Singer 29k-58 project

[Andy132]

So, yesterday, I was able to get the drive pinion ( new one) working.

The solution settled on was to emery down the step section of the pinion bush until the tapered holes lined up

This meant removing approximately -  •3/•35mm of material off the bottom.

As mentioned earlier,the effects of this was to cause the shuttle driver and pinion to bind on the bush as they no longer had the clearance required in the step of the pinion bush.

Luckily for me, someone in the past had retro fitted a 71 mdl shuttle driver bush to the arm. I removed this carefully and spent a couple of house with a flat sheet of glass, different grades of wet n dry emery paper rubbing down the larger diameter surface that the pinion runs on.

Removed slightly more material than what I removed off the pinion. Eventually,I was able to screw the tapered screw into the two holes fully - with the necessary clearance to the bush so that both parts move freely,but without slop.

[Andy132]

I then used the two new racks and the old following pinion.

The play in the drive pinion isn't too bad but the slight slack in the freewheel teeth transfer slop back to the shuttle plate movement still. It seems fairly excessive - about 2mm,but until the whole lot is put together and tried out, I'm not going to know if it affects the stitches.

I recall in an older post,Wizcrafts referencing no more than 1/16 " of play in the shuttle,I think I'm still over that.

After a bit of measurement and digging around on the net,it seems  that all of the new racks and pinions are utilizing the Mod 1 standards for gears.

Which makes sense given it's industry standard for a lot of items made throughout Asia. Particularly model RC cars.

I was interested to see the amount of different sized pinions available for rc's and the potential for adaptation to our machines.

However,the smallest size I can see is 10 teeth,not the 8 that we require. I've ordered some 10 teeth stock for the interests of measuring and adaptation, There is plenty of corresponding Mod 1 rack available - cheaply, but the smallest dimensions I could find it in were 10mm x 10mm ,not the 4.2 x 4.5mm the new racks measure at.

My thoughts were,the following pinion could easily be machined to specs, the nominal bore on the rc pinions comes in various sizes,5 mm being the closest.

That can easily be reamed out with some wet n dry to the 5.4mm that my pinion post at least,measures at.

My thoughts for the drive pinion,were- machine the stepped bush to dimensions,drill and fit a grubscrew to the backside of it. Mark where the shuttle drive sits in its normal resting position.

Fit the pinion stock,locate the racks and pinion in position and tighten the grubscrew.

I realize by this point, everybody is shaking their heads and thinking," just buy the parts".

This is just a thinking exercise for when the part quality or availability is not there,as in my following pinion saga.

Be happy to hear others thoughts or if anyone else has looked at alternative gearing etc?

The Mod or dp gearing comes in much smaller toothed variants ,so theoretically,a Mod • 5 could be used- racking and pinions from the rc world- that would allow larger toothed pinions in the same space, and tighter precision on the overall mechanism??

 

Ok, enough - I need to do something constructive with my day.

Andy.