Grasshopper wiring diagram

Sarah, who I guess is in the US, has been trying to find a wiring diagram for a Grasshopper, so here you go …

Grasshopper wiring diagramThat’s the only one I have, and it may or may not correspond exactly to your particular Grasshopper.  Even if it doesn’t, my own feeling is that if some aspect of your machine’s wiring is not obvious to you and you can’t work it out from this diagram, maybe it would be safer for you to have somebody else take a look at it.

Here’s the same thing as a PDF

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Elna Grasshopper flywheel removal

If you ever need to take the flywheel off a Grasshopper, you might like to know that, at least where the early machines are concerned, there’s a little more to it than meets the eye.

If your machine’s serial number is 45655 or higher, the flywheel comes off as you would expect – you just unscrew the screw which obviously locks it to the shaft, and pull the flywheel off.  If you keep unscrewing that screw and take it out, you will find that it looks like the top one in this picture …

Also shown in that shot is the two-part affair used on machines up to serial number 45654, and that consists of a “flywheel screw” (the long bit) and a “flywheeel pointed pin”.  When you unscrew the flywheel screw, it comes out just like you’d expect, but the pointed pin doesn’t, and it’s that which will probably prevent you from being able to slide the flywheel off the shaft.

On the later Grasshoppers, the point on the end of the one-piece screw locates in the groove cut in the shaft and thereby locks flywheel to it.  But on the early machines, it’s the flywheel pointed pin (the short bit) which engages in the slot.  The flywheel screw only applies pressure to the pointed pin and locks it all in place.

Why they did it like that is a moot point, but whatever.  Here we see the “inside” of the early-type flywheel with the flywheel screw unscrewed as far as it unscrews.  Note that the point of the flywheel pointed pin is still projecting through the bore of the flywheel, so if that flywheel was still in place on the shaft which is visible behind it in that picture, the point of the pin would still be located in the groove.

In theory, you should be able to take out the screw of an early flywheel, rotate it until the screw hole is at bottom dead centre, then either tap or jiggle the flywheel, whereupon the flywheel pointed pin will obligingly fall out and you’ll be able to pull the flywheel off.

In practice they tend to stick (or at least two I’ve met did), so flywheel removal on a Series One Grasshopper can become a rather protracted performance involving penetrating oil and patience.  Maybe even a small gear-puller too if you can lay your hands on one.

The good news is that reassembly’s a doddle with either type, and is just a case of making sure that as you slide the flywheel onto the (lightly oiled) end of the shaft, the screw hole is aligned with the slot.  It helps to have the slot at top dead centre, and a small torch is handy too.

If your machine’s one of the early ones, don’t forget to pop the pin back in its hole first, and then keep the flywheel hole-uppermost until you’re sure it’s all back together properly …

Elna Grasshopper bobbin winding – how it works

From the design point of view, one of the many really neat things about the Grasshopper is the way that when you put a bobbin on the end of the motor shaft in order to wind thread onto it, doing so disconnects the drive to the motion i.e. your bobbin goes round but your needle no longer goes up and down when you start the machine.

Actually, let’s make that “should disconnect” the drive, because if you’ve just acquired a Grasshopper which has been seriously neglected, putting a bobbin on might not disconnect it.  In fact, you might not even be able to get a bobbin on to the shaft …

I can’t with that machine, which is in a really sorry state.  Apart from the surface rust, what’s stopping a bobbin sliding on to that shaft is shown in the picture below.

The wedge-shaped doohickey running along the top of the shaft in that photo is properly called the coupling key, and it’s that which is the problem.  It’s seized solid.  It can’t sink down into the groove it sits in, which is what it needs to do when you slide a bobbin onto the shaft.

Now, the best remedy for any problem with this particular bit of a Grasshopper depends upon three things – the precise cause, your expertise with things mechanical, and what tools and magic potions you have available.  So I reckon the way forward here is to explain how the thing’s supposed to work, so that you can decide for yourself how best to proceed with your particular machine.

That’s what it’s supposed to look like, and here’s how it all works.  The motor pulley and the gear wheel behind it are one and the same plastic moulding, so we can ignore the gear wheel part of it here and just talk about the pulley.

The pulley is actually free to rotate about the shaft, but it’s prevented from so doing by the  coupling key, which sits in that slot in the motor shaft.  Now, if you look again at that picture above, you’ll note that about halfway along the key, there’s a semi-circular depression in the shaft.  That’s actually a round hole, in which sits the spring which pushes the key back up when you push down on it.  It’s that key which locks the pulley to the shaft.

As photographed above, when the motor shaft turns, so does the pulley, because the coupling key has coupled them together.  Push a bobbin onto the end of the shaft, and as you push it further on, it pushes the coupling key down into its slot.  When the bobbin’s on as far as it’ll go, the drive to the motor pulley is disengaged, because what locks it to the shaft is the end of the key, which is now depressed into its slot by the bore of the bobbin.

If that doesn’t yet make any sense, it soon will …

In the picture above, the arrow is pointing to the end of a slot which runs along the bore of the pulley.  And what you can’t see is that the far end of the coupling key engages with that slot.  It’s confusing because there’s a notch in the coupling key just where it continues into the pulley, as will shortly become apparent.

Hopefully all will become clear when we take the motor pulley off, and to do that we first have to remove the circlip holding it in place.  We then need to take off the flywheel, because otherwise the pulley won’t come off the end of the shaft.

As we slide the pulley off, you can see there the (worn) end of the slot in it, in which the coupling key engages.  And when we take if off the end of the motor shaft, this is what we see …

There’s the coupling key pushed all the way up by the little spring under it, and you can now see the notch in it that I was on about earlier.  It’s the bit of the key to the right of that notch which fits into the slot in the motor pulley and so locks the pulley to the shaft, in order to transmit the drive to the motion.

There’s your slot in which the end of the coupling key engages.

Now you can see why, apart from anything else, this all relies on the coupling key being free to retract completely into its slot in the motor shaft and to spring back up again when pressure is taken off it.

If the key won’t depress fully and return properly, you’re stuffed until you work out why and free it up so it does.

If you can get a bobbin on all the way but the motor pulley is still locked to the shaft, frankly your guess is as good as mine.  All I can think of is corrosion of the shaft inside the pulley, or, and most likely, somebody who didn’t understand how it works has “modified” it …

Elna #1 Grasshopper lubrication – part 1

One of the very first things I ever learned about Grasshoppers was that you must never go near the hook/bobbin case area with sewing machine oil.  Naturally I asked why not, and was told that sewing machine oil was too thick.  It would slow the machine down.

Oh really?  So what, pray, was a person to use instead?  “Petrol” was the answer.  Which made no sense at all to me – even when it was explained that (a) petrol was what it says in the instruction book and (b) it wasn’t a problem in practice because a can of lighter fuel lasts for ages.

(At this point I’d better point out that I’m English, I live in England, therefore I speak of petrol and paraffin, not of gasolene and kerosene.)

Fortunately, the first Grasshopper I bought came home with the instruction book, albeit the German one, so I immediately looked to see what it had to say about lubricants.  And would you believe …

Scan of Elna Grasshopper lubrication diagram (German)And lest there be any doubt about that, on the previous page under “Maintenance of the Machine” it says (in German, of course) that before each use, “the shuttle should be lubricated with 2-3 drops of petrol”.  So my informant was right.

Or was he?  Yes, Tavaro did seem to recommend sewing machine oil for everywhere but the shuttle – but petrol still made no sense at all to me.   Petrol’s a lousy lubricant.  And besides, what does it say on petrol pumps in Germany?  Yep, it says “Benzin”.

I was thoroughly confused.  Fortunately, I then acquired the French instruction book, and guess what …

Scan of Elna Grasshopper lubrication diagram (French)Now, if you go into Google Translate or Babel Fish or whatever with “pétrole”, what do you get?  That’s right – you get “oil”.

But that’s only part of the answer, because whilst it’s true that, for example, “une lampe à pétrole” is an oil lamp, that doesn’t mean oil as in sewing machine oil, it means oil as in lamp oil.  Which is a close relative of paraffin!   And sure enough, no sooner had I concluded that Tavaro meant the shuttle to be lubricated with paraffin, than I discovered that in the US-market Grasshopper instructions, it doesn’t say “gasolene”, it says “kerosene”.  Or paraffin.

This of course raises the question “why paraffin?”.  Given that paraffin has no magical properties at all, my guess is that Tavaro simply wanted any lubricant for the shuttle which had a lower viscosity than ordinary sewing machine oil, and the only thing which was readily available at a reasonable price in most of the Western world 70 years ago was paraffin.  It’s not much of a lubricant, but it’s better than none and it does creep into  very small gaps even better than sewing machine oil does.

So OK then, what exactly is it that you oil with your paraffin?  Funnily enough, the following diagram and text are missing from both the French and the German instruction books that I have here …

Sorry about the quality of that scan from a print of a dodgy PDF, but hopefully you can see that the idea is to put 2-3 drops of kerosene down one of the slots in what Tavaro called the Upper Guard Ring, before each use of the machine.

And why might it be important to do that?  Well, here’s a picture of the area we’re concerned with, on a really grotty Grasshopper …

Those slots in the upper guard ring are the slots down which the lubricant is dropped, and here’s why.  If you imagine a cross-section through the whole thing at, say, the point where the right-hand arrow’s pointing in that picture, then draw a diagram of it in Photoshop because that’s all you’ve got, it looks something like this …

In that much-simplified diagram, the red bit is the shuttle hook and the black is what on most other machines is called the bobbin case, on the top of which are to be found those slots.

When you’re sewing, the bobbin case stays put and the shuttle hook whizzes round and round it at a fair old speed, so you can see that it would be a good idea if that very narrow gap between the two parts was lubricated.  And that’s what you’re aiming to do with your 2-3 drops before each use – get them to creep into that gap, and hopefully stop the parts wearing against each other.

But what lubricant to use nowadays?  Well, not WD-40, that’s for sure.  You might just as well use paraffin – or even diesel if you can handle the smell.  Clock oil would probably be good, but you should see the price of it!  Actually, any modern low-viscosity automatic transmission fluid would do the job, and seeing as how you wouldn’t need to apply it every time you use the machine, you could probably scrounge enough to last you several lifetimes from wherever you get your motor car serviced.

In the end though, I’ve settled on Tri-Flow Oil from the US of A despite, rather than because of, the way in which it’s relentlessly promoted at every opportunity by its many fans on US sewing forums.  It’s a very thin oil with good penetrating properties, it has PTFE in it (so you really do need to give it a good shake before applying it) and it doesn’t stink, so for the time being at least, that’s what I’m using.

What I’d love to know, though is this – has anybody actually tried dropping good quality modern sewing machine oil down those slots and tested whether or not it really does slow down the machine?

[As to why the German instructions used the word “Petrol”, the only clue I can come up with is that if you look up “Petroleum” in a pre-war German dictionary, it translates as “crude oil, mineral oil, rock oil, paraffin, lamp oil, kerosene” …]