Posted 30 August 2006 - 10:25 PM
I am rebuilding my 3A arm and need to replace the arm trunnions(along with other parts). Can anybody tell me who makes them and where would I be able to get some.
Any lead is appreciated.
Posted 30 August 2006 - 11:46 PM
I did it once with my own 3A arm, replaced all bearings and put fixed axis in it instead of the original trunions.
But is is not easy, a mistake can cost you a dogbone, etc.
Looking back at it, I did not have much to loose at that time and there were no other companies that but CP that could do it for a reasonable price, but nowadays there are companies really catering to this.
Having said that, if you really want to do it yourself, find the bearings ( the typeno. is printed on them) and find also the hardened steel axis rods that fit them, they come in standard length (3" I think) and fit nicely in the arms. They connect the both sides this way, making it much more sturdy and reducing the twist under load,
which damages the original trunions. All you need to make is metal caps instead of the original trunions to keep these rods in place.
The old bearings can be pushed out with appropriate equipment when you heat up the aluminium dogbone, the same for replacing with new bearings.
Posted 31 August 2006 - 04:04 PM
Posted 31 August 2006 - 10:58 PM
Thank you for your advise guys.
Ron, I do have experience stripping the arm, replacing bearings and cleaning it every once in a while. It actually isn't all that hard. I do agree that you have to have the right tools and access to a machine shop. it makes a big difference after you give it a good lube job.
I can get all bearings from the local hardware store but not the trunnions. Are they special parts made by Tiffen (they look the same as the trunnions in the Master arm). "Rig Engineering" doesn't really want to sell just parts for the arm.
Are there more leads ?
Posted 01 September 2006 - 06:05 PM
Posted 01 September 2006 - 10:16 PM
I believe all the patents on the 3a arm are expired and there is no way to renew them which is why it has been open season for some time.
Posted 02 September 2006 - 01:42 AM