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form_change
03-13-2011, 09:32 PM
Currently I'm working on the lathe lubrication system and while doing this have discovered some things that may help others.
I started out trying to replace the oil metering valves. This did not go well and after much frustration decided to reassemble the carriage for another day. However, I managed to pinch one of the brass oil lines.
http://i1140.photobucket.com/albums/n574/form_change/P1010072Small.jpg
I could have replaced the crushed tube with brass, but plastic tube is far more readily available these days so went with that instead. The move to plastic means two issues need to be resolved

How to get it to the shape needed, and
How to get it to stay there

Brass is nice as it stays put. This is a typical brass tube routing -
http://i1140.photobucket.com/albums/n574/form_change/P1010068Small.jpg
You can see around the holes where the tube passes through the casting is some goo. After a bit of thought I worked out that some stuff called Plasti-bond (a brown, "in a tube" version of 2 part automotive filler) would act as a good filler and cement. I could have used automotive filler but didn't want pink spots on the carriage.
Shaping was more 'interesting'. Nylon tube will kink if bent in too tight a radius. I tried a little heat on the bends and it improved, but was still a bit lumpy. The final solution involved nylon cord from a weed trimmer. I passed the cord all the way down the tube (the tube ID was 2.2mm, the cord was 2mm), formed the bend and then gently heated. The cord stopped the tube collapsing and the heat softened the tube to take on the right set.
http://i1140.photobucket.com/albums/n574/form_change/P1010069Small.jpg
This is the inside of the carriage. The tube (with cord) is held using clamps, the bends heated and then a small amount of Plasti-bond was used to hold the tube in place. Once that had set the cord could be pulled along for the next bends (very important - too many bends and it will be too hard to pull out).

Michael

Elninio
03-13-2011, 09:46 PM
The oil might soften the plastibond glue you used. Try metallic putty, you can get it at a car store. Another thing you can try is getting a thick aluminium wire and bending that around your oil line. I've got a 1.5" wire from a construction site made of 1/8ths thick aluminium wires. They're pretty hard to bend but you can do it with your hands.

beckley23
03-13-2011, 10:12 PM
I used copper capalliary tubing for the 3/32" D lines, that I had in stock, and ordered some 5/32" tubing from Monarch along with the meter units and new ferrels when I redid my Series 60 and 10 EE lathes. Thought about the plastic, but the kinking problem, and the ease of getting the stuff from Monarch, solved that problem. For the bedding material, I used latex caulk. The plastic tubing and your methods are good tips.
Harry

macona
03-13-2011, 11:21 PM
Molten sulfur is used to hold in the lines on a Monarch.

form_change
03-14-2011, 12:24 AM
There are a whole bunch of things that could be used to hold the lines in. The Plasti-bond was good because it was a cold process, could be mixed as a small amount and (according to the box) is impervious to oil when hard. Sulphur in it's molten state would melt the plastic I would think, and I did think about things like RTV's (room temperature vulcanising rubbers ie silicone) but wanted something that would not flex. Two part epoxy was another option but the Plasti-bond can be filed, sanded, drilled etc, so was ideal.
Wire will hold a form and I experimented with it but the trouble is once you have the form you want and have heated the tube you then have to get the wire out. Using the plastic cord you can fit he tube in situ and being flexible it will pull out. The longest oil line I did was 500mm (20") long and I could pull right through. I was able to thread the cord into the tube, run it where it needed to go and put the tubing into the backs of the fittings, heat and when cool the bend would be purfectly positioned. (Then pull to the next bend and repeat...)

Michael

wbleeker
03-14-2011, 02:46 AM
Plastibond is great stuff I glued a piece of 2 inch brass threaded pipe into a concrete water tank with it eighteen years ago and it is still fine. We also glued together a concrete water trough with it and it is still fine too.
Will

bborr01
03-14-2011, 10:48 AM
Hi Guys,

Thanks for the tips.

I have a mill that has the same problem with crushed lines. This info. should be helpful when I finally get arount to fixing it.

Brian