Completed model with log fed trolley
Foam block on trolley ready to be fed through saw blade
Close up of belt drive for saw blade and saw raising mechanism
Model during construction
This is an historic model from a Super Model Leaflet dating from 1928 - 1936. One of the original illustrations is shown on the right. I have always liked these old models and first built this model many years ago when my interest in Meccano was re-kindled. The model at that time of its introduction would have been in dark red and green I built mine in the early nineteen seventies colours of zinc and mid-blue. This type of saw would have been used for cutting planks from logs and would have been used through the nineteenth century until as late as the mid nineteen fifties. The cutting was achieved using a reciprocating movement much as a hand saw each plank would have been cut by rising and lowering the saw unit, this can also be done with Meccano model. The log would be fitted to a feed carriage and pulled against the saw blade; this also can be done with the Meccano model. This type of saw would have been driven by either water power or steam. I have no idea as to whether this saw based on an actual prototype but I have certainly seen a similar saw but with a vertical blade at Upper Canada Village in Ontario, Canada. See picture below. Working vertically seems a much better mechanical proposition than horizontal. Meccano did also publish plans for a Vertical Log Saw SML23.
The model its self very straightforward to build with fairly clear instructions and photographs. I made several constructional changes including additional bracing to the drive unit for the saw, cosmetic changes included the addition of braced girders to the saw frame bracing. I use a modern non-Meccano 12 volt geared motor to give more power to the saw operation. The model specified the use of chain drive to the saw and feed drive. I just do not like Meccano chain so I substituted heavy duty Meccano rubber driving bands, this gives a nice smooth drive to a Meccano flywheel although I used a chain drive to raise and lower the saw blade. The prototype would not have used chain drive anyway but canvas belt drives. I fitted a hacksaw blade instead of the rack strips this was suggested in the leaflet, in the hope it would cut through wood but ended up using an expanded polystyrene (Styrofoam) block The feed carriage is driven by and endless sprocket chain and has a clutch to engage or disengage the drive. Trouble here is the carriage moves too fast to allow the blade to cut. By adding a crank the carriage can be progressed at a slower speed and very slowly cuts into the block but made a lot of mess. I have also built the SML 34 Vertical Log Saw details can be found by clicking on the link. June 05 2015 revised August 22 2020 |