Member postings for JasonB

Thought so image of my larger machine's one removed with pin still in place. You have even poste dpicture sof your topslide with the clamp plate and round bottom removed so if you have done it once it will come off again.

Edited By JasonB on 15/09/2023 14:46:14

I think from an earlier post you can just prize the round base off the compound now that the three screw shave been removed without worrying about the pin.

Is there an opening on teh opposite side? I don't think there is so driving it out with a Flat ended poun dpunch or bar is not going to work. Sonetimes the imported machines have the insid eof the blin droll pins tapped so you can put a screw into them an dthen pull on the screw to remove the pin.

Same with the valve gear on such a small engine a slip eccentric would do the job if there is a actual need to reverse it or Stephensons gear if you really must.

Is theengine intended to drive anything or is it just for display? even less than 30psi would do for display

Either way steam consumption is not going to be much and with that size boiler you would get a decent run time without the need to refill. 5/16 is only Mamod size and they run a smaller boiler, even allowing for two cylinder sit won't need much.

You would be best practicing with some of that tube first. The problems start if you need to remove and replace an overheated tude as it requires a higher temp to remelt the solder and you also have to get the assembled boiler completely clean as if you don't fresh solder won't take and you will tend to apply excessive heat trying to get it to flow which burns out more tubes.

Going down to 0.7mm wall tubes may just be pushing it too far.

Have you any experience silver soldering? I know of novice builders overheating and damaging tubes of far thicker wall so the risk is a lot higher with 0.7mm (22swg) For what you are going to exspend on solder, time, etc you may a swell spend out on some more substantial tube.

Pitty they don't give the full cod eso you know what you are getting, the images show several sizes of BAP300R and you will probably get the single insert 300Rc12-12-120-t1

16mm to 20mm tend to have 2 inserts, 25mm will be 3 insert see apt

Edited By JasonB on 14/09/2023 20:29:35

I had entered 0.040" for both. It does not suggest what to use for stays but entering 5/32" or 4mm stays at 3/4" spacing gives a sililar figure above the minimum that the 0.040" plate/tube does.

Nowhere to enter end plate thickness

No suggestions enter dia and spacing and it tells you max and how that relates to the minimum Calculated factor of Safety needed. As it doe swith teh barrel both drawn and Rolled & Welded (tig)

No just barrel and firebox sheet thicknesses, stay dia and spacing. certainly would not go below barrel thickness

The spreadsheet I have (used by a boiler maker) would also make 75psi quite safely.

Although Old in style the Hogger set does have it's uses and are not obsolete in far as being useful.

I'm not sure what the insert grades are but I have been able to cut hardened steels with those that other inserts have been immediately blunted by so the straight one gets used on heavily chilled castings and modifying tool holders.

The 45deg one is a handy chamfering tool.

The round one is good if you want to leave a large internal fillet for things like simulating castings

At the diameters Vic is looking at then the smaller inserts will allow 3 or maybe 4 inserts if you go to 25mm dia but you need to think how you are going to hold those with their plain shanks, the 20mm will go into a ER32 but you get overhang, the 20 and 25 won't go into an MT3 collet.

R8 or MT Body like ARC do is easier mounting and less overhang but it's only a 2 insert cutter so less insert engagement can make them noisy like teh Hoggers and feeds will be less than 3 or 4 insert so take slonger to get job done.

Ideal would be direct mounting with 3 or 4 small inserts

Big advantage of teh more modern inserts is better geometry than the "Flat" Hogger inserts and the availability of the inserts meant for non ferrous which work on all materials and reduce the load on hobby machines

Several news reports saying it stopped for several houlrs to have the "wheels" changes

I thought you were agreeing with Noels comment about the bearing which is at the tip of the rocker arm not the pivot.

Though looking closely it is actually a plain steel roller not a Ball Race as Noel commented on.

Edited By JasonB on 12/09/2023 19:48:15

What sort of run times would you expect to see wear after?

The average model engine may run for an hour or so a year once the initial playing with it once complete has worn off, bit more if in the US as they tend to run their engines at shows rather than the statick exhibits we tend to have. So will the bearings wear with this amount of use remembering that a hit and miss engine will only be fully opereting the exhaust valve once every 8-12 cylcles and even then they ar every slow reving.

There are many popular hit and miss engines that just run a cast bronze or GM rocker arm straight onto the top of the valve, others fabricated from mild steel that is not hardened. If a bearing is going to show wear then why do I not see reports of these softer rocker arms wearing and needing replacement or is it just theory over practice?

Edited By JasonB on 12/09/2023 18:39:32

As the OP's problem was a difference between the Stuart drawings and the 10V book I assume you won't be using the book so no problem.

Some build pics of a scratch built one to tempt you further

Problem is usually down to the hose, as they are sized by bore, usually 1/2" for domestic use the wall thickness can vary even Hoselock is quite thin walled so fittings don't grip as well as they do on something like CK hose which is thicker, never had an issue since changing to their Multiflex yellow one and still using teh plastic Hoselock fittings not CKs brass ones.

Probably be lower down the list than mild steel, why not just get some stainless steel, 303 is easy enough to work with.

As far as I know the Clough only controls leadscrew rotation in relation to the spindle and will therefore not stop and start the thread at specific lengths, it only replaces the changewheels/gearbox.

Maybe others can confirm

It's a metric profile so 60deg

Myself I don't angle the top slide but 29.5deg if you do