Chuck size for Axminster Sieg SC2 Lathe

[chippyminton59]

Hi everybody
This is my first post here.
I purchased an SC2 recently from APTC and it came with an 80 mm SC Chuck. I phoned ARCEURO and ordered a 100mm SC chuck, they told me that I would need to change the bearings if I wanted to use a 100mm chuck on the SC2-despite it being a brand new lathe. Axy said that it would be fine to use as it is-being new to metalworking I'm confused. Some advice would be great.
Regards

 

[Dr Al]

I used to use a SC2 (bought from Axminster). It came with an 80 mm 3 jaw chuck and a 100 mm four jaw chuck (on a backplate). I never had any problems with it at all.

Having said that, I did change the bearings to angular contact ones not that long after getting the SC2. That was nothing to do with the chuck; it just improves the rigidity under cutting forces and produces a much better cut. I'm absolutely sure I used the 100 mm four jaw chuck a fair amount before replacing the bearings though.

 

[AES]

+1 for the above. I too have a very similar Chinese Mini Lathe to the SM2 and regularly use a 100 mm chuck without problems.

But I don't think for one moment that Arc Euro are deliberately leading you astray - good company IME, usual disclaimers - they're just being cautious because at least theoretically, they're right - the head stock bearings in that lathe are not of the correct type to take the extra loads.

Like Dr. Al I too will be changing the head stock bearings on my lathe, but NOT because of the 100 mm chuck (taken carefully it seems fine) but because I want to increase the rigidity of the whole machine and that's an important part of it. In my case it's just a case of "getting a roundtoit" (my lathe is 15 years old this year)!!!!!!