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Parting off problems

Posted: Sat Jul 04, 2020 6:24 pm
by Alpha1
I have never had much success parting off on the Lathe. I failed miserably trying to part off a piece of 2 1/2" inch stainless 303. The piece is 4" long and I wanted to cut a 1" piece of it. I gave up and grabbed the hack saw after a couple of minutes swearing and huffing and puffing. I flung the hack saw. Right that's it I bellowed. I jumped in the car and headed off to my local machine mart.
I bought one of these after reading the reviews. Apparently it's a good piece of kit. Hopefully, the hack saws gone forever. I just need to find somewhere to put it then I can crack on.
clark 1.jpg

Re: Parting off problems

Posted: Sat Jul 04, 2020 6:55 pm
by FredB
I have some experience of the Machine Mart saw and they work well---but they take up a fair bit of space. A lor of people have a 9" angle grinder--when you need one, there is no substitute but the need does not arise too often. I mounted mine on a short pice of RSJ in a home made pivoting holder, together with an old machine vise. The whole thing is on industrial castors and slided away into a corner. Cutting bar, angle iron and so on is now easy. Just slide it out, clamp up the workpiece, plug it in and away you go. It cuts quicker than the machine mart saw.
Fred

Re: Parting off problems

Posted: Sat Jul 04, 2020 7:52 pm
by Alpha1
I have a couple of angle grinders. Noisy messy things spark,s everywhere. I prefer the leisurely way myself I am quite happy to let the bandsaw take its own time cutting stuff. Siting watching it with a cup of tea or coffee and biscuits is more my way of getting stuff done. I am looking forward to finding somewhere to set it up and put it to use. The plan is to blitz the shed tomorrow and see if I can get it in. Or find a temporary home for it until a new shed can be organized. I need to get the piece of .303 stainless sorted it's holding me up.

Re: Parting off problems

Posted: Sat Jul 04, 2020 10:07 pm
by bradaz11
what is the issue you are having with parting off?

Re: Parting off problems

Posted: Sat Jul 04, 2020 10:48 pm
by Alpha1
bradaz11 wrote:what is the issue you are having with parting off?
The lathe stalls I have used at least four different types of cutters, blades, inserts all to no avail. Ì dont think I have successfully parted off any thing since I have owned the lathe.
I am going to remove the motor and refit a new set of V pulleys with a beefed up V belt and see if that improves things.
The lathe has never been the same since I fitted the up rated motor and inverter. If anything its worse rather than better.

Re: Parting off problems

Posted: Sat Jul 04, 2020 11:46 pm
by bradaz11
is this the one with the bigger pulley? think you need to get that sorted./

Re: Parting off problems

Posted: Sun Jul 05, 2020 12:17 am
by Alpha1
bradaz11 wrote:is this the one with the bigger pulley? think you need to get that sorted./
Yes, thas the one it's even staling when taking facing cuts now. I need to sort it out. I plan on dismantling it tomorrow (Sunday) and fettling it.

Re: Parting off problems

Posted: Sun Jul 05, 2020 8:08 am
by ovenpaa
We run a horizontal band saw for cutting materials up to 4" and it is great, just gets the job done. It is a small Axminster that was a customer return and came from their factory outlet, I had expected it to last a year or so and it has been running for many years now. I buy bimetallic blades made to measure from a UK company. We also use a large vertical bandsaw for whatever, it is great for stock work.

Parting off is a bit of a black art until you are used to it. As you are running manual machines I recommend slowing the work piece down and keep a slow and constant feed. The work piece needs to be very well lubricated and beware the build up of swarf, slow down towards the end of the cut. Parting off tool designs are complex and you have a huge range to consider, square faced lead to the left or lead to the right (Where do you want the pip to be) Beware as these types of cutter do wander. Parting off is the only job/tool where I do use my own hand ground tools occasionally as opposed to exclusively carbide.

As ever, it is down to set-up, tool height and position, speeds, feeds and time spent on the jon and lets face it, none of us do much parting off. Practice on plastic or nylon, stainless is tough and worst still, it can work harden. Aluminium is gummy.

Re: Parting off problems

Posted: Sun Jul 05, 2020 9:37 am
by Andy
Centre height of the tool is very important for parting off.
If you are cutting stainless steel you need to get your speeds down or you'll just burn the tool out which them starts to rub and not cut then it starts to work harden the job.
Tungsten carbide tools are best really on stainless.

Re: Parting off problems

Posted: Sun Jul 05, 2020 5:00 pm
by Alpha1
Word of advice if you buy one of the clarke bandsaws get someone else to assemble it for you. What a faff on I am knackered. Not impressed with the base very flimsy. The first job will be to uprate the base and wheels I think. But having said that it coped with some 2 1/2" aluminium round and cut it very neatly it just needed the minimum of a facing cut to clean it up. Next up is a piece of 2 1/2" 303 stainless. Let's see how it copes with that. My shed is now a nightmare. It's an accident waiting to happen. I must make an effort to get a base sorted out for a new one. The wife has refused to even look in the door never mind go in there. Wich isn't a bad thing. shakeshout clapclap

teanews hmm whats next. A shower then a couple of cold beers. :good: