The Sewing Place

Restoring a Bernina 840 Favorit

Madame Cholet

Re: Bernina Favorit 840
« Reply #30 on: September 18, 2017, 02:12:16 AM »
Surface rust usually comes off with further cleaning and polishing. Is the thread guide polished steel or chromed? It's best to have it off the body to polish it up, I don't know if replacements are available. Is it glued on? If it doesn't come off maybe carefully polish it with steel wool twined around a match or something like that.

My next task will be to remove the plastic rearside cover, and I'll find out a little more about the thread guide then.
Also I notice there is a small opening beneath the plastic rearside cover, and hopefully when I am able to look through it I may be able to see a little more of the stitch width knob mechanism.
I've been peering down into the knob mechanism with a torch... I can see something else move when I turn the knob, something behind the buttonholer dial... it's really complex inside there! I'm getting a bit obsessed with that stitch width knob  :| 

An 840 is a very nice machine, once it was expensive and one of the best. I wonder why it fell in to disfavour and neglect? 10 years in a damp garage?

Maybe it was because the stitch width knob didn't work, lol  :[


Re: Bernina Favorit 840
« Reply #31 on: September 18, 2017, 02:18:22 AM »
A bit unfare though, it needed a service and repair. And all that grease, what a mucky job. It's probably been put through all kinds of misery and hardship. On the other hand it looks promising and like it will return to full function with a bit of tlc.

Madame Cholet

Re: Bernina Favorit 840
« Reply #32 on: September 19, 2017, 18:10:16 PM »
A bit unfare though, it needed a service and repair. And all that grease, what a mucky job. It's probably been put through all kinds of misery and hardship. On the other hand it looks promising and like it will return to full function with a bit of tlc.

Yes it is unfair and ever so sad what has happened to that machine - used and then discarded, and then forgotten, and left to rust.
But I am very happy that I found it, and it cost only £5!   :)

There are many tiny 'pimples' on the paint surface, and some of the paint has flaked off in parts, especially on the top lid, and more paint looks ready to flake off as well. The hand wheel is chipped and rusted too.
Arrow do you think I could touch up those parts with a few drops of suitable paint?

But yes I do believe that with time and effort and tlc it will indeed be up and running and sewing happily again!  :D
I am glad it still has its bobbin case and a bobbin; I looked on ebay and the bobbin case are very expensive. Also the needle plates, although scratched and rough in places, they are still present.
It is missing its knee-lever, but that is not an essential part really, just useful.

I've not yet removed the rearside plastic cover - the screws concerned, like so many of the screws on this machine, were locked solid, so I dabbed on some oil and shall leave them alone for now.
I am waiting for some TriFlow penetrating oil to to arrive from the US, but I'll keep dabbing oil on the stuck screws in the meantime as I don't want to force them.
There are many damaged screws on this machine, so I shall be patient as I do not wish to cause more harm.

Even though I cannot remove it yet, last night I gave the thread guide a very quick and cursory clean and it looks a little better. When I get the rearside cover off I will give it a better clean, and make sure the inner surface is smooth for the thread.

I also removed the tension mechanism and cleaned out much lint and dust and also carefully removed some slight rust build-up on the inside surface of the cover; I didn't dismantle the rings and springs etc as it didn't seem necessary, they looked clean and were moving freely and had lots of 'spring'. I forgot to take a photo though.
There was some rust in the thread channel in the machine top lid - the ends of the thread channel are metal - so those had a gentle clean too.

I posted my stitch width issue on FB and a sewing tech from Australia commented saying that if the stitch width knob springs back to any position when it is turned, then it means the buttonhole mechanism is engaged. I'm hoping he will elaborate more on how to solve the issue.
I have spend so long gazing down into the mechanism with a torch I am getting quite obsessed about it... I am dreaming about stitch width knobs...!  8)

Tonight I hope to clean up the bobbin winding mechanism. The rubber is rather cracked, as you can see in the photo.

Here are some photos I took just now:


Re: Bernina Favorit 840
« Reply #33 on: September 19, 2017, 19:29:15 PM »
I prefere touch up jobs on restration jobs like your 840. Is it the same light paint used on the 730s and 830s? It's a lighter white color on the 800 numbers, but much the same delicate paint, it scratches easily. Pfaffs have this type of paint, and the older Elnas. Touch ups and repair are well within reach if most of the paint is intact. I think you need to keep the original, because I don't think new decals or cut out stensils are avaiable? Everything can be done with enough time, effort and money, but it has to be withing reach and still give a nice result.

Paitning in missing spots requires the right type of paint, color match, and usually a bit of sanding down between layers. If you have a spray gun, or spray can paint available it will give the right result. Tiny scratches and needle punctures can be filled in with a fine brush. For smaller scratches there's clever toouch up products for cars that work for this type of paint.

Original Bernina Parts are always expensive, I don't know why. People insist the original bobbins and bobbin cases work better than the generic ones too, and tend to believe it. On a machine I know I will like and use I don't mind spending time and money on it, but not unnecessarily much. The Favorites are stronger and speedier than any of the others, unless you go for the even larger and heavier industrials.

Madame Cholet

Re: Bernina Favorit 840
« Reply #34 on: September 20, 2017, 00:56:17 AM »
There are 2 different shades of paint on my 840.
The top lid is painted the same light cream colour as my little 807, as is the machine body, while the hand wheel and the flatbed are a pale milky grey-green. I'm looking forward to doing some touch-up painting  :)

I didn't get any work done on the 840 this evening, too many chores that I have neglected since I took on this project caught up with me instead  :(

I have been thinking about the stitch width knob, actually I haven't stopped thinking about it, lol.
The last position on the buttonhole dial, position '5', which is the last position before it clicks back to vertical (and 'off'), has the needle set up to do a straight stitch in order to finish off the buttonhole.
I wonder if part of the buttonhole mechanism is 'locking' in some manner that corresponds to position '5', that is straight stitch, and is for some reason remaining activated and is being carried over to the buttonhole dial's vertical/'off' position.
Just a thought!
Off to turn in now, to dream of my stitch width knob...  |O   
« Last Edit: September 20, 2017, 01:08:08 AM by Madame Cholet »

Madame Cholet

Re: Bernina Favorit 840
« Reply #35 on: September 20, 2017, 20:28:38 PM »
I just found this strip of metal loose inside the machine - it was stuck to the inner surface of the base with old grease and goo...
The end which does not have the ridge looks like sheared metal, so it has snapped at that point.
As to whether it was once part of the machine mechanism - I'll see if I can see it in my parts list manual.

From the serial number I think the machine dates from 1980.

Madame Cholet

Re: Bernina Favorit 840
« Reply #36 on: September 20, 2017, 23:20:12 PM »
This appears to be the other end of the broken-off strip of metal:

It is part number 308.201.03.
Has anyone got a time machine so I can travel back to the 1980s and order one?!

Madame Cholet

Re: Bernina Favorit 840
« Reply #37 on: September 21, 2017, 00:08:47 AM »
I emailed Helen Howes, and she replied to my email with lightning fast speed (-as she usually does!) saying she hasn't got one, but will be in touch should she ever have a Bernina with that part in for breaking.

I'll ring Bambers in the morning and enquire there too.

I feel happy that I have (most likely) traced the root of the problem, but disheartened that as it is such an old machine, I may not be able to track down a replacement part.

Never mind, I shall continue doing what I can to fix up the machine, and live in hope of that part turning up  :)

If anyone knows of anywhere else I could try and source this part, please do let me know!  :)
« Last Edit: September 21, 2017, 00:12:05 AM by Madame Cholet »


Re: Bernina Favorit 840
« Reply #38 on: September 21, 2017, 01:02:51 AM »
These challenges can seem impossible at first, but give it a chance, and if Bambers have been around for a while, there's a good chance. Don't forget the berninathirtysomething group on Yahoo, it's worth asking there too, not to forget ebay, anything can turn up there.

Come to think of it, that's the sort of part any metal tool shop should be able to make. I was once told the local school who teach metal work take on tasks like this as a good training, it depends on the teacher. A metal plate of suitable thickness, draw the shape, drill a hole, and the tools to hold it in place and saw out the piece, bend it in to correct shape. In 1980 the town was full of shops that did this, 1950 even more, there are still quite a few, but I need to go out of town.
« Last Edit: September 21, 2017, 01:13:47 AM by arrow »


Re: Bernina Favorit 840
« Reply #39 on: September 21, 2017, 09:28:23 AM »
Yes, that was my reaction too, Arrow.  It's just a little piece of metal.  If you take both bits into an engineering or metalwork workshop and give them the two pieces to use as a pattern, they should be able to make you a new bit.

Nonetheless probably easier to get one off a supplier or eBay if available.

Madame Cholet

Re: Bernina Favorit 840
« Reply #40 on: September 22, 2017, 20:48:33 PM »
I rang Bambers, and umpteen other sewing machine shops where they repair vintage machines and/or stock parts from donor vintage machines, but no-one at present has the part in stock.

I've hunted round for a local metalworker who would be willing to make me a cloned part, but sadly to no avail.

Earlier I decided to dust off my Dremel and have a go at making one myself - I did a short jewelry making course at college many many moons ago - as SkoutSews said, 'it's only a little piece of metal'!
The only bit I am not too sure about replicating is the ridged/crimped section visible along the part's length. Hmmm...

Then someone suggested that I use JB weld - which is something I had never heard of - so I did some research and apparently it is incredibly strong epoxy resin glue from the US.
I think if I cut out a strip of thin steel sheet metal and JB weld it to the underside of the broken part it might just do the job.

So I have ordered myself a packet of the stuff from Amazon... fingers crossed it should be here in a day or two, and I can get to work!

Here's a photo of the part, now that I have managed to remove the stuck screw and have got the other end out of the machine:

« Last Edit: September 22, 2017, 21:05:48 PM by Madame Cholet »


Re: Bernina Favorit 840
« Reply #41 on: September 23, 2017, 00:07:18 AM »
Have you tried Bogods?

I've heard they're really helpful and well connected when it comes bernina accessories and parts, ancient and modern!
A bit of a vintage sewing machine nut! Singers: 500a, 401g, 48k Elnas: lotus SP & grasshopper, Bernina 530-2 F+R 504, Pfaff 30, Cresta T-132

Madame Cholet

Re: Bernina Favorit 840
« Reply #42 on: September 24, 2017, 12:50:36 PM »
No news back from Bogods as yet, but I live in hope - Thanks Roger!  :)

I cleaned up the handwheel last night with some 000 grade wire wool. It was covered in hundreds of tiny spots of rust, and also larger patches on the rim. I am surprised and happy that all of the tiny spots have gone now leaving no trace. The bare metal I intend to touch up with some suitable paint.

The JB Weld arrived today  :)

But before making a permanent repair to the part I wanted to check first that the extra thickness on the underside of the part due to the repair would not cause the part to foul on any other mechanism.
So I cut a strip of thin, rigid plastic and sellotaped it to the underside of the part, to act as a temporary splint.

^^ ...this is not the greatest repair in the world, this is just a tribute... 

I managed to wiggle the part in position and tighten the screw to hold it in place. There is free space beneath the part still, so I do not think the extra thickness would impede the part's correct functioning.

Now as I turn the stitch width knob I can hear a very satisfying 'whirring' sound, as tiny teeth on part of the knob mechanism graze against the little 'ridge' on the stem of the part.

Unfortunately however the stitch width knob still springs back to zero.....  :S  :S :S

I think the part, whatever its real name is, is meant to act as some kind of clutch or retarding mechanism, where on turning the stitch width knob the tiny teeth on the knob mechanism 'lock' on to the ridge on the part, thus holding the stitch width knob in position at the desired setting, counteracting the pulling force of the spring which would otherwise pull the knob back to zero.

I used quite a lot of oil though to free the knob and dial mechanisms when I first got the machine, as like everything else they were locked solid, and I suspect oil may be causing slippage and thus blocking any 'clutch' action. (At least I hope that's all the problem is).

So the next step is to clean the oil off... I think I have some meths somewhere... would meths damage plastic I wonder?

And I am fed up of calling it 'The Part', it needs a name!
[Edit: not a rude one though  ;)]
« Last Edit: September 24, 2017, 12:53:42 PM by Madame Cholet »


Re: Bernina Favorit 840
« Reply #43 on: September 24, 2017, 13:19:28 PM »
It has that groove which is obviously meant to stop the wheel, why not call it the clutch?  (until someone in the know tells you better)  How brave of you to tackle it all.


Re: Bernina Favorit 840
« Reply #44 on: September 24, 2017, 15:07:05 PM »
If you wanted a more personal name, and as it's the latest addition to the McCallit family, how about Wodger?