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Author Topic: Changing a Varigear on a Monotype caster  (Read 459 times)

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Christophe Slychan

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Changing a Varigear on a Monotype caster
« on: March 12, 2017, 01:27:19 PM »
Our museum has three composition casters (apart from those, we have two working super casters, both with Varigears):
1. a 1940/50s 15x17 large composition machine, incomplete, with a single-speed wound rotor motor + speed adjusting resistor from Meech. This machine is incomplete and acts as a spare parts donor and a remelting furnace.
2. a 1940/50s 15x17 large composition machine with a gearbox and a nice Varigear formerly attached to another super caster which was damaged in transport and stripped for parts,
3. a 1960s 16x17 unit-shift small composition caster with a leaking Varigear that could use a strip and rebuild. The unit is different from all other our Varigears: it has a speed control knob on the front rather than on the side.

John Cornelisse's other machine is a small composition caster with a wound rotor motor with resistor, and it runs impractically fast on its slowest setting. It could be slowed down with a frequency converter, but these are rather expensive.  So, I had an idea of swapping the drives and sending him a Varigear instead to make the caster usable. I can put a "classic" motor on "2" and still have a good speed regulation thanks to its gearbox.
The "3"'s Varigear will go to John. We'll give it some love and put it on the machine.
The "2"'s Varigear goes to "3", and the motor + electrical parts (as well as the plumbing) from "1" goes to "2". On top of that, I'm in the middle of rewiring & inspecting electrical installation on all casters to bring them to modern standards.

The catch? Varigear drive is quite a weight - 40kg or so. One person will have serious trouble lifting it (let alone putting it into position to attach it to the machine), but there's a way of doing it yourself if you're not very strong.
You can use a transport strap (similar to https://media.decathlon.in/86961/fastening-strap-kit-2-x-3-m-black.jpg - 2 meters/yards long and 2.5cm/1" wide is enough, the buckle must be durable enough).

First loosen the drive belt and take it off the motor's shaft.
Then simply hang the strap over the a37H12 swing frame table (through the slot between the melting pot and swing frame), with the buckle end going towards the machine. Swing the pot under the machine and route the buckle below the Varigear motor flange (it's the narrowest part of the unit and the strap will hold it nicely), tie it so the strap is rather tense, and make sure it can't be accidentally released. Now you can start unscrewing the Varigear; after all screws are undone, you can swing the pot away and carefully loosen the buckle while holding the strap end firmly and lowering the Varigear.

Attaching it is the opposite (you need to make sure it'll face the correct direction). Use the strap to lift it to the appropriate height, then bring it into position and bolt it down. After tensioning the belt, make sure that the clutch works correctly (i.e. machine starting when engaged and stopping when disengaged) and adjust if needed.


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Mechanic

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Re: Changing a Varigear on a Monotype caster
« Reply #1 on: March 12, 2017, 11:07:12 PM »
I know nothing about Monotypes. I've watched them working in job shops when I went into service their Linotypes. I'm pleased to see the postings that certainly must be of interest to other Monotype users. I don't know of any Monotypes that are working in Australia. My friend John Setek had Monotypes until a few years ago. He still talks about the machines and is quite knowledgeable.

If other viewers on Metal Type will at least comment if they are interested. The only way to keep this site alive is to make use of it, otherwise it will die of boredom.
   
George Finn (Mechanic)
Gold Coast
Queensland
AUSTRALIA

Dan Jones

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Re: Changing a Varigear on a Monotype caster
« Reply #2 on: March 13, 2017, 01:42:54 AM »
I too have been having fun with my Varigears, I recently changed both from the three-phase original power to single-phase. Both my comp caster and the Super Caster use the comp-caster version of the Varigear, it just worked out that way. From the picture, it shows the single phase motor attaching to the Varigear without visible fasteners. The motor was taken apart and the front face of it was bolted to the Varigear flange from the inside, then the motor was re-assembled. It is what the industry calls a "C" face motor. All went well.