Record Power BS350 still vibrating - any further thoughts?!

[Chris152]

The saw's about a month old, and about a week ago a vibration in the table started.

It comes and goes (sometimes it's there, sometimes not) and can even disappear while the blade is running.

I've checked all the bolts I can reach are tight, and changed the blade. No change.
I removed the drive belt to check just the motor, and replaced the drive belt with no blade so I can hear just the lower wheel. No vibration.
The upper wheel is balanced properly. There seems to be no play in either wheel so I'm assuming the bearings are fine (and the saw is new, so not warn.)

Does anyone have any suggestions for further tests?

OR - is some vibration normal? I made this little film so you can see what happens with a penny on the table. I guess the total side-to-side movement is about 1mm. Maybe I wouldn't be so bothered if I couldn't compare to those times there's no vibration at all (apart from the sort that doesn't lead to the wobble that causes side-to-side movement).

The film's here: https://vimeo.com/218924136

I've already had advice in my Axminster BS post but figure this issue's a bit buried in there now, and it's really starting to bug me! And I hope this new post is in the right Forum.

Thanks

Chris

 

[Ttrees]

Is the machine plumb ?

 

[Chris152]

It think it's on even ground (concrete garage floor) - if it's off, it could only be slightly.
And it was slightly off level, but I corrected that today and it was the same, sometimes fine, sometimes not.

Do you think it'd be worth placing a stable/ heavy sheet of wood underneath to see if that changes things re evenness of the fllor? I had wondered about your question. Part of the problem is it's so heavy and I'm on my own.

 

[Chris152]

I managed to get the rear and front legs of the stand onto two new planks, and made it all level. It went perfectly for a few startups, then the wobble came back! The funny thing is I left it running on the last wobble, and after a while it stopped and was perfect again.

 

[Ttrees]

You would be supervised how much a machine can seem to be plumb and be waaay off.
I made (albeit a carpy) plumb bob from a Co2 canister and stuffed it with lead.
I think it was from a pellet gun ?
It would have been far better to have a point on it though, I just used to always see them on the street and thought they'd be
useful fro something.
A bolt on a thin string would do just fine.
I don't see any blade wobble on your machine, that's the most important thing
Tom

 

[Chris152]

Yep, I don't really trust my spirit level at all. I'll try to rig something up! What would I test it against, the main upright at the back?

 

[Ttrees]

I'd aim for the blade, but that's difficult as the table is there.
I tried both ways and used the spine first to plumb it in both axis.
I wrapped the string around a stick of timber and put a weight on it
Watch you don't nearly crack it off your head during adjustments ops
Or drop it on your saw !
Choose wisely friend

 

[Chris152]

Well, I like to think I have a decent eye for parallels and it looks plumb from what I can see! Which is a shame, I got all excited about that possibility... :?

 

[Ttrees]

That was quick !
So you have plumed the machine and made sure the planks are laying flat on the ground, and are not deflecting,
and there's contact on four corners of the machine ...
Besides that, have you tried a different blade ?
I would not be concerned about it, as your not going to be resting coins on the table when your cutting, and you will have plenty of sawdust
in your pocket if you start using the machine and try this exercise again #-o
Is the blade running true ?

 

[Chris152]

Thanks for questioning that - I'd checked the table with a spirit level and the blade/ spine and front of upper wheel housing with my diy plumb line, all seem fine - but the planks are not! Both run downhill to the right, heading toward the garage door. I had to put a shim between one of the planks and a leg and that has made things where I measured look ok, but I guess there must a twist in the machine if the rear feet are on an un-level plank?

Do I now just put a shim under that leg at the back which is low and see what happens?

Thanks for your patience.

ps The blade seems to be running just fine.

 

[CHJ]

ps The blade seems to be running just fine.

As you say the vibration episodes come and go it might be worth checking that you are not getting Blade Flutter on the unsupported return side.
Not something that is visible with machine in working setup and doors shut.


With care to keep hands and body well out of the line of fire in case the blade should fail or come off the wheels.

With power off.
Prop both doors open.
Close door safety switches (override) with suitable packing tape, strip of contact wood etc.
Start machine and observe rising blade, is it fluttering?

If answer is yes, try adjusting blade tension, worst case scenario fit a fixed block of hard wood in centre of rising blade path to just lightly contact outside of blade.

 

[Ttrees]

I have seen some RP machines here that did not sit flat, but it looked very obvious and I suspect you would have noticed that.
You have nothing to loose from shimming it and trying it out.
You should really see if this vibration goes away with another blade as blades are really really fickle things.
Is the same dust pattern on each wheel and is it a consistent layer of dust on them?
I might guess they would, you always need another blade
Ian will sort you out
Good luck

 

[Chris152]

As you say the vibration episodes come and go it might be worth checking that you are not getting Blade Flutter on the unsupported return side.
Not something that is visible with machine in working setup and doors shut.

I hadn't even begun to consider this - instead of going through the shut-off override, I wonder if I could just increase and decrease tension to se if it changes anything? How far either side of the tension guide could I take this safely?

The blade, with the guides completely removed from the blade, does seem to have flutter at the moment, and it seems keen to rub up against the plastic insert on one side - see here: https://vimeo.com/218956183

Ttrees - I've tried 2 blades, and the saw is just the same with both. Do you mean the machines sometimes don't sit flat on the stand? The dust certainly seems consistent on the wheels, though I do keep fiddling with them so can't be too sure!

Thanks both.

 

[Ttrees]

I would shift the table a bit as the blade is touching the insert.
There is adjustments in the trunnion to do this.
You will not be able to set the saw up correctly until you do this.
First thing I would do...
you may/probably will have to adjust it again for drift after this the same way, so your fence is parallel
with the miter slot... instead of loosening 4 bolts and shifting , leaving a corner slightly snug so you can make small adjustments.
Makes no sense to be adjusting the fence for drift
Tom

 

[CHJ]

.....I hadn't even begun to consider this - instead of going through the shut-off override, I wonder if I could just increase and decrease tension to se if it changes anything? How far either side of the tension guide could I take this safely? ....

As far as you like, the tension guides are notoriously just that, a ball park guide.
Too tight and you will encourage the blade to break and put unnecessary load on tyres and mechanism, too slack and it will come off the wheels.
The margin between the two extremes is great and every blade is likely to be a few mm different in length due to tooth matching and weld.
Adjust until it runs without flutter and short of it singing like a guitar string if you tap it.

 

[Alexam]

Hi Chris,

I have the Record BS400 in my garage, which has a concrete floor. When I am about to use the machine, I pull it out to a suitable place, which has been determined previously by thick permanent marker outline marks. My garage floor is not 100% flat and true, I don't know one that is, so I move the machine and once its lowered from the wheels, I get at the corner of the machine and with both hands hold the table and push my weight forward and back to see if I can rock it at all. In many positions, it does rock, so I move again. Once I have found the right spot (I have 3 now) where I cannot actually rock the machine in the slightest, then I mark around the base on the floor.

I can now just roll the machine to any of 3 marked places and it is really stable and works a treat. I think many owners don't think about it but if there is the ability for the machine to move on the floor, you will get vibration.. Try it if you haven't.
Malcolm

PS If that doesn't work, ask Record to come out and test it. They are most accomodating and if they find something unusually wrong, they will change the machine under the 5 year guarantee.

 

[Chris152]

I think I've tried it all now! I guess I need to take a look at the rising blade to see if it has flutter as you suggest CHJ, sure I can concoct something. Following Malcolm's advice, I got in touch with Record who looked at my video and suggested it wasn't enough vibration of affect cutting accuracy, and went on to say:

'Bolts being tight, were these tight before the band saw was placed on the stand? It is always good practise to leave the bolt stand a little loose let them seat squarely on the floor and then with the band saw in pace and everything square nip up the bolts. If the legs aren't all meeting the floor square and are off set then this could be causing the vibration?

Another thing is to check the tyres for any high spots and give a clean with a Scotch or something like just to get rid of any sap or anything else that could be causing the blade to not sit correctly.

If you could check some of the above and get back to us. We are also working on a trouble shooting video to hopefully help customer eliminate vibration and any other issues customers may have. As soon as we have completed this I will forward on a link.'

It's a really helpful reply, though I tried both and no change in vibration/ wobble that I notice, so I'll get back to them tomorrow. That video sounds like a great plan, though!

Thanks

Chris

 

[Ttrees]

So you have shifted the table over, so the blade is not in contact with the insert.
Is their any blade wobble either side to side, or back and fourth now ?

You plumed the saw .

Do you get any vibration without any blade installed ?

Does this vibration occur while the blade is tracked in different locations on the top wheel ?

Is their any noise or creaking when hand turning the wheels with blade installed ?

Where is the blade tracking on the lower wheel ?...and does it move location when tracking the top wheel ?

Tom

 

[Chris152]

I've held off posting an update in case anything too positive is tempting fate. The saw sometimes vibrates but doesn't seem to effect cutting, and I'm pretty sure it's to do with blade tension when it does. I have it tensioned higher than the gauge says for a 1/2" blade - nearer 5/8" - and that seems to sort it, I think. So i guess it is the flutter on the way from the lower to the upper wheel as CHJ suggested? Anyway, I've kind of stopped worrying about it for now and just getting on with using it...

One thing - I'm finding the fence a bit annoying when I try to be precise with cuts. I position it so the wood I want to cut is in just the right place, and as I tighten the fence is shifts a couple of mm left or right as it takes up the slack in the bar it's connected to. Is this just something I have to put up with if I don't upgrade the fence or is there anything I can adjust?

Thanks.

 

[selectortone]

One thing - I'm finding the fence a bit annoying when I try to be precise with cuts. I position it so the wood I want to cut is in just the right place, and as I tighten the fence is shifts a couple of mm left or right as it takes up the slack in the bar it's connected to. Is this just something I have to put up with if I don't upgrade the fence or is there anything I can adjust?

I have that issue with my BS350S, I've just got used to it and compensate when I'm tightening the fence bolt.

I have watched your video of the penny falling over and I'm pretty sure I'd have the same thing happen on mine - I'll try it tomorrow. FWIW, yours sounds quieter than mine! Mine is on a reasonably level concrete floor.

I have had mine for a year or so now and use it mostly for preparing bowl blanks (up to 14" x 6" or so) for turning although on the odd occasion I've used it for doing anything where accuracy is required I've been pleasantly surprised at how straight it cuts. Mind you, that's after upgrading from an Axminster BS250N which was, to be frank, little more than a toy and not fit for purpose, even for "hobby" work - whatever that is. I did spend a LOT of time getting the 350S set up initially but after a lost weekend I told myself - "hey, it's a chinese mid-range BANDSAW, not a ten grand professional panel saw - don't expect miracles!" I use Tuffsaws general purpose blades (3/8" 3TPI if memory serves) on it which I use for everything. If I want to cut anything really accurately I have much more suitable kit for that - table saw, mitre saw, track saw.

Having said all that, I use it all the time and really like it. It does what I need admirably.