Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length.

[Telusboats]

Does anyone have the brass photoetched conning tower for this sub. I have been looking for one with little luck.

[Klunk]

http://www.modelbrass.com/

[Telusboats]

Thanks for the reply. I have emailed that outfit and the response was sporadic. I phoned as well but again I did not get any results. I think that since robbe has discontinued these boats the demand for these parts is not worth the bother for sellers.

[Subculture]

Draw a cad file and have it laser cut in acrylic- will be strong enough.

Or file out the holes from some GRP or plastic sheet.

[Telusboats]

Thanks for the suggestions but I would rather go in the direction of the brass photoetched parts. Hopefully someone will know where I can get one or has one they never used.

[essex2visuvesi]

As the U47 has been discontinued by Robbe I doubt there will be many people making addons for it now.

[Subculture]

I would rather go in the direction of the brass photoetched parts.

Why? Plastic is just as good as metal in this instance. You may find it difficult to get someone to part with a piece like this. Or etch your own- not that diffiult to photoetch at home. Another alternative is to have a brass deck water jet cut.

[Telusboats]

Have you any articles as to how any of these methods is done? And what is the level of difficulty and expense?

[Subculture]

For laser or waterjet cutting, it's a case of contracting to a professional. This kind of work is getting quite cheap these days, as the cost of the machines is lower, and they're faster at cutting- time being money for these things. You would need to supply a CAD drawing, if that is beyond you, then some places like model engineers laser will make a CAD drawing from a hand drawn image. However you will have to pay extra for this, so if you can do the CAD work ourself, it will be a bonus.

http://www.modelengineerslaser.co.uk/

To perform photoetching, you can do this at home with a minimum of materials. Big items like photoetched decks would be very difficult, but a small item like a tower deck should be well within the limits of home working.

Have a look on Youtube for tutorials on photoetching. At a minimum you can paint the pattern onto some brass, and etch it with ferric chloride (try ebay for supplies) in a plastic tray.

[Davy1]

Hi,
I have tried photo etching brass and it is not that easy - certainly more difficult than making Printed Circuit Boards, for example.
You have potential problems with cleaning the material. The brass is generally thicker than PCB copper so you can get undercutting and the resist can lift etc.
By the time you have experimented and produced a single item you may have wished you had gone into production!
You may be best to hope to buy one from someone's abandoned U47 project or go to a professional or a keen amateur. Anyone on here do photo etching on a regular basis?
David
 

[essex2visuvesi]

Not personally but I do know a chap who does limited run and one off brass etches for model railways.  He used to retail EB kits but has since retired.  He did keep the equipment and does a few bits on the side... not cheap tho

[Subculture]

For cleaning brass, try Cif, works great, and being a household cleaner, it is cheap. Pretty much any abrasive cleaner will work.

Undercutting is a fact of life with photoetching, experiment with various size holes, slots etc. and see what gives the result you're after. Etching from both sides at one cuts down on etching time, and helps reduce undercutting.

You can also purchase brass sheets with photo resist pre-applied. This eliminates the need for cleaning and adding photo resist, but is a bit more expensive.

You can make a photo tool using CAD and a laser printer. If CAD isn't your bag, draw the item by hand, four times the size would be easy for a piece the size you want. Scan it in at a high resolution, and shrink it down in software to the size you want, then print that. Laser printers will not produce a fully black photo tool, you get bits where the black is missing. A trick to overcome this, is to print the item out on two separate clear sheets, overlap and bond them together with superglue. This gives you a true black photo tool. Not sure about inkjet, haven't tried it. If you haven't got a laser printer, you could have the drawing printed at a print shop, but it's likely to cost you more.

If all this sounds like too much hassle, or you don't like to experiment with new techniques, then there are places that will do the photoetching for you. Generally the cost is about £20-30 to produce a phototool (a one -off expense) and then you are looking at about £30 per A4 size sheet. You could get several conning tower decks on an A4 sheet, so if you know others that require this part, then you could split the cost between you.

You will still have to produce the artwork though.