Gallery, Projects and General > Project Logs
Lister 6/1 Genset
Darren:
Thanks guys, appreciate the offer as I don't have a suitable size tap in my collection.....mind you though they are not the cheapest taps to purchase it still may be worth getting one of my own as the price is not that high.
But if anyone has a spare, I'll gladly trade some beer/food tokens for it :)
I was going to tear the engine down and do a de-coke and stuff, but now I'm thinking just do enough to get it fired up and go from there.
Have a listen, look to see if any seals are leaking and basic health check...might be wiser to check some stuff before going further into it.
Darren:
Making A Fuel Banjo Fitting For the Lister CS 6/1 Engine
On my engine all the fuel lines and fittings are present except for the banjo to the fuel tank.
I could have just bought one but decided to have a go at making it instead. Gotta have some excuse to turn the lathe on :ddb:
I had a piece of 28mm 316 Stainless Steel bar in the scrap box. I could have used 303 instead but I'd never tried machining 316 so I thought why not have a go.
I have read that 316 can be a bit hard and more difficult to machine over 303. But I can't say I noticed any difference? That is untill I tried parting it off.... :bang:
I had collets in 27mm and 30mm but not 28mm. So I used a coke can to make some shims to make the bar fit the 30mm collet.
This is by no means a perfect solution as I found it difficult to true the bar properly. but as you can see I managed :D
First the outer diameter was trued up so that it would match the inner boring to come next. It was turned down to fit the 27mm collet properly for later operations.
The center was drilled and then bored to fit the banjo bolt snugly. Next an inner groove needed to be machined to allow full oil/fuel flow around the banjo bolt.
I didn't have the correct shaped boring tool for this but managed by turning my regular boring bar approx 45 deg.
This seemed to work well enough. Next the parting off....what a pig !! The HSS parting tool tip disintegrated very rapidly trying to cut 316. I had to sharpen it four times to get just this one cut done. It's not that clever with 303 SS but nowhere near this difficult.
Note to oneself, I really need to get an index tipped parting tool.... :poke:
This is where I ended up tonight, as you can see there is more to do yet.... :whip:
sbwhart:
High Darren
It will help with the parting off if you get the work as far back in the collet as you can, with the parting tool as close to the collet as you can, also get the tool as far back in the tool post as you can, keep things nice a ridged. I don't know what speed you used, but don't be frightend to step it up a bit, people have a tendency to run too slow when parting off.
Have Fun
:wave:
Stew
Darren:
Hi Stew, nice to see someone is watching..... :wave:
Good comments, as always, though my 30mm collet is partially blind. Spose it needs some metal left in it to keep some strength. So the bar couldn't go any further back.
But, you raise a good point that I'd overlooked. Maybe the parting was much tougher because of the overhang as normally I'd be parting right up by the collet.
Thanks for bringing it up, I'll bear it in mind next time I work with 316. :thumbup:
bogstandard:
Darren,
Parting off is the thorn in the side of most model engineers.
In industry, if you can't do it, you are out of the door, it is classed as a normal turning job.
Stew has raised some good points, I will add a couple more.
Even if you have a QCTP, never trust it when it comes to parting off. A holder can put the tip of the cutter out of position by a couple of thou. That is enough to cause you major headaches. Always check your tool height before parting off, use the six inch rule trick. If anything the tip should be spot on or very slightly above centreline. If it is even a couple of thou low, the cutting pressures will push it even further down and the tip will usually be snapped off.
Don't play about with it, give it plenty of coolant (if you have it) or squirt some out of a squeezy bottle, and give it a fair speed and push the tip in. As soon as you stop feeding, it is a pig to get cutting again, and that is when jams and breakages occur.
I normally power feed up to mild steel hardness running at least 650 RPM. Any harder, like stainless, and I hand feed, but still at the same sort of rate, and 'feel' how the cut is going, the swarf should be coming off in nice thin ribbons.
Rigidity is paramount to parting off, and your gibs need to be tweaked up fairly tight.
When you come over, remind me, and I will give you a few instructional tips and get you to 'feel' what you are doing.
John
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