I possibly don't need to replace the screw, however for two reasons I was going to. Firstly, I only needed a nut, but Warco sent a nut and a screw. This made me wonder if they came as a matched pair? Secondly, with everything bolted in place apart from the bolt that goes through the cross slide into the nut, I noticed that the nut wants to sit slightly to the side and out of line with the bolt hole. This made me wonder if something was bent or misaligned with the old screw, causing the old nut to be under pressure and break, so I thought I'd replace both the nut and the screw.

Hi David, I will certainly try that when I'm assembling it. I even wondered if I might need a small washer/shim behind one of the two bolts which hold the hand wheel assembly onto the cross slide in order to align everything properly so that when the bolts are all tightened up nothing is under pressure.

Thanks Mick, I toyed with the idea of making a brass pin but just decided in the end to stick with the original roll pin. I can also see why Warco didn't drill the hole themselves, because the hole through the gear was not on centre, so a perfectly drilled hole wouldn't have worked. I set the gear up in the drill vice so that it was perfectly in line with the drill bit, then inserted the screw to the right point and drilled it. This left everything lining up properly, but if you flip the gear 180 degrees, the hole doesn't line up, showing the original hole was off centre.

I think my next problem though does merit a phone call to Warco in the morning.

With everything built up the bolt hole in the cross slide nut still doesn't line up with the hole in the cross slide. By leaving the two front bolts slack as David suggested I can get the bolt in, but tightening up the front bolts then results in everything going very tight and/or binding up completely. I tried shims at one side of the front plate, this moved the nut to the correct position when the cross slide is in the middle of its travel, but when moved to either end the nut moves too far to the left at one end, and to the right at the other. Now this suggests to me that nothing is bent, but that either the bolt hole in the cross slide, the hole through the handwheel front plate, or the hole in the saddle casting, have been machined off centre. I think the issue could be solved by the machining of a custom lead screw nut, but I don't really want to have to do that. I'll speak to Warco tomorrow, and hopefully they can provide a solution.

I spoke to Warco yesterday who said it's most likely that the plate at the front is has been drilled off centre, and they're sending me out a new one to try. Could be a slow process if that's not the issue and other parts need to be sent out, but at least they're trying to sort it. I must say they were very helpful.

Old Mart, the hole in the nut doesn't appear to be offset, but if nothing else works I think a nut made with a custom offset hole would solve the problem.