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13 records – page 1 of 2.

Development and mill trials of an active guide system for bandsaws (final report)

https://library.fpinnovations.ca/en/permalink/fpipub37418
Author
Taylor, J.
White, J.
Date
October 1996
Material Type
Research report
Field
Wood Manufacturing & Digitalization
and unscheduled blade changes and compensate for damaged or poorly prepared blades. TABLE OF CONTENTS Page
Author
Taylor, J.
White, J.
Date
October 1996
Material Type
Research report
Physical Description
19 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Stresses
Band saws
Saw bands
Saws
Bands
Blades
Sawing
Series Number
W-1330
Location
Vancouver, British Columbia
Language
English
Abstract
Research into the cutting characteristics of bandsaws has shown that the average cutting path of the sawblade is biased to one side of the ideal cut path. It has also been shown that a strong correlation exists between this cutting bias and sawblade deviation. This report is the second on the topic of bandsaw cutting bias and describes the development and mill trials of a PC based, self aligning bandsaw guide system. This system uses data from the sawblade, and programmable logic controllers controlling the bandmill, to monitor bandsaw cutting behaviour and align the guides to minimize the cutting bias and sawblade deviation. The system is shown to effectively reduce sawblade deviation and unscheduled blade changes and compensate for damaged or poorly prepared blades.
Saws - Band
Sawing - Blades
Cutting - Stresses
Documents
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Dynamic behaviour of saws and sawing systems : cutting characteristics of bandsaws

https://library.fpinnovations.ca/en/permalink/fpipub37194
Author
Taylor, J.
Hutton, S.G.
Date
March 1987
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Taylor, J.
Hutton, S.G.
Date
March 1987
Material Type
Research report
Physical Description
35 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Stresses
Band saws
Saw bands
Saws
Bands
Blades
Sawing
Series Number
CFS No. 42;02-12-15-022
W-491
Location
Vancouver, British Columbia
Language
English
Abstract
Saws - Band
Sawing - Blades
Cutting - Stresses
Documents
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Effect of bandsaw stresses on blade stiffness and cutting accuracy (thesis format)

https://library.fpinnovations.ca/en/permalink/fpipub37321
Author
Taylor, J.
Date
March 1993
Material Type
Research report
Field
Wood Manufacturing & Digitalization
r a i n Gauge Lo c a t i o n s and R o l l i n g P r o f i l e f o r Centre Tensioned Blades. 121
Author
Taylor, J.
Date
March 1993
Material Type
Research report
Physical Description
151p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Band saws
Saw bands
Saws
Bands
Blades
Sawing
Series Number
Forestry Canada No. 52A
Contract no. 1212K032
W-1046
Location
Vancouver, British Columbia
Language
English
Abstract
The effect of bandsaw roll-tensioning and bandmill axial forces on the stresses in the blade, on the interaction of the blade with the bandmill and on the stiffness and cutting accuracy of the sawblade are examined. The stresses due to roll-tensioning are measured and their effect on frequency and stiffness determined. The effect of the blade-wheel geometry on the stresses in the cutting region are analyzed showing how the stresses, frequency and stiffness of the sawblade relate to its cutting accuracy. Empirical relationships are developed that enable the stresses due to roll-tensioning to be estimated. Analytical methods accurately predict the effect of roll-tensioning on blade torsional frequency and lateral stiffness. A model was developed that successfully predicts the effect of overhang on the stress in cutting region of the blade. Both analytical and experimental results confirm that rolling in the centre 60% of the sawblade will increase blade stiffness while rolling outside this region will reduce it. Cutting accuracy is shown to be strongly related to lateral tooth stiffness, and it is also shown that optimum increases in stiffness and improved cutting accuracy are obtained by confining the roll-tensioning to be close to the blade centre-line.
Saws - Band
Sawing - Blades
Documents
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The effect of different amounts of roll-tensioning on the cutting accuracy of bandsaws

https://library.fpinnovations.ca/en/permalink/fpipub5536
Author
Taylor, J.
White, J.
Bouchard, A.
Date
September 1997
Edition
37463
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Cutting Tests 2 3.2 Blade Preparation 3 4 Results 4 4.1 Centre Tensioned Blades on the Five-foot
Author
Taylor, J.
White, J.
Bouchard, A.
Date
September 1997
Edition
37463
Material Type
Research report
Physical Description
11 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Band saws
Saw bands
Saws
Bands
Blades
Sawing
Series Number
W-1468
Location
Vancouver, British Columbia
Language
English
Abstract
Across North America the amount of tensioning used in bandsaws varies drastically. Sawblades tensioned to fit circle gauges from 28 feet to 80 feet in diameter are in regular use and performing very well. This raises the questions as to what is the right amount of tension and what effect does it have on cutting accuracy. In this study, the cutting accuracy of five sawblades, with varying levels of tension, have been measured and compared. The results show that little change occurs in cutting accuracy once enough tension has been put into the blade for it to fit an 80-ft circle gauge.
Saws - Band
Saws - Maintenance
Sawing - Blades
Documents
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Effect of multiple guides on the idling and cutting response of circular saws at high blade speeds

https://library.fpinnovations.ca/en/permalink/fpipub37742
Author
Hutton, S.G.
White, J.
Taylor, J.
Date
March 2005
Material Type
Research report
Field
Wood Manufacturing & Digitalization
of such blades. Tests were carried out with four different guide configurations: a front guide; a front guide
Author
Hutton, S.G.
White, J.
Taylor, J.
Date
March 2005
Material Type
Research report
Physical Description
27 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Blades
Sawing
Quality control
Qualitative analysis
Series Number
3602
W-2182
Location
Vancouver, British Columbia
Language
English
Abstract
When large saws are operated at high speeds cutting accuracy deteriorates and very high levels of oscillation occur after the blade exits the cut. These high oscillation levels may adversely affect the next cut. This report describes laboratory tests that were conducted to determine if the addition of extra guides would improve the response of such blades. Tests were carried out with four different guide configurations: a front guide; a front guide plus a pin guide; a front guide plus a pin guide plus a back guide; and a front guide plus a back guide. The results indicate that the addition of the extra guides has a marked effect upon blade response. In particular, the addition of a back guide results in a significant change in wedging of the cut boards. The results presented indicate that extra guides could be useful in reducing cutting deviation. Further work is required to determine the appropriate location of such guides and whether the addition of such guides can be accommodated in a mill situation.
Sawing - Blades
Sawing - Quality control
Documents
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Effets de la vitesse de coupe, de la bouchée et du nombre de couteaux sur la qualité de surface des sciages et des copeaux dans les équarrisseuses-déchiqueteuses munies de couteaux pliés ou de couteaux jetables (phase III)

https://library.fpinnovations.ca/en/permalink/fpipub42390
Author
Laganière, B.
Date
March 2006
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Laganière, B.
Contributor
Ressources naturelles Canada - Service canadien des forêts
Date
March 2006
Material Type
Research report
Physical Description
31 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Blades
Sawing
Chippers
Series Number
E-4259
Location
Sainte-Foy, Québec
Language
French
Abstract
Le but de cette étude était de déterminer les effets de la bouchée des couteaux, de la vitesse de coupe et du nombre de couteaux sur la qualité de surface des sciages et la qualité des copeaux lors de la transformation de billes d’épinette noire [Picea mariana (Mill.) B.S.P.] à l’aide d’équarrisseuses-déchiqueteuses munies de couteaux pliés (conventionnels, ordinaires ou courbes) ou de couteaux jetables. La qualité des sciages était fonction des pertes encourues à l’éboutage pour éliminer les grandes entailles de couteau et les fibres arrachées, qui réduisent le rendement de qualité. La qualité des copeaux était basée sur le pourcentage de particules fines (longueur et épaisseur) lors d’essais au tamis. Nous avons effectué 12 essais portant sur les variables suivantes : bouchée du couteau (22,2 et 28,6 mm), nombre de couteaux (3 et 6) et vitesse de coupe des couteaux (762,2, 1219,5, 1676,8 et 2131,1 m/min). Selon nos essais préliminaires, le pourcentage de fines augmentait avec la vitesse des couteaux, alors que la qualité de surface des sciages n’y était pas sensible. L’épaisseur et la longueur moyennes de copeau diminuaient à mesure que l’on augmentait la vitesse de coupe et la bouchée. Les essais avaient lieu sur des billes de 2,54 m de longueur et de 15 cm de diamètre, à une température de l’ordre de 15 à 25°C. La proportion de fines était plus faible avec les couteaux pliés, mais elle tendait à augmenter avec la vitesse de coupe. La proportion de fines n’était pas non plus sensible à la bouchée, mais elle l’était au nombre de couteaux, et elle augmentait avec la vitesse de coupe. L’épaisseur moyenne des copeaux diminuait à mesure que la vitesse de coupe augmentait; elle diminuait aussi quand on augmentait le nombre de couteaux. Pour un ensemble de paramètres donné, l’épaisseur moyenne des copeaux était plus élevée avec les couteaux pliés. Elle augmentait également quand on augmentait la bouchée du couteau, mais elle diminuait quand on augmentait le nombre de couteaux. Pour un nombre de couteaux donné, la longueur moyenne des copeaux était plus grande avec les couteaux pliés; c’était aussi le cas quand on augmentait la bouchée. Contrairement aux résultats obtenus pour la longueur moyenne, l’épaisseur moyenne mesurée des copeaux était toujours plus élevée au premier débit qu’au deuxième débit, les différences étant de l’ordre de moins de 1 mm. Il nous a donc paru raisonnable d’analyser les copeaux des deux débits en un seul lot sans affecter l’épaisseur moyenne mesurée des copeaux. La qualité de surface tendait à diminuer aux vitesses de coupe plus élevées; elle diminuait aussi quand on augmentait le nombre de couteaux, alors qu’elle augmentait avec la bouchée. Dans tous les cas, l’arrachement de fibres était moins fréquent avec les couteaux pliés qu’avec les couteaux jetables. La proportion de pièces atteignant la qualité « Premium » avec moins de 1/32 po d’arrachement de fibres se situait au-dessous de 30 % pour une épaisseur cible de 1,640 po, et de 10 à 40 % pour une épaisseur cible de 1,700 po. Dans le cas de Premium tolérant 1/16” d’arrachement de fibres, les proportions correspondantes de pièces acceptables étaient de 10 à 50 % (1,640 po) et de 20 à 60 % (1,700 po). Enfin, pour le Premium tolérant 1/8” d’arrachement, les proportions de pièces acceptables variaient de 50 à 80 % (1,640 po) et de 60 à 90 % (1,700 po). Dans tous les cas, l’angle d’attaque du couteau et du contre-couteau était plus faible au point d’entrée dans le bois qu’au point de sortie, et il était plus élevé pour les longs couteaux (couteau de tranchage) que pour les contre-couteaux. L’angle d’attaque des couteaux de finition était toujours plus grand au point d’entrée qu’au point de sortie. Il était plus faible pour les couteaux pliés que pour les couteaux jetables, l’inverse étant vrai dans le cas des contre-couteaux, et dans celui des couteaux pliés de finition. Les pertes financières se sont avérées plus importantes avec les couteaux pliés qu’avec les couteaux jetables. Une tête d’équarrissage munie de six couteaux jetables semblait présenter des pertes moindres à vitesse de coupe plus basse, et les pertes semblaient aussi plus faibles pour une bouchée de couteau de 22,2 mm que lorsqu’elle était de 28,6 mm. Note : Le calcul des pertes monétaires a été basé en assumant que la totalité des sciages avait le potentiel d’être classé Premium. En pratique, environ 30% des pièces peut se qualifier Premium car la flache naturelle, la carie, les nœuds et autres défauts causent des déclassements sans égard à la qualité de surface engendrée par l’écorçage et l’équarrissage. Les pertes dues à la classe (pertes en qualité) doivent donc être réduites à 30% de leur valeur si on veut tenir compte de l’ensemble des sciages produits à la scierie.
Sawing - Blades
Chippers
Documents
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Improving bandsaw performance : effect of side grinding swaged bandsaws on cutting accuracy and surface finish

https://library.fpinnovations.ca/en/permalink/fpipub5567
Author
Wang, A.
Taylor, J.
Szathmary, G.
Date
December 2001
Edition
37598
Material Type
Research report
Field
Wood Manufacturing & Digitalization
-in difference in side clearance caused a saw deflection of 0.002-in. Thinner circular blades were even more
Author
Wang, A.
Taylor, J.
Szathmary, G.
Date
December 2001
Edition
37598
Material Type
Research report
Physical Description
13 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Band saws
Saw bands
Saws
Bands
Blades
Sawing
Series Number
1996
W-1817
Location
Vancouver, British Columbia
Language
English
Abstract
The primary objective of the study is to measure the effect on cutting accuracy of side grinding swaged tooth bandsaws. The effect of side grinding on surface finish is included for comparison with previous work. Swaged tooth bandsaws tend to leave quite a rough sawn surface. Cutting with large bites or uneven teeth aggravates this problem. Previous studies have shown that side grinding could improve surface finish but it was not shown to have any effect on cutting accuracy. However, sawmills and saw manufacturers have indicated that side grinding can improve cutting accuracy. Therefore, this contradiction needs to be resolved in order to quantify any benefits from side grinding. The results indicate significant improvements in cutting accuracy and surface finish are possible. Side grinding 17-gauge and 16-gauge bandsaws respectively improved sawing accuracy up to 22% and 44%, reduced sawblade lateral displacement up to 36% and 68% and improved the sawn surface finish up to 24% and 11%. Extremely careful bandsaw fitting and tooth alignment was necessary in the preparation of side ground saws. This cost-time-effectiveness has to be considered when adding side grinding to swaged saw preparation.
Saws - Band
Saws - Maintenance
Sawing - Blades
Documents
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Off-centre cutting in bandsaws

https://library.fpinnovations.ca/en/permalink/fpipub37392
Author
Taylor, J.
White, J.
Date
December 1995
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Taylor, J.
White, J.
Date
December 1995
Material Type
Research report
Physical Description
17 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Stresses
Band saws
Saw bands
Saws
Bands
Blades
Sawing
Series Number
W-1260
Location
Vancouver, British Columbia
Language
English
Abstract
Research into the cutting characteristics of bandsaws has shown that, in nearly every case studied, the average cutting path of the saw is biased to one side of the ideal cut path. This paper presents the results of a laboratory investigation into this off-centre cutting. The influences on the shape and cutting behaviour of bandsaws of such basic factors as bandmill strain, guides, guide alignment, and blade overhang, are measured. It is concluded that bandsaw blades are curved in the cutting region and angled slightly out of the cut. The curvature and angle of the blade are due to the interaction of the bandsaw with the bandmill wheels, in the presence of bandmill strain, overhang and wheel crown, and are relatively insensitive to bandmill strain or pressure guides. The curvature and angle of the blade in the cutting region are most likely the cause of the cutting bias.
Saws - Band
Sawing - Blades
Cutting - Stresses
Documents
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Rendement des lames de scie utilisées pour le sciage courbe

https://library.fpinnovations.ca/en/permalink/fpipub42225
Author
Goudie, D.
Gingras, A.
Date
September 2002
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Goudie, D.
Gingras, A.
Date
September 2002
Material Type
Research report
Physical Description
19 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Blades
Sawing
Series Number
General Revenue 2681
Location
Sainte-Foy, Québec
Language
French
Abstract
Sawing - Blades
Curve sawing
Documents
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Results from a test of bevelled tooth bandsaw blades

https://library.fpinnovations.ca/en/permalink/fpipub5515
Author
Lister, P.F.
Sykes, D.
Date
October 1995
Edition
37390
Material Type
Research report
Field
Wood Manufacturing & Digitalization
O R T RESULTS FROM A TEST OF BEVELLED TOOTH BANDSAW BLADES by Peter F. Lister and David
Author
Lister, P.F.
Sykes, D.
Date
October 1995
Edition
37390
Material Type
Research report
Physical Description
8 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Saw tooth
Band saws
Saw bands
Saws
Bands
Blades
Sawing
Design
Series Number
W-1256
Location
Vancouver, British Columbia
Language
English
Abstract
This report describes the results of a mill test investigating the effect of a 15 degree alternate top bevel (ATB) tooth for bandsaws. The test involved comparing the sawing variation and surface roughness of Douglas-fir lumber cut by both ATB and standard saws. The test results showed no improvement in sawing accuracy with the ATB blades. In fact, as the blades became dull, the sawing accuracy of the ATB saws deteriorated faster than for the standard blades. Visual evaluation of surface roughness also indicated that the ATB saws produce slightly rougher lumber. However, this may be due to increased tooth bite associated with the ATB teeth. Further testing will be required to determine if the results of this test are truly representative of the performance of ATB bandsaws in general.
Saws - Band
Sawing - Blades
Saws - Tooth design
Documents
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13 records – page 1 of 2.