P4 Questions and Hopefully, Answers!

Lyndhurstman

Western Thunderer
Ratio made both as I recall. The problem was the lack of gauge-widening on our tight model curves. We used P4 bases on curves on our EM layout! The P4 bases are OK on straight track but that's about it.

Dave
Hi @daifly
Thanks for the clarification. I was retrieving from the further recesses of what passes for my mind.

Cheers

Jan
 

AJC

Western Thunderer
@WM183
Hello
Be wary of Ratio P4 track bases - they pop up sometimes on EBay. I seem to recall discussions that they are actually EM.

Cheers
Jan

Ah, not quite, no. They are rather tight to gauge (as the EM ones are - those come in at 18mm, ish), but from experience, Yeovil Model Railway Group's 'South Junction' - a large EM tailchaser - has quite a lot of the P4 bases which are gauge widened somewhere in the region of 18.5-18.6 and a bit. Chris Pendlenton used them on North Shields and widened the gauge with pressure from a blunt chisel. Whether that's a particular problem, I couldn't say as I don't work in P4. EM, as should be obvious, is a bit more elastic!

Adam
 

RodneyS

Member
I have some Ratio P4 track bases. I've just measured them and they seem to be about 18.80mm.
I've only ever used them for display and P4 wheels do fit but I would imagine curving the lengths at all would result in the gauge reducing quite a bit.
As Lyndhurstman says, they are best avoided for layout purposes.

Ratio also made EM track bases and many years ago a friend used them on a 2' radius spiral on his freelance EM layout.
The gauge tightened up so much that he had to resort to all sorts of bodges to get the stock to run well.
Rather wickedly I said that he should have used the P4 bases. I received a rather strange look........
Rodney
 
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RodneyS

Member
Whoops, I hadn't realised there was a page 2 to this thread. Oh dear.
Anyway AJC's comments about using P4 bases on South Junction makes me think I wasn't so daft after all.
Rodney
 
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AJC

Western Thunderer
Whoops, I hadn't realised there was a page 2 to this thread. Oh dear.
Anyway AJC's comments about using P4 bases on South Junction makes me think I wasn't so daft after all.
Rodney

It's worked fine for nearly 40 years, or rather, when things do fall off, it's not down to the P4 track on the corners. The whole thing is a bit of a museum of finescale track systems having something of everything produced since about 1975 on it somewhere.

Adam
 

JonTyler

Member
I'm impressed that Exactoscale offer correct pattern LSWR chairs in 4mm scale. If I were to set up a small P4 display track for my mantle piece, would there be any S4 Society members willing to buy the parts required on my behalf? I model in o gauge normally, so really don't want to join (yet another) society. Just a thought.
Kind regards
Jon
 

Lyndhurstman

Western Thunderer
I'm impressed that Exactoscale offer correct pattern LSWR chairs in 4mm scale. If I were to set up a small P4 display track for my mantle piece, would there be any S4 Society members willing to buy the parts required on my behalf? I model in o gauge normally, so really don't want to join (yet another) society. Just a thought.
Kind regards
Jon
I'm impressed that Exactoscale offer correct pattern LSWR chairs in 4mm scale. If I were to set up a small P4 display track for my mantle piece, would there be any S4 Society members willing to buy the parts required on my behalf? I model in o gauge normally, so really don't want to join (yet another) society. Just a thought.
Kind regards
Jon
Hello @JonTyler
I’m a member. I can help if you wish.

Cheers

Jan
 

Mancunian

New Member
Hi all.

I am building a High Level jinty chassis in P4. I used the "P4" spacers, and the frames came out to 16.2mm outside width. The bearings and hornblocks, however, are a bit wider; 16.55 over the hornblocks and 16.7mm over the fixed axle's bushings. My axles (Gibson P4) are 19.93 mm long give or take .02mm. If I press the wheels on with my GW wheels press until the face of the wheel is flush with the axle center, the back to back is too narrow. Even if I press them so the back to back is right, there is less than .1mm clearance between the back of the wheel hubs and the fixed axle bushings. I can file the bushings back a bit, but 1: How long should the axles supplied with the wheels be, and 2: should pressing them flush with the GW press set the back to backs for me? I am using a 17.75mm B2B gauge from DCC concepts, if that matters.

I suppose I can carefully chuck the wheels in my lathe and skim a bit off the back of the center boss, but - I'd like to avoid that if possible.

Help!

Amanda
Hi Amanda,
My experience with High Level (and currently with Judith Edge) is that the P4 frame spacers supplied are too wide. I use those for EM but that doesn't help you even if I had replied a lot earlier .
The frame outside dimension for Derby locomotive frames is 4'-0" and one quarter. Ignore the quarter and call it 16mm for 4mm scale. At 16mm there isn't much room for top hat bearing flanges &/or horn guides when the b2b is 17.75 mm so I find it's better to use the EM spacers and then use washers/shims to limit side play.
HTH but it probably doesn't, sorry.
 

WM183

Western Thunderer
Hi hi David,

The engine is long complete! It runs wonderfully on my test track. Here's hoping it behaves through switches whenever I get around to building those! I made sure I had a bit of side to side play, and a bit more on the center axle - perhaps 1mm on the middle axle. It seems to be great?

Also, welcome to WT!

Amanda
 

DavidB

Western Thunderer
My experience with High Level (and currently with Judith Edge) is that the P4 frame spacers supplied are too wide. I use those for EM but that doesn't help you even if I had replied a lot earlier .
The frame outside dimension for Derby locomotive frames is 4'-0" and one quarter. Ignore the quarter and call it 16mm for 4mm scale. At 16mm there isn't much room for top hat bearing flanges &/or horn guides when the b2b is 17.75 mm so I find it's better to use the EM spacers and then use washers/shims to limit side play.
I would suggest using the P4 spacers filing the flange of the top hat down - make it thinner.
 

Mike Garwood

Western Thunderer
Wouldn't it be easier to file the spacers?
On one Judith Edge build I used Comet P4 spacers and they were just right. I think Comet is a very underrated brand.
Agreed. I've used Comet (P4) spacers on most of my engines, I'll qualify that by saying that the chassis concerned have been Comet branded (Brit * 2, 8f * 2, Hall * 2, County to name but a few)...I wouldn't dream of changing High Levels spacers. 3 panniers and 1 56xx have proved their worth. If you do use Comet spacers then the front driver has to have washers added to remove side play.

Mike
 
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