Metabo bas260. Blade off when reversed and bearing issue

[Lard]

Hi,
I'm a newbie here and to bandsaws. I've bought a supposed new machine and although I have tracked it by hand and all seems ok including running it electrically the blade will not stay on the wheels if it is hand-turned backwards (only a 1/3 of a wheel turn).....you may be thinking why turn it backwards? But machine often turns itself slightly backwards (when power off and running freely) and hey presto...BANG!!.....before you reply consider this:-
1. Surely if upper and lower wheels are tracked I should be able to hand turn backwards AND forwards with no issue anyway.
2. My machine WILL turn itself backwards on its own every now and then when power is shut down/switched off as it seems to be adjusting itself through freewheeling.

Also, when front looking at both upper and lower rear wheeled bearings (from the perspective of a clock face) the lower bearings have the blade positioned at something akin to 7 and 11 o'clock ......the upper is more like 12 and 6 o'clock and so stops the blade when any pressure is applied through cutting as the bearing cannot turn in this position. There is no sideways adjustment on the upper rear bearing ?????

Have I bought a dud?

Any thoughts would be most welcomed.
Ta

Dq

 

[blackrodd]

There are several users of this saw on the forum but this sounds as if all the pics you can put on here will be a good idea for some one to solve you're problem.
Has the top wheel mounting slipped out of line during transport? I suggest NOT using the saw until the problem is resolved.
Something is badly out of sync here. Rodders

 

[woodndrum]

I have an old one of these, and it is a great workhorse. Yours will be too, what is needed is a step by step methodical approach. Firstly for goodness sake don't try to use the saw, and be very careful as your description sounds like you have run the saw with the doors either open or removed.

I would suggest that you start by digesting to and bottom blade guides at least 5mm away from the blade. That way by turning the upper wheel there will be no interference on the blade. This will check if the wheels are turninglace g in the same plane. If the blade come off with as little as one third revolution the two wheels are badly out of alignment.

Check YOU TUBE videos of wheel alignment. Carter in the USA have some amazing tutorials about tuning a band saw. There are also some fine books avail able. I'm surprised that someone can sell a new saw and not commission it in the new workshop. If you email some photographs of the problem then a step by step solution should be possible. These are good machines and should run and run, especially if fitted out with a quality blade.

 

[Lard]

Hi both,
Thanks for early responses. Please don't think I'm putting myself in any danger here as I'm not that kind. I have run it by hand with the doors open but closed when powered up....as stated it ran well (dare I describe it as beautifully) and also very quiet (prior to me setting all bearings) as I did spend time aligning both wheels before doing do. My problems came to light when I tried a very 'light' thin cut which completely stopped the blade turning, due to the 'rubbing' against the rear top bearing.
The other problem only came to light when the saw simply half-turned itself backwards after it had stopped and blade popped off. I simply refitted and checked alignment/tension etc and thought all was ok until I turned it backwards by hand and hey presto it was immediately obvious that the blade was coming off the front of the top wheel. However, running by hand forwards realigned it and maintained it so much so that I turned power back on and, again, not an issue.

I'll try to get some photos to show the position of each top and bottom bearing set.

I'm assuming that the top bearing shouldn't need to have sideways alignment ability as there's no option for this on the machine.

Ta
Dq

 

[Myfordman]

One comment I 'll make is that the guide bearings/posts/blocks whatever you have should not be set to divert the blade from its natural position.
Set them all back out of the way and track the blade untill it is running happily. I can't think of any reason at all why if you switch off now that the blade will want to run backwards other than some inferior attempt by the makers to bodge some braking action on the motor so get that established first.

Then bring the guides back so they support but not move the blade from its 'happy' position.

 

[owen]

Try watching the bandsaw clinic with alex snodgrass on youtube. Copy what he does and you can't go far wrong. Ive set up my bandsaw a few different ways but find his way the simplest and the best.

 

[John15]

Hi Lard,
I have the same model bandsaw as you. I don't get any reverse movement of the blade when I switch off and have no idea what will be causing this. Regarding the blade sliding off the front of the top and bottom wheels, could it be that your rear bearings are too far forward. I believe both rear and side bearings should just clear the blade so there is no contact when running. I replaced the blade that came with the saw with a new one from Tuff Saws, maybe this would help.
Cheers,
John

 

[Lard]

Thanks again to everyone who's giving advice etc.

I've just reread my own text and want to clear up a possible misunderstanding......forget any power source (ie even with the plug out) in regard to the 'running backwards'.....if you think of a bicycle wheel that has some random additional weight at some particular point along its rim then if you spin it forwards it will continue until all energy has run out....it MAY then run backwards ever so slightly as it rebalances itself....it's this that I'm trying to describe. I initially thought this was a good sign as everything appeared to run so 'freely'. Apologies of I'm not doing a good descriptive job.

Please also believe me in regard to my initial setting up. I've had it running brilliantly with ALL bearings pulled back (ie no unexpected noises at all)....I've then watched various you tube videos and read the manual and one by one have introduced the bearings.....none of which have ever touched the blade (ie again, no unexpected rubbing or noises) when it's simply running, ie none of my bearings change the path of the blade. It's only when I tried to cut anything that it was obvious (even to this bandsaw novice) that the top rear bearing is not turning but simply getting pushed against and so, through friction, gets stopped.

She who must be obeyed may not let me visit the man cave (my workshop) in the week so I will get some photos as soon as I can but may not be until weekend.

A number of people recommended tuff saws and I did try to get hold of him over Xmas (to have a conversation) but missed him and due to the problems have not tried again because I'm not actually going to try to cut anything yet......I will ring him tomorrow.

This is a helpful forum and so thanks again.

Dq

 

[Myfordman]

I think I understand what you are saying about a bicycle wheel but just can't relate that to something like a bandsaw where the tension in the blade and losses in drive belts take up any hint of ability to freewheel.

I'm intrigued!

 

[woodndrum]

From what you have said in the later posts. The blade runs true and freely with the guide bearings backed off. Careful alignment of each guide in turn and still the blade runs true.
You try a light cut, and the blade wants to stop. Then the problem lies in one of two areas. Or both.

There is insufficient tension on the saw blade. That is to say there is not enough force attempting to force the wheels apart. There is at the bottom left of the top wheel housing a rough tension guide for each blade width.

If this is not the problem, then is there a problem with the motor drive belt slipping under load?
My bet is insufficient blade tension.

Again your description of the blade and wheel freewheeling to a stop and 'rocking' backwards to a balance point suggests to me blade tension is way too low. The saw should not stop in this way. Ten second rule and all that.

 

[carlb40]

Hi
I have just downloaded and read the manual. On page 17 it shows/ tells you how adjust the bearings inc adjusting the thrust bearing so it is in the centre of the blade.

http://www.recordpower.co.uk/assets/pro ... 505778.pdf

 

[Lard]

Hi Carl,

Thanks for response. I've seen that manual but it's not my machine.....by that I mean that it must be an older model as my bearings are a completely different set and the thrust bearing is in a different plane by 90 degrees.
The left and right bearings are (as you may expect) simply 2 'wheels' that have the potential to simply run along the flat of the blade should it touch them.....no problem there.......however, the rear bearing 'wheel' is not rim-onto the blade but wheel-face onto it??? And so I cannot see how this 'wheel' can ever run properly. The manual link you attached appears to be a much better design.
As I've said previously I'll get some photos uploaded over the weekend.
Even though I may end up with egg on my face I'm hoping its a simple error to be put right BUT I've had to do very little setting up and so am still assuming that the machine has been put together correctly......can't imagine that the bearings could have been put on in the wrong position.
Dq

 

[carlb40]

Ahhhh ok.

While expensive, i wonder if these would work / fit your bandsaw.

http://www.axminster.co.uk/bandsaw-blad ... em-upgrade

 

[C7trp]

My one week old bs250 has the guide bearings as per the manual linked above, so I think this is the current design.

I haven't looked in detail but are you sure it's been assembled correctly?

Also, my machine doesn't roll backwards as you describe, it just stops nicely.

I'm no expert, and this is a long shot, but have you checked the brush on the lower wheel is properly set, maybe this is causing the bottom wheel to spring back as the machine stops?

I can post some pics of mine if that helps

 

[paulm]

the rear bearing 'wheel' is not rim-onto the blade but wheel-face onto it??? And so I cannot see how this 'wheel' can ever run properly. The manual link you attached appears to be a much better design.Dq

That's a common configuration for rear bearings on many bandsaws, works fine.

Cheers, Paul

 

[Grahamshed]

the rear bearing 'wheel' is not rim-onto the blade but wheel-face onto it??? And so I cannot see how this 'wheel' can ever run properly. The manual link you attached appears to be a much better design.Dq

That's a common configuration for rear bearings on many bandsaws, works fine.

Cheers, Paul

It is on the Axi saw as well and despite me wondering how it was going to work..... it does.

 

[Lard]

Hi everyone,

Firstly I have to apologise. My machine is not a record bs250 but a metabo bas260......I've spent more time on the damn internet than with the actual machine and so must have mentally switched over as they both look identical on the web!!!.......sorry.....this doesn't change the issues however.

I've uploaded some photos to a new flickr account......please see here.....

http://www.flickr.com/photos/117100753@N04/

I've also uploaded 2 short videos to a new you tube account......excuse the camera work as I'm holding an ipad with one hand and trying to move the machine with the other hand.......please see here....

http://youtu.be/ybcCGrKmkYo
http://youtu.be/q6qO96wucD0

Although I've not powered up the machine, and so everything is by hand, I've tried to show that the blade rotates forwards with no problem BUT it only takes a small reversal to cause it to start to come off the front of the upper wheel. As noted previously I have had the machine running (electrically) and the blade stays where it should do! Within the video I've also tried to show the tendency for the blade to turn itself backwards.....in fact after I made the videos I was taken a photo when I noticed the blade moving in reverse by itself (through the ipad viewfinder) and was surprised that it didn't go 'bang' and come off the wheels.

Within the photos I've tried to show the position of the upper and lower bearing sets. Please see that the blade is much further to the right in the upper bearing set and so the right hand bearing is in a much different position to the left hand unit.

Please also note that there is no side to side lateral repositioning available on the upper bearing set and so how can I centralise the blade????

Any thoughts fellows?....any help would be welcome.

Dq

 

[Lard]

Also....is there a way of me changing the subject above from record to metabo?

 

[carlb40]

Also....is there a way of me changing the subject above from record to metabo?

Yes on your first post - click on edit and then you can alter the title etc

 

[blackrodd]

Its difficult to see but the blade guides and rear wheel don't look right, somehow. blade tension looks caught on the guides.
Have you tried slacking off the guides enough to be free at top and bottom, say 1mm gap on two sides and thrust rear wheel,1 set above and 1 set below the table, then try, by hand foreward and back, and see if the blade stays on the wheels and where abouts on the tyres they are.check the correct tension from you're handbook, or the internet for that model, and then, set up the tracking.
If all appears well, Put the guards back on switch on and see if it runs ok.(Don't try and cut wood without the guides set up!)
Wouldn't be surprised if it is the guide set up!
HTH Regards Rodders