I originally developed this idea after Jim Pairman had an article in the S4 News about making cube rivets, I thought the bolt heads on the outside of the wagon body had washers and nuts and in our scales these should be circular. The punch is a bit of 0.33 steel wire and you may want to use something slightly larger for Scaleseven. This is mounted in a universal mini drill press.
I took some not very good photos some time ago as I had intended to write an article for the S4 News. I never got round to taking better photos so the article was never written. Anyway these should be OK for our purpose.
The secret really is to set the punch so that it just penetrates the plastikard. Underneath the plastikard is a plastic eraser. This one I think came from the Science Museum courtesy of my son. It is quite easy to produce bolt heads in quantity.
My piece was in Scalefour News, issue 196, about using black styrene to represent nuts etc. The contrast of black against white styrene made positioning much easier - using a No.11 blade, of course.
I can provide a screenshot for anyone interested - please send me a pm
Jim P
Oh dear - I seem to be the odd man out re bolt/nut heads! I didn't fancy all those tiny pieces of styrene so my method is to drill 0.5mm holes and insert styrene rod to represent the nuts - Plastruct do a 0.4mm diameter which fits nicely. Then finish of with a tiny drop of MEK to round off the protruding end. OK it's a bit demanding to get rows of holes in line, but I used a little jig for that which I showed in my Diagram 124 build. I've since acquired a Proxxon compound table which I think might be even better for drilling dead straight rows of holes but haven't tried it yet. One of the advantages of this method is that by drilling through the washer plate on the inside you can get a representation of the (flush/countersunk) bolt heads and another is that the inserted rod helps to hold laminations together!
On a different topic, sorry to hear about your hip JimG. Hope your recovery goes well.
Thank you very much for posting those pictures and providing an explanation. It looks to be a far more professional way of producing bolt heads than my current method, I may well give it a go.
I haven't used Tony's method for washers or the likes and I'm now wondering why not, as I've used the method for larger pieces. For instance a blunted oval nail (possibly 2") will punch out oval builder's or number plates. I punch into a bit of lead and they come out neat each time (haven't done so for a few years now tho').
A couple of follow up thoughts. I think Len Folkard developed the first method of forming bolt heads back in the early 1970s by using a punch to form tiny domes in 10 thou plastikard and then slicing these off with a single edged razor blade. I used this method myself for many years and I guess Mike Williams uses the same technique for his TLM patterns.
A brilliant way of combining my punch method and Jim Pairman's would be to use 10 black plastikard. The modelling trade doesn't offer this as far as know but at the South London Group of the P4/S4 Society in the early 1970s we used to buy plastikard direct from the manufacturer. I don't have any details of this now but has anybody ever explored suppliers outside the modelling trade? If not I will try it myself.