Member postings for Andrew Crow

Hi Mick, back in the nineteen seventies Don Young designed a 4F loco in 3 1/2 gauge and that used Joy valve gear which might help. It looks like you already have the weigh shaft, however you would need a reverser in the cab and corresponding reach rod. I think I may still have the original article and could possibly email you the appropriate pages if you are interested.

Andy.

Hi Steve, when I owned a BCA Miller I made 2 er collet chucks and the material I used was what used to be known as EN24T now 817M40 it's a high tensile steel but machines well and should have all the strength and wearability needed

Most drills wander slightly caused by various factors and exacerbated as the hole is drilled deeper. The best way I have found to keep the hole true is to start with a centre or starter drill followed by a drill about 1/32 under finished size then bore the hole to just under the next drill size that will leave a few thou for reaming. Bore as deep as possible, follow up with the next drill ( at a reduced speed, about half normal drilling speed) which should follow the bored hole then finally use the reamer. It sounds a bit laborious but does work.

I remember Chuck and always looked forward to the next cartoon as a bit of humour was and is always welcome. Amid the humour though, Terry always raised a valid point on good engineering practice and safety in the workshop.

Hello Ken, many thanks for your reply, I think I have the grasped the concept, I assume that this device also eliminates anti-rotation pin. I have an old selector handle from an ML7 which I will try to incorporate into the design if it doesn't involve too much carving of the gear cover.

Best regards,

Andy.

Many thanks to everyone for the information to my query, lots of useful points which I will try to incorporate. However, one further question has cropped up concerning a disengagement arrangement. I am assuming that this involves using something similar to the existing Myford tumbler arrangement. I would like to incorporate this as it's useful to disengage when using the leadscrew handwheel for milling.

Any information would be gratefully received.

I have read Graham's article on the Myford screw cutting clutch which contains quite a bit of grinding. I don't have grinding facilities and I'm not sure I would want to cylindrical grind on my lathe. Have other builders completed the unit without resorting to grinding?