Slant spool-pin fix

A Singer spool-pin fits snugly into the complete unit.

Looks neat on the top. The Singer spool-pins are an easy push fit into the hex keyhole.

Top is the original, broken as usual, Singer plastic spool pin. (minus its lost rubber spacer)
The long tube (Bike pump part) is what I used for washers, cut off to length.
Lower right are 3 bike chain-ring bolts, The left of the 3 showing the unit screwed together & the spacer washer, cut to length, under it.
We need two of these.

A much neater & sturdy fixing under the lid. Only 2mm thick, it doesn’t interfere with the pattern plate as the original does.

The thin spacing washer is all but invisible under the top flange.

Slant spool-pin breakage problem?

Looking for a solution I found some replacement original pins online for circa $10 each + shipping!!

Not for me at that price, so I thought of making my own…

Then I thought to look through my stock of small bicycle parts first, to see what was possible, & came across these chain-ring bolts…

This is my solution, using bicycle Chain Ring bolts & 2 washers.

.If you have a Slant with the common spool pin problems & don’t mind using non original parts then this is an elegant solution. I’d be amazed if I’m the first to think of it, but you can buy these Chain-ring bolts cheaply & easily online. Look for double chain-ring bolts.

They usually come in sets of 4 or 5.

Photos explain it best.

These “Double Chain ring bolts” can better be described as a nut & bolt, with flanged ends, & a hole through the middle for a standard plastic pin to fit snugly into: )

Many of these have a 10mm diameter behind the flanges & happily this suits the 10mm hole in the Slant lid. The flange is slightly larger than this & effectively locks it to the lid when screwed together. Just needs a spacing washer 5mm thick on the upper side to lock it up slightly above the lid surface.

The top washer needs to be the correct height to place the top of the pin (where the spool will sit level, or slightly above) but height can be adjusted with a thin 10mm washer on the lower side. Thus you can adjust the top end height to suit your needs.

So, a 4mm washer on the top & a 1mm washer on the bottom, moves the whole unit 1mm down.

The spool felts conceal the unit in use, but if a thin, tubular spacing washer is used (As I did) there is space for a decorative filler. Maybe a bobbin winder tyre?: )

Needs no alteration to the machine lid, it simply bolts on or off, with only a 2mm thick nut showing underneath. Takes a 5mm Allen/Hex key to remove the unit.

So the original pins can always be fitted later if required.

Much neater underneath & will interfere less with the pattern plate.

Any of my Slants with damaged, weak or sloppy Singer units will have this upgrade in future. (Unless I find a better one: )

The delicate & complicated original plastic unit was a design fault for me. I’m more interested in utility than originality on my machines.

Standard’(?) Singer plastic spool pins fit nicely into the 5mm Allan/Hexagonal key hole.

The pins I used are 5mm diameter with a 4 mm insertion stub. 45mm overall, with 6mm stub. (Came new as spares with my Singer 6061 in 1980ish & never used.) Others will probably fit, or adapt easily.

The complete unit before fitting is pictured top. No more push nuts, this is a quality, engineered fixing. The spool-pin fits into both ends, & the unit fits both ways, but I think the Hex key hole looks neater on the top.

The original Slant pins are 6mm diameter & my replacements are 5mm, so mine will look a little skinny.

I made my thin spacer washer from a bicycle pump inner cylinder. See the long tube pictured above. Just cut it off at the length you require. (There are other solutions for the top spacer washer, for example 2 or 3 10mm spring washers, which could give some flexibility to the spool pin. Or you could use rubber to fill the gap, but that would need a thin washer under the flange.)

The pump tube is not welded along its length so it can be opened up slightly to make a snug, tight fit under the top flange.


Had occasion to compare a 401G with a 431G recently & noticed the neat 401s spool-pin base. No irrelevant holes like the 431.

See bottom photo.

I discover that the lids are interchangable: ) Seems like a good upgrade for my 431s (& probably 411G 411M too)

Job done. For now: )

401G front 431G rear. Compare the cam stack lids. The 401 is so simple & elegant compared to the 431s wells. Why did they change it? They are interchangable in any case.