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

[John_Hughes]

I'm a little reluctant to put my oar in here and interrupt a good fight! But I will...

 

One thing I have learned over the years is that there is no substitute for really good tools, and specialised tools can get very expensive - so the OP either needs to already have them, or to find practical work-arounds.

 

For instance, jigs for chassis construction have been mentioned, and I would concur that they help no end; but it's possible to start small - eg with the sort of simple axle jigs that Perseverance made and that show up on eBay from time to time - and work up to something more complicated and advanced as and when the need and cash come to the fore.

 

Or wheels - good old Romford / Markits are self-quartering and self-gauging, but not exactly suitable for P4! - and Gibsons don't suit everybody, and I've certainly had some trouble with them over the years - though the new ones seem much less likely to lose their tyres than the old ones did. Once again, a jig (like the lovely GW Models one) can help no end; but it sure as heck isn't cheap!

 

In other words, buy tools as and when you need them - but it may be a good idea to factor in just what you'll need to buy to get that first model built. And take it very easy and remember that it's meant to be a relaxing hobby!

[mikemeg]

I suggest you buy a kit of a "Basic" 0-6-0T or similar, and "Get on With It". We only learn by experiance, and "Having a Go". The best part of sixty years ago, I started modelling by cutting up "Shreaded Wheat" boxes, and making houses for my "Hornby 3 Rail". Give it a try, you will be surprised at what can be achived  by practise and determination.

 

This is very good advice. None of us were born with a natural ability to build models; we learned to do it. There are numerous books on the subject and there are some excellent modellers who contribute advice on technques and approaches to this topic area; ok some more stridently than others but c'est la vie.

 

And as one who does enjoy model locomotive building, then I would echo Mick's comment -'have a go'.

 

Set your own aspirations for what you'll start on and set realistic aspirations as to how well that first build might go.

 

In my own case, I was an enthusiastic modeller from around sixteen to twenty years old. Then a near forty year lay off, during which the whole modelling scene had changed completely. When I took the hobby back up again, I bought a few books on modelling (Iain Rice, Guy Williams, etc.) then built a few dozen wagons. As I had absolutely nothing left from my earlier modelling days, then I could make the choice of gauge and scale and chose 4mm and P4.

 

I always had the intention to build locomotives and, when I thought I might be able, I built my first 4mm loco. I've now built or converted close on thirty, over the last few years, and I'm still learning.

 

Give it a go!

 

Oh and Mick, for me it was Cornflake boxes, they were bigger, provided more cardboard and I didn't like Shredded Wheat. But they were a free (the parents bought the Cornflakes) source of material which could be fashioned into all sorts of things. And it was doing just that which led you, me and probably many others, into this world of making models. Cheers my old friend!!

 

Cheers

 

Mike

[micknich2003]

Mike, do you remember in the mid '60's when we were first introduced to "Araldite" and you, as a "Test Piece" glueing a brick to the garden path? The experiment worked, and much to the cost of your father when he attempted to kicking out of the way.

[Guy Rixon]

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

 

Add to your list jigs to align the hornblocks. The axle spacings have to match accurately the crankpin spacings in the coupling rods. If you build a rigid chassis, this finesse should be built into the etchings: build it square and the rod centres should match the axle centres. When you fit hornblocks, for either beams or springs, you lose the accuracy of the match and you have to restore it using jigs. The posh jigs align the whole of the frames and hornblocks for you and cost about £100. The simple jigs just align the hornblocks to match the rods and cost  less than £10. I think you'll definitely need one or the other.

 

It's not clear to me from the thread if you're going to try springing or beam compensation. If you're going to use springs, you might consider using the High Level hornblocks in place of the Gibson ones. The Gibson springing design, using a coil spring bearing on each box, is said to be a swine to assemble and (IIRC) it's "spring assisted" rather than fully sprung.

 

"Fully sprung" means that the loco rests with the suspension in mid travel and the springs partly compressed. Any track deviations up and down are taken up by the springs.

 

"Spring assisted" means that the loco rests with the springs fully compressed and it will lurch when it passes a track bump. When it passes a track dip, the springs push the wheels into the dip to maintain rail contact.

 

The advantage of spring-assisted suspension is that you can easily tune the ride height at each box by adjusting the spring stops. You trade this off against the quality of ride.

 

The high-level boxes have optional fittings to support Continuous Springy Beams (CSB), which is a fashionable way to fully-sprung systems. You would need to decide if the extra complexity is right for you in a first build. If you like the sound of CSBs then there is some background reading and design to be done before you cut metal.

[mikemeg]

Mike, do you remember in the mid '60's when we were first introduced to "Araldite" and you, as a "Test Piece" glueing a brick to the garden path? The experiment worked, and much to the cost of your father when he attempted to kicking out of the way.

 

Mick,

 

Yes, I remember my introduction to Araldite and I remember my testing its adhesive qualities, under arduous conditions. I think my father remembered that same test also though the utimate removal of the brick was deemed to be my responsibility as my dad rested his sprained ankle!

 

Sounds like a plot for one of those Eric Sykes/Tommy Cooper/Jimmy Edwards films with no dialogue - 'The Brick'.

 

But we digress.

 

Cheers

 

Mike

[Horsetan]

Mick,

 

Yes, I remember my introduction to Araldite and I remember my testing its adhesive qualities, under arduous conditions. I think my father remembered that same test also though the utimate removal of the brick was deemed to be my responsibility as my dad rested his sprained ankle!

 

Sounds like a plot for one of those Eric Sykes/Tommy Cooper/Jimmy Edwards films with no dialogue - 'The Brick'.....

 

[mikemeg]

 

And you digress as well but it's great.

 

Many thanks and cheers

 

Mike

[mightbe]

The posh jigs align the whole of the frames and hornblocks for you and cost about £100. The simple jigs just align the hornblocks to match the rods and cost  less than £10. I think you'll definitely need one or the other.

 

It's not clear to me from the thread if you're going to try springing or beam compensation. If you're going to use springs, you might consider using the High Level hornblocks in place of the Gibson ones. 

Let us assume for sake of economy I'll go for the latter.  Where do you find those jigs? I had been looking at the Comet cylindrical jigs, but I take it those won't be of any help with hornblocks? 

I'm not planning on attempting to buy a GW wheel press--not only are they expensive, but the man who makes them has lumpen views about the internet, thus entirely precluding me from buying one anyway. I think I shall use washers and a vice, in combination with a B2B gauge (is the Alan Gibson S4 or P4? It says S4 but the measurement looks like P4)

 

I'd like to try springing, mostly because it looks so much less complicated than compensation.  CSBs might be doable, but I think I'll just go for the traditional springing. (I'm not planning on springing the tender--I'm not even sure I can!). 

 

I'll wait until I get the kit to figure out which maker of hornblocks--I'm not sure how wide the slots are, and whether High Level ones are small enough. 

 

Quentin

[Jol Wilkinson]

Quentin,

 

the jigs - with tapered ends to fit a variety of crankpin sizes - are available from London Road Models.

 

http://traders.scalefour.org/LondonRoadModels/various/components/

 

Hornblock "cut outs" are usually a standard 6mm wide, extending 4.0mm above the axle centre line.

 

Jol

[Siberian Snooper]

For more info on CSB's go on to the Scale four forum, you don't need to be a member and in the section on chassis and suspension in the Trains: model & prototype section you will find several informative items on CSB's including spreadsheets where you can input the various values for your model to get the size of guitar string. The High Level hornblocks have the necessary bits for CSB, you just need to add the jig for drilling to the order, also needed are some WD handrail knobs.

 

I am unable to add links to the various sites.

[Horsetan]

Let us assume for sake of economy ....

If you're splashing out on a PDK kit, economy has long gone out of the window.

[mightbe]

If you're splashing out on a PDK kit, economy has long gone out of the window.

 

Unlike others, I am not made of money. I will spend money where it seems worthwhile to do so. If the LRM jig has the same utility for me as a fancy $160 whatnot does, I'll go for the one that costs less than $10. On the other hand, if a crappy loco kit costs me $60 but the one that seems actually buildable and worth my while costs $150 I'll go for the latter, but that doesn't mean I'm not carefully watching the bottom line. 

 

Reminder to all: I live 4000 miles away. I cannot visit the UK any time soon due to financial constraints and have no connections there. Please keep this in mind (e.g., a GW wheel press is out of the question)

 

I will dig out a picture of a simple chassis or two, if anyone is interested.

 

Yes, by all means. That would be lovely. I'm trying to wrap my head around how hornblocked chassis are put together completely square.

 

the jigs - with tapered ends to fit a variety of crankpin sizes - are available from London Road Models.

 

Hornblock "cut outs" are usually a standard 6mm wide, extending 4.0mm above the axle centre line.

 

Many thanks. Do these also help ensure the chassis itself is square? Maybe I'm completely lost on how to build a chassis with hornblocks. Do I solder in the hornblock frames and half of the spacers to the each loco frame and then (with the aid of the LRM jig) solder the chassis together?

 

Quentin

[Jol Wilkinson]

Quentin,

 

the LRM jigs do not align the chassis/frames. They are used to get the spacing of the hornblocks/bearings consistent with the coupling rods. Only the expensive Hobby Holiday or Avonside jigs will align the frames/bearings for you.

 

Good chassis design will provide frames and spacers that "interlock" to give good alignment. I have built all my locos with compensation and once the frames are assembled, use the LRM jigs to locate the hornblocks.

 

If you are unfamiliar with building etched locos/compensated chassis,/etc, then I would suggest a copy of one of Iain Rice's books such as "Etched Kit Chassis Construction in 4mm" should be your first purchase - available online from  www.titfiled.co.uk . While it predates CSBs, much of the information Iain provides still provides the basic information you need.

 

Jol

[Guy Rixon]

Many thanks. Do [the LRM jig axles] also help ensure the chassis itself is square? Maybe I'm completely lost on how to build a chassis with hornblocks. Do I solder in the hornblock frames and half of the spacers to the each loco frame and then (with the aid of the LRM jig) solder the chassis together?

 

Quentin

No, the jig axles do nothing at all to keep the frames square. They force the axles to be parallel, but allow the chassis to be rhomboidal in plan view.

 

First, you assemble the frames, prepared with the hornblock cut-outs but without the hornblocks, using home-made jigs and engineers squares to get it in square. The jig axles are not in play here.

 

Then you assemble the hornblocks and bearings, put the jig axles in place of the proper axles, put the rods onto the ends of the jig axles, and fix the hornblocks into the cutouts. There will be a little play of the hornblocks in their cut-outs, before you fix the blocks. The jig axles fix the exact position of the blocks within this tolerance such that the axle centres match the rod centres and nothing binds (in principle).

 

When the hornblocks are fixed, you drop out the bearings, remove the jig axles and fit the bearings to the proper axles with the wheels.

 

Note that you either have to drop out the bearings prior to wheeling up, or you have to fit the wheels to the axles through the bearings already in the frames. The latter approach may be trickier, especially for anybody using a wheel press.

 

If you use the Gibson hornblocks, you don't need to fit the springs when using the jig axles. This reduces the chance of losing a spring from a racing certainty to ~50%, :-/

[mightbe]

I've been looking through the Scalefour forum (haven't signed up for it yet). Lots of helpful info, usually picking up right after the frames are together and square! 

 

Though more seriously, I've learned so many things already just lurking through their forum.

 

From your explanation about hornblocks (I do intend to spring all three axles at the moment), it sounds like you're saying that a completely sprung chassis can be squared using a couple of carpenter's squares? I don't  trust myself or the spacers enough to do the job. It sounds like there aren't tabs, (maybe half-etched lines?), and that the springing arrangement is completely unlike the Comet one (no little nib above the slot to hold the spring in place). I'll wait until the kit arrives though before I come to any conclusions on what kind to buy or how to assemble the kit.

 

Quentin

[Horsetan]

I've been looking through the Scalefour forum (haven't signed up for it yet)......

 

You may need to join the Society as a member, as a membership number is required before you can register for full access to the Forum

[Jol Wilkinson]

 Quentin, Guy Rixons advice on the hornblocks and bearings is sound, as is the rest of his advice. If you are to follow the P4 trail then invest in a good, proven, chassis jig. You won't regret it. A good square chassis is paramount in all 4mm. scales. If anything is even slightly out of kilter then it will punish you. Springing or compensation cannot disguise a poorly built, out of plumb job. Belts and braces (or suspenders) is the way!  Regards. Regards. Serron         

The same applies to rigid chassis, if not more so. A slight twist in the frames can be compensated by the vertical "tolerance in the hornblock bearings. With a rigid chassis, the axles will always be out of line.

 

I've looked at both makes of chassis jig, but have yet to be convinced that they would provide a value for money benefit for me. Partly because I don't build that many locos and partly because I have developed the techniques to build locos without one. It may well be that those of us that started many years ago are in that position, whereas a newcomer such as as Quentin might find them more useful.

 

Jol

[Kenton]

 

I've looked at both makes of chassis jig, but have yet to be convinced that they would provide a value for money benefit for me. Partly because I don't build that many locos and partly because I have developed the techniques to build locos without one. It may well be that those of us that started many years ago are in that position, whereas a newcomer such as as Quentin might find them more useful.

 

I also am finding it a difficult decision to make. It is difficult to justify on cost (they are far from cheap) and complexity (I cannot help thinking that they introduce a new learning curve - almost doing something in a completely different way than previously) and then there are two to choose from!

 

I have seen very little said on the pros and cons of each and nothing regarding a direct comparison. It would perhaps be good to see that done in a magazine. Or even a trial before you buy class/expo. I haven't even seen either one in action at a show. Add to that I build in both 4mm and 7mm so more than one unit, more additional bits/cost .. how versatile are they.

 

I should be able to justify on the cost given that they are simply quicker to use otherwise it is down to ease of use and that is a difficult one when you can have been able to manage without.

[KalKat]

I have a collection of brass stock to make one !

[Mike G]

 

I also am finding it a difficult decision to make. It is difficult to justify on cost (they are far from cheap) and complexity (I cannot help thinking that they introduce a new learning curve - almost doing something in a completely different way than previously) and then there are two to choose from!

 

I have seen very little said on the pros and cons of each and nothing regarding a direct comparison. It would perhaps be good to see that done in a magazine. Or even a trial before you buy class/expo. I haven't even seen either one in action at a show. Add to that I build in both 4mm and 7mm so more than one unit, more additional bits/cost .. how versatile are they.

 

I should be able to justify on the cost given that they are simply quicker to use otherwise it is down to ease of use and that is a difficult one when you can have been able to manage without.

 

I've got both and used both with equal success. The Hobby hols one has an advantage, it can be used as a rolling road. It's draw back is that it's difficult to use. As far as you're concerned Kenton the red box (Avonside) would be down your street as 7mm 'spigots' are available to go into the 4mm models chassis - so you could use it for 7mm chassis building - dependent on the wheel centers of the chassis you were building.

 

The up side on the Avonside jig is it's so simple to set up and use and very robustly made.

 

http://www.avonsideworks.com/assets/CHASSIS2_Pricelist.pdf

 

regards

 

Mike

[Flymo748]

 

You may need to join the Society as a member, as a membership number is required before you can register for full access to the Forum

 

Ivan is partly right...

 

Anyone can view the vast majority of the Forum.  I hope that people do, because there is a wealth of information there.

 

To post on topics, or to access the Members Lounge (where we tend to talk about the quality of the catering at Society shows, oh and our cunning plans to take over the world...) you need to be a member.

 

Oh, and you will also receive a crackingly good magazine five times a year as well.  See other places on RMWeb for a discussion of it and its content.

 

HTH

Paul Willis

Scalefour Society Deputy Chairman

[Flymo748]

 

I also am finding it a difficult decision to make. It is difficult to justify on cost (they are far from cheap) and complexity (I cannot help thinking that they introduce a new learning curve - almost doing something in a completely different way than previously) and then there are two to choose from!

 

I have seen very little said on the pros and cons of each and nothing regarding a direct comparison. It would perhaps be good to see that done in a magazine. Or even a trial before you buy class/expo. I haven't even seen either one in action at a show.

 

Derek at Eileen's Emporium will demonstrate the Avonside one, I'm sure.  He manufactures and sells them.  And I've always see one of the Hobby Holidays ones on the stand at shows, so if you ask Phil, I'm sure that he will demonstrate as well.

 

I think that you'll find them both at Scaleforum this weekend...

 

Oh, and I bought my Avonside one after seeing John Brighton demonstrate just how easy it was to put a chassis together using one when he was demonstrating at a show.  And there's always several in use at any Missenden weekend!

 

They are out there to be seen and discussed...

 

HTH

Paul Willis

Scalefour Society Deputy Chairman

 

[Edit: Hobby Holidays, not Hobbytime.  Something entirely different]

[mightbe]

Hi again.

 

The main kit just arrived yesterday and today I opened it up to have a look around, see that all was well, etc.

 

First impressions were excellent. Everything was wrapped many times over in tissue paper and bubble wrap. I opened the boiler first, fearing the worst. It's okay. It's very slightly egg-shaped but this can be easily fixed with a 20mm diameter cylinder. 

 

Once I opened the tissue-wrapped pack of etches however, some things turned out to be not so good..

 

There are several damaged pieces, mostly on the fret that includes the mainframes. The damaged pieces are: the half-etched back of the tender, the corresponding buffer beam, the frame for the back side of the tender, the half-etched overlay for the left side of the cab, and the boiler bands (which I wasn't planning on using anyway, but they're completely wonky.

 

I had at very first glance assumed that the back of the tender was in fact a pre-rolled roof that had been bumped in transit!

 

I have not opened the bag of castings yet, as there are many small parts that could easily be lost. The larger pieces look OK. One of the pipes that runs along the side is arching like a rainbow, but that shouldn't be difficult to straighten.

 

The pics will below show the extent of the damage.

 

 

 

 

 

Please tell me--what can I do to fix these pieces. I'm afraid to touch the cab side overlay at the moment for fear that I'll simply break off the bit that's twisted.

 

EDIT: aside from that, the parts are very cleanly etched. I really had no idea what to expect when I opened the little plastic box. Overall, things look promising. 

 

I have decided a few things about the chassis--let me know what you think:

 

I will temporarily leave the hornblock fillers (whatever that bit is called that has the axle in it) and use the existing axle holes to assemble the chassis squarely with the aid of the Comet cylinder-jig. The kit DOES NOT include EM spacers. If it did I would've probably tried cutting out the blocks first and possibly have used those spacers for P4. As it is, they're held in place by three tiny half-etched nips. I will use the Comet P4 jig with the Comet spacers--that seems like the easiest and most certain way of doing it. 

 

Once together I'll pop them out with a pair of Xurons and then use the LMR hornblock jig to assist in aligning the hornblocks. I haven't decided what ones to buy yet. I'll be placing orders from Comet, LMR, C&L, Alan Gibson, and High Level--if you can recommend hornblocks from any of those that would be ideal.

 

I still have no idea what size/type of wheels I need for the tender. The instructions don't mention them, or indeed how to assemble half of the tender, though I do have a curiously blank page in the packet. 

 

Quentin

[Spitfire2865]

About the bent pieces.

Brass is a lot stronger than you realize, even when bent.

Im currently building an LNWR Cauliflower, and the kit had 2 wrappers for the smokebox. I accidentally soldered the outer, decorative wrapper a tad too far back, so I grabbed it with a pair of pliers, and forcefully ripped it off with the help of my iron set as high as it could. I then straightened it out flat, and resoldered it, putting it further forward.

 

Can barely even tell I massively screwed up!

 

So for your problem. The worst part seems to be that twisted boilerband, even then, just straighten it out with tweezers and flatten it carefully.

[Jol Wilkinson]

About the bent pieces.

Brass is a lot stronger than you realize, even when bent.

Im currently building an LNWR Cauliflower, and the kit had 2 wrappers for the smokebox. I accidentally soldered the outer, decorative wrapper a tad too far back, so I grabbed it with a pair of pliers, and forcefully ripped it off with the help of my iron set as high as it could. I then straightened it out flat, and resoldered it, putting it further forward.

 

Can barely even tell I massively screwed up!

 

So for your problem. The worst part seems to be that twisted boilerband, even then, just straighten it out with tweezers and flatten it carefully.

I wouldn't bother with the etched boiler bands. The real things were so thin that a lining transfer is all you need, or a narrow strip of thin tape for an unlined loco.