The Sewing Place

Restoring a Bernina 840 Favorit

Madame Cholet

Restoring a Bernina 840 Favorit
« on: September 14, 2017, 21:54:13 PM »
I found this on Gumtree recently - the seller was asking £5 for it   :D
It is a Bernina 840 Favorit that was run on a table with an industrial motor, and had sat unused and forgotten in a garage for many years.
So there's no motor and the mechanism was locked up solid, but for £5 I couldn't resist  :D :D :D :D :D <3
I'm looking forward to de-gunking the innards and getting everything moving again - watch this space!







[Edited to amend thread title and add photos from Imgur]
« Last Edit: September 24, 2017, 19:15:34 PM by Madame Cholet »

arrow

Re: Bernina Favorit 840
« Reply #1 on: September 14, 2017, 22:03:15 PM »
I've had my hands on a 740 Favorite, and another flatbed version, but I can't remember the model number. There are two types of bobbins on the flat beds, and I think you have the one with the rotary hook and race, not the occilating. It's extra speedy and quite tought as I'm sure you aware of. They are described as industrial others semi-industrial, some call them artisan, but it's the same machine either way. I hope you find a motor for it.

Madame Cholet

Re: Bernina Favorit 840
« Reply #2 on: September 14, 2017, 22:19:18 PM »
Yes Arrow you are right, mine has the rotary hook and race.
Interestingly there is also an oil pan beneath the flatbed. I took the cover off to have a look, and realised it was an oil pan when a whole load of oil came pouring out. The oil was so old it was brown.
It looks as though it will fit in my Singer treadle base, so it might be fun to set it up as a treadle machine in the short term!
It had been used with an industrial motor; I am not sure how I would attach a domestic motor to it, as there does not appear to be any motor mounting points on the casing.
It's early days yet though, I need to get the mechanisms freed up first.
The seller assured me it was working when it was put away, and that it was complete, so fingers crossed I can get her sewing again.
I do love vintage Berninas - I have 6 now  8)

arrow

Re: Bernina Favorit 840
« Reply #3 on: September 15, 2017, 00:40:43 AM »
You might be able to find a motor you can fit under the table, various Bernina parts should turn up, even if they aren't as plentiful as some others. I have seen some of the older Berninas in treadle cabinets, not often at all, but it looks like the 500 numbers and probably even 730s could be ordered as treadle. The treadle cabinets I have seen are of a the later kind, with irons painted in brown and of a more minimal design than the older. The Bernina name is sometimes in the pedal casting. I was surpised when I noticed treadles probably were made as late as the mid 1960s. It will probably be the first 840 as treadle ;- )

Madame Cholet

Re: Bernina Favorit 840
« Reply #4 on: September 15, 2017, 10:21:56 AM »
Thanks Arrow, that is really interesting information about Bernina treadles. I have never seen an original one, although I have heard of people running 717s on a Singer treadle base after removing the motor.

The good news is that this morning, after a couple of days of letting oil soak in and heating now and then with a hairdryer, the mechanism is free and is turning!
The nylon cam stack gear is intact.
All knobs and dials turn freely.

The bad news is that there seems to be an issue with the stitch width knob - when turned manually it 'springs' straight back to '1', and does not stay in position on any other setting.
Also the buttonholer dial feels loose and sloppy when turned to positions 5 and 6. I have never used an 800 series with a buttonholer dial, so I do not know if this is normal or not, but it feels odd to me.

I have not yet tested whether it sews, as there is so much cleaning yet to be done.
 8)
« Last Edit: September 15, 2017, 10:56:57 AM by Madame Cholet »

arrow

Re: Bernina Favorit 840
« Reply #5 on: September 15, 2017, 12:07:54 PM »
The buttonholer dial doesn't feel sloppy as far as I know, but I don't know how they work. When you turn them you feel you are turning other parts behind there as well. This is something the Bernina yahoo group might have some info on, like a service manual, or parts lits.

This is the type of cabinet I'm thinking of. There's [urlhttp://www.ebay.de/itm/Bernina-Favorit-Nahmaschine-mit-Schrank-Fus-oder-Strombetrieb-/401401204818?hash=item5d75605052:g:LOoAAOSwB-1YugRO]one more[/url] on german ebay. These have both motor and treadle option. The threadles have a different hand wheel, I guess to make it easier with the leather belt. Some liked the treadle option a lot, I guess it gave them a feel for the stitch formation for some type of work. That's someting hardly any of us bother about today.

Madame Cholet

Re: Bernina Favorit 840
« Reply #6 on: September 15, 2017, 14:10:49 PM »
That cabinet is beautiful, and I especially like the key!
I really like the look of this one too, is it walnut?:
http://www.ebay.de/itm/Nahmaschine-Bernina-642-1-Made-in-Switzerland-Baujahr-1960-1962-antik/322731703556?_trkparms=aid%3D888007%26algo%3DDISC.MBE%26ao%3D1%26asc%3D46153%26meid%3Da083ab053c354089b071a2d3a8b7eb83%26pid%3D100009%26rk%3D1%26rkt%3D2%26sd%3D172835586028&_trksid=p2047675.c100009.m1982

I have the service manual, and also the parts manual, and this evening I plan to spend a few hours cleaning, oiling and investigating the stitch width knob and the buttonholer dial mechanisms.
Turning the buttonholer dial from 1 through to position 4 you can definitely feel resistance from the other moving parts behind, but turning from 4 to 5 and from 5 to 6 there's no resistance at all. Looking at the parts manual there are 3 springs involved in the mechanism. I'll check those first perhaps I think.

arrow

Re: Bernina Favorit 840
« Reply #7 on: September 15, 2017, 15:52:56 PM »
The buttonholer on my 900 is the same as on the 830, but I have never investigated that much. You 840 must have been treated a bit harshly when it comes to cleaning and oiling, but it can usually be cleaned up and done right. It's a  model worth spending a bit of time and effort on at least.

The veneer in the door looks like birch or beech root, it's used for the pattern in the grain. It's often given the pale look by leaving it unstained and just trated with layers of transparent lacquer. Ash can have a similar type pattern in the grain. I don't think it's walnut, because it doesn't turn yellow with age in the same way as birch or beech.

Roger

Re: Bernina Favorit 840
« Reply #8 on: September 15, 2017, 21:47:42 PM »
Hi Madame,

That is quite a machine! Most industrial motors are 'Clutch' but these aren't very efficient and can have user quirks... like gradually accelerating without increasing pressure. The more recent approach is the servo motor, these are more efficient and have higher torque. And cost about £100,
Clutch motors can be had more cheaply because a lot of people are upgrading to servo motors.

If you're looking at industrial motors
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 #9 on: September 15, 2017, 22:20:30 PM »
The blond birch/beech root veneer on that cabinet is utterly stunning, I keep going back to the German ebay ad to look at the photos! It looks more like an elegant drinks cabinet than something built to house a sewing machine. Gorgeous. I had no idea the vintage Bernina cabinets are so utterly beautiful  <3
Arrow thank you for enlightening me!

I think I may have worked out what the issue is with the 840 regarding the stitch width knob, although I could well be wrong as I am obviously not a Bernina tech just someone who knows very little but enjoys playing around with the insides of sewing machines  8)
I don't know what the proper names are for the parts I am talking about, and my account is rather rambling, so please forgive me for that. If anyone can shed more light on what I am trying to fix here I would be very grateful!

I had a good look at my little Bernina 807 minimatic, and the stitch width knob set-up on it looks to be more or less the same as on the 840.
It seems to be essentially a slider mechanism, consisting of a channel and a sliding 'block' which slides up and down the channel. The 'block' connects to a linkage attached to the needle bar, so as the block moves up and down the slider channel - when the stitch width knob is moved - the needle bar moves correspondingly from side to side.
 
At 2 points in the channel on the 807 there are 2 drilled-out 'circles', and I assume that some kind of raised 'peg' which protrudes from the sliding 'block' clicks into these circles, such that the pre-set buttonhole stitch widths can be selected on the 807 (- which does not have the buttonholer dial of course). You can hear and feel the 'click' as the 'peg' clicks into each circle.

In between the circles the slider is flat, but the 'peg' or whatever it is, I assume (- I could be wrong though) must protrude such that the 'block' can nevertheless be held in place at whatever point on the flat channel you select (-by turning the stitch width dial), by the 'peg' pressing on to the slider channel's flat surface (?).

On the 840, although I can see a circle towards the top of the slider channel, (- the same as on the 807), there is no 'click', so I assume that there is some kind of problem with the 'peg'. Also since the knob bounces back to 1 when you turn it, I suspect the 'peg' does not touch the channel at all (?).

(I could be totally completely and utterly wrong here... :S)

2nd EDIT TO ADD: yes, after a rethink, I think I was totally wrong...  :|  :| :|

I'll see what more oil, heat, and patience will do.

Here's a pic of the parts I am taking about, with an arrow pointing to the slider channel, and another to what I assume is the 'peg'. The 3 other bits inside the circle make up the sliding block.

[edited because I got my words mixed up...]
« Last Edit: September 18, 2017, 14:16:35 PM by Madame Cholet »

Madame Cholet

Re: Bernina Favorit 840
« Reply #10 on: September 15, 2017, 22:24:31 PM »
Hi Madame,

That is quite a machine! Most industrial motors are 'Clutch' but these aren't very efficient and can have user quirks... like gradually accelerating without increasing pressure. The more recent approach is the servo motor, these are more efficient and have higher torque. And cost about £100,
Clutch motors can be had more cheaply because a lot of people are upgrading to servo motors.

If you're looking at industrial motors

Yes an industrial motor would be wonderful!!!
Are the servo ones the silent ones?
I used to work as a machinist on a flatbed industrial Brother many moons ago, and that was definitely a clutch motor.

Roger

Re: Bernina Favorit 840
« Reply #11 on: September 15, 2017, 22:59:50 PM »
The servo motors are apparently silent, although I kinda like the tardis style hum of the clutch motor:)

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

arrow

Re: Bernina Favorit 840
« Reply #12 on: September 16, 2017, 01:09:46 AM »
Ohh, rather random reply from me, but look at this.



Madame Cholet

Re: Bernina Favorit 840
« Reply #13 on: September 16, 2017, 14:27:52 PM »
Oh wow... is that a Horn cabinet?!

Sewingsue

Re: Bernina Favorit 840
« Reply #14 on: September 16, 2017, 15:17:59 PM »
Looks like it. The one thing I do like about the newer cabinets is the clear plastic boxes on the inside of the door. Much easier to see what is in there.
Bernina Aurora 440QE, Brother BC-2500, Singer 99K (1938), Silver Viscount 620D overlocker.