29k15 shuttle gear remanufacturing

[29k15engine]

Some more footage of the new rack showing correct timing

https://1drv.ms/v/s!AoQ4CZYzE-ZEjijYYPdbCPapexKS

https://1drv.ms/v/s!AoQ4CZYzE-ZEjinebhd-7y_c5KCi

https://1drv.ms/v/s!AoQ4CZYzE-ZEjipwRRCQJiU9uWyd

And resulting stitches top and bottom, has not dropped a stitch at all even through 5 pieces of leather.

 

[shoepatcher]

great Job 29K15engine!   I have been playing with these gears and rack over the last couple of years.  SItamaco in Spain has the 29K1parts made in China I believe.  They are new.  The drive gears, short rack, following gears, shuttle carrier and set screws are all needed today for 29-4, 29K1-33, 29K51-56machines.  Other than Sitomaco, no one is making them.  thee is a big need for these parts.  Singer made over 250,000 29-4 machines!   

Gear #8608 was used in 29K1-4,10-18,21-23, 32, 33. right of of original singer parts book.  I know no one is making gears for the 51-56.

glenn

Very nice result!!!!!

glenn

[29k15engine]

so bit of an update, this is what I am thinking of for an adjustable rack. Rod either threaded M6 metric fine

 

or

 

smooth tube and rod with clamping bolts drilled through tube. Will need to hole up to reciprocating forces so undecided. All in steel, just transparent for drawing:)

 

Edited July 14, 2021 by 29k15engine

[29k15engine]

looking at simplifying the pivot end so here the part could be laser cut from 1 thickness, then 2 short tubes of id 6mm od 10mm welded to the laser cut part.

Then two opposing m6 nuts clamp the rack, keeping parts simple, available and easy to make.

 

 

Edited July 14, 2021 by 29k15engine

[chrisash]

Have you considered metal 3D printing

[29k15engine]

Thanks Chris for the suggestion

I think the price would be too much.

This would be quite simple to Mig or Tig together and the strength of metal could be chosed off the shelf to an appropriate spec (not sure what that should be yet, any suggestions for parts that would be metal on metal moving)

Edited July 14, 2021 by 29k15engine

[29k15engine]

I have bought some 6mm id 10mm od steel tube, so I'll try get the other part laser cut then hone the pivot hole to the correct diameter, then mig the tubes to the pivot part.

See where that gets me.

I have dropped the threaded rod by 2mm and adjusted the pivot section so the parts do not take up any more vertical height under the arm.

Thing is I could make this one solid section but I don't have access to a lathe, this way if people want to make this all they need is the tube, get the other piece laser cut or hand cut to dimensions and weld together.

 

 

 

Edited July 15, 2021 by 29k15engine

[29k15engine]

Just waiting now for the EDM pieces to be cut, hopefully in the next few days.

[chrisash]

The beauty of 3D metal printing is that you can do quite a few at the same time making it more attractive price especially cogs, worth asking for a quote in your country

[29k15engine]

You got me interested Chris, are we talking sintering? Do you have a web link of an example company in the US that would do this?

[chrisash]

Here is a UK company that does DMLS that may give you some idea, never used it myself, just read about it https://www.3d-alchemy.co.uk/3d-printing-metals.html

 

[29k15engine]

Ok so bit of an update, I am very happy with the racks supplied from Italy, part 8600 this can be easily modified to fit the 29k15 and like machines as described below. Part 8599 also stocked in italy can also be adapted to make a 29k15 rack.

I am also proceeding with the development of an adjustable rack to reset the shuttle timing to stop drop stitches and timing issues.

I have also recieved supply from italy of 8608 following gears for the 29k1, unfortunately the gear does not fit easily in the 29k15, the dimensions of the gear teeth are too fat to mesh properly without alot of teeth root filing and thickness, for me that is a no no, with the rack mods below all the filing is on the backs and not on the teeth.

I believe these 8608 gears will fit the 29k1 as the tollerances needed in combination with the long and short rack are not as critical as the 29k15 3 gear 1 rack system.

In fact I am starting to believe that the only way singer got the 3 gears to perform to the tollerances needed was to "finish the 3 gears (2 followers and 1 driving gear)" by finish I mean run them together on a jig until they cleanly meshed and ran smoothly, this may be collaborated by the fact that 29k15 gears have punch marks on the sides of the gears where they were originally meshed, rear follower one puch middle follower 2 punches and the driving shuttle gear 1 punch.

I am still therefore pressing onward to get these EDM cut gears, this will mean I can get gears cut accurately that will be a guaranteed fit without any rework after and therefore be the only new rack and gear designs and sets that fit to the 29k15s out of the box in the world.

 

any thoughts on these finding would be appreciated.

 

Any thoughts on my findings

 

 

[29k15engine]

[shoepatcher]

Keep us posted please!!   great job Matt!

[29k15engine]

will do, just waiting for the gears to be cut, in the mean time Im redecorating our bathroom, plastering and tiling is not fun

[29k15engine]

Ok so after many weeks my friend has got the peices done on a wire erosion machine, what a good job was done!

I have tried the rack part which meshes perfectly with both original pinion gears and the machine itself.

So does the bottom plate i had made.

The new gears mesh perfectly with each other and original gears. I have yet to hone them to fit the pinions in the bottom 29k arm ( made them to hone as i didnt want to go through all this to find them too loose. Plus after that they need the lower bearing shoulder to locate in the bottom plate. So ill be back soon. After this i can let you have the universal files so you can make your own.

Edited November 14, 2021 by 29k15engine

[29k15engine]

Parts placed together

[DrmCa]

On 6/25/2021 at 2:08 PM, 29k15engine said:

made from copper brake pipe wrapped round a pipe, then cut and formed into a ring.

Thank you for a neat trick! I too have a coil of brake cupro-nickel pipe lying around. Mind you, it turns green if left in the moist environment, so probably it is a good idea to find a way to coat them rings.

[29k15engine]

Here you go all parts fit in the 29k15.

The gear thickness needs to be spot on as it is sandwiched between the arm and bottom plate.

The bottom plate needed a slight file to the two long sided so it seated where the screw and pinion bearings wanted it to go( we are talking a few thou)

The hole in the gears was made undersize to allow differences in pinion wear( ream to fit your machine)

My friend used hardened tool steel so only a hardened tip drill would do the job.

 

Next job is make up the adjustable rack. Getting there now, i will post the gear , rack and base DXF files soon for anyone to try them in their machines

 

 

https://1drv.ms/v/s!AoQ4CZYzE-ZEkWlLataRevmLAfCu

Edited November 18, 2021 by 29k15engine

[29k15engine]

Some photos of the new gear on the right and an original out of my 29k15 on the left

[29k15engine]

Just threaded up the machine and it stiches perfectly. Fine through 2 pieces of 1mm leather and 6 peices of 1mm leather !

[29k15engine]

After much work these are the DXF files required to cut correctly profiled shuttle gears for the 29k15 Singer Patcher, although I have extensively tested these on my machine I take no responsibility that these fir yours, they are however ovet 6 month work and are as accurate as i can make.

These can be cut with an EDM wire erosion machine from a suitable steel (Hardened tool Steel)

I will provide side profile drawings for the depth to cut the shuttle gear after the EDM has cut the gear profile.

I have tweaked the shuttle so it does not need to be reamed out to correct pinion size.

thickness for pieces before being cut on EDM, surface grind to these sizes,

1. ideal shuttle5-25mmdia.DXF           Description:- pinion gear 6.68mm
2. ideal rack.DXF                                     Description:- rack 3.8mm
3. ideal plate.DXF                                    Description:-Locating plate 2.73mm thick

ideal shuttle5-25mmdia.DXF ideal rack.DXF ideal plate.DXF

Edited November 27, 2021 by 29k15engine

[DrmCa]

Just one question: why did you not have them make the whole length of the rack?

[29k15engine]

Hi thanks for the reply, Due to these machines not having an adjustment for shuttle timing the length of the full rack would be subtly different from machine to machine after 100 so years.

due to this I have worked on an adjustable rack (see earlier posts) which would allow timing adjustment equivalent to the later machines with a eccentric bush.

If you look at earlier posts you will find an old 60s catalogue picture from italy which shows the replacement rack end as a weld on item, so without the adjustable rack the end can be replaced on an existing machine rack (with care)

 

Edited November 27, 2021 by 29k15engine

[chrisash]

First class work, I am sure many will appreciate your hard work