Member postings for Simon Collier

I mounted and tested the 4 jaw chuck I had converted from Hercus to Myford (see above 2 days ago). There was a visible wobble, and TIR on the front face was at least 10 thou, so I'll have to call the project a failure. For comparison, I tested my direct mount (no backplate) 4 jaw on the Hercus: perfect, with undetectable runout on the face. I can always reclaim the chuck by chucking it in my Chinese 8" 4 jaw and bore away my Myford threaded sleeve. I suppose it was a big ask to get a precision result with such a project.

Thank Ian for you idea, and thanks Nick for your endorsement. Losing the chuck body bore is a necessary sacrifice but I don't see how a genuine, directly threaded Myford 4 jaw could be any different. By the way, I am going to use the spare backplate for an ER32 collet chuck for the Hercus. Two chucks from one (almost)!

Thanks Swarf, I had thought about scotch keys. I know people don't trust Loctite but with this large surface area, and the access to clean it properly with acetone, I'd bet money it would take any amount of torque an ML7 could throw at it. I think the bad reputation came from the widely held mistaken idea that Loctite required a gap to fill. A close sliding or light push fit is correct, leaving only micro structure to fill.

I converted a Hercus 4 jaw with backplate into a Myford 4 jaw without backplate. I made an adaptor from cast iron, screwcutting the Myford spindle nose thread and turning the register. The outside diameter was turned to a close sliding fit in the bore of the chuck body. I will Loctite it in tomorrow. The chuck was given to me, an ex-school one. The schools are closing down metal work these days because it is, apparently, too dangerous. Our club was given a 3-phase lathe and drill for the same reason. I have an excellent directly threaded Hercus 4 jaw, but not a 4 jaw for my ML 7. I'll probably never use it, but I wanted it for completeness. The threading was extremely difficult for me as you can't test it until you remove it. In fact I ended up removing it twice, and returned it and clocked it up and continued. Good fit in the end, if a bit ugly.

Yes, as a boiler feed pump. The engine has this and one excellent injector, also made by Warwick Sandberg. I almost always use only the injector but the pump does work well.

Thanks John. In the absence of any opinions I would have gone for the New Shay. I find gear cutting very appealing but I am not going to get around to it in this lifetime.

I have heard nothing but praise for Kozo's books and would like to get one for general interest, not to build the loco therein. Which is the best, by which I mean, which has the most interesting and varied techniques and content?

I have one of these on my Simplex:

http://www.hugin.com.au/modelrail/single1inch.htm

Probably my favorite episode of Dad's Army.

I do it. Can't hurt, might help. I do the first with little more than a nip, then successively tighter on the next two. I can't justify it and I am not an engineer, but it feels right.

Where do you live? Cairnes or similar? My ML7 was a lucky find. I got it from the original owner who was going into a retirement village. He was happy with $300A and really just wanted to get rid of it. All original equipment and sales brochures! Sounds as though you are fully capable of restoring it and I hope you will post progress pictures. How do local smash repairers get on in the wet season?

i just measured mine. Two are 1/2 inch and one is 15 mm. I also have the left hand one. They all take 1/4 bits. In theory a 16 mm/8 mm might be more rigid if you like to take 3 mm cuts, but in practise, negligible. If you have the bit low down, it can bring the front of the tool bit jaws too close to the work for comfort on some jobs, such as facing. I would strongly recommend the 12 mm.

Edited By Simon Collier 1 on 10/01/2017 03:52:51

There is only one way to learn boiler making, and that is by making boilers. I admire you for doing it. All the theory in the world tends to go out the window as soon as you light that big, scary torch. The block falling off is a classic example. I had a top fitting block not fall of, but rotate slightly because the screw was a bit loose. I make bronze 5 BA screws from Colphos 5/32 hex. I avoid rivets mostly. This allows me to assemble and disassemble the parts to check and adjust fits etc.. As mentioned, don't use brass screws or rivets; you want copper or bronze. Some things are really important to get right the first time, the foundation ring being the obvious one. If you don't get penetration the first time when the joint is clean and fluxed throughout (HT5 type, not Easyflow type), it is near impossible to get penetration later. You end up relying on a coating of SS "painted" on the bottom of the ring and wrappers. You can fix a specific leak by drilling a hole for a 1/16 rivet which you then flux and drop in and solder up, but I would say that you need oxy for foundation ring "repairs". Just last week I helped a friend fix his badly soldered foundation ring, using oxy propane with a big heating tip, not a little brazing tip. We got it pressure tight in the end and it passed it's hydro, but it was a horrible job.

It is important to go to any amount of trouble when the job is cold, to help things got smoothly when the job is hot. You need the right heating equipment (with excess capacity, not barely enough), the right firebricks, the right flux, spare flux, gas and silver solder on hand, etc., etc.. This is after you have read everything you can on the subject and made practise joints and got comfortable with your equipment. You need gravity working for you, so you need to be able to move the boiler while hot. Practise this when cold with two pairs of molegrips, tongs, whatever but not gloved hands! Even two pairs of welding gloves won't save you (how do I know this?). Be mindful of damaging the annealed copper with the jaws of the grips:- wrap a bit of copper round them or something.

If at all possible, have an experienced friend to help. A second person of any sort helps enormously, to hand you things, pick up lengths of solder you drop, etc.. Wives can sometimes be persuaded!

Unless you are happy to pickle overnight after every heat, you really want reasonably strong sulphuric acid. Mine is 2 molar, but 1 molar would be OK. I bought a couple of winchesters of conc from a chemical company. It is not restricted here (Oz) but people assume it is or don't know that you can simply order it. I was a laboratory based medical scientist so I am very comfortable, but suitably careful, with strong acid.

The great thing about silver soldered copper boilers is that they are so forgiving. That is why beginners can manage it, and I am not aware of a boiler under construction having to be scrapped at my club.

I fitted to a cheap oil can a brass end with an internal o ring selected to squeeze over my ML7 oil nipples. It was a quick and dirty prototype to test the concept, but it worked so well it remains in service. Works a treat.

I can't understand why so many people are comfortable buying copper boilers anyway. They are a rather large and dominant part of the engine. If you haven't made the boiler, you haven't made the loco. And you are denying yourself one of the most enjoyable and satisfying (and yes, at times stressful), parts of the build. A friend recently completed his first boiler, for a large 5" gauge pacific. The barrel section has two diameters, rolled and butt strapped. It has a combustion chamber with Galloway tubes, it has palm stays, and also a complicated regulator fitting on the backhead. It shows what can be done, even with a first build.

Fizzy, concentrated sulphuric is about 18 molar.

I have both. The 4" has a chuck mounted permanently. I use it almost exclusively, but the 6" comes out for e.g., rod bosses. Also, the 4" is a nice blue but the 6 is that ugly rough black finish. Both Vertex.

Thanks Neil. I do find the subscription renewal page confusing. I have emailed a query.

I went looking back through emails. Renewed for one year on 26-11-15, Order No. 708. Last magazine I received was 4543.

I have not had an ME for weeks. I can't find details of my subscription end date but assume it has run out.