve Smith]

Some preliminary analysis of the etches and castings in the conversion kit compared with the dimensioned weight diagram in Russell (from Eastleigh dwg. SR80) suggests that the overall length of the Crownline running plate, and lengths of cab and smokebox are all correct, but the length of the running plate in front of the smokebox is perhaps 1mm too long and the cab 1mm too far forward.  This can only be because the Crownline firebox and Airfix 4F Boiler combo are about 2mm too short overall.  Since the relationship of cab to rear driven wheels seems to be correct I could reasonably trim 1mm from the rear of the running plate.  It may also be an option to move the smokebox 1mm further forward and add the missing 1mm at the back of the Crownline firebox which appears a fraction short compared with the 7' (28mm) specified.  These minor changes would leave the running plate slightly too short, but everything else more or less in proportion which is what really matters. In this case the rear of the cab appears to be 3mm from the end when it should be 2mm.  Proportionately that's a whopping error compared with say 1mm on the length of the 40mm boiler or a 1mm almost anywhere in the 35mm front overhang. 

 

Errors in the Roche Drawing so far (IMHO):

• No characteristic narrowing of the running plate.
• Buffers are drawn too short resulting in the running plate being too long - all of this extra length being in front of the smokebox. 
• Shape of cab roof in plan and front/rear elevation is wrong and cab front windows wrong shape.
• Controls for the steam reverser wrongly drawn.
• Chimney looks to be a tad too far forward.
• The two prominent sloping rows of fastenings for the cylinder/piston casting are in the wrong place and there are too many of them.

Happily the Crownline conversion kit has only one of these errors in not having the running plate narrowing.  Bottom line is that dimensionally there doesn't seem to be much wrong with the kit even built as intended.   A start has been made on assembling the now partially narrowed running plate.

[Guest Jack Benson]

 

This was the actual basis for DLT’s build of the Q some ten years or so ago. I used a SEF chassis and Bachmann tender but not sure if I would choose the same underpinnings again after the Comet 4F chassis was used on the recent 0395. 
 

Moreover, thanks to Hornby’s decision to upgrade both the 4F and 2P with loco drive there is  a viable option for motorising either the SEF or GAP Q class kits and no doubt, GAP’s exSECR 4-4-0 kits.
 

StaySafe
 

 

[kevinlms]

Another source of Q Class drawings is Railway Modeller 1991 June, with corrections in the October issue.

[Steve Smith]

The Bachy Maunsell N Class tender is an excellent model and was well ahead of its time, but from my point of view has a weakness in not having room between the frames for EM Gauge wheelsets without a lot of messy and time consuming rework.  On my conversion I also chose to cut the plastic coal load out and model the coal space, although that was a piece of cake in comparison with the frame widening!

 

Thanks to Kevin, for the tip on what I hope will be an Ian Beattie drawing that will be really useful once I've tracked it down in the club library. 

In the meantime my Q has a narrowed running plate ready to receive the Airfix 4F parts to be cut from the loco body which I'm hoping is at least in the post by now.  The supplied etched splasher tops were too narrow*, so I substituted them with some cut from thin N/S sheet.   The drawbar beam needs to be removed to fit the Airfix boiler and at that point I'll trim the running plate at the rear, not least because the valances are taking a more circuitous route than envisaged by Mr Hill, and are now slightly too short.  The valance is fitted almost flush to the running plate and not in the groove provided which would be too far back.  A relief to see that the 'underneath' written on the etch is indeed underneath!

 

In the absence of the SEF chassis kit - currently out of stock at Squires - it's time to tackle that tender.

Edited June 22, 2021 by Steve Smith
* Examination of the bag of castings subsequently revealed what can only be a set of cast whitemetal splasher tops, I'll never know if they would have fitted...

[Robin Verth]

I have just notice there is a newly listed Crownline kit to convert the LMS 4F to a Southern Q on eBay  with a buy it now price of £54.99.

I only recall ever seeing one Q class, it was being towed by a diesel at Clapham Junction and was on the Windsor Line side, i think it ended up in the carriage sidings as a stationary boiler providing steam to heat to the carriages stabled there.

[hayfield]

2 hours ago, Robin Verth said:

I have just notice there is a newly listed Crownline kit to convert the LMS 4F to a Southern Q on eBay  with a buy it now price of £54.99.

I only recall ever seeing one Q class, it was being towed by a diesel at Clapham Junction and was on the Windsor Line side, i think it ended up in the carriage sidings as a stationary boiler providing steam to heat to the carriages stabled there.

 

At £54 it makes the SEF/Wills option very attractive

[Steve Smith]

This is not intended to be a blow by blow account of the build, just some notes about what can be expected from this conversion. 

Work on the tender commenced by assembling the frames, buffer and draw beams to the tender base.   The buffer beams for loco and tender are half etched with the rivet detail so were laminated up for robustness.  The valances were then attached (soldering from the outside which is not ideal), again I opted (or at least tried) to mount them slightly outboard of the etched slot provided. 

 

My stock of full size High Level Kits (HLK) hornblocks did not stretch to the tender so instead of using my Persy chassis (with etched full size cutouts) I opted instead for the Comet 6'6" + 6'6" tender chassis - speedily supplied by Wizard Models together with the most suitable (or least unsuitable) AGW wheels (being 3'11" 10 spoke).  It was tricky to accurately enlarge the 2mm slots  to suit the HLK Miniblox that I did have in stock, and there certainly wasn't much material left when I'd finished.  The MiniBlox were then carefully soldered in before assembling the two frames together with the supplied slotted frame spacers.   The twin equalising beams and trim screw arrangement are of my own design.

 

The coal hole was tackled next.  The Crownline conversion kit is clearly intended to take the Airfix tender drive, so there is just a very large hole where the coal should go.  I used the drawing in Russell to knock up something to fill the hole.  Although I'd photographed 31806 on the Mid-Hants when it ran with this type of tender I hadn't captured the coal space, so if I'm wrong now is an excellent time for me to find out...

 

The Comet brake shoes were a bit flat looking, so I fretted out some separate shoes in N/S and soldered them on.

 

I had to fabricate some quite substantial mounts to join body to chassis - these are not yet attached to the body.  The wheels are some rough old Romfords on pinpoint axles while I fine tune things, but I'm relieved to report that the tips of the pinpoints are centred on the holes in the frames, and the bearings centred in the hornblocks.  Pleasingly, the tender thus equipped runs very smoothly (both ways) through the crossover points on my test track - just like a bogie coach would.

 

Cloud on the horizon?   What is beginning to look a lot like the non-availability of the SEF Q Class chassis - I suspect that no news is bad news in this case!

Edited April 3, 2022 by Steve Smith
Restore as many photos as possible...

[Blandford1969]

On 31/05/2021 at 06:26, Robin Verth said:

I have just notice there is a newly listed Crownline kit to convert the LMS 4F to a Southern Q on eBay  with a buy it now price of £54.99.

I only recall ever seeing one Q class, it was being towed by a diesel at Clapham Junction and was on the Windsor Line side, i think it ended up in the carriage sidings as a stationary boiler providing steam to heat to the carriages stabled there.

They normally sell though at about £25 to £30 so the seller is being ambitious.

[Steve Smith]

It turns out that the one on Ebay that I missed out on (0 bids at £44.99), was relisted (buy it now at £49.99), and that's the one I bought.  Looking at sold listings it's a tiny market with extremely limited supply - and demand!  This fairly comprehensive kit is giving me a great deal of amusement - so reasonable value.   I do regret buying an Airfix 4F body when it turns out there was an unwanted example in the club that would have been free to a 'good' home!

 

[Steve Smith]

On 23/05/2021 at 12:57, kevinlms said:

Another source of Q Class drawings is Railway Modeller 1991 June, with corrections in the October issue.

The June 1991 issue was a very rare Toddler that I had bought and then not discarded.  Not a bad effort by Mr Beattie, but surprisingly it doesn't show the narrowed running plate and as with the Crownline kit the shape of the cab cutout is wrong in that the lower radius should be larger than the upper one.  Roche did pick up on that detail though his cutout is perhaps a tad small in relation to the window.  The half etched cab sides will be laminated up, and I'll try to improve the shape of the cutout then.  Maunsell cabs have a very distinctive look, and it is the cabs of the DJH D1 and E1 kits that look so very wrong to me.   The Beattie drawing seems to suffer from the short buffer/long overhang syndrome too.  Now I need to wait for the October issue to arrive for all the corrections!

[kevinlms]

13 hours ago, Steve Smith said:

The June 1991 issue was a very rare Toddler that I had bought and then not discarded.  Not a bad effort by Mr Beattie, but surprisingly it doesn't show the narrowed running plate and as with the Crownline kit the shape of the cab cutout is wrong in that the lower radius should be larger than the upper one.  Roche did pick up on that detail though his cutout is perhaps a tad small in relation to the window.  The half etched cab sides will be laminated up, and I'll try to improve the shape of the cutout then.  Maunsell cabs have a very distinctive look, and it is the cabs of the DJH D1 and E1 kits that look so very wrong to me.   The Beattie drawing seems to suffer from the short buffer/long overhang syndrome too.  Now I need to wait for the October issue to arrive for all the corrections!

I wouldn't like to comment on the Beattie drawings or corrections. Just that I know that revised information is available. 

Whether it's useful, that's for Southern experts to decide. 

[JohnR]

This thread has made me realise what a loss the Crownline detailing/conversion kits are. 

[Steve Smith]

8 hours ago, kevinlms said:

I wouldn't like to comment on the Beattie drawings or corrections. Just that I know that revised information is available. 

Whether it's useful, that's for Southern experts to decide. 

It's a very useful source thanks; if you could combine the correct proportions of the Eastleigh outline drawing in Russell with the level of detail in the Beattie drawing you would be very close to the truth! 

[Butler Henderson]

On 23/05/2021 at 10:33, Jack Benson said:

Moreover, thanks to Hornby’s decision to upgrade both the 4F and 2P with loco drive there is  a viable option for motorising either the SEF or GAP Q class kits 

Not as straightforward as it might seem, the height of the gear tower is too much for the GAP Q and has to be partially rebuilt.

[Steve Smith]

The October 1991 RM duly appeared with the much anticipated corrections relating only to the narrowing of the footplate being omitted.  The drawing is appropriately corrected, but is reproduced to a smaller scale.

 

Steady progress is being made on the tender with steps and tank now fabricated.  Fit is pretty good, but the slots are etched a tad wide and this feature of the etch is probably not unconnected with the etched splasher tops falling through the gap that they should have bridged.   Have been gently reminded that when soldering big bits of brass you need a big soldering iron and should start at one end work along the join to avoid buckling.  I'll solder the bulkheads in once I've added an internal bead, but will epoxy the sides and rear on once they have been detailed up. 

Edited April 3, 2022 by Steve Smith

[Steve Smith]

 

The tender bulkheads sides and rear have all had a bead added to the inside and even though only 0.3mm brass wire was used it has both stiffened them and improved the appearance.  The rear (not shown) needs lamp irons fitted for which no provision is made in the kit.  More evidence visible that the holes/slots are etched slightly too large/wide.

As mentioned earlier I didn't rate the shape of the cutout on the cab sides, so decided to tackle that next.  First I drew up a reinforcing piece with curves based on photos, the radius being 1.5mm at the top and 3mm at the bottom.  Provision was also made for the window to be flush glazed and a rebate left at the front to take the cab front.  This was printed out and UHU'd to some .015" N/S and fretted out.

Once sweated to the brass etch the whole was carefully filed to fit the revised opening and any remaining etched bead filed down.  Nickel silver strip pre-drilled for the handrail was then soldered in.

 

In other developments I phoned SEF/Squires about my missing chassis kit and this time the boss picked the phone up.  It turns out that the FC-106 Q Class specific chassis has been replaced with a generic FC-202 chassis suitable for Q Class and Collett 22xx.   That chassis kit was in stock and arrived the next day.   It will need some changes to suit the Q, particularly the coupling rods which are of a slightly exaggerated fish belly type and only nominally correct even for the 22xx - they'll need to be straight for the Q, and that's a lot of filing.  Also not entirely sure how I feel about ending up with what looks a lot like a GWR 22xx loco chassis under my LMS 4F conversion to a SR Q Class.  😕

 

 

Edited April 3, 2022 by Steve Smith
Restore as many photos as possible...