The mystery machine

Discussions on Talking Machines of British or European Manufacture
moosepr
Victor Jr
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Joined: Wed Apr 21, 2021 10:45 am

Re: The mystery machine

Post by moosepr »

the old springs seem to be 5mm wide, 0.12mm thick

the new ones will be 6mm wide, 0.1mm thick

just im not sure how springs work in general, but the cross sectional area will be the same, just a slightly different shape, so im banking on it working to a similar strength.

than being said, im sure that material variations, heat treatment variations, etc may impact things somewhat.

once I get the basic spring made I could potentially reduce its strength by thinning the width, or increase its strength by getting some thicker steel stock.

In the mean time, im still looking on ebay for spares just in case it all falls down :)

moosepr
Victor Jr
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Re: The mystery machine

Post by moosepr »

So I have had some moderate success, rather than trying to drill holes, punch them through instead!

The 3d printed jig needed a few tweaks, but has made it super easy to line up.

Managed to grind the end of a broken drill into a "Pringle" shape to help it cut through
IMG_20210501_123740.jpg
Then it's a case of sliding some spring into the jig, punch the 3 holes, trim the ends with a chisel, and you have a ragged edged spring
IMG_20210501_123721.jpg
I need to tidy them up a little, then I can see if they will work

moosepr
Victor Jr
Posts: 14
Joined: Wed Apr 21, 2021 10:45 am

Re: The mystery machine

Post by moosepr »

That will do!

https://youtu.be/--aWIyLWayU

The gears are all super dry, wanted to get it working before I lubricated

A quick test with an app on my phone and it sits at 100rpm with the speed control lever not attached, so hopefully I will be able to get it to a proper speed

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Inigo
Victor IV
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Re: The mystery machine

Post by Inigo »

What is very importan is to balance the governor, so you don't feel any vibration while it's running at full speed. Vibrations loose energy, and kill the bearings if sustained for time enough. Much like the wheels of a car need to be balanced.
Inigo

PortAbility
Victor Jr
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Personal Text: There's always something new to discover

Re: The mystery machine

Post by PortAbility »

I suspect/ fear that shortening the governor springs won't work. Even if you've made accurate holes in the spring steel they will become too short - and the governor brake will prevent it spinning in the correct speed range.

If your replacement "punched" ones don't work you should be able to pick up a set of 3, either from a donor motor (via eBay), or from one of the Dealers/ Repairers listed above.

moosepr
Victor Jr
Posts: 14
Joined: Wed Apr 21, 2021 10:45 am

Re: The mystery machine

Post by moosepr »

I did consider trying to shorten the broken springs, but like you say, the changes would do more harm than good.

So far the home made springs seem to be working out. The speed control ranges from 90-65 rpm so it's pretty much what I would expect.

I tried it with a broken record just in case anything bad happened and it plays well

https://youtu.be/9Z9tSin_uBk

The sound is quite tinny/buzzy but it's loud and clear, with consistent speed

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