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Diagram3D GNR 4 Comp 3rd Class Brake (Dia 281)


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Like others I have seen these mentioned but had no idea if they were any good. Other than the supplier's web site there was very little information on them so I decided to swallow the bullet and purchase a Diagram 189 GNR Composite Brake body.

 

An order was placed on Monday night via their web site and the kit arrived today (Wednesday), so a promising start.

 

The kit arrives packaged like this:

post-3717-0-36363900-1435179834_thumb.jpg

 

On removing from the packaging and instruction sheet there are a pack of laser cut components, some glazing material and the plastic moulded Smartframe locating pins:

post-3717-0-39377200-1435179947_thumb.jpg

 

In addition to the MDF Smartframe (which in this case includes the floor as well) there are a lot of thin card frets:

post-3717-0-15644600-1435180008_thumb.jpg

 

Here is a closeup of one of the end panelling overlays complete with holes for handrails. The quality of the laser cutting is beautiful and the panelling notably thin:

post-3717-0-53152000-1435180091_thumb.jpg

 

More layers which will ultimately be laminated together:

post-3717-0-33777200-1435180143_thumb.jpg

 

Door lines are supplied ready cut with the laser:

post-3717-0-54110700-1435180188_thumb.jpg

 

Still more layers (I did say there were a lot). The instructions suggest there should only be one partition layer, but I seem to have 2:

post-3717-0-75254400-1435180256_thumb.jpg

 

The instructions also suggest that the individual layers are treated with a spray fixative, however I have followed an old fashioned approach of covering them with shellac (in this case French Polish) by pouring into a foil dish and applying thinly using a cotton wool bud for getting into those important little places. The bottle shows evidence of the supplier which is long lamented having closed some years ago.

post-3717-0-55333800-1435180435_thumb.jpg

 

Both sides have been treated but now need a couple of days to really harden off. In the meantime I will try and work out what adhesive I am going to use to laminate the various layers together. Diagram3D recommend using PVA for the MDF components but do not mention a glue for the card layers. An email to them the other night has not resulted in a reply so I will probably use diluted PVA as the treated card should not expand from the water content (hopefully).

 

So far the quality has been excellent and I am really looking forward to seeing the sides laminated together.

Edited by MikeTrice
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Looks like a good start Mike and an interesting kit. I thought about doing something similar in N gauge but decided I was pushing the boundaries a little too much for some <0.2mm beading!

 

One query though, if I may. I once used French Polish due to it's, shellac content, but then found I couldn't paint over the top of it. Is this a common problem and do you use anything specific to provide a barrier between the polish and paint? In my case at the time, I got around this problem by coating the card with a thin layer of Halfords car resin and letting that soak into the card - it created the hardest 0.25mm cardboard I've ever seen!

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I've been looking at those too Mike, Steve White had one at Ally pally and the layers look superb. Any idea what you're going to do with underframe ? ( I realise I'm asking a bit of a silly question there.....)

 

I'm working my way through my pile of wagons and did think about one of these 3D's afterwards but I do have a few locomotives to do and I do have all the parts for them......and there is an A5 and a G1 to do........

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Before continuing with the saga, the kit is for a Brake Composite which had Fox bogies. I went for this coach as I felt it would be easier to build an underframe for it from styrene than for a 6 wheeler.

 

I will probably try using permanent spray mount to laminate the layers together, but like the idea of using meths. It would be interesting how strong a shellac joint would be. Curious about problems painting over shellac as it is used amoungst other things as a knotting treatment in timber before painting. I will have to produce a test piece.

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I thought I would press on and assemble the Smartframe jig.

 

The instructions state "Attach the clips to the bottom section of the Smartframe. Partially insert the clips and then press firmly home by placing a firm flat surface such as a table top" (that is their grammer not my miss-typing). All the clips broke in two:

post-3717-0-90936300-1435246028_thumb.jpg

 

The clips I suspect are resin cast and are really too tight for the mdf frame. They look as if they have a slight meniscus curve to the surface and are a bit tight in the layer slots:

post-3717-0-86777400-1435246029_thumb.jpg

 

At this point I thought that would be it, but I realised that most of the clips had at least one half that had most of its prong. The clips were sanded down to be a nice fit in the layer slots then glued in place on the MDF with 5 minute epoxy.

post-3717-0-47770400-1435246030_thumb.jpg

 

The instructions suggest that the central elements of the mdf frames are removed which leaves the bulk of the laminations unsupported during the gluing process. I was not keen on this approach and would prefer to have a completely flat surface as my base layer of the jig. To that end the internal components have been taped in place. The original design of the locating clips would have raised this fret off of the worktop, but now the clips have broken with a little sanding the base plate now sits flat on the surface ready to proceed.

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After a lot of careful filing I am now happy that the locating pegs are a good fit in the layers and the top mdf frame. So starting from the bottom layer they have been slotted info the jig with 3M Craft Mount Permanent Adhesive being sprayed on the back of each subsequent layer:

post-3717-0-83685900-1435248297_thumb.jpg

 

With the lower support still taped in place I can replace the removed centre section thus and put under a heavy book for the adhesive to go off:

post-3717-0-52042200-1435248298_thumb.jpg

 

When placing the glued layers in place it is important to locate the bottom two pegs and slots first before allowing the glued layer to come into contact with the layer below as the glue does not allow for adjustment.

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I like the way this uses modern methods with old materials.

 

I would not worry about shellac sticking. As a watchmaker we used it to glue parts to the lathes faceplate for turning. They were smooth and it stuck well with porous card I would say it would be excellent.

Edited by N15class
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Set of laminated sides on removal from the assembly jig, before placing under a weight again:

post-3717-0-64326100-1435266159_thumb.jpg

 

Close up of sides:

post-3717-0-71144400-1435266161_thumb.jpg

 

The end laminates were loaded up next. Unlike the sides these are not all 4 layers deep so I had to be careful when spraying the adhesive to mask any parts that did not have a corresponding component on the lower level. The top surface felt a bit sticky from the adhesive spray so to play safe I put a layer of cling film over it before putting in the mdf filler piece and weighting down to cure:

post-3717-0-90055600-1435266162_thumb.jpg

 

The end panels removed from the jig:

post-3717-0-47191200-1435266164_thumb.jpg

 

Close up of the guard's end:

post-3717-0-25777500-1435266165_thumb.jpg

 

All are now under some heavy books to cure overnight. So far they seem quite flat.

 

BTW I am wondering whether to do a light coat of shellac to seal the various layers together as a back up for the adhesive.

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From what's been said by others , I'd feel more confident about the sticking powers of shellac than spray mount. I'm not sure I'd give spray mount more than 5 years , and the last thing you want is that lot delaminating . Belt and braces seems very attractive

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The fact that you found it necessary, or at least desirable, to alter the construction of the assembly jig before you could make a proper start doesn't boost my impression of the kit so far. No doubt the model will be good, you'll see to that of course.

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With your interest in Silhouette cutters Mike, are there some useful ideas here, including the Smartframe, worth applying to home produced kits? How would card and shellac compare to plasticard?

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The kit is made up of MDF which is around 2mm thick and card which measures approx 0.24mm thick.

 

When producing axlebox springs on the Silhouette I used a similar technique using a pin point bearing as the locator. 

 

Moving on the sides have been separated from the frets with a new knife blade. The lower one has had the additional tabs removed from the panelling:

post-3717-0-90903300-1435348063_thumb.jpg

 

Closeup of one of the sides showing the level of detail. Once finished I have applied another coat of shellac in a hope of sealing the panelling in place once and for all.

post-3717-0-36261800-1435348065_thumb.jpg

 

At this point I did not feel I could continue to follow the build of the kit as designed. For some strange reason the interior partitions and roof supports are made from a single layer of 0.24mm card which I consider totally inadequate for the task. Why on earth the partitions were not laser cut in the MDF from the scrap in the top jig plate I will never know, at least this would have given a rigid base to attach the side to. As an alternative I glued the partition fret to a sheet of mounting board:

post-3717-0-33681200-1435348066_thumb.jpg

 

Here two of the partitions have been cut from the original layer and mounting board resulting in a thickness in the region of 1.64mm, much stronger than the measly 0.24mm provided in the kit.

post-3717-0-70450300-1435348067_thumb.jpg

 

So that is it so far. Unfortunately family commitments over the weekend will mean this project will now have to wait until next week to be resumed.

 

 

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I have some of their 7mm kits on order...

I for one would be interested to hear how you get on with them.

 

In spite of my earlier prediction I have managed to squeeze some construction time in today.

 

The turnunder was formed very simply in the lower panels of the sides by pressing the bottom panel against a piece of 155mm copper tube with my thumb, and working my way along the side. None of the beading came loose in the process:

post-3717-0-55749900-1435424816_thumb.jpg

 

View of one of the sides after the turnunder has been formed:

post-3717-0-19127800-1435424818_thumb.jpg

 

There is a really strange design "feature" for the non break end. These are intended to fit between the sides however the outer beading is not fully reinforced by the inner layer and remains unsupported. It also concerns me that the inner end is only 2 card layers thick and would much have preferred the design to be 4 layers like the rest of the sides:

post-3717-0-94168700-1435424818_thumb.jpg

 

Here you can see the non-brake end against one of my mounting board partitions. All very odd, and I will need to think about refactoring this when I get to that part:

post-3717-0-62083000-1435424819_thumb.jpg

 

The design is similar in ways to the Jenkinson approach of having the glazing inserted from the end of the coach before the outer ends are finally fitted. For this reason I have not yet fixed any outer partitions/ends in place but started by fixing one of my strengthened partitions in place using tacky glue supported by a couple of squares: 

post-3717-0-00393500-1435424821_thumb.jpg

 

Whilst the first partition is drying I decided to add a strengthening piece to the inner guard's partition to have something to glue the sides to:

post-3717-0-88760500-1435424822_thumb.jpg

 

This was then glued to the floor, however the inner end had the tabs which are designed to fit into slots in the floor. These slots were not wide enough so I had to file them thicker by folding a piece of wet and dry in two and forcing the resulting double sided abrasive into the slot and dragging it up and down a few times:

post-3717-0-89619600-1435424823_thumb.jpg

 

To fix the sides to the floor and the first two partitions I changed tactic and used Evo-Stik in contact mode. The side is positioned tight against the inner end of the guard's compartment.

post-3717-0-95540000-1435424824_thumb.jpg

 

The rest of the side was pressed against the floor/partitions.

post-3717-0-82861000-1435424825_thumb.jpg

 

The remaining partitions have been stuck in place, again with Evo-Stik:

post-3717-0-79367700-1435424826_thumb.jpg

 

And the second side stuck using the same method as the first. It is now starting to look more like a coach.

post-3717-0-89784800-1435424897_thumb.jpg

 

Interestingly the design of the kit is such that at the moment there is no upper support of the side to the partitions and also remember that in the original design the partitions are a single layer of 0.24mm card:

post-3717-0-76593600-1435424898_thumb.jpg

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Hi Mike

 

I've been following your moves daily. I'm not criticising what you have done in any way, it's great, but are you going to line the coach? If so, wouldn't it have been easier to do it whilst it is still in pieces and whilst the sides are still flat?

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The instructions also suggest that the individual layers are treated with a spray fixative, however I have followed an old fashioned approach of covering them with shellac (in this case French Polish) by pouring into a foil dish and applying thinly using a cotton wool bud for getting into those important little places. The bottle shows evidence of the supplier which is long lamented having closed some years ago.

attachicon.gifIMG_2907.JPG

Is there a difference between products sold as French Polish and those sold as Shellac, and if so, does it matter for this purpose? Living far from civilisation, I don't get much of a range to choose from when I go shopping, so would like to know if it's OK to buy anything I come across under either name.

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Button Polish is another variant I believe.

 

Kestrel, the instructions do suggest that it might be easier painting as you go and I have reached a point where it is almost impossible to continue without painting what I have produced to date. The reason I have hesitated is I am really not clear how to proceed and circumvent the design flaws.

 

Lining was discontinued in 1928 so I can happily ignore it unless I give in and finish the coach in GNR livery to go with the NRM Atlantic.

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Have started my teaking process by applying a thin coat of Vallejo Bright Orange:

post-3717-0-44983000-1435681503_thumb.jpg

 

The inside of the guard's compartment:

post-3717-0-95256700-1435681512_thumb.jpg

 

The ends:

post-3717-0-29577300-1435681523_thumb.jpg

 

It was at this point I realised that with the end windows the infilled partition would block the view into the full length of the guard's compartment. Fortunately carefull work with a sharp blade let me slowly cut through and open it up however it leaves a VERY weak top profile:

post-3717-0-34065600-1435681532_thumb.jpg

 

To strengthen up the partition I added two strips fixed with tacky glue:

post-3717-0-31218000-1435681542_thumb.jpg

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The Vallejo Bright Orange has been given a coat of Klear to seal it.

 

The design of the Guard's compartment has two full width laser cut acrylic glazing sheets. Here you can see one, still with its protective covering. As you will see it locates below the top of the side:

post-3717-0-79441800-1435777112_thumb.jpg

 

The Guard's end itself has a laser cut recess in the end, presumably to locate the toplight of the sides:

post-3717-0-50935400-1435777122_thumb.jpg

 

As can be seen it is far too wide as supplied:

post-3717-0-22435400-1435777133_thumb.jpg

 

Here you can see how the supplied side glazing sheets are fitted. These will hopefully stiffen up the sides once complete, but at present are just placed to illustrate:

post-3717-0-74817800-1435777141_thumb.jpg

 

To address the recess issues on the end I clamped one of the glazing sheets in place, then glued a strip of mounting board across the top cut to he revised width between sides:

post-3717-0-66275900-1435777160_thumb.jpg

 

The same was done for the inner partition:

post-3717-0-02889900-1435777172_thumb.jpg

 

Unfortunately the clamp was a bit too harsh and has dented the panelling overlay slightly. I will use a peg next time:

post-3717-0-16994000-1435777183_thumb.jpg

 

The end has been fixed in place using tacky glue ensuring that the top of the gurad's lookout is located up against the extension of the side so it matches the inner partition:

post-3717-0-48383200-1435777193_thumb.jpg

 

The two extensions to the sides have now been glued using tacky glue:

post-3717-0-63344500-1435777202_thumb.jpg

 

So a quick recap. The inner partition is fixed by the slot in the floor, the outer end by the end of the floor. Unfortunately when one of the duckets is tried for fit the bottom shows a gap:

post-3717-0-40212700-1435777213_thumb.jpg

 

Moving camera position illustrates this more:

post-3717-0-60736500-1435777223_thumb.jpg

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