The female plug

picture of mains connectors for Elna Grasshopperphoto of female plugs used with Tavaro GrasshopperPictured above are the three different types of female plug used to connect the mains lead to a Grasshopper

The big one on the right with the porcelain insulation on the business end is for a Series 1 machine.  It’s a type of plug which was used quite widely on all manner of Continental domestic and commercial equipment until the early 1960’s or thereabouts.

The one in the middle is the more common of the two all-Bakelite plugs which mate with the later flat-blade male socket used on the Series 2 and Series 3 machines.  As far as I know, it’s an obsolete connector which was used almost exclusively in Switzerland, usually for domestic and office machinery, audio amplifiers, slide projectors and suchlike.

The one on the left is simply a variant of the one in the middle, with added earth contacts.

Of the three, the big one is nowadays relatively easy to find  The earthed one is definitely a rarity, although it’s the only one of the three which I know is still available on the Continent brand new – at a price.

So what are these things called, apart from a female plug?  Well, I’ve asked a lot of people and searched a lot of websites and I still don’t know what the proper designation is of any of them, so if you’re an authority on obsolete European mains connectors, I’d love to hear from you.  I can though say for sure that despite what you might read elsewhere on the internets, a Euro C9 female plug does not fit the later type flat-blade socket on the Series 2 and 3 machines.  However hard you try.

Actually, I should perhaps qualify that by saying that a Euro C9 female plug as moulded onto the end of replacement mains cables sold for Revox tape recorders does not fit, and it does not fit because although the socket blades are the right distance apart, they are too thick and too wide.

Anybody want a spare mains lead for an old Revox?

One obvious way forward if you’re stuck for a mains lead for a Series 2 or 3 is to hard-wire it to the blades of the male socket on the machine then try to get some good-quality heat-shrink tubing over them.  You probably won’t be able to get the machine back into its case and it won’t look pretty, but it’ll work, and you’ll be able to unsolder the wires and remove the excess solder if in due course you do acquire the kosher plug.

The other option seems to be fitting a different connector to the machine, and I have looked into this.  The existing socket removes easily enough and all that’s needed for a replacement mounting plate for a new one is a nice piece of black 3mm acrylic, but the big question is what connector do you put in it?

The ultimate problem-solver would be the ubiquitous Euro C14 chassis plug, but there’s nothing like enough room to fit one without surgery to the motor housing.  After that, it seems to me that almost every readily-available socket would either foul the screws with which you mount the new plate to the motor cover (assuming you use the two existing tapped holes), or it would be deep enough to risk contact with the fan on the motor shaft.

If you’re not bothered about keeping the machine in original condition though (or capable of being readily returned to its original condition), I guess you could take inspiration from some of the “modifications” which surface from time to time.  Perhaps the wackiest one I’ve seen so far involved a conversion to foot control and a vintage Singer mains socket screwed to the back of the motor housing …

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Shipping a Grasshopper

One advantage of the Grasshopper over most other vintage sewing machines is that it comes in its own steel case.  However, relying on the felt-faced spacers inside that case to stop the machine moving about in transit is definitely not a good idea.  You don’t have to see many Grasshoppers before you can work out which areas of missing paint are down to normal use, and which were rubbed away by contact with the inside of the case.

Here’s how to make a proper job of packing a Grasshopper …

That’s the Elna packing instructions dated 1945, and here’s what a properly packed Grasshopper looks like when you open the case …

Picture showing How to pack an Elna #1 for shipping

This is a machine which came over from Germany via DHL photographed as I opened it up, and I could find no evidence at all of it having suffered any damage in transit – thanks to Karsten following the directions in those original packing instructions, which I’d sent him a copy of.

That masking tape (painters tape) he used had no effect upon the paintwork, although I wouldn’t have wanted it to stay stuck on for very much longer in case it did have.

Incidentally, you’ll note that the instructions advise you to tie a bit of string round the arm to prevent the light carrier dropping down.  I can vouch for the fact that if you ship a Grasshopper without doing just that, the light does indeed drop down and flap about.

As you can see from the bottom picture, there’s plenty of space in the throat area to pack bits and bobs like oil cans and so forth, provided they’re properly wrapped up so they can’t do any damage if they do move about.

There is actually one more useful tip to pass on about packing Grasshoppers for shipping, but I need to take a couple of pictures to illustrate it, so that’s going to be another blog post.  Maybe even the next one.

The vintage Elna oil cans

Picture of vintage Elna sewing machine oilcansIn case you’re not familiar with them, that’s a picture of the two oilcans which were originally supplied with Grasshoppers, alongside a standard spool of Gütermann thread.  And just in case the size comparison is meaningless because you’re not a Gütermann user, I’d better say that they stand 12.5cm tall to the top of those screw-on caps.  Or, if you prefer, 5 inches.

As you can see, one is black and the other is green.  And this is where life gets complicated, because one is for oil and the other is for kerosene.  That’s what it says in the Parts List.  It doesn’t say which is which though, so maybe that was left up to the purchaser.

The green one in that picture has definitely had sewing machine oil in it.  What the black one had in it, I have no idea.  I can’t unscrew the top because whatever was in it has gummed it firmly in place, but I can take the cap off the nozzle and take a sniff.  It smells remarkably like eucalyptus oil, but it can’t be.  OK, maybe it could, but it shouldn’t.

Whatever, we are now on the verge of getting into the vexed question of what to lubricate the shuttle race of a Grasshopper with, and that’s a topic which undoubtedly warrants a post all of its own.

I’ll do it next week.

Meanwhile, if you happen to have a pair of these oil cans for sale, or indeed if you’re after a pair, do let me know and I’ll put something appropriate on the for sale and wanted page.

The Elna Grasshopper Speed Reducer

As far as I know, there have only ever been two domestic sewing machines made with a true low gear.  One is the 1970’s Viking 6570, and the other is the Grasshopper.  Unfortunately that low gear’s gone missing from a lot of machines over the years, so in case you’re not familiar with it, here’s what we’re talking about …

Picture of Elna Grasshopper Speed ReducerThat black gizmo is properly called the Speed Reducer, the casing contains a small gear and a big gear, and fitting it does three things to a Grasshopper.  It slows down the drive such that for any given position of the knee-lever, the machine sews five times slower than it normally would.  It increases piercing power.  And it makes the machine noisy.  So, let’s have a look at the thing …

Picture of Elna Grasshopper drive w/o speed reducerAbove we see the drive end of a Grasshopper as it normally is.  That shaft with the slotted end to the right of the picture goes by the name of the eccentric axle (we’ll soon see why), and its sole purpose is to be the mounting for the speed reducer.

To fit the speed reducer to a Grasshopper, you line it up so that the long gear with the hole through it fits onto that eccentric axle, and the short bush sticking out the narrow end fits over the motor shaft.  You then slide the thing forward and wiggle it so the teeth of the speed reducer gear mesh with the teeth of the gear on the motor shaft, then push it just a bit futher until it clicks into place like in the picture below.

Picture of Elna Grasshopper drive with speed reducerThat’s the theory.  In practice, you may find that you can’t get the thing on properly because however hard you try, you can’t get the gears to mesh because they need to be further apart.  This is where the eccentric axle’s eccentricity comes into play …

Picture showing Location of Elna Grasshopper eccentric axle locking screwSee that hole?  At the bottom of it, there’s a screw with a slotted head, and that screw retains the eccentric axle.  Slacken off the screw and you can remove the axle …

Picture of Elna Grasshopper SPEED REDUCER eccentric axle and as you can see, the reduced diameter (which fits into the motor housing) is off-centre.  Now you know why that axle has a slot in the rounded end of it.  Yep, if you slacken off the locking screw with the speed reducer in place, you can then rotate the axle eccentrically and vary the distance between it and the motor shaft so as to set the correct meshing of the the two gears.  OK it’s a bit of a fiddle, but it works – providing you remember to tighten the locking screw once you’ve got the gears meshing properly.

So how does the speed reducer actually work then?  By sound engineering principles and ingenuity is the short answer, but here’s the long one.

First off, you need to bear in mind that the motor belt pulley and the gear on the motor shaft are one assembly.  They never move relative to each other.  Furthermore, all that stops them rotating freely about the motor shaft is the spring-loaded key seen in the picture below. That’s what locks them to the shaft so that the motor can drive the machine via the pulley and belt.

Detail picture of Elna Grasshopper drive shaft

That key is the means by which the Grasshopper automatically disconnects the drive to the needle bar when you wind a bobbin.  As you push the bobbin onto the shaft, it depresses the key, which disconnects the drive to the pulley/gear, which then can’t drive the belt, which means there’s no drive transmitted from the motor to the needle bar.  Taking the bobbin off allows the key to spring back up and engage with the pulley again, thereby restoring normal operation.

Getting back to the speed reducer, here’s what’s inside the casing.  Note that the small gear A and the bush which goes over the motor shaft is one piece, as is the large gear B and the long gear C which goes over the eccentric axle.

Picture of Elna speed reducer gearsAnd here it is in place on a Series 3 Grasshopper …

Picture of Elna Grasshopper speed reduction drive

Fitting the speed reducer depresses the key and disconnects the drive to the belt pulley/gear assembly in exactly the same way as putting a bobbin on the end of the motor shaft in order to wind it does.  The difference is that the bore of that bush poking out the small end of the speed reducer has a shallow groove in it, which engages with the key on the motor shaft just enough to lock itself to it while keeping the key depressed enough to allow the belt pulley/gear assembly to freewheel.  The motor therefore drives the speed reducer instead of the belt pulley/gear.

So, with the speed reducer fitted as in that picture above …

The motor shaft is driving small gear A of the speed reduction unit – not the  pulley/gear assembly, which is now free to rotate about the shaft.

The small gear A inside the speed reduction unit is meshed with the big gear B inside it.  That big gear B and the long gear C which fits over the eccentric axle are one piece of steel.

That long gear C meshes with the gear on the motor shaft which is one piece with the belt pulley.

So the drive train is motor shaft > speed reduction small gear A > speed reduction big gear B > speed reduction long gear C > big gear/belt pulley which is freewheeeling on motor shaft, and from there to the machine crankshaft via the rubber belt as normal.

Given that both small gears involved have 17 teeth and both large gears have 40, that’s  two successive speed reductions of 40:17 or 2.35:1, so the overall reduction is just over 5:1 or 80%.  Readers who did mechanics at school will know that where there’s a speed reduction through a gear train there’s a consequent torque increase, but what that might amount to here in practice is anybody’s guess.  Suffice it to say that piercing power is definitely increased by a useful amount.

I think we’ve just about done the speed reducer now except for two last things.  One is that the small gear A is plastic, no doubt so that in the event of the drive train getting overloaded, the small gear fails before the motor suffers damage.  That had certainly happened with one unit I’ve seen, which had one tooth missing and one a bit dog-eared either side of it, despite which it ran well enough (albeit noisily).

Finally, the speed reducer does need lubrication.  I have no idea what the original Elna recommendation was, but given that we have here both steel and plastic parts under variable load in close contact, my own preference is for a synthetic Tri-flow type grease as used by folks into radio-controlled cars and suchlike.

[By way of a footnote, connoisseurs of things mechanical will have noted that with 17 teeth meshing with 40 teeth, the speed reducer was designed on the hunting tooth principle, the aim of which is to distribute wear evenly.  And that reminds me – if you’re a gear-head, check out the three awesome PDFs by Phil Miller which are linked to at the top of this article …!]

An introduction to a Grasshopper – part 3

In this, the third and final part of this general introduction to the Elna No.1, we take a look at bobbin winding and threading the machine.

spool pin and thread guide of Elna No.1 Grasshopper

The first step in winding a bobbin on a Grasshopper is to swing the guide arm down from its parked position to where it is in this picture.  Having placed an empty bobbin on the winder shaft, you then run your thread from your spool, along to the wire loop guide at the top of the faceplate, then back round this guide and down to the bobbin …

Elna Grasshopper thread path for bobbin winding

Now at this point on most other domestic machines, your next move would be to declutch the handwheel so that when you press the go pedal or whatever, your bobbin winds but your needle doesn’t move.  Not so on the Grasshopper – putting the bobbin on the shaft magically disconnects the drive to the needle bar.

Bobbin winding on Elna Grasshopper sewing machine

Having looked at this close up, you probably have two questions, which I’ll now answer for you. That shaft with the bobble on the end which is alongside the bobbin winder/motor pulley shaft is what the speed reduction gear fits on to (there’s a post about that coming up before long), and no, vintage Elna bobbins are not the same as Singer 15 ones.  These have a keyway in them, and they’re slightly taller.

Elna Grasshopper threading

Here’s a shot of the rather manky faceplate of this 1945 machine which is still in exactly the same state as when I bought it, but hopefully you can see the thread path for normal sewing.  It also shows a weird red reflection and I can’t for the life of me think what that was, but never mind.

There’s nothing weird about threading a Grasshopper though – you go from spool to wire guide on top of faceplate (it’s just visible top left in that snap) then down, round the top tension and back up, through the take-up lever from back to front, then down through the bottom guide and the guide on the needle clamp.

The needle goes in with the flat to the left, which of course means that you thread it from right to left.

bobbin/shuttle area of Elna Grasshopper

Finally, here’s a shot of the shuttle assembly with a bobbin in place and threaded up ready to rock, which reminds me that with the introduction to this fine machine now done, I mustn’t forget to do a post about the proper lubrication of the shuttle race.  With paraffin …