Swiss made Elna SU and Blue Top Supermatic repairs

Elna are now owned by Janome. I'm hoping that it's false, but I was told by an ex Elna dealer that when Janome bought the brand, they immediately dumped (destroyed) all the spare parts for the Swiss made machines and declared that they wouldn't support the machines at all. 

Thankfully, the parts that fail are usually simple gears and are still being made well in places such as Taiwan.

You can read about the history of Elna at ISMACS but they are as amazing as Berninas are and for the same reasons: The high quality of the components and the tight tolerances. Necchi had the latter, but failed in the quality of the component steel (it was not nearly as durable as it could have been).

So, the best sewing machine ever made is not an Elna (it's Bernina's 830 Record - ask any sewing machine mechanic), but in second place is the 1970s SU. This machine is almost identical to the 1960s version (Supermatic, some were just labelled Super but the top is always blue) but Elna tweaked a few small things and got a very slightly smoother machine. They are both called 62C by Elna and they're both fantastic.

I get a lot of Elnas into the shop, and the most common problem by far is that the needle position wheel is seized. Also, often the balance wheel is slipping.

Repairing the two most common problems with a
62C 

Needle Position Seized

Even if you think you don't care about the needle position wheel, it is important if you want to take advantage of the no-turn buttonhole feature (it must be on the left setting).

The solution to this is to work solvents in to dissolve the dried stuff that's causing it to be glued. Here is what I do. You will need a bottle of methylated spirits with a spray top.

If you can move the wheel but it is very stiff, you can try this:

Remove the top of the machine.

Place the machine on its side with the needlebar up, and you see the view below.

The area in red, under the wheel

Spray methylated spirit at the bottom of the needle position wheel. Don't get any on the red or black printed indicator part or they will dissolve.

Move the wheel back and forth. You might need to do this for more than 15 minutes, but it will get easier as you go. I put a piece of fabric between my fingers and the wheel to prevent blisters. You will need to reapply the methylated spirits every few cycles. You're finished when it is very easy to move with one finger. It should 'snap' into the centre needle position.

If you can't move it at all, your next step is to heat the seized area. I have a heat source as part of a soldering station and use that. Before I had that I used a heat gun and before that a hairdryer. You must approach heating this with the knowledge that if you are careless, you will melt the position wheel. Try not to do this. Putting the whole machine in a hot car is anopther good option.

After heating the same area (the underneath part of the position wheel), it should be possible to move the wheel. Now, spray the methylated spirits, move wheel, metho, move, repeat.

When it is completely freed as above, you need to test it again when the temperature of the metal has become even with the room. If the gunk that was gluing it is still there, being warm would change its viscosity. If it's still good when cool, your task is complete.

In extreme situations, the wheel will not move at all even when heated and a fair pressure applied. Repairing the problem when it's this bad requires removal of the whole elnagraph. This removal can only be done by also removing the top drive shaft. Definitely not a task for an amateur. When removed, you can attend to the seized parts much more easily. Putting everything back isn't enough. You will need to ensure that the timing belt is in exactly the right spot. The star series service manual is an excellent resource here.

Slipping Hand Wheel

When you put your foot down and go nowhere or you hear that it is slipping, it will need to be repaired.

The hand wheel is driven by an intermediate rubber wheel, and over the years this friction wheel goes hard and sometimes crusty. I saw this more often in Brisbane due to the hotter and humid climate but I've seen it many times in Melbourne too. 

Repair is a good mix of easy and challenging. You must remove the friction wheel, which is the challenging part. 

Remove the hand wheel and you can see the rubber friction wheel. Press it with your fingernail. If it's good, it will give slightly and allow an impression. More likely it will be either smooth, shiny and hard or cracked and crusty looking. 

Picture taken from a later model

This photo is from a later machine, the Air Electronic. The AE is also fantastic, but the electronic speed control just makes it slightly less reliable than its immediate predecessor. The drive setup, however, is identical and made for a better photo. The SU has a large amount of solid metal body in the way, which is why you will need to remove multiple C clips.

Marked 1 is the tension clip. Remove this with long nose pliers.

Remove the C clip near where it says 2. This is difficult to reach and if you have dental type tools, choose the one that allows you to snag the c-clip to pull it towards you. Otherwise, small, bladed screwdrivers at an angle will do it. After the first C-clip, you can move the wheel's shaft and expose the second one. There are three C clips and the only one you don't need to remove is holding the wheel onto the bracket.

Once off, you do not need to seperate the wheel from the bracket. Make sure it rotates freely though.

You now resurface the wheel. You can use either a bench grinder or dremel. 

Using a grinder, choose a grinder wheel that's not too rough. A rough wheel will destroy the friction wheel. Wear eye and maybe hand protection, as the removed material will be very messy.

Hold the bracket with pliers against the rotating wheel and angle it slightly. As the surface comes off, keep stopping and check if the wheel's suface is still hard. As soon as it isn't, you can stop and reinstall the friction wheel in the machine. If you only have a dremel, attach a grinding wheel and do the same thing.

The second most common problem found with 1970s SUs is the machine stops driving the hook, or the hook timing goes out. This is caused by breaking of the pinion gear, which drives the rotating hook. The original pinion gears were made from a dark coloured plastic which go hard. Teeth break off or the gear just breaks completely. The replacement gears are white in colour and are not expensive. The