I saw his demo at an exhibition recently and while I was very impressed, I didn’t immediately see a use for me as my new layout will run on DCC, including point and signal control (via slow action point motors).
But one of my concerns with signal control was matching the throw of the point motor to the throw of the signal. Tortoise motors have a raw throw of nearly 20mm, where as my signals have a throw of about 7mm. The signals are robust enough – they are made of brass from MSE parts – but I didn’t want to rely on them to stall the motor by having the motor pushing directly on the signals and 13mm is a lot to be taken up by omega loops or the like.
So when I saw MODRATEC at the next exhibition, I realised that there was a solution.
So what I have done is place a sig-wit and a crank-wit between the motor and the signal. Because I have set things up with a vertical motion, the crank doesn’t change the direction of throw, it just increases the throw of the signal from 7mm to 14mm. And the clutch mechanism of the sig-wit takes up the remaining excess throw of the motor. I built a little combined motor, clutch and crank unit off-line and am about to mount it under my base board and connect it to the signal. Before I do, I have tested the operation of the unit by powering up the motor in each direction.
Harold has agreed to post a photo of the unit and I hope that will better explain what I have done.
The unit looks pretty rudimentary but so far, it seems to work fine.
I should note that the depth of the unit is governed by the depth of my (portable) baseboards below rail height. In an ideal situation, I would have increased the distance between motor and clutch and between clutch and crank. This would minimise the impact of the “swing” of the crank movement and the motor movement. It would also relieve some of the pressure to get everything lined up exactly square and get all wires at an equal distance away from the backboard of the unit (neither of which I have quite managed with my first attempt). The extra distance could probably be achieved by building a unit with horizontal movement and using the crank to change it to vertical movement. But I couldn’t do that because the area I am working in is particularly cramped with other equipment so I was limited to a vertical motion. Elsewhere on the layout where there is more room, I will try a horizontal system.
I hope this gets a few minds ticking!
