Rob Pulham
Western Thunderer
That looks superb Steve
, like Graham I will be pinching ideas too
, like Graham I will be pinching ideas too
Stevesopwith's S7 Workbench
- Thread starter Stevesopwith
- Start date
mickoo
Western Thunderer
Your right, there isMick,
There's more than you probably need to know in Russ Elliot's contributions to the CLAG web site. Try this page for starters.
Jim.
I don't want to dilute Steves thread any more than necessary, does anyone have a rough idea of spring wire needed for 7mm locos, I determined to get at least something to push along the tracks next time I'm at Sudbury!.
Steph Dale
Western Thunderer
Mick,
That's one hell of a can of worms you've opened there. I've played with CSBs on several locos and can assure you there's no simple answer. Start by having a play with the spreadsheets on the CLAG site and see where you end up.
Otherwise, it's time for a new thread, IMHO...!
Steve,
Very neat and tidy work although I'm a little perplexed about your need to move the pickups off the wheel treads. Any of my locos which have wiper pick-ups have them on the tread as they seem to self clean - I use Isopropyl Alcohol or lighter fluid to clean the track and wheels and have no problems at all.
Steph
That's one hell of a can of worms you've opened there. I've played with CSBs on several locos and can assure you there's no simple answer. Start by having a play with the spreadsheets on the CLAG site and see where you end up.
Otherwise, it's time for a new thread, IMHO...!
Steve,
Very neat and tidy work although I'm a little perplexed about your need to move the pickups off the wheel treads. Any of my locos which have wiper pick-ups have them on the tread as they seem to self clean - I use Isopropyl Alcohol or lighter fluid to clean the track and wheels and have no problems at all.
Steph
mickoo
Western Thunderer
JimG
Western Thunderer
Your right, there is
I don't want to dilute Steves thread any more than necessary so just one final question, does anyone have a rough idea of spring wire needed for 7mm locos, drivers, pony and tender, appreciate weight is an over riding factor but for this situation lets just assume average weight, oh and a source where such spring wire can be acquired. I determined to get at least something to push along the tracks next time I'm at Sudbury!.
Mick,
The recognised source of spring steel wire for CSBs, etc., is single strand, unwound guitar wire. You can get it in thou (and sometimes half thou) increments up to about 20 thou IIRC. There's the Ernie Ball range starting at 0.008" here and the D'Addario range starting at 0.007" here and with some 0.0005" increments. But there are several other makes which you can find on Google using a search term like "plain steel single guitar strings".
For 7mm, i would reckon that you would be looking at gauges into double figures but Russ Elliot's spreadsheets which Steph mentions are quite accurate for deflection/weight/gauge as I've found out myself.
Jim.
[Edited to removed dodgy link to Stringbusters]
Stevesopwith
Western Thunderer
Steph
I'm also puzzled at the performance of the top wiper pick-ups on this loco. I've used them in 4mm with acceptable results, but all my most reliable runners, including the 7 mm. 0-4-0 Wantage Tram, have back wipers, either n/silver or p/bronze.
The rail itself seems a bit more 'greasy' than previous supplies, but the Tram seems ok. Fry has a very short wheelbase, making wire thickness more critical, balancing effective electrical contact against braking effect. I tried 0.4 mm and 0.3 mm brass wire, and finally 0.3 mm p/bronze. I also vaguely wonder if there might be a pressure reducing interaction between the down force of the pick-ups and the springy beam wires.
I admit I was lax in cleaning the rail, before the discovery of significant 'blobs' on the wires, either side of the contact points... the Tram ran with no problems, so I assumed it was something specific to the system on Fry. I then used lighter fuel to clean the rails, wheels and wires.. with an immediate improvement... but I wondered how long this would last.
The discovery of some suitable p/bronze strip in the goody box led to trying out the present set up. You'll notice the mountings make replacement fitting very easy. They are outside because I wanted to keep the underside profile clear, and there's insufficient room between the tyres and the frames at the top. I was pleasantly surprised how well they worked from the word go.... I haven't had a single stall in many, many trips over several days, up and down my 4 ft fiddle yard. ( Warning... Jinx Alert! )
I'll let you know how it has held up in the next post.
Cheers.... Steve.
I'm also puzzled at the performance of the top wiper pick-ups on this loco. I've used them in 4mm with acceptable results, but all my most reliable runners, including the 7 mm. 0-4-0 Wantage Tram, have back wipers, either n/silver or p/bronze.
The rail itself seems a bit more 'greasy' than previous supplies, but the Tram seems ok. Fry has a very short wheelbase, making wire thickness more critical, balancing effective electrical contact against braking effect. I tried 0.4 mm and 0.3 mm brass wire, and finally 0.3 mm p/bronze. I also vaguely wonder if there might be a pressure reducing interaction between the down force of the pick-ups and the springy beam wires.
I admit I was lax in cleaning the rail, before the discovery of significant 'blobs' on the wires, either side of the contact points... the Tram ran with no problems, so I assumed it was something specific to the system on Fry. I then used lighter fuel to clean the rails, wheels and wires.. with an immediate improvement... but I wondered how long this would last.
The discovery of some suitable p/bronze strip in the goody box led to trying out the present set up. You'll notice the mountings make replacement fitting very easy. They are outside because I wanted to keep the underside profile clear, and there's insufficient room between the tyres and the frames at the top. I was pleasantly surprised how well they worked from the word go.... I haven't had a single stall in many, many trips over several days, up and down my 4 ft fiddle yard. ( Warning... Jinx Alert! )
I'll let you know how it has held up in the next post.
Cheers.... Steve.
Steph Dale
Western Thunderer
Thanks - I'd appreciate it!
As an aside, I'm very cautious of using nickel-silver wire as a wire pickup as the stuff work hardens at an alarming rate. On the couple of locos I built with it, they very quickly ended up with the pickups replaced with PB or drawn half-hard brass...
Steph
Stevesopwith
Western Thunderer
Best Christmas Wishes from Sopwith and Steve.
Stevesopwith
Western Thunderer
This newest addition to projects I have yet to finish has it's origins even further back in time than Wantage.
By the age of 10, having moved to Cockfield, Suffolk, to a farmhouse about 100 yards from the Bury St Edmunds to Sudbury line, I knew of the GER , so I was interested in a 'very old' railway carriage in the garden of an acquaintance of my father. Later, I took photos and made a few notes and dimensioned sketches, of what I was, much later, able to identify as an Eastern Counties, or very early GER 21 ft Four Compartment Second.
With Buckjumper's help, and a lot of money to NRM and HMRS, I now have a large collection of GAs of carriage and wagon stock of the period, which I am using to make 7mm drawings, and hopefully, eventually, models.
Here's an example: a First Class from 1863.
( This was drawn using PaintNet, and thus is not usable for etching or other processes. I am now learning to use TurboCad, )
Long ago, when my eyesight was better, and I still had a lifetime ahead of me, I wanted to build models like Geoff Pember, and I had made some slow progress towards the techniques needed to make the underframes as he did.
An alternative approach was inspired by Andy B, the Parlytrains range, and our own Brush Type 4, and involved laser-cutting the underframe outlines in 1/8th" MDF.
I supplied Phil with a Turbo-Cad file of the frame outline, plus the details of the solebars and headstocks, complete with all bolt holes.
Two 1/8th" outlines can be glued together, giving a correct scale 11" depth. Small grooves on the mating faces provide locations for the longitudinal tie rods. Solebar and headstock overlays of 0.3 / 0.5 mm ply can then be glued to the frames, thus disguising the joins, and acting as a drilling template.
What is basically a fairly simple process can be made even easier by the use of a couple of jigs.
This one ensures that the two layers are aligned as accurately as possible:
Very simple; the layers are held while being tacked with CA, the unit is then removed and fixed permanently using 'Superphatic' glue, which is a bit like PVA, but can be brushed along the joint which it then fills by capillary action. The model aircraft guys use it to make balsa frames.
The outside edges are then lightly dressed with a sanding block checked for squareness, and after a sealing coat of PVA, the solebar overlays can be glued in place. I used the above jig to ensure they fitted correctly.
I then used this home-made angle plate attachment to my old Unimat to hold the frame vertical, while sliding it along the shelf at the bottom, to enable the accurate drilling of all the bolt holes to 0.4mm.
All holes pretty dead square, and no drill breakages!
By the age of 10, having moved to Cockfield, Suffolk, to a farmhouse about 100 yards from the Bury St Edmunds to Sudbury line, I knew of the GER , so I was interested in a 'very old' railway carriage in the garden of an acquaintance of my father. Later, I took photos and made a few notes and dimensioned sketches, of what I was, much later, able to identify as an Eastern Counties, or very early GER 21 ft Four Compartment Second.
With Buckjumper's help, and a lot of money to NRM and HMRS, I now have a large collection of GAs of carriage and wagon stock of the period, which I am using to make 7mm drawings, and hopefully, eventually, models.
Here's an example: a First Class from 1863.
( This was drawn using PaintNet, and thus is not usable for etching or other processes. I am now learning to use TurboCad, )
Long ago, when my eyesight was better, and I still had a lifetime ahead of me, I wanted to build models like Geoff Pember, and I had made some slow progress towards the techniques needed to make the underframes as he did.
An alternative approach was inspired by Andy B, the Parlytrains range, and our own Brush Type 4, and involved laser-cutting the underframe outlines in 1/8th" MDF.
I supplied Phil with a Turbo-Cad file of the frame outline, plus the details of the solebars and headstocks, complete with all bolt holes.
Two 1/8th" outlines can be glued together, giving a correct scale 11" depth. Small grooves on the mating faces provide locations for the longitudinal tie rods. Solebar and headstock overlays of 0.3 / 0.5 mm ply can then be glued to the frames, thus disguising the joins, and acting as a drilling template.
What is basically a fairly simple process can be made even easier by the use of a couple of jigs.
This one ensures that the two layers are aligned as accurately as possible:
Very simple; the layers are held while being tacked with CA, the unit is then removed and fixed permanently using 'Superphatic' glue, which is a bit like PVA, but can be brushed along the joint which it then fills by capillary action. The model aircraft guys use it to make balsa frames.
The outside edges are then lightly dressed with a sanding block checked for squareness, and after a sealing coat of PVA, the solebar overlays can be glued in place. I used the above jig to ensure they fitted correctly.
I then used this home-made angle plate attachment to my old Unimat to hold the frame vertical, while sliding it along the shelf at the bottom, to enable the accurate drilling of all the bolt holes to 0.4mm.
All holes pretty dead square, and no drill breakages!
geoff_nicholls
Western Thunderer
I'd like a train of Sinclair carriages to go with my Gooch class A. I'll be very interested to see how you deal with the shape of the bodysides.
Stevesopwith
Western Thunderer
I'm still pondering that question..... they are quite tricky, because three layers are needed.
From the lower waist upwards, the sides are about 3/8 " proud of the lower sides, while the rectangular waist beading makes a further layer. That beading is a flattened half-round section, between 5/8" and 3/4" wide... ie 0.35--0.43 mm.
I have tried scraping 0.5 mm plastic rod to half-round to make up the rectangles......Don't go there!
I have tried the Geoff Kent 4 mm LNER technique of using a scraper board cutter to engrave rod locating grooves in plastic; I failed miserably.
Some DS kits have half-etched beading panels that sit in suitable recesses etched in the coach sides. This is ok for some variants, but won't work for the vertical beading above the rectangles in the drawing.
I'm currently considering two possible approaches:
Now I can use Turbocad, I might try etching the upper side, complete with beading as one piece. to be soldered on top of a whole side. I'm concerned that expansion distortion might be a problem. I'd welcome advice from those with experience of this issue.
Again using the TurboCad drawings, Phil and I plan to try laser-cutting lamination in 0.3 mm ply, with rod locating grooves in the top layer. These may make the fitting of the beading less problematic, but there are still issues of accurately
aligning the laminations.
I had assumed, perhaps naively, that they would be easier to manage in G3; but I'd get into such trouble if I started down that road.....
From the lower waist upwards, the sides are about 3/8 " proud of the lower sides, while the rectangular waist beading makes a further layer. That beading is a flattened half-round section, between 5/8" and 3/4" wide... ie 0.35--0.43 mm.
I have tried scraping 0.5 mm plastic rod to half-round to make up the rectangles......Don't go there!
I have tried the Geoff Kent 4 mm LNER technique of using a scraper board cutter to engrave rod locating grooves in plastic; I failed miserably.
Some DS kits have half-etched beading panels that sit in suitable recesses etched in the coach sides. This is ok for some variants, but won't work for the vertical beading above the rectangles in the drawing.
I'm currently considering two possible approaches:
Now I can use Turbocad, I might try etching the upper side, complete with beading as one piece. to be soldered on top of a whole side. I'm concerned that expansion distortion might be a problem. I'd welcome advice from those with experience of this issue.
Again using the TurboCad drawings, Phil and I plan to try laser-cutting lamination in 0.3 mm ply, with rod locating grooves in the top layer. These may make the fitting of the beading less problematic, but there are still issues of accurately
aligning the laminations.
I had assumed, perhaps naively, that they would be easier to manage in G3; but I'd get into such trouble if I started down that road.....
JimG
Western Thunderer
Steve,
One method I used many years ago when building some Gresley suburban stock in G1 was to use styrene strip for the beading, then make a half round scraper by drilling an appropriate sized hole in a piece of steel plate, then cut across the sheet through the hole and file the cut edge flat until you have the semi-circular shape you require, then use that as a scraper on the styrene strip, holding the steel at right angles to the strip. In fact my shape was not semi-circular, but more an arc of the circle a bit less than semi-circular. If you make sure that the flat edges of the steel are smooth with the sharp edges taken off, then these edges can sit on the sheet of the coach sides on either side of the strip and give a constant size to the scraping without making marks on the sheet.
Jim.
geoff_nicholls
Western Thunderer
Steve,
for applying that beading York Model laser cutting may be the way to go:
http://www.yorkmodelmaking.com/
they laser cut a material called Rowmark It's acrylic, so doesn't give off poisonous fumes like styrene. If they cut the grooves then you can apply round beading using a solvent glue. I think they do a lot of work for the broad gauge crowd. it might not be cheap though.
for applying that beading York Model laser cutting may be the way to go:
http://www.yorkmodelmaking.com/
they laser cut a material called Rowmark It's acrylic, so doesn't give off poisonous fumes like styrene. If they cut the grooves then you can apply round beading using a solvent glue. I think they do a lot of work for the broad gauge crowd. it might not be cheap though.
Stevesopwith
Western Thunderer
First, thanks for the suggestions..... lots of ideas to consider while I finish the underframes.
I planned to use Exactoscale springing units, modified by the addition of correctly shaped outer hornplates as in the photo. These overlays were produced on the Taylor Hobson. Fortuitously this brings their outer faces to within 0.2 mm of the correct width.
Fitting them to the frames required a rebate on the top surface to accommodate the cross bridge.
A simple milling table fitted in the machine vice on the Unimat did the job surprisingly well. The MDF machines easily, though light cuts were needed to avoid breaking out the thinner sections. The finish is a little fluffy, but a coat of Klear sealed and stabilised the fibres, allowing light sanding .
The internal timbering at each end is only 8" deep, so the rebating process was repeated on the underside of the appropriate sections.
I planned to use Exactoscale springing units, modified by the addition of correctly shaped outer hornplates as in the photo. These overlays were produced on the Taylor Hobson. Fortuitously this brings their outer faces to within 0.2 mm of the correct width.
Fitting them to the frames required a rebate on the top surface to accommodate the cross bridge.
A simple milling table fitted in the machine vice on the Unimat did the job surprisingly well. The MDF machines easily, though light cuts were needed to avoid breaking out the thinner sections. The finish is a little fluffy, but a coat of Klear sealed and stabilised the fibres, allowing light sanding .
The internal timbering at each end is only 8" deep, so the rebating process was repeated on the underside of the appropriate sections.