P4 Q Class from PDK kit (go to p. 6)

[hayfield]

The Southeastern Finecast Q loco is one of the un-revised kits. The quality of the casting is very good, though the amount of detail is not quite up to the quality of the revised kits. The body is designed to fit on to the Triang/Hornby 3F(or is it 4F) chassis namely the tender version of the Jinty

 

Having said that other than the fitting to the body and wheel centres that's where the comparison ends

 

 

The 3 etches and bag of bits

 

 

A close up view of 2 etches, as can be seen you can cut out the chassis for hornblocks.

 

The loco body has a cut out for the Hornby motor, so you will have to find/fabricate the cab details, also work out the best motor/gearbox combination. You may also decide to add a few extra details

 

I don't think the tender comes with an etched chassis, might be worth having a chat with the owner Dave Ellis who is so helpful. Having said all this would make an ideal starter kit 

[Deano747]

Quote: Several manufacturers seem to have M7s or M7 parts, but I'm afraid I'll have to decline. They seem to have mostly been swept away to the branches by my era.

 

 

No problem! I might even finish it one day but I've fallen for 7mm!!

Good luck!

 

Regards, Deano

[mightbe]

Thanks Hayfield. 

 

I guess that shows that the chassis won't be immediately suitable for the PDK body. 

 

Does anyone know if the PDK chassis is designed for compensation?

 

Moreover (here's the heretic's question) can an EM chassis be used for P4 with very short spacers to make up the difference (ignoring the question of vertical compensation)? 

 

Admittedly I added up the total cost for the project and am looking to save a bit of money somewhere.

[Siberian Snooper]

Here is a quick piccy of a PDK 42XX chassis, not the best I admit but it does show what you get.

 

 

It is my intention to build it with split frames to EM gauge. the frames fold down with the spacers shown on the bottom right of the other fret used to make the frames rigid. there is provision for compensation, I intend to use the CSB method of springing. All this when I get round tuit.

 

I should also point out that the box is big enough to more than hold the loco when complete and with the packing inside it more than adequate to protect the rolled boiler from damage during transit. with the proviso no one jumps up and down on it or sticks under an elephant etc.

 

edit to add details of packaging.

[Horsetan]

....Does anyone know if the PDK chassis is designed for compensation?

Not all of them are. The Bulleid Pacific kits, and some of the GW ones, also the S15, do have a compensation system in them:

 

 

As you can see, the PDK S15 chassis is a bit no-frills. Spacers for OO only, no pretence at EM or P4. Very basic valve gear. Very basic bogie frame. Quite a bit of work to make it P4-able.

 

Contrast with the SEF "Schools" chassis, which has loads of detail, three sets of spacers (widest set is for P4), very refined valve gear:

 

 

 

Moreover (here's the heretic's question) can an EM chassis be used for P4 with very short spacers to make up the difference (ignoring the question of vertical compensation)? 

Well, you can replace the EM spacers with your homemade P4 ones. Or you could split the EM ones down the centre, then have them held together at P4 width with the help of patches soldered on, but you'd need to be confident of attaining the right width every time.

 

Admittedly I added up the total cost for the project and am looking to save a bit of money somewhere.

This is not a cheap hobby, but you can save money by scratchbuilding most of the structure. That just leaves you the cost of detail castings (if they're available), wheels, motor and gears.... Oh, and the tools if you don't have any.

[mightbe]

Here is a quick piccy of a PDK 42XX chassis, not the best I admit but it does show what you get.

 

42xx chassis.jpg

 

It is my intention to build it with split frames to EM gauge. the frames fold down with the spacers shown on the bottom right of the other fret used to make the frames rigid. there is provision for compensation, I intend to use the CSB method of springing. All this when I get round tuit.

 

I should also point out that the box is big enough to more than hold the loco when complete and with the packing inside it more than adequate to protect the rolled boiler from damage during transit. with the proviso no one jumps up and down on it or sticks under an elephant etc.

 

edit to add details of packaging.

Thank you for that. Good to know these kits are well packed.

 

But maybe I'm a bit thick, but how can those frames work with compensation? I don't see how a wheel could move up and down.  And by "provision" I guess that means that the kit doesn't come with the compensation parts themselves, right?

 

 

Not all of them are. The Bulleid Pacific kits, and some of the GW ones, also the S15, do have a compensation system in them:

image.jpg

As you can see, the PDK S15 chassis is a bit no-frills. Spacers for OO only, no pretence at EM or P4. Very basic valve gear. Very basic bogie frame. Quite a bit of work to make it P4-able.

Contrast with the SEF "Schools" chassis, which has loads of detail, three sets of spacers (widest set is for P4), very refined valve gear.

 

Well, you can replace the EM spacers with your homemade P4 ones. Or you could split the EM ones down the centre, then have them held together at P4 width with the help of patches soldered on, but you'd need to be confident of attaining the right width every time.

I'll send the guys at PDK an email asking about the chassis then. If push comes to shove, I think Alan Gibson does one-off frames for the Q class that probably are hornblock-ready (and I can of course buy the hornblocks, bearings, and wheels at the same time).

 

Out of curiosity, how wide would a typical P4 spacer be? That shouldn't be too hard to make out of brass sheet (20 thou?).

[Horsetan]

Thank you for that. Good to know these kits are well packed.

But maybe I'm a bit thick, but how can those frames work with compensation? I don't see how a wheel could move up and down.  And by "provision" I guess that means that the kit doesn't come with the compensation parts themselves, right?

There are compensation parts in the form of dog-bone cradles - you solder bearings into them to carry the axles. Then you remove the rigid axle holes from the chassis frames before putting the dog bones in with their pivots.

 

....how wide would a typical P4 spacer be?....

15 to 15.5mm is a reasonable place to start. Overall chassis width including frame thickness is usually 16 to 16.2mm

[Paul Cram]

Comet sell sepaerate P4 spacers for use with their frames but due to the design are usabale by other makers frames.

[Guest Lyonesse]

>Out of curiosity, how wide would a typical P4 spacer be? That shouldn't be too hard to make out of brass sheet (20 thou?).

 

I seem to have settled on 0.620 inches, i.e. 15.75mm.  With .018in frames that gives an overall width of 0.656 or 16.66mm.

[hayfield]

How about a Craftsman Lord Nelson Class  http://www.craftsmanmodels.co.uk/cat.pdf

 

Like most manufactures comes in a very sturdy box, if its like the 1F chassis designed for 00 and rigid, but EM/P4 frame spacers can be used and horn blocks fitted

[Kenton]

 

How about a Craftsman Lord Nelson Class  http://www.craftsmanmodels.co.uk/cat.pdf

 

How about them indeed !! http://www.rmweb.co.uk/community/index.php?/topic/97228-craftsman-detailing-kits/?view=getnewpost

[mightbe]

While I'm waiting for a reply from PDK (I don't expect one until Monday), I've basically come to the following conclusions:

 

*The Q class is likely the all-around best option. As much as I like the larger 2-6-0 and 4-6-0 Maunsells, I'd better stick with something simple.

*Many over on the Scalefour forum openly say that they get away without compensating converted RTR models, even ones without vertical movement on the center axle. This seems to indicate to me that whether I build the frames with EM or P4 spacers, compensated or not, I'm in good company (Keith Norgrove has several RTR locos using their original chassis with thick lead sheets filling the space). Of course ideally I would want full suspension and hornblock, but we aren't living in an ideal world, are we?

If I take the same ultra-careful approach that I took in laying 00-SF I should be *okay*. It's still perfectly flat (That board is probably excessively  sturdy upon reflection) and stock doesn't gently pitch back and forth.

*Working in P4 is looking less and less frightening, assuming that everything is done squarely and carefully. 

*Doing it right will be expensive, but worth it.

 

At some point I really ought to join the S4 Society.

 

Quentin

[Horsetan]

....At some point I really ought to join the S4 Society.

At some point, you really ought to come over here and visit Scaleforum.

 

JFDI

[hayfield]

  How about them indeed !! http://www.rmweb.co.uk/community/index.php?/topic/97228-craftsman-detailing-kits/?view=getnewpost

 

 

I had better start searching eBay for  a 1P

[Kenton]

 

I had better start searching eBay for  a 1P

You will be really lucky to get anything for 1p - for some reason those kits seem to be going for a significant premium on ebay. (could be something to do with the hen's teeth factor.

 

On the subject of compensation, I know I've said it before but a really well built compensated/sprung chassis is far better than not and will run/glide like a dream over track imperfections. However a badly or even marginally built compensated.sprung chassis will trip/slop/stumble on the best laid track where a rigid chassis will run smoothly. It doesn't matter how perfectly prototypical and fine the scale body is on a loco, if it doesn't run on YOUR track it may as well be placed in a display cabinet. (I know many that are)

[Jol Wilkinson]

  You will be really lucky to get anything for 1p - for some reason those kits seem to be going for a significant premium on ebay. (could be something to do with the hen's teeth factor.

 

On the subject of compensation, I know I've said it before but a really well built compensated/sprung chassis is far better than not and will run/glide like a dream over track imperfections. However a badly or even marginally built compensated.sprung chassis will trip/slop/stumble on the best laid track where a rigid chassis will run smoothly. It doesn't matter how perfectly prototypical and fine the scale body is on a loco, if it doesn't run on YOUR track it may as well be placed in a display cabinet. (I know many that are)

The implication of "a rigid chassis will run smoothly"  is that any rigidly built chassis will run well.

 

It takes as much effort to produce a well running rigid chassis as a compensated one in my experience. Using jigs to get the axle/coupling rod relationships correct, which is what you have to do with "aftermarket" hornblocks takes away any inaccuracy that may result from design errors, frame/spacer misalignment, etc.  

 

Compensation/springing also improves current pickup, another aid to smooth running.

[Kenton]

If so, then one wonders why nearly all kits are not supplied with the parts and with the chassis already etched out to take them? Also if it is so easy then why are not all chassis built in this state for ALL gauges.

 

Note, I am not anti compensation/springing. Just that I do not see it as easier to build a good one as it is to build a rigid one. So sure, of course it is quite possible to build a rigid chassis out of alignment, but dispute the idea that it is easier to build a compensated/sprung one (which it clearly cannot be as there are more parts to "get right".

 

As has been said, many manage perfectly well with rigid chassis - therefore it is not a MUST do. Just that if done well it CAN improve running and to some extent appearance. It should never be used as an excuse for poor track or inadequate pickups, as those areas can be solved by taking the same care and attention they deserve.

[mightbe]

I didn't mean to cause controversy over compensation or springing--sorry about that.

 

Anyway, PDK has sent a very prompt and helpful reply.

 

The Q class frames are etched for hornblocks, the owner recommending Alan Gibson ones. He's also recommended 16-spoke 5'0" drivers, as 5'1" drivers are not available. I guess is 100% fine, because IIRC wheels were only replaced after 2" had worn away. 

 

So I have compiled the following shopping list for the loco itself (excluding gauges, solders etc): 

 

PDK: Q class kit

Alan Gibson: 3 sets of 5'0" drivers, 3 sets of tender/bogie wheels (I'll get the size from the kit instructions), P4 spacers, set of 6 hornblocks 

High Level: Mashima 1224, Roadrunner gearbox (both recommendations from PDK)

 

Thanks to all who have contributed. I think I know where to go from here, and no doubt I'll be back to ask questions once I get all the components.

 

Quentin

[Kenton]

 

I didn't mean to cause controversy over compensation or springing--sorry about that.

 

Don't fret, you didn't.

 

I think I know where to go from here, and no doubt I'll be back to ask questions once I get all the components.

 

We all look forward to a detailed build topic on here. Good luck with it, I hope you find it suits your needs.

[Kenton]

 

That would be you.

Why of course, who else would you expect but remember it always takes two opposing views to create an argument or discussion - so I'm happy to own up as one ... where do you stand?

[Kenton]

 

I have my own prferences and my own construction methods, but I don't foist them on other people.

 

The strange thing about RMWeb is that it is a forum where people seek the advice and experiences of others.

 

That advice is usually given freely and by more than one contributor, and all are free to add and contribute to the discussion. It is rarely "foisted" and generally given in the spirit of helping others make an informed decision.

 

As you probably realise there are many ways to do most things in modelling. They can range from the obvious to the obscure but if it works for one then it is worth considering for others.

 

Are your preferences and methods so unique or so special to yourself that you do not wish to share them with others? Have you never asked a question and sought an answer on the forum? Have you contributed (sorry, in your terminology "foisted") something here?

 

I respect the opinions of any one who contributes on here. I also see those opinions as freely given and treat them for what they are worth. One opinion or related experience among, hopefully many, that cover a wide range not narrow and single minded.

 

 

One thing I do think, is to remember the wise words of the late Donald Boreham: "Scrap anything which you know is not good enough [and make it right next time]".

I'm sorry I never knew the man and I'm sure there are many sayings by others that could be plucked out of the blue as being relevant or not. But that is about equivalent to me smashing up a kit that is unbuildable with the 6lb hammer. I would generally prefer the quote of "If you cannot make it work first time, seek help, and keep trying until you do." or the one that goes "Don't waste your life making things more complicated than they need to be, life's too short." or "If it works, stop trying to break it."

 

I'm sure we could keep quoting, some relevant, most probably not, but all equally applicable whoever they are penned by whether famous or some personal acquaintance.

[Jol Wilkinson]

One of the difficulties with forums is that conflicting advice is often given, or at least that which is given is sometimes challenged or disparaged.

 

There is no way of knowing if any advice is "good" or not for one's own needs, without trying it.

 

Some contributors advice is usually seen as worthwhile, where they have established a justified reputation in a particular field. Normally that means having produced/displayed examples of their work in the media. Even then, it doesn't mean it'll work for everyone, depending on their level of skill and confidence.

[Kenton]

 

One of the difficulties with forums is that conflicting advice is often given, or at least that which is given is sometimes challenged or disparaged.

 

There is no way of knowing if any advice is "good" or not for one's own needs, without trying it.

 

That is absolutely right. However, it should never be used as an excuse to censor or pooh pooh a contributor. Surely t is better to have a multitude of options and then be able to select the most suitable or the one that has been argued/agreed/supported the most.

 

I think there is nothing worse than keeping quiet on the subject (or simply refusing to add one's own experience on a subject). The questioner (and all those others simply searching or watching would feel misled and cheated if they later followed a single given advice and then later found out, perhaps by other means, that there was a perfectly viable alternative.

 

Often, as we have seen in this topic there is wider support for both opposing advice than we might otherwise have thought.

 

Those who know me on here, I have been around a bit, will know that I contribute on a fairly narrow range of topics (within modelling that is) and add nothing to advice on topics of for example weathering. That is simply because I have no experience to offer advise. all I can do is add subjective like/dislike. In general that seems true of nearly everyone on here.

 

There is also bound to be some amicable sparring between those familiar posters, who probably know what to expect and see it coming. Such is the nature of forums, just as is the general chit chat that seems to pop up now and again, especially where members have actually met.

[Kenton]

 

Just to be clear, you foisted your opinions on rigid vs. compensated (beam or sprung) into this thread, when it was neither helpful nor necessary.

Actually I was the third poster to bring the subject up. But as always let's not let the facts spoil a good forum debate. Actually I don't give a damn what you think of me, you don't know me and I clearly don't know you. If you care to ignore my posts that will keep you happy. I'll just continue to post as always. This has got too personal for a civilised debate on locomotive building.

[Horsetan]

That avatar picture of someone with fingers in their ears: is that you ignoring comments you don't like? I just wondered.

Nah, that's him ignoring everybody.