Tuning a 50 lb Bull air hammer?

[Steve Shimanek]

Aloha, my mentor has a 50 lb Bull air hammer; some time back the cylinder rod broke and he had it replaced by a local outfit. It seems the length of the rod they installed was shorter than the original and the shop that did the work threw out the original so the stock length is not known. Is there a way to adjust the valving to eliminate the slamming at the top of the stroke and to maintain adjustability of the striking force? Is there an online schematic for the airflow and how to tune the performance of this machine? Thanks for any replies, Steve

[ciladog]

Steve,
If the cylinder still has a nameplate on it, take down the model number and go to the manufacturer’s website where you can find specifications and part numbers. That being said, it would be unusual for the local outfit to install a shorter ram than the length of the cylinder. Check to see if the cylinder air cushions (if the cylinder has them) are adjusted to near maximum. They may have been changed during repair.

Check out this link to a previous thread on the bull hammer link. There are two different types of bull hammers but the valves pretty much work the same way.

[John Larson]

Steve and David Kayne are the Bull experts and can supply some parts.

[Steve Shimanek]

Thanks for the replies; please forgive my ignorance, but what do the cylinder air cushions look like and how are they adjusted (if present) ? Thanks, Steve

[ciladog]

Thanks for the replies; please forgive my ignorance, but what do the cylinder air cushions look like and how are they adjusted (if present) ? Thanks, Steve

Cylinder air cushions are like small check valves in the side of the head and/or cap of the cylinder. They create a high pressure air cushion at the end of a stroke to prevent the piston from slamming into the head or cap.

Look for a small setscrew on the side of the cylinder head. Here is a link to a PDF file from Parker with an exploded diagram. link

[Steve Shimanek]

Thanks for the Kayne contact and the Parker link; I will check this out next time i am over at the shop.

[Steve Shimanek]

Ciladog, your previous thread on your hammer build and description on the operation of the Bull controls is extremely helpful; I printed that thread out and will use it to troubleshoot issues on my mentor's Bull. 5 star rating, much appreciated. I like the modifications on the hammer you built!

[ciladog]

Ciladog, your previous thread on your hammer build and description on the operation of the Bull controls is extremely helpful; I printed that thread out and will use it to troubleshoot issues on my mentor's Bull. 5 star rating, much appreciated. I like the modifications on the hammer you built!

Thanks Steve. I'm glad I could help.

[John Larson]

Air cushions in a cylinder do not always have the set screws for adjustability. If you don't know the serial number code, you can physically test by pushing the rod with gusto and feel the cushion work or not. I've gone from adjustable cushions to Norgren's standard nonadjustable types. Saves money and doesn't impair performance at all. Check out how to order a Norgren cylinder to learn the coding. Other vendors will have an ordering rigamarole that teaches the same thing. I doubt Norgren is unique.

[Steve Shimanek]

Thank you John; I am going to check out the cylinder now that i have a better idea of what to look for. Is there any available information on the air schematic for the Bull hammers? I have not found anything yet searching the web. It seems something like a service manual that explained the air flow and functions of the individual components would be very helpful. I hear good things about your Iron Kiss hammers; thanks for your assistance. Steve

[John Larson]

If you post some pictures of the hammer's innards, I can refernce the components in a discussion of how the hammer wortks. Others will undoubtedly have something to add as well.

[Steve Shimanek]

I went over yesterday and did some troubleshooting and poking around; the turnbuckle connecting the treadle to the main valve needed adjusting, and I played with the limit switch adjustments some. The hammer is more well behaved now ;I made my mentor happy as he said he was almost ready to give up on that hammer. Ciladog's previous thread and the discussion in there helped me greatly. I am unsure if the cylinder cushions are working as designed but screwed up my shoulder muscles lifting the ram to check.....duhrrr! The exhaust/main valve adjustment valve was probably key as the previous adjustment did not let it close fully when the treadle was up; I am guessing this would allow the tup to slam at the top more that way. Thanks for the assistance on this thread; I may have some more questions after next weekend. Aloha, Steve