sawmill Operator Notes

Backing carriage

    Reduce water flow to half to reduce grinding when engaging reversing bevel gear to rag wheel 

Loading logs and preliminary cuts-to come

Using electric power winch

need photo 

Chains
Use heavy oak planks to bridge from edge of door to carriage.
Wrap chain around log and fasten to eye bolt in floor. Attach cable to chain end that passes over top of log allowing it to roll inward.

Safety considerations
Eye bolt should be installed through floor to anchor one end of cable from winch. Remove eye bold when after log has been loaded on carriage. If left in location it is a tripping hazard and may cause someone to stumble near the saw.

Do not stand in line with stretched cable when moving logs. Cable to winch may break and snap back on winch operator or those helping guide log.

Those guiding logs should not stand between moving logs and others on ramp. If log breaks loose, it could roll back on those guiding it up the ways with peaveys and cant hooks. 


Hew flats on both ends of log to stabilize it from rolling during first cut. Otherwise it may roll and may bind saw.

Hew flats when log is almost in position of carriage on a side where a partial roll will put flats down on carriage bed.

Use of winding sticks to check plane of cuts.

Operating saw-to come

Safety considerations--operators, public


First cuts

Booking

If boards are not sawn through to end and left attached to the log by 3" or so of uncut wood, the saw may be backed out of the log, the log moved over and new cut started. Doing this maintains the weight of the log during the cutting operation so that is has less of a tendency to lift up on the saw's recovery stroke. This is called booking as the attached boards resemble the pages of a book attached to its binding. When all cuts have been made in log, the boards can be split off and any ridges of wood left can be shaved off with a framing slick. 

How to remove live edges and wane

 If log was not squared with preliminary cuts, some of the boards may have a "live" edge, i.e. an edge that is wavy because it is actually the outer surface of the log. The edge can be cut off with modern tools. A hand held circular saw can be used to follow a chalk line struck of each board. If one edge of board is straight and one wavy, a table saw with a fence can be used to remove the wavy edge. A third alternative is to use the mill saw. To do so the boards with wavy edges are placed aside. When the next log is brought in for sawing, three of its sides are squared. After the third cut, the wavy boards are placed on top of the log and held in position with F-clamps: the wavy edge overhanging the last cut made on the log. Two or three boards may be stacked. Now the log can be advanced through the saw and the live edges cut off, producing wane or slash. This can be made available as firewood.


Trouble shooting  -    to come


At the start of each season after prolonged shut down

  • Lubricate all moving parts
  • Check blade alignment to friction tubes on fender posts
  • Run saw at slow speed and check for vibration

Friction robs power.  Friction can come from:
  • Misalignment when saw blade is not parallel to friction tubes which determine up and down axis; 
  • Misalignment of the saw so that its front to back axis is not parallel to direction of movement of the carriage; 
  • Build up of saw dust in kerf causing drag on side of blade; will occur when
  • Log is greater in diameter than travel of blade;
  • Gullets have gotten small from repeated "quick" sharpening that has reduced height of teeth and thereby depth of gullets; 
  • Quick sharpening happens when filer does not file entire tooth profile and only "touches up" the tips of the teeth; 
  • Set of teeth is insufficient to allow clearance for thickness of the blade plus compacted sawdust in the kerf. 
  • Rake angle has gone from being acute to now oblique after repeated "quick" sharpening. An oblique angle on the downstroke does not pull sawdust away from tips of teeth.
  • Sliding blocks have been adjusted so that they are too tight against friction tubes on fender posts; some slop if necessary. 
  • Drive shaft components have not been properly lubricated; 
  • Meshing of pinion gears between turbine shaft and main shaft is too tight; 
  • Power take off belt from main drive shaft to reversing gear is too tight or jammed and acts as a brake on main shaft. 
  • Sawdust has accumulated around the base of the flywheel, slowing it. 
  • Debris has entered the turbine and is impeding its rotary motion. 


Excessive vibration of carriage and saw frame

  • Too aggressive of an angle for saw blade in frame.
  • Improper filing of tooth pattern so rake angle is oblique rather than acute. 
  • Advance of carriage is too aggressive for hardness or thickness of log.
  • Loose sliding bearings on frame connecting to friction tubes on fender posts.
  • Log moves back on carriage during sawing
  • Log rises with saw or carriage deflects down during sawing
  • Angle that blade is set in frame is incorrect. Too much angle will create down pressure on log, causing carriage to bend. Too little angle, will cause teeth to catch on log on upstroke, causing it to bounce on carriage. 
  • Nails and imbedded foreign material
  • Check drive belt on reversing gear for misalignment





Anyone having information about the technical operation of up and down sawmills should send an e-mail to info@ledyardsawmill.org  so this page can be expanded


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