One of the latest mechanical movements, which were launched in the early 1980ies by Rego, was the caliber 2125-216, which contains a plastic lever.
Its construction is Roskopf-alike, with an minute wheel, which is indirectly driven by the mainspring barrel.Video on YouTube
This movement is clearly constructed with minimal costs in mind. Since in the 80ties, quarz watches were available at almost the same prices, as mechanical watches, those mechanical watches were hard to sell, unless they were sold at extremely low prices. To achieve those dumping-like prices, the constructions had to be as cheap and simple as possible.
The construction of this pillar movement is the same, as on a Roskopf movement. From the mainspring barrel (which has got no cap!) the second wheel is driven, then the center second wheel (which means, that we have a directly driven center second here) and finally the escapement wheel. The gears are already made of full plates and have only small cut-outs - this cheap construction is normally only seen on quarz movements.
The four gear transmission is a bit problematic: Since none of the bearings contains rubies, but are only holes on the plates, the friction is rather high (compared to better mechanical movements). And since the plastic lever also adds friction at both sides, on the escapement teeth as well as on the ellipse of the balance wheel, it can happen, that the movement does not easily start or has a lower power reserve. And since plastic also hardens and tends to break with time, the long-time reliability of this movement is not optimal, too.
The specimen shown here has got, although almost NOS, problems because of the higher friction.
The three leg balance beats with 21600 A/h and is beared in two KIF Protechoc shock protections. One of them (the one on the top) contains a ruby, the other one just a metal bushing.
The hairspring is soldered to a long regulator arm which makes it very easy to adjust the beat error.
On the dial side, which is not spectacular at all, you can see the yoke winding system and its simple setting lever.
There’s already space for an additional date indication mechanism, and what purpose the other cut-outs have got, is unknown to me.
As usual on Roskopf-type movement, both, minute and hour wheel, are driven by a friction coupling on top of the mainspring barrel. You can see them on the next picture:
|Number of jewels:||1|
|Escapement:||Plastic form lever|
Nickel anular balance|
|Balance bearing / direction hairspring:||Clockwise|
|Adjust mechanism:||Hairspring key|
|Construction type:||pillar construction|
|Winding mechanism:||yoke winding system|
|Setting lever spring:||1 hole(s)|
|Functions:||hour, minute, second|
|Size:||11 1/2''' (measured: 26,4mm)|