The Sewing Place

Restoring a Bernina 840 Favorit

Madame Cholet

Re: Bernina Favorit 840
« Reply #45 on: September 24, 2017, 15:18:05 PM »
If you wanted a more personal name, and as it's the latest addition to the McCallit family, how about Wodger?

As in 'Wodger McCallit'?
Yep, the 'Wodger' it is then!
 0_0

Madame Cholet

Re: Bernina Favorit 840
« Reply #46 on: September 24, 2017, 15:20:58 PM »
Oh no, now my hyperactive mind has chucked out this:
https://www.youtube.com/watch?v=G7_oNBT9wsc
 :S

(edited for a better clip..)
« Last Edit: September 24, 2017, 15:31:13 PM by Madame Cholet »

Madame Cholet

Re: Bernina Favorit 840
« Reply #47 on: September 24, 2017, 17:10:37 PM »
The saga continues...!

I had a peek at the teeth (- with a dental mirror, lol), and as you can see they are really very tiny, and much smaller than the ridge on the wodger:





I had to attach a safety line to the wodger as it was awkward to position into place and kept falling down into the machine innards; as you can see the ridge has been worn down somewhat on the front edge by movement of the teeth over the years:



I cleaned all around the stitch width dial mechanism with some methylated spirits, so that oil-related slippage ought no longer be an issue.

Unfortunately though when the wodger was replaced there was no change, and the stitch width dial sprung back to zero, again  ><

The next step is to cold weld a suitable metal splint to the underside of the wodger, and see what happens then.

The plastic I used as the temporary splint was not quite so rigid as the sheet steel I intend to make the permanent splint out of, so there would have been a very slight bend at the break, which may well have affected the grip of the teeth on the ridge.

Also the machine was so packed full of old grease and hardened oil that the notches between the tiny teeth may be clogged up; to clean them though I would have to dismantle the knob mechanism, which I didn't want to do, because it looks so complicated.

I also wonder if the wear on the ridge of the wodger is affecting its function, not to mention possible wear on the teeth, but I'll cold weld the wodger together first, screw it back on, see what happens, and take it from there.

« Last Edit: September 24, 2017, 17:18:25 PM by Madame Cholet »

Barnyard

Re: Restoring a Bernina 840 Favorit
« Reply #48 on: September 24, 2017, 19:50:52 PM »
That's some dedication and determination you have trying to get this sorted and I applaud you for sticking at it. I will keep eyes open in my locale for donor parts as it would be fantastic to see it running. I do love a cheapo find, sometimes they do end up becoming a pain in the @ss and I pop them to one side and carry on with something else for a while.
Would I be correct in saying Bernina had part of their factory washed away in a flood and more specifically their spares warehouse? I could have imagined it but if true that would make vintage Bernina spares rarer than rocking horse poop.

I have just taken a Nova 900 into the workshop... Fingers crossed the problems are just the usual suspects!

Barny

Madame Cholet

Re: Restoring a Bernina 840 Favorit
« Reply #49 on: September 24, 2017, 20:24:02 PM »
Yes Barny I heard that too, about the flood, and the chucking away of all of the spares  :(

Tbh though I didn't even realise that Bernina supplied spares for such elderly machines; I contacted Bernina some years ago about a replacement motor inside cover for my little 807, and received a rather curt reply advising me that they do not provide spares for a machine so old...! So I got some Plastic Weld glue and made it (almost) as good as new  8)

Thanks for keeping an eye out for spares though, I am very grateful!  0_0

Best of luck with the Nova btw.
I have an instruction manual for the 900, and also a service procedure manual for 700/800/900 series machines, not paper but downloaded, if you need them.


Barnyard

Re: Restoring a Bernina 840 Favorit
« Reply #50 on: September 24, 2017, 21:16:55 PM »
Madame, the service manual for the 900 would be really appreciated. I do have one, or did have one but right now it is not to hand and is probably 250 miles away in my other residence in South Wales. If you would be so kind, I would really appreciate the link. The 900 is a great machine but it does have it faults. Mainboard capacitor, carbon tracks in the foot control and a locking free motion that sticks like glue. Hmm... The better they get the more unreliable they get also.

Barny

Madame Cholet

Re: Restoring a Bernina 840 Favorit
« Reply #51 on: September 24, 2017, 21:37:53 PM »
I found the service manual today on the Vintage Bernina FB group, funny as I had not noticed it before!
It is my bedtime reading for tonight  8)
If you are not in that FB group (it is a closed group) and do not want to join then feel free to pm me an email address and I can email it if you would be happy with that  :)

Madame Cholet

Re: Restoring a Bernina 840 Favorit
« Reply #52 on: October 04, 2017, 18:31:34 PM »
Here's the latest installment of the continuing drama of my 840.

Well I set up the two bits of the wodger on some double sided sticky tape on a wooden block ready for cold welding with the epoxy glue, and cut out a splint from thin steel using a jeweller's saw; I had earlier taken a file to the smooth steel surfaces like the glue instructions advised. (Please excuse the cat hairs... I had a little helper just out of shot...  :meow:)



Then I mixed up some JB weld, put the bits in position, and left the glue to work its magic:



After 24 hours like the instructions advised, I fixed the now splinted and complete wodger in place in the machine.

Then I turned the stitch width knob.... and there was an almighty 'ping' sound, as the wodger snapped into two again, at the point of its original break...  :'( :'( :'(



The other half of the wodger has disappeared down inside the machine somewhere and I've not found it yet  :'(

Oh well never mind.
I think I'll try and make a wodger myself next and try that.
In the meantime though I think I'll put the 840 away for a while and do some sewing instead  0_0
« Last Edit: October 04, 2017, 18:49:21 PM by Madame Cholet »

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Re: Restoring a Bernina 840 Favorit
« Reply #53 on: October 04, 2017, 18:48:25 PM »
This is something my grandfather would make himself with out thinking much of it. We are just not used to make things our self any more; and I know I probably should get better at it. I don't mind bying replacement parts, but when we can find them a piece of metal, a vice and a file will get us far.

Unfortunate about the glue. I don't think there are very big differences when it comes to epoxy glues and super glue, which are of the best types to begin with. I have tried several brands, and it seems to be much the same stuff. Some materials glue better together than others. Maybe the surface area is too small to hold up when glued together. I have glued together a plastic accessory box, so far it holds up, but it is a weak point.


Barnyard

Re: Restoring a Bernina 840 Favorit
« Reply #54 on: October 04, 2017, 22:02:42 PM »
Madame. Could you tell me the dimentions of the leaf spring? I may just have an idea. 99k bobbin plate leaf spring and the bobbin release finger both might be adaptable? I have both here as spares and I am happy to play but I will need pretty accurate measurements.

Barny

Madame Cholet

Re: Restoring a Bernina 840 Favorit
« Reply #55 on: October 11, 2017, 11:16:03 AM »
Madame. Could you tell me the dimentions of the leaf spring? I may just have an idea. 99k bobbin plate leaf spring and the bobbin release finger both might be adaptable? I have both here as spares and I am happy to play but I will need pretty accurate measurements.

Barny

Barny - Thank you  :)
The great news is that I have got hold of a spare one, and now my stitch width knob works as it should!

A battered and cord-and-pedal-less 1971 Bernina 830 found its way to me, so I took the leaf spring out of that.

It did not have the 'ridge', like the 840 leaf spring, it is just flat steel, but works wonderfully  :)
I wonder if the presence of the 'ridge' prompted the break in some way, like some kind of metal fatigue build-up each time the knob was turned back to zero...? hmmm...

Here's a pic of the 830:



Someone in the past has got rather emotional about the motor cover and attacked it with a hammer by the looks of it. The broken bits of cover are missing and one of the under base fixing bolts and the thread it belonged to are also lost.
The brushes seem fine though and the motor itself turns freely.
The capacitor has blown, which probably prompted the assault on the motor cover, so the motor itself is most likely salvageable.

I bought the 830 for very little and intended to salvage it for parts, but I may decide to fix it instead at some point  -<

Here's a pic I made re. the leaf spring measurements - if I decide to fix up the 830 I will need another one...!
(Shaft width is 4mm).



Now to get back to getting the 840 cleaned and painted and polished and back together, and, hopefully sewing...
« Last Edit: October 11, 2017, 12:38:04 PM by Madame Cholet »

Madame Cholet

Re: Restoring a Bernina 840 Favorit
« Reply #56 on: November 09, 2017, 13:33:23 PM »
This is just an update to say that the machine is back together now, everything turns freely, and the light works (hurrah!), but I need to disassemble the bobbin hook and race area as it is not making a stitch - I am getting thread tangles around the bobbin.

I want to strip down and clean around there but there are two tiny screws that hold the hook gib in position that have been badly chewed up by someone in the past trying to get them out. They are locked in solid so I don't know if that person was ever successful in removing them, which begs the question - besides the stitch width problem, was it an issue with the bobbin that eventually led to this machine being cast aside? Also the machine, when I got it, had a broken needle, which makes me wonder if there are broken bits of needle jammed in the bobbin mechanism somewhere I can't get at.



The bobbin mechanism area wasn't touched in my initial deep clean of the machine because of the state of these frozen screws.
 
If I got them out the heads are so badly damaged that they may not go back in again. I could drill them out fairly easily but I need to source replacements first. I can't seem to find them in the parts manual, so I don't have parts numbers.

I'll get in touch with Bambers at some point, and ask, but I'll have another scan of the manual when I get chance to this evening to see if I can find them and their parts number.

I am hoping that they are some kind of standard Bernina screw that popped up in other machines, and not the Bernina equivalent of hens' teeth...  :\
« Last Edit: November 09, 2017, 13:42:08 PM by Madame Cholet »

b15erk

Re: Restoring a Bernina 840 Favorit
« Reply #57 on: November 09, 2017, 15:12:16 PM »
Good luck with those screws MmeC.  I spent days trying to free a screw on the o/locker, and had to buy a special grippy plier thing.  After all that, and various parts, the dratted thing is still not sewing nicely......  :S

Your Bernina is too nice a machine to give up on though, as long as it's economical to fix it.  There's usually a reason that someone gets rid of a good machine.  My Bernina 730 needed a new motor after years in a damp garage, but it didn't cost me anything so it was worth it.

Good luck, look forward to hearing how you get on.

Jessie
Jessie, who is very happy to be here!!  :),  but who has far too many sewing machines to be healthy, and a fabric stash which is becoming embarrassing.

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Re: Restoring a Bernina 840 Favorit
« Reply #58 on: November 09, 2017, 15:34:55 PM »
A lot of hand me dow machines sold or given away as faulty usually only needs cleaning, correct bobbin in stead of the wrong one (a supermatic), correct needle (in case of my  Phoenix), maybe a new motor belt. The 740 is a bit more advanced and sometimes they need a more thorough inspection and sorting out. It still sounds very promising Madame Cholet, being down to the last thing preventing it from stitching properly.

Madame Cholet

Re: Restoring a Bernina 840 Favorit
« Reply #59 on: November 09, 2017, 17:05:17 PM »
Great joy!!!!

SHE STITCHES!!!!!!!!!

 0_0 0_0 0_0 0_0 0_0 0_0

I went back to basics, and removed the needle plate and the feed dogs.
There is a fork-type part which fits below the needle plate, and which I had thought looked as though 'something' ought to slot into the gap in its 'fork'.
I had put the parts back together as I had first found them, following photographs I had taken on disassembly and originally, according to my photos, the gap in this fork space was clear.

So just now I removed the fork, and slotted the bobbin assembly 'finger' into the fork, and then screwed the fork securely into place.
I have put the feed dogs back and the needle plate, and the bobbin case and bobbin, and threaded her up, and .... she sews!!!
It makes sense now as the bobbin stays still while the hook turns around it. Without the 'finger' set into the fork space, the bobbin would not have remained stationary. So to greater minds than mine it would have been instantly obvious. Never mind, I worked it out in the end 
:)

B15erk and arrow - thank you for your helpful comments  :) :) :)
I am very glad I do not have to faff around with those screws!
And yes, one of my machines which I acquired for next to nothing was sold as not working...  turned out the problem was just a short piece of thread between the bobbin and the race, which took a couple of minutes to sort out, and now that machine sews beautifully  :)

The next step is to mount her in my treadle base... watch this space!

There is also some more painting to be done. I mixed up what looked a perfect match using 3 different pots of enamel paint. Then to my dismay the paint dried several shades darker than it was when it was wet  :'(
That was on the top of the machine, where much paint was missing; at least the rust is gone now and the bare metal is covered, even though the colour doesn't quite match.
The same happened with the handwheel too - it is darker in the places where the new paint was applied. But at least the handwheel is no longer covered in rust, lol!

At some point in the future I shall do some paint tests. I have the approximate recipe, it just needs to be slightly lighter. I intend to at some stage mix up a pot full, and then I will have it on hand for the 800 series Berninas that have found me over the years  :)

In the meantime the 840 looks less battle-scarred than she did when I got her, and she is sewing again, and that is what counts most I suppose  :)

I will post some pics later  8)