7mm At the Western End of F7

[SimonT]

Chaps,
about time that I started my own thread showing what I am working on. So here goes:



This is a David Andrews 52XX kit that I got in NS before that option went away (can't stand brass!). It will be finished with finescale frame spacing, S7 wheels and axles with shim washers to control side play. Power will be a Mashima 18x30 and a Branchlines 40:1 gearbox. I will probably fit CSBs to it rather than individual coil sprung horn blocks. The chosen loco is 4237 which was resident at Aberbeeg in 1963 and I have found a photograph of it in Barry a year later.


Latest tool on the bench is this Form 1 3D printer and the latest product from it is this....



Replacement springs as the laminated ones just don't look right to me. The next prints will be replacement brakes and hangers (no danger of shorts) and then replacements for the valve casings on the front footplate.

Also in hand are etches to improve the Parkside Dundas 21 ton minerals. These will be etched sprung W-Irons, etched brakes to suit all three patterns and prints of the various axleboxes, springs and brake blocks. After that it is the Plates/Coil Fs that I intend to target.

All the best

Simon

 

[iploffy]

That box looks like this one

Is it an all knowing computer as well

 

[SimonT]

So that's where ORAC went to!

 

[mth]

So that's where ORAC went to!

showing your age..................

 

[SimonT]

Just delivered from PPD, my first set of etchings. The burning smell this afternoon will be my fingers as I build an MDO suspension and brake gear.

PS. This is my OCD area, I cannot see the work surface to the right and this may yet save my fingers.

 

[daifly]

Bright, shiny, new etched sheets like this always fill one with a delicious sense of anticipation - tempered in this case, perhaps, with slight trepidation in case Mr Cockup has got involved with the drawing when it's ones own production! Hope they make up as well as they look, Simon!

Cheers

Dave

 

[SimonT]

Mr Cockup called at the first shot stage when I realised that the numpty on the mouse had forgotten to put keeper plates onto the etch!

Simon

 

[SimonT]

W-Irons on and starting to build the brake gear. This is for an unfitted BR Longlink brake.


There is, of course a small list of things that I could do better Oh, I've changed the method of retaining the spring onto the carrier and this has resulted in a far simpler method of assembly.

Simon

 

[Pugsley]

Mr Cockup called at the first shot stage when I realised that the numpty on the mouse had forgotten to put keeper plates onto the etch!

I'm so glad it's not just me that does that kind of thing!

 

[SimonT]

As I assemble the brake gear I finally realise what I find annoying about the various after market brake improvement kits. There are three main pieces that can float on the floor of the wagon - the two W-irons and the V hanger pivot. Any small difference in position or alignment of any or all, creates a difference in how the brake shoes sit on the wheel and hence the angle the brake rods sit. One small wiggle can upset the entire set up. I now think that the brake hangers and V hanger should hang down from one etched piece, ensuring proper alignment of all the brake components. This can be placed on the floor of the wagon and then the W-irons offered up the give proper positioning of the wheel against the brake shoe.

Thoughts please chaps.

Simon

PS Found more muppetry! I was also working on brake gear for the Plates/Coils. Guess which length brake rod is on the soon to be retitled MDO Brake Gear etch.

 

[JimG]

Just delivered from PPD, my first set of etchings. The burning smell this afternoon will be my fingers as I build an MDO suspension and brake gear

Got my etches today as well, but a bit later in the day so I'm not so far ahead as you. But my etch is just a test etch - not the full sheets as you have done. Knowing how long it took me to work out my relatively simple "W" iron etch, those sheets of yours look like a lot of work, and they do look good.

Jim.

 

[adrian]

Just delivered from PPD, my first set of etchings.

Looks good. My new project this year was to try some etched components and I was considering PPD so a few questions if I may? What were they like to deal with? Did you follow their drawing guidelines and if so were there any queries? They mention something about defining the scale or providing a reference scale. Did you draw out your components to model scale (1:1) or prototype scale and how did you tell PPD what scale to etch at? I'm not sure I've got your courage to print out a full sheet as a first attempt. Although I presume it's cheaper to produce one large photo tool and one etching rather than one smaller photo tool and multiple etchings. Finally what was the turnaround time like. Thanks in advance.

Adrian

 

[SimonT]

Jim, Adrian,
I did a test shot of each before Christmas. My mistake was in only having one W-iron etch as this meant that I couldn't assemble all the brake gear. I assumed that the push rods would be ok; my chief concern was to test the folds as I was concerned that they were most likely to be the thing I got wrong. Please call me Pike.

Adrian I learned a lot from your drawing! The PPD definition of the use of colours made no sense to me and your artwork showed me what they meant. To me there is just a drawing for the front etch mask and one for the back mask. I based a lot of my technique from the article in MRJ by Gordon Gravett, although I did do some bits differently.

I found PPD to be very friendly and helpful. I have talked/e-mailed the chap who is doing my work regularly. All my drawing is done at 1:43.5 (model scale), so PPD just have to print. I tried drawing full (prototype) size when I started on the 3D stuff and realised that it made no sense as the critical part of the model is the tabs, cut outs, fold lines which have to be drawn actual size for etching/printing; hence the calculator is always at my side. The test shot was for one of each etch. I phoned on the Monday to discuss what I was trying to do; I spoke to the lady at front of house. I e-mailed up the drawings that afternoon. On Tuesday I had a call from the guy doing my work and we discussed it and handed over the credit card details. On Friday morning the postie delivered the new toy. Cost was of the order of £30. The production run involved a new tool as well as the extra NS, so the cost will be higher. I don't know the cost yet. If there are no changes to the tool, future runs will be cheaper. For me the time saving and accuracy make the cost acceptable.

I've attached a pdf of one of my drawings so that you can see what I got away with!

All the best

Simon

 

[JimG]

Looks good. My new project this year was to try some etched components and I was considering PPD so a few questions if I may? What were they like to deal with?

They are good to deal with. I've never pushed them for a quick turnround and I generally get my results back in about a week, although I hit them at the wrong time just before Christmas and didn't get my etch until this week. It looks as though they shut down over the Christmas/New year period. They are pretty good with email contact, but the best way is probably a quick phone call.

Did you follow their drawing guidelines and if so were there any queries? They mention something about defining the scale or providing a reference scale. Did you draw out your components to model scale (1:1) or prototype scale and how did you tell PPD what scale to etch at?

I used the metal etching guides in the Hollywood Foundry website

http://www.hollywoodfoundry.com/HowToPapers.shtm

I found them to be the ones I could understand.

I draw the top layer in red and the bottom layer in blue and generate red fills and blue fills on separate layers. I draw to actual size for the etching since, as Simon says, you have to calculate grooves, slots, etc., in actual size to allow for undercutting in the etching process. I usually start off drawing the "visible" part of an etch in full scale units if it's easier to do it that way from a dimensioned drawing, then scale that down to model size to add in all the etching detail.

I use AutoCAD LT and DraftSite. I draw with lines, arcs, etc to start with then, when the drawing is complete, I go round all the outlines and convert them to polylines before trying out the fills. If there are any gaps in your outlines, then forming polylines will show them up. If you have got a gap and try a fill you will find it will "leak" out through the gap(s). I believe that the fills are used to generate the photo tools.

I don't provide reference marks or scales. I provide PPD with a .DWG file to actual size and they seem to be happy with that. It could be that they might do more work themselves to amend the drawing to their needs, but they have never asked me to change anything I do.

I'm not sure I've got your courage to print out a full sheet as a first attempt. Although I presume it's cheaper to produce one large photo tool and one etching rather than one smaller photo tool and multiple etchings. Finally what was the turnaround time like. Thanks in advance.

I've now started doing smaller test etches since I learned that getting a large sheet of faulty (my faults!!) etches is a bit of a drag. On my latest test etch, I included more than one test etch so that costs were minimised. PPD have a minimum size for their etches - from memory it is something like 300mm x 100mm. (I believe their sheet metal is in rolls 300mm wide) so going smaller than this area won't save you any money. Note that the cost of getting further etches from a phototool cost considerably less per etch than the initial etch which includes the costs of setting up the phototool. I can't remember actual costs at the moment, but I think I remember it being less than half the cost of the initial etch.

Jim.

 

[adrian]

Jim, Adrian,
I tried drawing full (prototype) size when I started on the 3D stuff and realised that it made no sense as the critical part of the model is the tabs, cut outs, fold lines which have to be drawn actual size for etching/printing; hence the calculator is always at my side.

Thank you very much for the feedback, it is useful. It's given me the confidence to jump in, PPD seem like they are geared up for the hobbyist.

As ever I had to do it differently. - I had a works drawing so drew it out to full scale. I then converted the tags up to 12":1ft. So the tags are all 3" square blocks! I found in QCAD there is a built in calculator, so any model dimensions I just factored with *43.543.

 

[AndyB]

Adrian,
You need to be a bit wary relying on CAD doing accurate scalings when using scale factors that high unless you are just doing something simple. Yes, in theory it should be a simple case of the computer doing lots of sums for each coordinate of each element, and I won't pretend to understand fully why it can fail - but sometimes it does with complex drawing files!
That's why I draw from works plans at 12mm/ft and then scale (up in my case by 1.125 to get to 13.5mm/ft) - just my preference.

I'll 'third' (or is it 'fourth') the above comments on PPD - for the hobbyist they provide a great service at a reasonable price.
From what I've had done,
305 x 100 brass 0.006" thick phototool is about £18 + VAT, per sheet cost £4.80
A3 size brass in 0.018" thick, phototool is about £40 + VAT, per sheet cost £27
Andy

 

[JimG]

Adrian,

Please note that with the prices being talked about the post and packing charges are quite significant. PPD use "guaranteed next day delivery" so the mailing costs are higher than normal. My recent order had a £10 (+VAT) P&P charge. So getting more than one job done at a time could have benefits on P&P.

Also, I just checked and their minimum size is 285mm x 50mm. I believe that their sheet width is around 300mm (maybe even 308.4mm ) and they need a margin to work with. But their minimum charge equates to about 285mm x 100mm. I've just realised that I'm talking prices relating to 15thou nickel silver - the cost calculations might be different for other metals and gauges.

Jim.

 

[adrian]

Thanks for all the replies everyone, it's been very useful - and apologies for hijacking your thread Simon.

 

[SimonT]

Adrian,
you are more than welcome; without hijacking we don't get conversation and to me, that is the point of WT.

Simon

 

[SimonT]

Morning chaps, time for an update.

The MDO has been finished looks reasonable for a prototype with a few more errors found. These have all been corrected. The biggest problem was getting the brake guard/guide to work with two reverse folds at the top and the bottom. I have now redesigned it and produced separate front and back etches which are aligned with a .7mm wire pin and then soldered up.



Remembering that I have a dozen wagons that have been running faultlessly on Mike Osbourne's internal springs, which feature a bearing that is soldered direct to the spring, I decided to solder the spring onto the carrier. Seems to work perfectly.

The carrier sat in the W-Iron. Rather than drop the complete wheel/carrier set in and then thread the springs through the .6mm holes, which is very fiddly, I now put them in like this and then spring the W-Iron open to allow the axle to enter the bearings. No distortion or swearing!



Finished article ready to be set into the vehicle. The clearance of the brake block is set at this stage by defecting the wheel to mid position, moving the brake block and suspension arms to the required position and then supergluing the block, pin and arms together to lock the position. I used a medium CA. Again no swearing, etc!