I too had the same problem using all 3 mounting plates I had. They sent me another mounting plate and it was just as bad. Poor quality control. My friend had to shave of .013 inches of metal to make a new plate work.
Exactly what I did. Except I didn't have a friend who could do it so I had to pay a machine shop. After going through a couple of replacement saddles from iOptron, I realized that the actual top of the mount head, the surface that the saddle bolts onto, was not machined flat. They were able to provide me a saddle that worked fine when it was not attached to the mount. But as soon as I bolted it to the mount, the Losmandy rail would no longer slide through it. Apparently, bolting the saddle to the top of the mount caused it to warp slightly to conform to the top of the mount. The tolerances were so tight on the saddle that even a small amount of warping caused it to be unusable. So, like you, getting it machined for larger tolerances was the answer.
Indeed. As mentioned in my reply to Michael below, I eventually resolved this by having a local machine shop shave some off of the saddle. I have to say though, now that I'm past this issue I'm thrilled with the performance of the mount. I have about a 65 pound load on it and I regularly get 0.3" to 0.5" guiding. That's twice as good as my previous mount, the iEQ45.
I too had the same problem using all 3 mounting plates I had. They sent me another mounting plate and it was just as bad. Poor quality control. My friend had to shave of .013 inches of metal to make a new plate work.
Exactly what I did. Except I didn't have a friend who could do it so I had to pay a machine shop. After going through a couple of replacement saddles from iOptron, I realized that the actual top of the mount head, the surface that the saddle bolts onto, was not machined flat. They were able to provide me a saddle that worked fine when it was not attached to the mount. But as soon as I bolted it to the mount, the Losmandy rail would no longer slide through it. Apparently, bolting the saddle to the top of the mount caused it to warp slightly to conform to the top of the mount. The tolerances were so tight on the saddle that even a small amount of warping caused it to be unusable. So, like you, getting it machined for larger tolerances was the answer.
Finally send the mount back to iOptron. They replaced the saddle that was undersized, and replaced a defective dec motor.
That is so disappointing, not what you would expect from such an expensive mount
Indeed. As mentioned in my reply to Michael below, I eventually resolved this by having a local machine shop shave some off of the saddle. I have to say though, now that I'm past this issue I'm thrilled with the performance of the mount. I have about a 65 pound load on it and I regularly get 0.3" to 0.5" guiding. That's twice as good as my previous mount, the iEQ45.
@@dkuchta5 thanks for the info :-)