Part built Allchin 1.5 inch

Engine fitted together in the sun, still plenty to do and the new 4BA studs to make which will hopefully hold in the troublesome fixings.

Hopefully the previous owner will be glad to see it getting close to looking like an engine.

Looking good

H

Many thanks Harry

Derek,

You look to be making a fine job of that, up and running next year?

Just to show I do make stuff! Couple of shots of my Little Samson 6" scale from last year to spur you on! It has advanced a bit since these but a paying job has hindered progress lately!

Hoping to get it finished over the winter!

Paul.

Hi Paul

Makse my little engine look so insignificant, must be lovely to be able to build one like that. please keep me informed with the progress as id very much like to see things being built.

Regards,

Derek

No real work tonight but played around with the stud issue, and opted for what I was advised and that was to loctite in the studs, unfortunately one of them is 5BA but that was before I realised going up to 4BA would help.

i was going to just screw in the studs but no matter how many studs I made I couldn’t get a good fit that wouldn’t make the hole bigger, another skilled engineer like yourselves could of done it easily but this option for me seemed the best idea, I also very gently tapped with a punch to close around the thread, only gently but this helped even more to stop and wiggle.

i will let the loctite set 24hrs but I have to say the studs feel very snug so fingers crossed all’s well.

i now have to decide the best time to do final cylinder lockdown, so that I don’t need to remove again.

I've recently acquired a part built 1.5" allchin so watching this thread with interest. Yours is looking really good so far

Thank you Terry, I’m sure you will see from my thread it’s been a very up and down journey.

feel free to ask any questions you may have or pictures you may like to send me, i always like to see other builders engines to learn.

You are doing great Derek, the pic you posted looks fabulous! Studs and gasket in last photo also look great. The technique you mentioned re closing up the holes a bit is one you will often use if you repair or refit old stuff, especially if someone ham fisted has been there before you! seen it a lot on cars trucks and agricultural equipment......

Thank you Jeff, that’s very encouraging words.

Regards

Derek

Evening all,

so I have a small question, I’m looking to cut some studs myself as the commercial studdings seems to keep arriving with a lot of slop.

and the 4BA that arrives measures around 3.35mm, but I’m looking to be closer to 3.5

however when I try and cut studs on the lathe I get so much flex I can’t get a consistent thickness along the turning, I’m only sticking 16mm out of the chuck and removing around 0.5mm but one end keeps going 0.8.

obviously the bar is flexing and I think this is what you can run out, but is there something obvious I’m missing to make things easier.

Thank you in advance i

What tool are you using for the turning? For that diameter of work, a very sharp tool is needed, well honed HSS or, if a carbide insert, then one with a ground finish, sold as intended for aluminium etc. The ordinary coated inserts for steel are not sharp and will cause too much deflection of slender work.

Incidentally, 4 BA spec. is 3.6 mm OD if you're making studs as tight as possible.

Hope that helps,

Clive

Edited By Clive Brown 1 on 03/09/2019 19:19:35

Hi Clive

yes my tool probably not good enough, it’s an insert type.

every stud I’ve purchased has come in at 3.38mm or if lucky 3.42 so both have been wobbly in my holes so reluctant to use them.

i have some 4mm bronze on its way so I will try a new cutter and try again as I don’t need to remove too much material, and see how I get on.

thank you

Cylinder fixed down, made some Stainless fixings in the end as they were a good fit.

if a Stainless is good enough on Jason’s Fowler it’s good enough for me, i guess we will have to wait and see if it’s sealed.

i used loctite 638 on the bronze studs of which there are 4, partly wish I had used red thread locker but hopefully it still holds ok, which I’m sure it will.

so I’d go as far as saying the lockdown of cylinder is complete, still nervous of leaks but I can’t do anymore than I have especially with my limit skills and knowledge, I will now concentrate on the more fun stuff like making steam fittings.

i assumed you must also seal the studs so I used what have on the other steam fittings and that loctite 542, i will upload more pictures soon for anyone who maybe interested.

I don't want to hijack this thread but I've recently acquired a allchin and started to look at a few bits. Has anyone been successful in making the square/acme thread on the brake?

Hi Terry

hijack as much as you like, it’s nice to hear from another Allchin builder,

however I can’t help as the previous owner had made that part on my engine, do you have the build book as this goes how it’s done.

Del

I screwcut the square brake rod thread for my Fowler and made a silver steel tap at the same time which I used to make the nut

Evening all,

hope no one too disappointing with the cricket! Not a huge amount done on the engine but I did make a new piston as the last one seemed a little sloppy in the bore.

this one has a better shaped grove for the O-ring which brings me onto a question please, I have an O-ring for the piston rod, this instead of graphite yarn but how snug should the ring be on the shaft, should it be squeezed up.

i have graphite yarn fitted to all other areas, apart from the piston itself.

i just wrapped it around the rods a few times, and well tighten down the nuts more if I get leaks I guess but how do you deal with a leaky O-ring?

thanks in advance

The fit of the ring is dealt with when the recess for the gland is machined as that needs to be made to a specific size to squash the ring around the rod by the right amount. If you did not do this then revert t graphite yarn.

Would anyone mind advising if it’s OK to have the exhaust pipe made of bronze?

Thanks in advance..