Thumping sound from new lathe... errr... help?

[sploo]

Its possible its the wrong belt. My 2 month old axminster bandsaw drive belt failed, completely snapped. When I checked its length it was so long that the jockey wheel had the belt bent right back on itself. I got a smaller one locally rather than fit another from then in case it was the same over length.

Axminster service is first rate, but I have found the original factory quality control to be sadly lacking on the last two machines I've bought.

I think the belt is the right sort of length. There's enough travel in the motor that I can have it very loose (looser than I think it should be, but still working) all the way to pretty taught (tighter than I think would be right for such a belt).

That said, if the motor tends to be too high, maybe the belt is tad too short.

Overall quality otherwise looks OK. Certainly it seems the inverter is an afterthought though - there's easily enough room to mount it under the bed of the lathe (I noticed the electronics for the Jet were slung under the bed). Instead the inverter sticks out of the back in a rather ugly fashion, and you end up with exposed cables to the rpm display. It doesn't cause and functional issue, but looks ungainly.

Are the pulleys in proper alignment with each other?

I believe so. Certainly I couldn't visually see any twisting or misalignment of the belt. The headstock casting means it'd be difficult to get a straightedge in place to do a better check though.

 

[Lons]

I dont know this machine, but the noise you describe sounds like the motor mounting bolts are loose.
You say the motor weight tensions the belt? That doesnt sound right to an old fashioned guy like me. The belt should be tensioned and then the motor securing bolts tightened.

The motor hangs underneath Bob and is lifted to change pulleys easily then lowered and tightened by a single handle clamp, works very well.
though I give mine just a little tension it does run smoothly enough just with the weight of the motor.mine

EDIT: #-o Just seen Sploo reply so ignor the above.

 

[sunnybob]

Got to admit I dont like the fact that the motor weight alone tensions the belt. It must bounce like a good un on start up, and any load applied to the chuck would again make the belt stretch and slacken before settling down again. Any drive belt is just like a car fan belt. It needs constant tension to perform correctly.

 

[sunnybob]

Just looked at the lathe manual.
That motor shift handle should also be the tension adjuster. If it were mine, I would push down on that lever and lock it off exactly as i would adjust a car drive belt.
Of course, the original noise might not be caused by a loose motor, but I think it should be tensioned and locked off.

 

[Lons]

Just looked at the lathe manual.
That motor shift handle should also be the tension adjuster. If it were mine, I would push down on that lever and lock it off exactly as i would adjust a car drive belt.
Of course, the original noise might not be caused by a loose motor, but I think it should be tensioned and locked off.

Just tried mine Bob.

lathe runs fine with motor hanging on the belt but I would expect it to slip under load if not locked down. I've never used it like that and always lock the lever for obvious reasons and give it just a tiny bit of extra tension. Surely that's normal as a belt shouldn't be too tight or it will put undue pressure on the other components.

cheers
Bob

 

[sunnybob]

Ordinarily a drive belt should be tightened enough that deflection between the longest contact points would be about as much as your thumbs width, by just using your thumb pressure. As theres no actual measurement in the book, I would expect that to be good enough.
Have you looked at the inside surface of the belt? an imperfection there on the joint would give you the whump whump sound
This is the belt off my bandsaw. less than a dozen hours running time.

 

[sploo]

Just looked at the lathe manual.
That motor shift handle should also be the tension adjuster. If it were mine, I would push down on that lever and lock it off exactly as i would adjust a car drive belt.
Of course, the original noise might not be caused by a loose motor, but I think it should be tensioned and locked off.

Bob - that's exactly what I've been doing: loosen the Bristol lever, push the tension lever down, lock the Bristol lever.

I did check the belt - both inside and outside - and I couldn't spot any damage, debris, flat spots, damage to the ribs etc. I spoke with Axminster this morning, who scratched their heads a bit and are going to send me a new belt as a first attempt.

Maybe the belt is a bit short (the issue of the motor being scratched by the banjo, unless the belt is tensioned way too much). I can't immediately think why that would cause a knocking sound as it's not like the motor is at the top or bottom of its travel in use (i.e. not bumping against the casting).

The frequency of the knocking matches one cycle of the belt, so it must surely be belt related... I think.

 

[sunnybob]

you'll most likely get the belt tomorrow, but i went to a car spares place and bought a new one. The material of that belt looked liked it was made down to the lowest possible price.
i bought a belt a couple mm shorter so the jockey wheel didnt turn it in to an alpine road course outline, and its been fine ever since.
You might well need a belt a couple mm longer.

 

[sploo]

you'll most likely get the belt tomorrow, but i went to a car spares place and bought a new one. The material of that belt looked liked it was made down to the lowest possible price.
i bought a belt a couple mm shorter so the jockey wheel didnt turn it in to an alpine road course outline, and its been fine ever since.
You might well need a belt a couple mm longer.

The belt is marked 280J, and I measured the outside length as 713mm. There seems to be a standard size available that's 280J4, 28" Length (711mm), 4 rib (3/8" Wide).

That though would point to the existing belt being pretty spot on in terms of size. Given that I can't see any flaws I'm struggling to see how a new belt will fix the issue, but here's hoping.

 

[Lons]

Ordinarily a drive belt should be tightened enough that deflection between the longest contact points would be about as much as your thumbs width, by just using your thumb pressure. As theres no actual measurement in the book, I would expect that to be good enough.
Have you looked at the inside surface of the belt? an imperfection there on the joint would give you the whump whump sound
This is the belt off my bandsaw. less than a dozen hours running time.

Hi Bob

I'm not saying it's not the belt, probably is but the one fitted to the 1416vs is a poly V belt which in my experience is much more forgiving when it comes to tension. The belt is very easy to examine without removing from the lathe, just loosen the tension and turn over as I've done to take this pic and any fault or damage is obvious.

 

[sploo]

Hi Bob

I'm not saying it's not the belt, probably is but the one fitted to the 1416vs is a poly V belt which in my experience is much more forgiving when it comes to tension. The belt is very easy to examine without removing from the lathe, just loosen the tension and turn over as I've done to take this pic and any fault or damage is obvious.

That looks familiar

 

[sunnybob]

Yes, its rare for that type of belt to faulty. It will interesting to see what happens.

 

[Robbo3]

I hope they (Axminster) are exchanging the gouge as well as sorting out the lathe.

 

[sploo]

I hope they (Axminster) are exchanging the gouge as well as sorting out the lathe.

I spoke to a guy at Crown Tools who told me they should be straight, but the cooling process and variable thickness of the metal (due to the flute) means they will usually move a bit.

A ~2mm tall curve across the 10" length was beyond what they'd normally want to see, and he said he'd be more than happy to exchange it directly. However, it shouldn't make any difference in use, and certainly wouldn't be noticeable. TBH I'll probably just keep it, as the cost/hassle of replacing something that should be fine isn't really worth it.

 

[sploo]

Well, I got the spindle out. Rather more "persuading" required than I was happy with. The spindle pulley is pretty tight on the keyway, even with the pulley's grub screws removed.

I see there's a 6004 and 6005 bearing as expected - rubber sealed.

I was hoping to get the replacement belt today... only it turns out it hasn't even been shipped yet as Axy didn't have any in stock ](*,)

I can see there's visible thread at some points on the sides of the belt (or conversely, rubber) but nothing that really looks like damage or unevenness. As such I'm less than confident a new belt will be the answer, but I'll have to wait regardless.

 

[Lons]

Hi Sploo

I'm completely confused over this. :?

The lathe is brand new is it not and clearly is not fit for purpose.
Axminster is a reputable company with good customer service record.

IMHO, you really shouldn't be removing the spindle and pulleys, changing belts etc as that can be construed as unauthorised repair and affect the warranty.

I would have spoken to Axminster and insisted they deliver a new replacement machine and collect the old one which I'm certain they would do. Just doesn't make sense to me as the lathe even if sorted will always be a "repaired" model. It's not a cheap item and should be perfect out of the box or rejected - full stop!

Even if waiting for a courier is inconvenient, there's always a way, maybe a neighbour, relative or work address.

Bob

 

[woodpig]

On my 1416 the inside of the belt cover rubs on the belt on the slowest pulley setting. Not an issue for me so far as I don't usually use the lowest speed range. I should clean up the inside of the cover with a dremel or something though.

 

[Sheptonphil]

Have to agree with Lons 100% here.

A premium priced piece of equipment should be perfectly usable out he box, not going through repair procedure by you.

To then not even have the part is just taking the p***

You could have had a replacement lathe quicker. I think Axi are having a laugh at your expense.

Phil

 

[sploo]

Well, yea, it's not exactly been a great journey so far (with the lathe or any of the other bits TBH).

When I first spoke with Axminster they asked if I could take it to a local store, which I didn't want to do for the same reason a replacement would be a hassle - it's pretty heavy for me these days, and simply man-handling it back into the box will be a pain.

The option to try a new belt was therefore just about acceptable, but the fact it wasn't in stock has really annoyed me as I've been waiting two days for it. To be fair, the lady I spoke to today was very apologetic and said they'd try to get one out overnight (though I haven't seen an email that indicates it's happened).

I've ordered a pair of SKF bearings as I might as well take the opportunity to change the original cheapo ones.

If the new belt works, then we're OK I guess. If it doesn't then I will be pushing for a same day collection and replacement - I can't really afford to take multiple days off, and I'd struggle to get the box in/out of the car and into the garage if they delivered to my workplace.

BTW I can't see how changing a belt is an unauthorised repair (especially as they've asked me to do it) - at some point you'd have to do it on a lathe anyway.

 

[sunnybob]

I think its ultimatum time. No belt within 24 hours or take it away.

And yes, I have also had to change bearings on my axminster bandsaw wheel. Something that should not need to be done after a 1000 hours working, let alone 10.
I'm starting to realise that axminster is so good at customer service because they get an awful lot of practice.