I would like to start this blog entry with a request for some help. Hopefully there is someone out there who will be able to help me out....
Amongst all the other things I am trying out is my attempt at making my own wheels, not only for standard gauge but also for the smaller narrow gauge bits and bobs where wheels are hard to find. Now I have figured out how to most of the bits for wheels with the exception of the wheel rims which to date have been beyond my capabilities. I have seen on the interwebs articles where a form tool for wheel rims can be made by producing a wheel and using that to produce the form tool but that means producing a wheel rim in the first place. I have also seen on this blog http://otiraminiatures.blogspot.co.uk/ a tool which has been wire eroded but sadly the guy hasnt replied to my request.
Therefore I would like to ask if anyone knows of, has access to, or knows someone who has the use of a wire EDM machine who would be willing to produce some form tools for me? I can provide everything (apart from the EDM machine!) needed. I have approached a few engineering companies so far and I have had only a single reply quoting a couple of hundred pounds to produce one. If there is anyone out there who could help, it would be VERY appreciated...
Anyway, on other matters I have added a little bit of colour to the layout. I know everyone likes pictures so here are a few...
I am guessing I should add some trains sometime soon!
Julia :o)
Form tools used to be just ground up using a bench grinder and slip stones. I've done that for buffer stocks and heads, but you need a decent lathe to push a form tool into without chatter. n older book on lathe work will explain the process. I believe "The Amateur's Lathe" by L. Sparey is a good one. I think that's the name. I learned at school. My little modelmakers' lathe won't take the pressure, but if you rough out the rim to a template, then finish with a form tool, it should be possible. Very brave of you. How are you doing the spokes?
ReplyDeleteThank you for the reply Odds.
DeleteI am trying to produce a wheel rim profile as detailed here http://www.2mm.org.uk/standards/locochassis.htm so I feel it would be very tricky to produce something similar using a grinding wheel and slip stones.
As for the wheel spokes, have produced them in various ways including lost wax casting, 3D printing, and etching. Each method had its merits and disadvantages.
I don't see it as being brave, its just engineering at the end of the day, something that I should be good at!
J.
Hi Julia, trains not a requirement, this looks fantastic even without them :-)
ReplyDeleteI like those lupins.
Thank you Mikkel.
DeleteI wonder how long I can last before someone asks me to add some trains! To me the trains are very much just part of the whole scene.
J.
Julia - there's an article on the MMRS site which may be of interest which I've also linked on the RMWeb 2FS forum: http://mmrs.co.uk/making-wheels/
ReplyDeleteThank you Chris.
DeleteI have seen a similar idea to that MMRS site which does sound like a good idea. I have thought about trying it out in the past but for some reason I cannot get me head around how to form the tread of the wheel, even when I have ground up a tool to produce it. I guess the wire EDM is a bit of a lazy way around things but I was hoping that if I found someone who could produce the tools using one then it opens up the possibility of making them available to others too.
Thank you also for posting it on RMWeb, you never know there might be someone there who actually knows what a wire EDM machine is! :oP
J.
There is someone on German ebay who sells wheel profile tools for Z and TT along with larger scales, although strangely don't appear to do anything in the N sizes. Maybe one of those could be used to form the basis of a "Sid Stubbs" type tool, then modified to 2mm FS or even approach the seller to make a 2mm FS one as a special order?
DeleteThank you for the reply Graham, it sounds very promising. I don't suppose you have a link to them do you?
DeleteJ.
I do. http://stores.ebay.co.uk/carbide-solutions I tried to post it earlier, (twice) but it never appeared on the page.
DeleteThey don't appear to have the Z gauge ones listed at the moment but I know they had them when I bought TT Gauge ones last year.
DeleteThat is brilliant Graham!
DeleteThat is the best 'lead' I have had so far so thank you. I have sent them a message asking about other tools, hopefully they will reply.
J.
I wanted the TT ones primarily for TT wheels but I did think of using it to turn the basis of a tool as described in the MMRS article Chris Veitch linked to and then finesse it to 2mm FS standards before finishing and hardening it.
DeleteI don't know how similar the profiles are, it seems to b a minefield of all sorts.
DeleteI have emailed a couple of guys regarding 2mm profile tools now so fingers crossed I get something back.
J.
The TT gauge ones I bought from them are to the NMRA RP25 code 54 standards http://www.nmra.org/sites/default/files/standards/sandrp/pdf/RP-25%202009.07.pdf (bottom row) which are very close to the 2mm FS standards. Within 2 or 3 thou at most. I haven't got any 2mm wheels at the moment to compare with to see how closely the form tool matches but if the tool is accurate I think wheels made from it might well work with 2mm as they come out.
DeleteThank you Graham.
ReplyDeleteI will look into these, it sounds promising if the profiles are that close.
I have also got a reply back from the Carbide Solutions guy too so hopefully the Z gauge ones will be available soon.
J.
He's already put the Z ones up on Ebay http://www.ebay.co.uk/itm/VHM-Radprofil-Drehmeisel-4-0-mm-NEM-310-Spur-Z-cutting-lathe-Drehstahl-CNC-/111599960360?pt=DE_Modellbau_Modelleisenbahnen&hash=item19fbe04128 I see they also sell on Amazon.de. The Z gauge ones are to the NEM310 standards http://www.morop.eu/de/normes/nem310_d.pdf
DeleteThank you Graham, you have been a great help.
DeleteI went to order a Z gauge tool this morning but couldnt find a 4mm diamter tool holder so I have sent him another email to ask if he could list one.
Its all quite exciting!
J.
Well I have now ordered a Z gauge profiling tool along with a tool holder for it. I am quite looking forward to giving it a go once it arrives. Fingers crossed it does what I would like it to do.
DeleteThanks again for the link Grsham.
You should be able to start with some silver steel, file the profile with Swiss needle files and then harden and temper the tool. The remarkable live steamer "L.B.S.C." did it often when making very fiddly parts for his little engines like injector needle reamers and the like.
ReplyDeleteI think wire EDM is basically spark erosion.
Hello Odds.
DeleteThat definately is a solution but I fear I wouldnt get the accuracy I would need for such a small scale. To me this is definately a case where technology rules over 'old school' techniques!
Wire EDM is basically spark erosion using a fine wire as the electrode, its a very accurate method for cutting hard steels amongst other materials.
http://en.wikipedia.org/wiki/Electrical_discharge_machining
J.