Further saga of the Bernina 950

Claire that motor is to fast for that machine. Remember the 950 is basically a home sewing machine. The low speed motor is advised. The high speed will sooner than later destroy the machine completely.

Ron, I'm curious, is there no way to slow the motor down? Maybe a rheostat or something? Or would that just make matters worse?

:I have had more problems with my Bernina 950. :Having cured the timing in May I then had a broken cog in August. I :then had a repeat of the looping of the threads underneath which then :threw the timing out on the machine in the beginning of December.

:I finally got to take the machine to my service man, 2 hour round trip, :on Tuesday and he fixed the timing while I waited. He is puzzled as to :why I having so much trouble with a Bernina.

The only thing 'Bernina' about a 950 is the sticker, and the price sticker.

:I love this machine when it works well but I am reluctant to spend yet :again to change the motor, it will be the best part of 500 ?uros. Does :anyone think it's really going to make a massive difference? I :understand my service man's theory but is it just clutching at straws :for reasons ?

In the US, a new variable speed servo motor is available for about $125 US. I'm sure they're available in Europe, but even shipping one from china to the US to France will cost rather less than 500 euro. Any one of modest mechanical competence can install one, it mounts to the table in the same way as the existing motor. You'll also probably need a new belt, of a different length. Suitable belts are available from hardware and auto parts stores; they're used on all sorts of equipment.

BEI Design wrote: :Ron Anderson wrote: :> "Claire in France" wrote in :> [...] Claire that motor is to fast for that machine. Remember the :> 950 is :> basically a home sewing machine. The low speed motor is advised. :> The high speed will sooner than later destroy the machine :> completely.

:Ron, I'm curious, is there no way to slow the motor down? Maybe a :rheostat or something? Or would that just make matters worse?

Typical industrial sewing machine motor on older machines is an AC induction motor. They run at a fixed speed, based on the construction of the motor and the frequency of the current they're fed. Speed control of the machine is managed by slipping a clutch. (Why they're called 'clutch motors'.) It's possible to change the pulley on the motor, fitting a smaller one will reduce the speed the machine is driven.

Nicer machines have servo motors, which have actual speed control, and don't run at all times, and with the right options can allow things like needle positioning.

Le 08/01/2014 16:35, Ron Anderson a écrit :

Thank you confirming that Ron, I am going to call the business that originally sold me this 2nd hand machine . They have a lot of machines so I am hoping I can get them to exchange the motor for one that is appropriate. Of course this will not easy with them in the UK and myself in France.

I will let you all know how it goes.

Le 08/01/2014 18:53, David Scheidt a écrit :

I have a clutch motor.

My service man did mention possibly changing the pulley but it's not something he does . There is a motor and electrical workshop business in a nearby town , so if I can't get any joy with an exchange motor with the original seller I will look into that option.

My service man did mention that there is not much difference between what I have and an electronique moteur which will be silent until I begin sewing, he also says that this will be easier to control stitch by stitch.

i will see what today's round of phone calls brings

Le 08/01/2014 18:05, David Scheidt a écrit :

The price he has quoted is between 340 ?uros and 400?uros before TVA / value added tax which has just increased to 20% . As I am a small business I can't reclaim the tax. I will then have fitting on top.

Some items in France are very expensive , I have found since living here there is a lack of what I was used to know in the Uk of a recommended retail price. Prices vary in a big way so I may get it cheaper by shopping around however it takes an age to shop around . For example a grease gun for my husbands tractor varied between 5 ?uros and 35 Euros in a 50 Km radius

If the UK firm won't play ball I may look at importing one. At least I can comfort myself taht my 2850 RPM motor will have a good value if I have to sell it on myself. I will just have to hope I can get an exchange.

Thank you for your comments.

I have just had a phone conversation with the owner of the firm that I purchased the machine from. He confirmed that the motor would be too big but talked me through checking the size of the pulley which according to him should be 60mm about 2 inches. So that it should be working in the right way for this machine.

I explained the birds nesting and he couldn't come up with anything concrete. We talked about the start up procedure which I am already doing. He mentioned a possible over run free spinning of the bobbin as a potential reason for the bird nesting, but he's not sure on this model.

The service man is having a day off so I will call him tomorrow to ask about that and to confirm the pulley size. We will see where we go from here.

Le 09/01/2014 10:33, Claire in France a écrit :

Forgot to add, My pulley appears to be the right size 6.3 cms

It certainly could make a big difference. Have you thought of replacing it with a servo motor? Or just changing out the pulley on one you have, assuming you've got the standard clutch-type?

Kay

Claire, I don't know where in France you are, but did it ever occur to you that you might be closer to Steckborn, Switzerland, than your UK dealer? Perhaps it might be an option to turn to the headquarters of Bernina directly? As for buying - although I hate to say it, in some cases the net is better than real life. I got my Bernina Aurora 440 QE from a dealer in Bavaria, some 500+ km off, who made me a special price, about 25 % less than the recommended retail price. I found out since that this was due to the fact that it is a discontinued model.

I have to admit that I'm a bit out of touch with the actual problem you had but thought that my 2 c might be a valuable addition to the discussion. Beg your pardon if I missed the mark entirely. ;-)

U.

Le 09/01/2014 16:20, Ursula Schrader a écrit :

Ursula,

I am a fair way down in France we are only 2 hours from the Spanish Border

I have found out that the motor seems to be all right as I have the smaller pulley, I am waiting to talk to the service man in the UK tomorrow in the hope that he can shed some light onto why I get this birds nest / looping problem. This seems to be what is causing the problem with the timing. The build up underneath in the bobbin area happens often and is blocking the bobbin and throwing the timing out, even when I stop as soon as I hear it. Of course I can go for ages and have no problem at all, what I really have to narrow down is what is causing the loping in the bobbin area. I think the service man was suggesting the motor as it could be starting too fast and throwing too much thread into the mix!!!

Ant thoughts and suggestions are always welcome. My guesses are entirely uneducated (Grin)

Yes, if it was a sewing machine business that sold it to you, they should have never sold it with that motor. The smaller pulley will decrease the maximum speed but depending on the size of the pulley that is there may not be enough. A repair shop that will not change a motor pulley should be dumped as quickly as possible. It is a very simple thing to do.

The 6.3cm would put it at 2.5 inches just a hair smaller than the standard 3 inch pulley. 1.5 inch would be the best option for a pulley but a servo motor would be better all around.

That looping is a tension issue. Either no top tension or way too much lower tension. It could be bobbin backlash due to the high speeds, this is not uncommon. Could also be the thread finding its way out of the top tension disks.

Claire in France wrote: :Le 08/01/2014 18:05, David Scheidt a écrit :

:> :> In the US, a new variable speed servo motor is available for about :> $125 US. I'm sure they're available in Europe, but even shipping one :> from china to the US to France will cost rather less than 500 euro. :> Any one of modest mechanical competence can install one, it :> mounts to the table in the same way as the existing motor. You'll :> also probably need a new belt, of a different length. Suitable belts :> are available from hardware and auto parts stores; they're used on :> all sorts of equipment. :>

:The price he has quoted is between 340 ?uros and 400?uros before TVA / :value added tax which has just increased to 20% . As I am a small :business I can't reclaim the tax. I will then have fitting on top.

Ebay shows suitable motors availalble for 150 pounds, which is 175 or so euro, and that would the right electrical requirments. (I looked there for language reasons, nothing else. They'll be available for that price in France or germany or italy, too.) Fitting is easy for anyone with basic mechanical and electrical competence: it's a matter of remvoing the motor, installing the new one, and fixing the wiring. (Many servo motors have a regular cord and plug, insead of being wired into the swtich box on the table, though you can wire them into that, if you want. They also tend to not use the god-awful 6 v lamps that clutch motors have, but provide a mains voltage outlet to plug a normal lamp in.)

Anybody who can install a light switch or fix a washing machine can do this, even if they have never seen a sewing machine before.

Your mechanic sounds either incompetent (can't change a pulley!?), lazy, or he doesn't want you as a customer. Whichever it is, I'd go look for someone else.

Le 09/01/2014 22:46, David Scheidt a écrit :

That sounds interesting can you point me in the right direction (link?) please.

Fitting is

I can do both of those so no problem for that.

I'm not sure where you got that impression from David. My service man is great however he is a 2 hour round trip away, so fixing things does end up taking longer as I don't always go to that town. He is also the only person in this area that is willing to look at a Bernina, French people seem to be surgicaly attached to their Singers , there is nothing else for them.

The reason he hasn't changed the pulley or measured the pulley is that he hasn't seen the table and motor part of the machine yet. The three times I have had problems I have taken him the sewing machine itself. It was only while discussing with him on Tuesday that he started to query the motor as he realised that he hadn't seen it yet. So he sent me home to check the size of the motor , he mentioned that it should have a small pulley if it was the 2850 motor in order for it to be functioning correctly.

Le 09/01/2014 17:05, Ron Anderson a écrit :

That is my next area to eliminate , I will be watching the top tension discs like a hawk. The tension block itself seems to be OK but I have to check what's happening with it next time I get a birds nest. Bobbin backlash is the suggestion of the UK firm that sold the machine, that is to be looked at but I am watching the tension discs first.

Le 09/01/2014 17:03, Ron Anderson a écrit :

I am seriously considering it, I shall probably look at Ebay as per David's suggestion, even if it's a UK one my father is in the UK at the end of the month and might be able to pick it up then.