Sunday, November 23, 2014

Unpacking a new mainspring

Waiting for the new rubber grommets as feet for the #2 Portable. What did however arrive in the meantime was a new mainspring for the HMV102 portable gramophone.

A couple of months ago it started to have trouble keeping speed. At first only on some louder passages, but then on any record. Even after re-greasing the spring it was painful to listen to the false notes as the motor struggled and failed to keep speed. This meant that probably the mainspring was just spent and needed replacing.

Luckily and amazingly newly manufactured mainsprings are readily available, so an order was placed and duly received. It arrives tightly wound and held by a steel wire.


Unpacking a new mainspring is a bit tricky. To contain the force of the spring uncoiling and prevent the inch-wide steel spring from inflicting injury, it was first wrapped in a rag. With the spring in the rag the steel wire was cut, immediately followed by a roar and rumble as the spring expands against the rag. Slowly releasing the rag then gives a controlled uncoiling of the new mainspring (without injury).


For the HMV102, disassembly and taking out the spring is very clearly and helpfully described at a blogpost at Project Repair. Following those steps, the old spring was taken out again. Ultimately the new mainspring needs to be packed tightly again into this drum, but first it needs to be greased all over. Then its end needs to be hooked over the peg inside the drum wall. Can be done but the new straight spring makes this harder than it was with the old one.

Re-packing the new spring into the drum made clear that the old spring was spent. The new spring put up much more of a fight over being forced into the drum than the old spring. Again: do NOT let go of it when halfway.


Going through the steps in reverse order assembles the whole thing again. Hardest step is fitting the drum back on the centre shaft again, this is a very tight fit and the new spring centre hole does not centre over the drum opening. Several tries and some tweaking gets it back on however.

With the new mainspring fitted the HMV102 now keeps speed again.

Analog and fixable machines :)

Friday, November 7, 2014

Model C from Belgium

In the school playground I remember seeing other kids with the red Viewmaster (or View-Master), but never paid much attention. Vaguely remember looking in one and 'not getting it'. Until the recent post on i-dream-lo-tech about these stereoscopes, I hadn't realized how long they've been around for. That post made me very curious to experience one of these again.

The bakelite Model C (as I learnt) is remarkably common and before long a viewer that was made in the Belgian factory made its way to here. (From the hive-mind that is the internet this viewer can be dated as mid-fifties. The Belgian factory started 1953, the model C being sold up to 1956.) 


No different from the Portland-made viewers, but 'Made in Belgium' and with text mainly in French. Complete with instruction card (remove before use).





With already a few reels dating from the same period - I 'get it' now. The kids by the way also 'get it', were totally wow-ed by the images.


By now the 3D images have the added dimension of time. The views of Windsor Castle e.g. are very period typical, right down to a proper bobby pointing the way in the first image.

Nice :)

(Thank you Ton!)

Saturday, November 1, 2014

How to wrap that around a platen?


The typewritten look must be in fashion. That's a sizable tablecloth (linen). Am trying to imagine how they wrapped that into the typewriter... :)