Hey guys...
So , the boss walks in this morning and goes , 'Hey mike , you know the little hammer in the storage shed?'
i go ' Yeah? why?'
' Well , i think its time to fix her up.'
Happy days!
But now i have a problem...
i have absolutely no info on these hammers as far as tolerences for the piston , hammer or valve ...
does anyone have any info about these at all or know anyone who has knowlege that i can contact?

ANY info would be greatly appreciated


Mike

If you add your location there may be someone close by that can help.

info added , not sure if theres anyone in nz that can help though....
i know of four , but none of them could help.....

Alldays and Onions are well known here in the UK, mostly for forges and blowers for them, you may get more help from here.

These are very simple hammers , I have no idea about the tolerances but I have stripped and rebuilt a couple.
Does it work?
The ram has a huge bearing surface, valves are very simple.
If its free and all moving you are probably all good....probably.....


I've got the manual somewhere as a pdf, Email me and I'll dig it out.

thanks owen.

email sent to your website.

mike

http://www.iforgeiron.com/topic/37484-alldays-and-onions-on-piece-airhammer-anvil-removal/

Some discussion here also re 1cwt Alldays

Phil


Alldays manuals uploaded

Wow Phil, all those amazing old documents that you keep scanning and posting! Are you some sort of 'Southern out post ' for the library of congress :)

thanks owen.

email sent to your website.

mike

 

Mike Phil has posted pretty much what I have...

Wow Phil, all those amazing old documents that you keep scanning and posting! Are you some sort of 'Southern out post ' for the library of congress :)

 

phil the southern out house.

library of pong-gress

best place to do "paper work" or fill out a "log book"

you can even "log onto the inter webs" from there :unsure:

Thanks for the quick reply and the info! will post pix up when shes all done....

pix? we need vids!

http://home.tallships.ca/mspencer/shop/alldays2.html

thanks for all the info guys...
i till have a few questions though.....

1. What should the clearance between the tup and the housing be?
im machining a new tup . its sitting in the lathe , waiting for the final cut...
The old one is too loose ( 2.5 mm clearance )
luckily the bore of the housing is true to about 6 thou

2. the original tup is hollow...
would it matter if i make the new one solid?
it would suck pretty bad if i had to , because the 4340 billet im making it out of jus got out of the tempering oven yesterday.



mike


And yes , ill post video.... ;)

I really have no clue as far as clearance is concerned  someone else will though..., the ram wants to easily rotate in the front cylinder.

I will be very surprised if the hammer will work with a solid billet as the tup as the hammer is relying on partial vaccume to lift the tup. how much will the solid billet weigh?

My 100 pilkington has a hollow ram that weighs 79lb (so not a true 100...)

 The ram dimensions are roughly 19.5cm diameter by 56 cm long, If it were solid it would weigh roughly 130 kg or 293lb (give a little bit for where the hammer is machined square).

The hammer develops a partial lifting vacuum , for arguments sake lets say 50% vacuum or around  7psi (pushing the ram up from the surrounding air pressure)..... surface area of the ram is roughly 48 square inches...so 48 x 7  gives 340 lb which may just lift a solid ram ...just...

 I am guessing air pressure on a ram acts in the same way as rocket thrust, giving a constant acceleration in relationship to the thrust that overcomes the falling weight of the hammer ram... so in my case there would be an upward thrust of  nearly 40 lb on a solid ram and 260lb on my hollow one a difference of 6.5 so my guess would be that whilst the hollow  ram has just enough time to rise to the full height inside the front cylinder a solid one would probably rise a few cm or inches in one upward cycle of the drive piston (around 0.15 seconds).

 Just conjecture , not sure of internal hammer pressures ?but about right I think...

I agree with Basher and suspect the lift will not pick up a solid tup. Discounting the available air volume in the circuit, the weight alone is probably too much. The original engineers would not have overdesigned the system with that much tolerance. It would be like hanging a 300 lb ram in a 100 lb mechanical hammer - you might get away with 130 lbs but not a whole lot more.

i just measured the weight at 50 kgs , and my foreman and i got to the same assumption tha this hammer creates half a bar of pressure and i also had a llok at the tup itself and its pretty xxxx hollow....

now to manufacture a new on from scratch......

ill keep you posted......

Instead of all that boring, you might be able to weld a piece of thickwall pipe to a short piece of shafting to eliminate the excess mass then clean up the welds and do the finish cut...although a big lathe could do the stock removal with a 4-jaw and steady rest.

that is the plan hopefully....

weld a spigoted cap and hammer to a hollow tube and machine...

2.5mm does sound a lot. Presumably though the machine was still working with it like that…or maybe when it was only 2.4mm and 2.5 was just too much! A friend with a 2cwt cut a groove and made a piston ring when his started to become inefficient, might be a solution for you. He had a gap in the ring and it was prevented from rotating by a grub screw in the groove. I think this was done (possibly after the event  :( ) to prevent the ends of the ring from springing into the air port in the cylinder wall.

 

I have a 1cwt which still has the milling marks showing on the flats at the back so I assume it has not seen much work, I can measure the tup... though I suppose the actual diameter is not so important as the tup to cylinder clearance. If I can do it without taking the cylinder head off I will do it tomorrow.

 

Mine has the dead loss lubrication system but yours looks like it has the crankshaft cam operated oil pump…very posh.

 

Alan

Thanks Alan...
i would appreciate ani info i can get... ( helps me make informed guesses)

Yes , it ran before the stripdown but it had no lift on auto with the pedal up and i used to get it up by lifting it with a bar and then placing the job in...
initially i thought i might have a failed non return valve , but i checked all of them and they are mint...

my other problem was when the tup was down , you could actually swing the tup around and it had lateral movement of about an inch and to me that is waaaaay too much.... the guide bearing was worn but even without one , i dont think it should be that loose...

Yes , its the self lubricated one with the piston crank driven pump.... the pump/ crank cavity was SPOTLESS...
happy about that.....
mike

I have replaced the guide bearing on the back on my 3cwt. It had worn a couple of grooves in the brass and when you tightened up the nut to pull the wedge across, the edges of the grooves bound on the tup. As soon as you released it enough to drop, the tup could / would rotate. Easy job to fix though, lump of brass flat and I made the rivets from copper I think (or were they bolts? hmmm).

 

What are the respective diameters of the tup and the cylinder on yours?

 

Alan

the tup measured 191.22mm and the bore 193.72....

Well I have measured as well as I can with the tup in situ. I could not find my big bow calliper but managed to take the internals direct with a vernier calliper and the externals with a bow type and then measure that with the vernier...

The cylinder bore measured 193.6mm and the tup 193.5mm so pretty tight. The flats on the back of the tup still have the milling marks clearly defined so it looks hardly run in.

I also measured the 3cwt for comparison, this has been well used, the cylinder bore was 266.8mm and the tup was 266.3 so still only half a millimetre.

Hope these help.

Alan.