Welch 1400 Repair

[Ed Meserve]

Back in March we managed to crack one of the plates on our Welch 1400 (don't ask me how) and we've been working to machine a replacement in aluminum.

Broken Plate

Took a while, but we recently finished the replacement.

Broken Plate and Replacement

I've reassembled the pump and filled it with oil and it holds the oil, which is great, but it's not pulling hardly anything as far as real vacuum goes.

Pump Assembled

Filled with Oil and Ready to Run

I couldn't find the post in the archives about using rolling paper to set the rotor tolerance, but I remembered that using two pieces would give you the proper spacing. What I couldn't remember is if you needed to set the paper at the top of the ring and rotor, or at one of the gaps in the ring (at 45 and 135 degrees).
Can anyone advise?

Thanks,
Ed

[Brian Glen]

Here is a post at the Bell Jar that talks about using rolling paper to set the rotor tolerances:

http://belljar.net/forum/index.php?topi ... een#msg512

Brian

[Ed Meserve]

Thanks, Brian! I completely forgot where I had read that.

Ed