Charnwood W815 belt tension

[Esqy]

My lathe was making a clicking sound once per revolution, so I popped the brushes out and re-seated them, which solved the issue.
Turned a couple of pens, and all was good in the land.
I decided to try my hand at turning a bowl. I only have 1 bowl gouge I got from a car boot sale, and not sharpened it yet, so I went with the carbide tools.
The blank was a circular bit of Ash from Yandles - Not brave enough to try turning a square one yet - and from the outset I was having trouble. I'd taken a solid few mm off the outside to true it, but was still getting chatter, and when I stopped it, I found a still-waxed section that it appeared my chisel was jumping over. I sanded it a bit, thinking that the wax was somehow causing the skip, but nothing changed. I managed to remove that bit by coming in from the side. but still, there was chatter.
I then found that if I pushed through with any force above a light touch, the bowl would slow down. I put this down to the fairly slow speed I was running it at, however this was just below where it started vibrating.

Because I didn't want to fry the motor (The machine is only a few months old), I stopped and checked through all the bits, and then hit up google. Looks like my belt is slipping.
Is there a rule-of-thumb when it comes to setting the correct belt tension? I understand that it needs to be loose enough that the motor can cruise through it, but tight enough to stop slippage. Is it a 'trial and error' deal?

 

[Robbo3]

I don't know actual figure, but about 10mm deflection when you press on the belt should be about right.
With a bowl blank if your tool rest is parallel to the bed then you are trying to cut end grain, side grain, end grain, side grain as the blank revolves.
If you place your tool rest at ninety degrees to the bed, parallel to the face & cut into the front of the blank it's all side grain & much easier going.

 

[Esqy]

Thanks Robbo, I saw that 'cutting into the face' tip on youtube, so I gave it a go - I think the main issue was the belt slippage, as the whole process was really slow going. The carbide tip had 2 or 3 projects under it's belt, so was still pretty keen.

Thanks for the belt tip - It's exactly what I was looking for - I wouldn't have the tools to 'officially' check belt tension, but I certainly have the tools to wiggle the belt!

 

[Esqy]

Grrrrr.
Turns out, the 1 click per rev was nothing to do with the brushes - It was also related to the belt tension. To get to the brushes, I had to loosen the motor, so thats probably what cured it.
However, I'm still getting slippage on the belt, and pretty erratic turning results.

I'm hoping to tap into the wisdom of this forum for some things to try.

Using carbide bits - Yeah, yeah I know, But I am also learning to turn with traditional tools, and learning to properly sharpen them and I found I was spending more time sat at the grinding wheel muttering curse words than actually turning. So, the edges are sharp.

I was turning an Ash bowl - I got the blank from Yandles, so I would guess its European Ash, so not the hardest of woods - That being said, I made a Wenge bottle opener, a Zebrano pen and a Purpleheart pen, with no issues turning - So even if it's the more hardcore White Ash, it should be in my wheelhouse.

I was having issues from the start - Found the centre, Screwed in the faceplate and started trueing it and... Well, I already said this bit in my original post!

I got the outside fairly flat, and figured it was just my inexperience that was causing it. I eventually made the tenon and flipped that badboy to start hollowing, and again was getting slippage. I could shave off a small bit at a time, but certainly nowhere near what I expected, and every stoppage/slippage caused some tearout, so I was being gentle. Took me bloody ages, and I got a few minor catches - Again, It's a learning experience.

I went into my house to grab some food and regroup a bit so I could go back with fresh eyes.
Turns out, the blank wasn't truly true, which was causing me to keep it at a pretty low speed, so I went back to the scraper. Got most of the outside walls smooth, but there was a section towards the bottom - Just above where I started the bottom inward curve, that would not smooth out for love nor money until I used the side of the cutter and took of a... I guess strip? from where the curve went in.
I did a bit more work on the outside base of the bowl, which really redused the vibration, but again - Couldn't really get it flat - Didn't bother me too much, as the intention would be to properly finish the bottom later anyway.

It started getting late, and I don't like to be using noisy tools too late as I have neighbours with kids etc. The 'bowl' I have is smooth to the touch on the outside walls, The inside bottom has ridges and the transition from bottom to side has a bit of a ledge and some tearout. Part of this, I think is my positioning. The arse end of the chisel kept bumping against the tailstock, and even when I was being careful, the angles I was attacking at probably weren't all that nice.
I also noticed a couple of sections - one on the outside wall and one on the inside wall that seemed to not cut as well, and looked as if the chisel was 'skating' over them, which would explain the chatter. The bits didn't really have anything in common though. They are at different points around the bowl, and theres no knots or different colouration or anything.

So, based on all that - Is there anything I can try to rescue this bowl and at the same time improve my turning? Machine settings maybe?
I've watched SO MANY videos on bowl turning, but they make the whole thing seem way more fluid than the results I was getting. I get that they are pros or been doing it for years, but with spindle turning I followed the tips and, although janky I could feel the chisels doing what they should be, and I know I can build on that, y'know? With this bowl, It feels like it's just not playing ball.

Apologies for the wall of text, but it's been a mildly frustrating evening in the workshop this evening

Any tips would be awesome

 

[Robbo3]

Need to know what lathe to give more specific help. Photos of the problem also help.
If you add a rough area of where you live to your profile you stand a chance of someone local offering help.
A day with a professional turner should sort out both your technique & your sharpening problems eg you could be attempting to turn a bowl with a spindle gouge whilst those giving advice presume that you would be using a bowl gouge.

 

[Esqy]

The lathe is a Charnwood W815, and I'm using Carbide tools.
I'm based in Plymouth and there is a local woodturning group which meets once a month which runs beginner courses, but they are fully booked each month until November.
I feel like many of the issues I'm having are down to the belt slippage, so I figure If I can get that sorted I can then work on the technique side of it.

 

[Democritus]

I don't know actual figure, but about 10mm deflection when you press on the belt should be about right.
With a bowl blank if your tool rest is parallel to the bed then you are trying to cut end grain, side grain, end grain, side grain as the blank revolves.
If you place your tool rest at ninety degrees to the bed, parallel to the face & cut into the front of the blank it's all side grain & much easier going.

Hi Robbo
I’m not sure what you mean when you say ‘cut into the front of the blank.’ As I understand it, for truing up the blank ie making it round, the rest is parallel with the lathe bed, as are the cuts are across the rim of the blank. As you say, this means end grain, side grain etc.
Turning the rest to 90 degrees to the bed enables cuts to true up the face of the blank. Can you explain what you mean about cutting into the front ?

 

[Esqy]

Think it's along the lines of this video:



The guy explains how and why, but I've linked the start of him actually turning it.

 

[stenik]

Esqy,
Like you I've watched endless videos on the tube. I've found Glen Teagle my go to guy for carbide turning. He makes and sells his own tools and has videos on each one and what you can and can't do with them ( which is everything with a trad tool you can do with a carbide).
As for the belt tension I have an Axminster AW305 which is similar to yours and if I press to hard in the tools when taking a cut then it does slip a bit but then is ok. Is the belt clean, no dust or debris on the pulleys. Just a thought

 

[Esqy]

Thanks Stenik, I just looked up Glen Teagle, and it turns out I'd actually watched one of his videos last night! the one where he turns a bit of firewood into a little cup with bark still on the rim.
Was a really nice video, As it came across as a genuine 'I had some spare time this evening, So gonna give this a go', and he made a few mistakes and it was nice to see how he just rolled with them. I watch a lot of worththeeffort - Probably because he has so many videos, although I find I tend to skip around a bit, as he likes to talk! I guess that comes with the territory of him being a high school teacher!

As for the lathe - I got home late today so instead of firing up any noisy tools to annoy the neighbours, I decided to .... sigh.... be an adult and give the workshop a clean. Once I got bored of that and the lathe worktop was clear, I checked the stuff you mentioned.
Took the belt right off, and cleaned all the pulleys and the belt with isopropyl alcohol. Reassembled it all, and turned it by hand while pushing down on the motor until it sounded right and was hard for me to make it slip on purpose. Tightened it all up, and it feels and sounds much better.
I'll give it a spin tomorrow to see if that's solved the challenge.

I get that it may slip occasionally, but what I was experiencing was from anything more than a very light cut was slipping it.
I reckon part of it might be that the tenon on the bowl looks to be slightly uneven - No idea how that happened, but hey - Learning curve!

 

[Robbo3]

@ Democritus - the video Esqy posted explains it. The rest may need to be re-positioned so that not too much of the tool overhangs the rest as wood is removed. Just remember that the guy's a pro turner, taking a large cut on a forgiving piece of timber & like any pro, he makes it look easy but it's something to aspire to.

@ Esqy - Sounds like you have sorted your belt problem. Carbide cutters can be rotated to get a new cutting edge & they can be sharpened with a diamond hone used on the top surface.

 

[Esqy]

Fingers crossed for tomorrow. I'd already turned the carbide bit once, just in case it was that. With regards to sharpening - A whole set from amazon is £12, and a 10pc box of a single flavour is less than a tenner, so I don't really see the need to sharpen them.

All that being said, I'm still using regular chisels for spindle turning. I have a couple of of the Tormek jigs arriving in the next couple of days for my Record grinder - Looks like that puts sharpening onto 'Easy mode', which suits me as I'd rather spend that time learning to turn, and I can work on sharpening later.

 

[Democritus]

Robbo
Thanks for that. I get the technique, but, as you say, it looks a bit iffy from a safety point of view. There is a clear danger that a descending corner could flip an overhung tool violently. I think I’ll stick with round blanks, either bought or cut by myself on my bandsaw.
Espy, make sure the Amazon cutters will fit your tools
D.

 

[Esqy]

I'm with you on this one, Demo. I'd much rather spend a little more prep time taking the corners off on the band saw
As this is just a hobby for me, I don't really need to monetise my time.

 

[Esqy]

A little update, I turned a couple of pens no trouble at all, and I loaded a new bowl blank on there today - This time Sycamore - on the hardness scale is a little softer than the Ash I was using before.
I got waaaay less stoppages, so that's a bonus. I did find I had to be fairly gentle, as it was slowing down the motor a lot.
I think it's just that turning bowls is at the limit of what the motor can handle, and along with the belt not being tensioned enough was causing the catches.

Now I know what I'm working with, I'm well on the way to making sawdust in new and interesting ways!

 

[Paul Hannaby]

If the lathe motor is slowing down under heavy cuts, try putting the belt on a lower speed range.

 

[Esqy]

Theres only 1 pulley, and the speed is changed on the control panel

 

[alex robinson]

A little update, I turned a couple of pens no trouble at all, and I loaded a new bowl blank on there today - This time Sycamore - on the hardness scale is a little softer than the Ash I was using before.
I got waaaay less stoppages, so that's a bonus. I did find I had to be fairly gentle, as it was slowing down the motor a lot.
I think it's just that turning bowls is at the limit of what the motor can handle, and along with the belt not being tensioned enough was causing the catches.

Now I know what I'm working with, I'm well on the way to making sawdust in new and interesting ways!

It sounds as if you are making excellent progress - nothing like just trying things to get a feel of what works.

Once you get over the hassle of sharpening you may find life easier with the traditional tools. You have a lot more control of the depth of cut and it takes less power to slice than to scrape wood away. It will also feel easier once you are comfortable with higher speeds.

I spent ages trying to make excessively big bowls on a 1/2 hp lathe and it does wonders for your sharpening and tool control!

 

[Esqy]

Thanks Alex. As with most newbies, I was/am a little... impatient and kinda wanted to be getting things made, hence the carbides.
I got the Tormek jigs, and they are a dream come true. I spent half of saturday just sharpening/honing.
Turns out there was only 1 bowl gouge in the job lot of chisels I got, it's a medium sized one, so just right for learning with.

I'll dedicate some time this week to throwing a cheap bowl blank on there, and have a crack at some of the cuts I've seen on youtube

 

[alex robinson]

Thanks Alex. As with most newbies, I was/am a little... impatient and kinda wanted to be getting things made, hence the carbides.
I got the Tormek jigs, and they are a dream come true. I spent half of saturday just sharpening/honing.
Turns out there was only 1 bowl gouge in the job lot of chisels I got, it's a medium sized one, so just right for learning with.

I'll dedicate some time this week to throwing a cheap bowl blank on there, and have a crack at some of the cuts I've seen on youtube

Totally understand - I am all for impatience. You really won't regret getting the sharpening jigs. If nothing else, they will pay for themselves by not grinding the tool away nearly so fast.

If you want to practice getting used to the tools, it might be worth trying some green wood. It is softer and so easier to try out different angles with the tool. So satisfying when it is just right and there are huge long streamers coming off. Also has the benefit of being free! Just be warned things will warp and split as they dry. Either accept that they are firewood, or try having a look on here for some of the threads about turning in 2 stages, allowing to dry when rough shaped.