Fortis lathe rebuild-at long last

I am at last getting round to completing a lathe restoration which for various good reasons has not been finished. I have odd things (grub screws, pins, lost screws, etc) to do as I rebuild in sequence.

The last item to attend to is the sliding gear arm of the quick change gearbox which should give 4 to 28 threads with lever in, and out position 32 to 224 threads. Indecision, dithering, and doubt creep in causing stagnation of any thought and I would really like any comments and help offered please. I dont envisage ever needing 224 tpi.

It looks dirty from a rust solution I had it soaking in having dried on it so it has has a light brush up to go. I cannot move it apart. Totally locked solid. I tried home made wedges but possibly due to not being accurate enough did not work at all. I may have levered it very lightly apart. My assumption is; it is one shaft (or one with in one) with the direction division being at the a cog wheel with a gap of about 3.5mm. There are I presume two balls on springs which locate and stop the arm on the left in the wanted position. As it is on a sliding 'thingwaybob ' (key way?) it does not turn. I suspect the buried srings will be badly corroded and stuck fast or broken, and so to clean it up by stripping down.

Can anyone give help please with possible advice as how to best to get it off and strip? It is a Fortis late, built in Cornwall late 40's early 50's and was based on the American Clausing lathe. I think I have managed to save it but would like to see it finished, test it and see if I have or not! All help would be most appreciated. I havent wanted to use force in case anything goes wrong!

I could make up a puller of sorts and try that using flat bar and a screw possibly bolting them together (could dig out old welder) for rigidity. I could buy and an willing to buy a prop. made one just to get on to do the same task. The small space for puller teeth of the cast variety limits access is about 3mm. The larger cog, at present removed, is joined to the small cog by the dowel pin.

I may need to put it under tension and wait a day or so for it to crack in the night and so brake the rust bond. I dont see how I can bore or dig out the balls and springs. I am sure I have seen slide levers like this many years ago....somewhere, and must have been fairly common on pre-war machinery.

Every best wish to you all.

M

PS

I learnt many years ago not to go out to the workshop for a second chance late in the evening to resolve something. It invariably meant you were tired and didnt do it quite right and were heavy handed. Best to wait until the morning!

It may be best to really soak for a while in a good penetrating oil (not WD40). Diesel will be a good compromise. Give it a few days to soak in well. Then try a tappy tap tap with a copper or plastic hammer to see if it moves. Patience is a virtue in these situations.

regards

Thanks for your reply Oldiron.

I will be out tomorrow (mon) and will pick up some diesel and give it a soak for a few days. I have sused release oil but never it too successful. The old stuff from years ago seemed to be so much better at it. WD40 is a refined paraffin. Paraffin did work sometimes. Thank you once again and progress restarted..

Plusgas saved me again today. Locked ladders stored outside, lock seized. I already had my angle grinder in my hand but gave it one more jiggle with the key and it released. I’ve had the same tin for 25+ years. It may help you. Leo

Thank you. Yes it was Plus Gas, now being remade again as I think it disappeared for years. It is hard to get locally due to closures at the moment. Have part soaking in diesel now for three days so may give it a light dunt or two this afternoon to help penetration.

I nearly tripped up yesterday carrying the bottle. I have never moved to fast in fifty years. I held on.

Plus Gas came in small oil cans with a spout around 1960 and before perhaps. Price was like gold then.

M

Well. I managed to move it all so a big thank you. It has been soaking in diesel for 3.1/2 weeks with a bit of thumping occasionally it moved after a week or so. The last part where the shaft had spread, needed a bit of friendly persuasion, with intelligence of course! It is now stripped down and ready to go. The internal spring and ball cleaned up rather well, so the world is rosy now. Suspect it perhaps hadn't been used much, if ever. A little corrosion round a shaft with a big surface area can make a tight seal so took a while to break.. Bought a tin of Plus Gas and it is really thin, so happy with my purchase for the future.

A big thank you gents to Old Iron and Leo.

Edited By Marischal Ellis on 27/06/2020 17:01:55

Hi soaking in paraffin or oil is good but you need the application of heat! This cycle needs to be repeated 2 or three times! In fact last week I had two! a seized wheels on axles (2 inch clayton ) , not moved for maybe 20 years... wd plus heat , then leave for a day ; took three attempts both now free!

regards

vic