- The equipment
- Base and pivot
- The cutting support
- Control panel and suction
- Practical advice
- Realize the frame of the structure
- Assemble, flip and weld the frame
- Fit the table
- Join the table to the back support
- Finish the different parts
- Constituting the cradle of the engine and its bearing
- Install the saw block
- Attach control panel elements and cables
- Fix the extractor and its tube
- Secure pulleys and bolts
- Set the end stops and do a preliminary test
Directed by Guillaume Tempesta, this machine has nothing to envy to those of professionals in the wood cutting. It accepts panels up to two meters wide and allows for miter cuts. It has the added feature of being usable horizontally, and removable to facilitate its storage.
Level : initiate
Production : 3 to 4 weekends
Cost : about 700 €
Mini equipment : arc welding machine, grinder, locksmith tools
See the plan of this realization (in pdf): saw with panels: the plan
The machine has a base mounted on wheels and a swivel table. It can tilt horizontally, resting on a folding foot. The table has a cutting support, sliding vertically, where the panels rest. It is also surmounted by a 90 to 135° swivel guide, which allows the circular saw carriage to move all the way.
The central frame of the table measures 260 cm high and 84 cm wide. Two removable extensions, placed laterally, bring the width of the assembly to 258 cm, knowing that the cutting support reaches 280 cm. In running order, the overall dimensions are about 300 cm high and wide, for 150 cm deep. However, once the extensions and the cutting support disassembled, then the guide folded to the table, the footprint is only 1 m2. Guide, table and pedestal may also be disconnected for extended storage or transport.
The saw blade of Ø 240 mm offers a maximum cutting depth of 70 mm in the wood. Driven by two twin belts and pulleys, it is driven by a 1 HP engine powered by 380 V and running at 2800 rpm. Engine and blade are mounted on an articulated support, integral with the sliding carriage. The latter is suspended by a steel cable (Ø 6) to a counterweight of sixty kilos. It also serves to maintain the tension of the power cable and the suction hose, both of which accompany the movement of the carriage.
■ With an inside diameter of 80 mm (88 outside), this hose has at its free end a kind of funnel fixed just behind the blade housing. At the other end, the hose joins an extractor (centrifugal) equipped with a canvas bag that collects sawdust.
■ Saw and extractor obey the same commands (on-off switch and emergency stop button type "punch"), grouped on a small table provided to the right hand of the user, about 60 cm from the ground. The power is supplied via a 30 mA high-sensitivity differential circuit breaker, which is also shown in the table.
Base and pivot
The base consists of two longitudinal members and two welded cross members. After assembly, the front cross member is cut in the middle and welded on both sides of a flat iron piece curved in a semicircle (Ø 100 mm). It provides sufficient clearance to the lower hinge bearing (Ø 80) of the saw guide, when the table is straightened. Inclined then about 110°, it is held in position by bolting on two stops (flat iron or angle) welded to the front of the base.
■ The longitudinal members of the frame receive at mid-length the uprights of the base: two tubes (Ø 60) welded in the lower part on a square plate, itself welded on two angles. The tube-platinum assembly is further reinforced by four welded gussets all around. At the rear, the uprights are joined by a double bracket and a crossbar, which partially support the weight of the table in a horizontal position.
■ In the upper part, the uprights are capped with two bearings allowing the table to rotate. Cut in 60/70 tube, they are welded at 90° on two segments of the same section. These, split lengthwise and completed with a threaded locking device, serve as flanges for securing the bearings to the uprights.
■ Bearings accommodate the ends of a Ø 60 mm tube, reduced to Ø 58 by 130 mm. It is this tube that serves as pivot to the table. Its central part is surmounted by a flat welded UPN of 60 x 30 mm, and it is capped with three rectangular spacers (in flat iron of 16). These parts are used to weld over the table support, made of an IPE of 140 x 75 mm lying flat. The table is itself welded.
Highly stressed - since it supports the saw and its guiding system - the central frame of the table consists of two longitudinal members and two U-shaped cross members of 60 x 30 mm. The sleepers are joined by a longitudinal IPE of 120 x 55 mm, connected laterally to the longitudinal members by two series of 15/21 and 20/27 tubes.
■ The U-shaped iron segments forming the sleepers and their reinforcements are welded face to face. at mid-length and below are also welded two bearings Ø 80 x 40mm, drilled in the center of a hole Ø 24. They allow the saw guide to rotate to perform miter cuts.
■ On both sides of the frame are four brackets, bolted or welded, for mounting extensions. Made in bent and welded tube 20/27, these assemble by means of beta pins. Behind the top rail of the table are welded screeds for mounting the folding foot.
This element supporting the carriage of the saw, is made with two spars of 25 x 50 mm, welded on crosspieces of 30 x 30. To reinforce the rigidity of the side members, U-shaped stiffeners of 50 x 25 mm, drilled (Ø 6 ) every 100 mm, are bolted on top.
■ In two parts welded at 45°, the end crosspieces of the guide receive screw stops, responsible for stopping the carriage at the end of the stroke. This set is articulated in the lower part and at each end, thanks to a welded bearing of the same dimensions as those equipping the table.
Its cradle receives the engine and, laterally, a pivoting blade support to raise the whole. The pivot of the support engages in the center of the plate of the trolley, rectangular and in flat iron of 8 mm. Equipped with its four rollers (turned in aluminum and each equipped with two bearings "6208"), it is connected to the cable of the counterweight and slides between the longitudinal members of the guide.
■ To tension and loosen the belts driving the blade, the motor cradle (flat iron of 10 or UPN of 50 x 25 welded) is articulated by means of a rotated bearing, Ø 35 x 95 mm, welded to the back. This pivots between two other side bearings, Ø 45 x 23, welded at the top of the blade support. The cradle can thus move away from or slightly closer to it, causing tension or relaxation of the belts.
■ Made in a curved 20 x 20 bar, the blade support is equipped with a tapped center pin. This part engages in two bearings ("6206") nested at the ends of a bearing Ø 80 x 100 mm, bored at 50/62 and welded in the center of the plate of the carriage. The blade is secured to an axis, also ground by turns and guided by two pairs of bearings ("6205"). Which are inserted at the ends of a bearing Ø 64 x 122.5 mm, similarly bored but at 45/52 and welded along its length at the bottom of the blade holder.
■ The fourth side of the support is made up of a bent and bolted flat iron, allowing to attach the protective cover of the pulleys and belts, located opposite the blade, on the other side of the carriage. This one is completed with several handles: three used to raise and lower the saw, another (long enough) to stretch the belts. Finally, the depth of cut is adjusted using a long threaded rod, completed by a rotating handle (and a locknut). Do not forget: the cable duct (15/21 curved tube), provided at each end with a turned nylon cable gland.
■ The counterweight of the carriage is fixed between two rods welded at the end of a flat iron support of 30 x 10 mm, bent. It is through the latter that the counterweight is suspended from the steel cable of the truck. The motor supply cable and the suction hose are directly attached to the counterweight by two M12 round bolts, screwed into threaded holes.
The cutting support
It consists of an angle 70 x 70 mm, bolted across the table on a flat tapped M10 / 150 iron. On the upper flange of the angle are clamped three sections, 80 x 40 mm, supporting the panels to cut. At the front, a screw stop complete the set. It is used to stop the truck when the cutting support is not placed at the bottom of the table. The latter having another stop which then replaces that of the support.
Control panel and suction
Measuring approximately 30 cm of sides, the table is a 15/21 tube frame, also bent and welded, which surrounds an insulating panel allowing to screw switches and circuit breaker. The whole is fixed at the top of a tubular foot of 26/34, formed in L and bolted against the right crossbar of the base, via a fixing plate in angle of 50 x 50 x 120. The support ensures at the same time the passage of cables. It is completed at the back of another flat iron support, vertical, which keeps winding the long power cable when the machine is at rest.
■ The extractor is placed transversely at the back of the base, on two flat iron ties of 30 x 10 mm bolted between its longitudinal members. Thanks to a 90° PVC elbow, the machine draws sawdust from the center of its rear face and rejects it laterally. Its exit opens into a canvas bag, with a Ø 80 PVC tube clamped to the back of the left pillar.
■ On the saw side, the suction hose ends with a rectangular funnel. Its sliding mounting bracket allows positioning according to the depth of cut. Fixed on the counterweight cable by two Rilsan collars, it slides on a large pulley placed at the top of the table. Same for the steel cable and the motor power cable, but with narrower pulleys.
Very neat, this realization has rotating assemblies which are all mounted on ball bearings; a guarantee of precision and longevity. A number of these bearings are mounted in bearings, mostly machined in sections of steel bars. Other bearings equip the rollers of the saw carriage. This machine also has a half-dozen pulleys to guide the cables (supply and attachment) and the suction hose, not to mention the rings, cone and spacers that allow to secure the blade...
■ The manufacture or boring of these cylindrical parts therefore involves mastering metal turning and having the right equipment. Also foresee the material usually required for metalworking: arc welding station, grinder Ø 230 and 115 (+ metal cutting discs), metal lathe, locksmith tools (including taps M10 x 150, M12 x 175, M14 x 200, die M20 x 250...).
■ To keep the budget within reasonable limits, it is preferable to go to the recuperators to acquire the motor and the extractor. They will probably also be able to provide the profiles (UPN and UAP in particular) in sections comparable to those recommended here.
Realize the frame of the structure
1. Drill the pedestal rails, weld the cross members and bolt the casters.
At the bottom of the tubular uprights, assemble in the same way the plates and their reinforcements, then all at mid-length of the side members.
Assemble, flip and weld the frame
2. Assemble the frame of the table frame, add the central UPN followed by the bars on either side. Turn everything over to weld, in the middle of the sleepers, the bearings intended for the guide of the saw.
Fit the table
3. To mount the table, tighten the flanged bearings to the top of the studs. Thread the pivot pin and weld over the two brackets, separated by the three spacers. Position the table upright (its inclination is then 110° approx.) To weld it to its support.
Join the table to the back support
4. Wedge the table horizontally and weld along the uprights, the brackets and the crossbar forming its rear support. Assemble the saw guide and bolt its bearings to those on the table.
Finish the different parts
5. Check that all parts are swiveling easily. After disassembly and degreasing, remove those that require it (sandblasting or other). Finally protect the threads and paint the whole (with the pistol for example).
Constituting the cradle of the engine and its bearing
6. Once the engine cradle has been built, weld the bearing laterally to rotate and tension the belts. Prepare bearings, axle and blade pivot, rollers, pulleys, etc.
Install the saw block
7. The carriage rollers bolted between the guide rails, the saw block is installed. In order: blade holder, cradle, motor, blade, belts, tensioner, guard and handles. The counterweight is then suspended.
Attach control panel elements and cables
8. The foot of the control panel must first be fastened to the side, before installing the panel, the switches and the circuit breaker. The cables are then passed to the motor and the extractor.
Fix the extractor and its tube
9. The extractor is fixed on its sleepers, between the longitudinal members of the base. It is provided with a PVC elbow, on which is connected the hose, itself attached to the cable of the counterweight. The tube ending in the cloth bag is engaged at the top exit.
Secure pulleys and bolts
10. The pulleys on the power cable and the hose are fixed with bolts. The latter leads to the funnel, fixed on its adjustable leg. The electric cable is connected to the motor.
Set the end stops and do a preliminary test
11. The end stops of the carriage are precisely adjusted before performing a first test of the machine. Same thing with the device to adjust the depth of cut.