Pratting about with a Peckett (W4)

[Dave]

I'm Dave and I'm an industrial locomotive kit addict...

I bought another one, another Peckett. I really shouldn't be building soft southern engines, being Leeds born Iought to be building Hudswells and Hunslets, but I couldn't help it.

The kit is from Agenoria and builds Henry Cort, as supplied to the Ebbw Vale Steel & Iron Co. in 1903, although I won't be building mine as that particular engine.

The kit is supposed to be built as a rigid chassis and no provision is made for springing or compensation so I've started from scratch on that.

Some lumps of brass that I hacksawed from bar.


And then sqared off in the miller and drilled holes in...


To make into hornblocks to take ball bearings.



Horn guides made from brass angle and the portion of frames with the holes for the usual plain brass bearings cut away. The blocks have now had slots milled in two opposite sides to locate them laterally in the frame plate.


The chassis as far as I've taken it. The spring guides are made from the inserts from electrical connectors and will be either blocked up at the top to retain the coil springs, or have inserts and screws to retain the springs and adjust the ride height.


Sure it's overkill for a 4-wheeler - I could have kept the plain bearings and fitted simple 3-point compensation but I like messing about with these things.

 

[Dave]

Setting aside the frames, I've done quite a lot of the bodywork today. I've made the tank up and the lower half of the boiler is now on the running plate and full of lead shot, glued in place with superglue.

The bufferbeams on the prototype appear to be made from wood, sandwiched by steel plates. In the kit the bufferbeams are made from an inner (as a fold-up of the running plate), a middle (that has to be folded to give the depth of the wood) and an outer with the rivet detail on. I didn't like the look of the fold-up thing to give the depth as it inevitably had slightly radiused corners, so I have replaced these parts with solid brass bar.

 

[AJC]

That looks rather sturdy Dave (though Pecketts of all stripes are favourites of mine). The work on the chassis shows the engineering 'play value' available in 7mm. Lovely stuff.

Adam

 

[Dog Star]

An interesting approach to weighting a model... how does the motor fit in relation to the firebox front?

regards, Graham

 

[Rob Pulham]

An interesting approach to weighting a model... how does the motor fit in relation to the firebox front?

regards, Graham

You took the words right out of my mouth Graham

 

[Dave]

An interesting approach to weighting a model... how does the motor fit in relation to the firebox front?

regards, Graham

Hi Graham,

The motor sits upright wholly within the firebox. I've just finished gluing some sheet lead into the saddletank to add a bit more weight. In fact there's loads of space in there but I've restricted it to the section that will be between the axles to give an even spread of weight. I have just put the three assemblies on the scales and it's at 600g as is, so I reckon by the time it's finished it'll be somewhere around 700g, which is plenty heavy enough.

 

[Steve Cook]

Nicely done Dave, your progress puts me to shame - my 1/32 version has only got this far



Something else to be getting on with
Steve

 

[Simon]

Likewise I'm enjoying the progress here, I have one too, it's a bit further on than Steve's in the bodywork department but my cab vertical joints aren't half as neat as his

I like the way you have added the hornblocks Dave, a really worthwhile improvement I think.

Looking forward to seeing the next step, I must get back to mine too

Simon

 

[Phill Dyson]

Dave, did you just flood the leadshot with superglue?.....I've done this myself with PVA in the past, although I understand others have had problems with using PVA & I had no thought of using superglue as an alternative

 

[Dave]

Hi Phill,

Yes, I put the shot in first and then dripped the really thin type of superglue into it. Since I took the pic I've found that the top layers are prone to coming loose so I've since put a coat of Araldite over to seal any loose bits in and prevent any more from coming loose in future.

@ Steve Cook - is that 1/32nd version also from Agenoria?

 

[Steph Dale]

Hi Phill,

Yes, I put the shot in first and then dripped the really thin type of superglue into it. Since I took the pic I've found that the top layers are prone to coming loose so I've since put a coat of Araldite over to seal any loose bits in and prevent any more from coming loose in future.

@ Steve Cook - is that 1/32nd version also from Agenoria?

Another trick is to mix a quantity of 'liquid lead' shot into some 2-part epoxy and poor it into the area to be filled. Otherwise I do as you suggest, Dave, but find that Chemical Metal or similar fast-setting filler works well as an overall sealing/smoothing coat.
Steph

 

[Osgood]

.......The spring guides are made from the inserts from electrical connectors and will be either blocked up at the top to retain the coil springs, or have inserts and screws to retain the springs and adjust the ride height......

.
That is a really neat idea. In fact (although I guess you've probably finished this by now) you could simply tap a thread into the top half of the guides, insert a spring and use a grub screw with lower face ground flat to retain spring / adjust ride height.

If it's ok by you I think I'll pinch your idea hee hee.

 

[Ressaldar]

Dave, did you just flood the leadshot with superglue?.....I've done this myself with PVA in the past, although I understand others have had problems with using PVA & I had no thought of using superglue as an alternative

the use of PVA is fine - so long as it is not in a sealed environment - like a smoke box or boiler, as the water in the PVA mixes with the shot and gives of a gas which has nowhere to go and consequently blows the joints due to expansion. It is fine to use PVA on the underside of wagon chassis as the shot is 'open' to the air and the gas escapes.

cheers

Mike

 

[Steve Cook]

@ Steve Cook - is that 1/32nd version also from Agenoria?

Hi Dave
It is an Agenoria etch. If my memory serves me correctly, Simon Castens had a batch of six etches done as a special. Wheels were done by Slaters, castings etc up to the purchasers. I know of the whereabouts of three of them, mine, Simon's and Dave Walker's (built in less than a week and fitted with RC, see photo below).




Having looked back through the photos, I stopped when driving myself nuts trying to fabricate the sand boxes and lids for inside the cab.

Steve

PS - should have added - top idea for spring retaining

 

[Simon]

The etches were actually arranged by the estimable John Taylor, I just bought enough of them to make it do-able, I think - it was all quite a long time ago

Simon

 

[Dave]

.
That is a really neat idea. In fact (although I guess you've probably finished this by now) you could simply tap a thread into the top half of the guides, insert a spring and use a grub screw with lower face ground flat to retain spring / adjust ride height.

If it's ok by you I think I'll pinch your idea hee hee.

That's an excellent idea and would be the ideal solution but I don't have a tap of suitable size. I haven't done any more to the frames since that photo so I still may do that if I can get hold of a tap and the appropriate screws.

At the moment I'm painting the cab interior before I put the cab back and roof on. I usually get a rolling chassis before doing the bodywork but I seem to be going from one thing to another with this build.

 

[Overseer]

the use of PVA is fine - so long as it is not in a sealed environment - like a smoke box or boiler, as the water in the PVA mixes with the shot and gives of a gas which has nowhere to go and consequently blows the joints due to expansion. It is fine to use PVA on the underside of wagon chassis as the shot is 'open' to the air and the gas escapes.

cheers

Mike

I don't think this is correct. The problem with encapsulating lead shot in PVA is that compounds are formed which have a greater volume than the original lead shot and therefore increases the pressure on the container (boiler etc) with the result that seams fail. It may not be as apparent under a wagon as the lead shot is probably not fully enclosed.

PVA is made from acetylene and acetic acid, and PVA adhesives are acidic (pH 4.7 - 5), apart from specialty pH neutral conservation adhesives. The acid conditions result in the relatively stable oxide etc. surface film on the lead breaking down. Lead acetate or lead salts then form that are far less dense white powder or crystals. This increases the bulk of the lead shot/PVA and causes the problems with models bursting apart.

Epoxy and other adhesives will probably not result in the same problems but there is far less risk of failure using solid lead or lead sheet to provide weight as it has far less surface area to interact with contaminants.

Do you really need so much weight anyway? I have built quite a few small locos with space planned for weights but have found on testing that the extra weight is not required, particularly in O scale where the sheet metal body, motor etc add up to a fair weight. They work reliably under exhibition conditions on small shunting layouts and on occasional visits to a garden railway.

 

[Ressaldar]

Hi Overseer,

either way, you end up with your pride and joy needing a rebuild and therefore, repaint as well, so it is advisable not to go down that track in the first place.

cheers

Mike

 

[Dave]

It's been a while but it's finished now.Maybe needs a bit of dirt on the bufferbeam but not too much.




The final weight is a whopping 800g! That's quite a lot for such a small engine and should make the springs work.