7mm The next project. (B1)

Eastsidepilot

Eastsidepilot

Western Thunderer
mickoo said:
You're a very naughty boy;), we don't let all of the cats out of the bag at once :cool:

Seriously though, there's plenty of holes to fill first and the B17 is served by DJH which puts it in the secondary engines to consider.
Click to expand...

To be honest I thouht I'd heard sometime ago that the DJH B17 was to become un-available and in any case your product would knock it into a cocked hat mate.:thumbs:.....and I would'nt be throwing half or two thirds of your kit away :))

Col.
 
John K

John K

Western Thunderer
The whole DMR range is with Phoenix Precision and has been for some time. They are very much available and very buildable.
No connection except as a content customer.
John K
 
Eastsidepilot

Eastsidepilot

Western Thunderer
John K said:
The whole DMR range is with Phoenix Precision and has been for some time. They are very much available and very buildable.
No connection except as a content customer.
John K
Click to expand...

I've built a B17 using a DMR kit, not a bad bases but it's a bit short on accurate detail and fittings especially the cab interior, no inside motion at all, there was still a lot to replace and add but then the kit design is getting on a bit now.
For what it is it's bloody expensive as well or should I say over priced, I think I'd say that about the DJH kit also......this is just my personal opinion of coarse :D.

Col.
 
farnetti

farnetti

Western Thunderer
I always struggle to hold laminations in place whilst soldering, the little blighters always move under the heat.

Hi Mick, like you I find small laminations difficult to keep in place when soldering.

I have no experience in the arcane art of etch design but couldn't the use of half etched rivets and half etched relief on the overlay allow correct positioning. I appreciate this might involve an extra layer and therefore be impractical, just a thought.

Ken
 
mickoo

mickoo

Western Thunderer
Ken,

There are several ways to hold overlays in place, one is a half etch depression into which a full depth part is placed, thus leaving an effective half etch raised piece, normally this works particularly well.
But it can suffer in rolled parts as the half etch depressed area bends at a different rate to the surrounding full thickness and creates stresses and micro bends in the surrounding material; the area around the depression tends to bulge out.

The one snag here is if the full etched part has rivets to punch and is very small, it's very difficult to hold, form and punch them, so what you gain in doubling the thickness to hold it in place, you loose in fidelity and work-ability, the vacuum ejector flange on the left side of the smoke box is a good example. It would be very hard to punch those rivets that close to the flange edge, a half etch part with raised detail is better but needs holding in place.

Another way if you need full thickness overlays which have rivets punched on them (as in the case of the steam pipe cover flange) is to also punch identical rivets in the wrapper behind to match the holes in the rear of the overlay. If the part has no punched rivets then simple half etched holes on the rear to locate on the rivets punched in the base layer will suffice, so long as the punched rivets below are not over done, if they are you end up with a part floating on the surface and a gap to fill around the edge.

In the case of the buffer beam bracket the web (large flat bit with the hole in) has a tab which passes through the flange plate which is riveted from behind, on the main frame is a corresponding slot into which that tab locates.

However, even with all those aids, I still struggle to hold bits in place ;)

MD
 
farnetti

farnetti

Western Thunderer
mickoo said:
Ken,

There are several ways to hold overlays in place, one is a half etch depression into which a full depth part is placed, thus leaving an effective half etch raised piece, normally this works particularly well.
But it can suffer in rolled parts as the half etch depressed area bends at a different rate to the surrounding full thickness and creates stresses and micro bends in the surrounding material; the area around the depression tends to bulge out.

The one snag here is if the full etched part has rivets to punch and is very small, it's very difficult to hold, form and punch them, so what you gain in doubling the thickness to hold it in place, you loose in fidelity and work-ability, the vacuum ejector flange on the left side of the smoke box is a good example. It would be very hard to punch those rivets that close to the flange edge, a half etch part with raised detail is better but needs holding in place.

Another way if you need full thickness overlays which have rivets punched on them (as in the case of the steam pipe cover flange) is to also punch identical rivets in the wrapper behind to match the holes in the rear of the overlay. If the part has no punched rivets then simple half etched holes on the rear to locate on the rivets punched in the base layer will suffice, so long as the punched rivets below are not over done, if they are you end up with a part floating on the surface and a gap to fill around the edge.

In the case of the buffer beam bracket the web (large flat bit with the hole in) has a tab which passes through the flange plate which is riveted from behind, on the main frame is a corresponding slot into which that tab locates.

However, even with all those aids, I still struggle to hold bits in place ;)

MD
Click to expand...
Thanks Mick, all very helpful. My preferred method to attach smaller laminations is with the RSU and a very small amount of solder cream. The pen is used to hold the part in place, but it can be a bit tricky to get the orientation exactly correct before heat is applied.

Ken
 
Scale7JB

Scale7JB

Western Thunderer
There's an awful lot to be said for just holding things with fingers...!! Either bare, or folding up some paper with a few laminations and holding with that. A little dab of solder in certain places which will hold it in position and then solder around the rest of the edges.

JB.
 
Eastsidepilot

Eastsidepilot

Western Thunderer
Sometimes I hold small parts in place with a cocktail stick and place the carbon rod close to it to get the heat in.

Col.
 
mickoo

mickoo

Western Thunderer
7mmMick said:
No blu tac square, disappointing :D
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I haven't transcended to that Dan yet ;)

mth said:
Just a idea, have you tryed Guard-Tex self adhering safty tape. see Coming Soon - Future home of something quite cool
wife gets it for her jewellery making.
View attachment 66848
Click to expand...
Interesting, that'd be worth a look.

JohnFla said:
Or you could try these, very useful.

100 Mini Small Natural Wooden Craft Pegs Clothes Paper Photo Hanging Spring Clip | eBay
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Yes I have those, only problem with wooden pegs, small or large, are the oils in the wood, once they've been heated to 300-400° a few times the oils weep out and blacken which tarnishes the work and makes them slippery little devils.

MD
 
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