Four years ago, White River Sawmills installed their first Mohringer Deal frame saw. According to Robbie Watson of WRS, they were so impressed with its technology and performance that they recently decided to invest in another unit.
White River Sawmills replaced their old Esterer Log Frame with a brand new Möhringer E71 Framesaw. The machine was commissioned by Wood Industry Supply's engineer Johan van Reenen in January 2003 and has been operating in double shift ever since without problems.
The Mohringer E71 has a passage width and height of 710 mm, 550 mm stroke, automatic overhand, roller bearings on the steel flywheel and feed of up to 15 m per minute. The two mainframe uprights are cold formed out of 15 mm steel plates and the total machine weighs 15 tonns. Möhringer is the only framesaw manufacturer who guarantees their main frame for a period of 10 years.
The all-steel flywheel has many advantages over cast iron. Steel can tolerate high injection pressure and creates durable and secure connections, particularly in the press fit of the crankpin. Framesaws made of cast-iron have a looser press fit to prevent the cast iron wheel from cracking. With time, these crankpins can rust in the bore and become loose, causing the conrod to break, often resulting in a total loss of the machine. An added advantage of the Mohringer's all steel flywheel is that both main bearings can easily be changed on site in one day. Both wheels can be pulled off with the help of a hydraulic pump, which expands the bore of the wheel.
WIS pointed out some facts regarding steel versus cast iron:
There are a number of reasons why steel framesaws have an advantage over those made of cast iron. The tearing strength of steel is double that of cast iron during tensile stress. Castings can generally support only pressure forces, and cannot resist high and dynamically alternating cyclic stress.
Steel can resist more than twice as much stress during elastic deformation. Castings cannot survive this kind of deformation and tend to break.
Due to different wall thicknesses, residual stresses remain in iron castings after manufacture. These can cause fractures, whereas steel can be forged, welded and cold deformed without stresses remaining in the material.
Volker Bächle from Wood Industry Supplies, Möhringer's agent for Southern Africa recommends: "When replacing or investing in a framesaw, we trust that you will carefully consider above facts and reasons, as we believe they are decisive."
According to Watson, White River Sawmills are now looking seriously into purchasing a Möhringer Optimising Board edger. Once installed, this will make White River Sawmills the first complete all Möhringer wet mill in Africa.
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Tel (044) 533 3651
Cel 082 555 8506
Fax (086) 600 3724
Email wis@iafrica.com
