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Workshop Manual for ORBACH Owners
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See below a complete manual for the 3 Orbach models: SM1500, SM2200 and SM3000. The GM series uses exactly the same parts but the positioning of the mower behind the tractor is different. These mowers were manufactured in South Africa specifically for local conditions and high performance with low wastage and minimum maintenance. 

Feedback in order to improve Orbach machines are much appreciated.

Owners of Orbach machines can get all the information regarding their mowers in the section below. It is a complete manual for the models from 2006-2013, ORBACH SM1500, SM2200, SM3000.

 

 

CONNECTING THE ORBACH MACHINE TO THE TRACTOR

OPERATING THE ORBACH MACHINE

ROUTINE INSPECTIONS

ADJUSTING THE MARGIN ON THE LOWER ROLLER BEARINGS

HOW TO REMOVE THE MAIN SHAFT

PARTS

 

CONNECTING THE ORBACH MACHINE TO THE TRACTOR:

The ORBACH SM1500 requires approximately 35 KW, the SM2200 55 KW, and the SM3000 about 65 KW to fully utilise the machine's potential. It also depends on the crop being cut.

SM1500 and SM2200

  1. Connect the three arms to the three-point connection of the tractor so that the main frame of the machine is 100% horizontal and does not lean forward or backwards.

  2. Connect the PTO of the tractor's outlet to the gearbox of the machine and make sure that the shaft is not too long in which case a piece of each tube needs to be cut for the PTO to be the correct length.

  3. When the machine is lifted by the tractor's three-point connection, the machine must be balanced - a little bit lower on the right side but almost horizontal.

SM3000

  1. Move the draw bar of the tractor to the right until it can't move any further. Now connect the draw bar of the machine to that of the tractor.

  2. Connect the PTO and make sure that the PTO is not too long when turning sharp left or right. If necessary, cut a small piece of inside and outside tube, otherwise the PTO will put pressure on the shaft which will bend the frame.

  3. Connect the hydraulic pipes to the tractor's external connections. Hydraulically lift the machine a bit, move the machine to cutting position with the hydraulic cylinder and drive straight ahead. Adjust the tie beam so that the machine runs to the right of the tractor with the inside cutting disc about 200mm to the right of the tractor's wheel. Lower the machine completely and adjust the bolt by the joint so that the machine runs horizontally (not forwards or backwards). It is easier to put the weight of the machine on a stone or rock by putting the rock underneath the disc and then lowering it to make the adjustments. Otherwise it is too difficult to turn the bolt because of the machine's weight. Lock the adjustment bolt when the machine runs correctly.

  4. Now adjust the outside wheel suspension of the machine until almost all of the weight is on the wheel. The disc must touch the ground. There is a big nut by the shackle bolt and also an adjustment on the shore beam of the wheel.

  5. Now do the same with the inside wheel.

  6. If the machine is connected correctly, it will run beside the tractor without gliding inwards with most of the weight on the wheel. All the discs must touch the ground to control the cutting height. If the discs don't touch the ground they will vibrate because they're not balanced and the machine will cut unevenly.

 

OPERATING THE ORBACH MACHINE:

In order to transport both the SM1500 and SM2200 models on the road, the cutting part of the machine can be folded in behind the tractor. At the front of the machine close to the hinge hook is a bolt that determines the position of the machine. Remove this bolt and adjust the cutting shore beam to the required position. Put the bolt back into the corresponding hole.

The belts can be arranged so that the barrels all turn anti-clockwise or one can turn clockwise and the next one anti-clockwise. With all of them turning anti-clockwise, the biggest benefit is that the cut grass is more evenly spread out to dry and the machine is practically rock proof because rocks can't be drawn up in between the barrels. On the other hand, the benefit of one barrel turning clockwise and one anti-clockwise is that the machine can cut dense grass and high volumes because the barrels work together to pull the grass through so that it doesn't block up in front of the barrels.

A Cutting pattern with a minimum lift and lower action also requires a minimum stop and start activity, and is the best pattern for the tractor and the mower. We recommend cutting round corners in the field and also starting on the outside and moving inwards. This ensures minimum wear and tear on the tractor and the mower. The ORBACH machine is designed to carry its own weight, with the gliding drums/discs and the prop wheel underneath the gearbox. Therefore, make sure that the tractor's three-point arms are not carrying the machine's weight when cutting. Otherwise, the cutting height will be uneven.

Start the tractor and let it idle while connecting the PTO. The ORBACH machine's cutting discs need extra power to start moving because of the bigger cutting discs' momentum. Slow idling of the tractor can let the engine die. Engine revs too high, can damage the PTO draw bar.

The tractor's engine revs will depend on the crop being cut. It is not necessary to keep the revs at their maximum. It is however important to keep the rate of revolution high enough for the blades to cut nice and clean. The higher the revs, the higher the blades' speed and the better they cut.

Sharp blades also make a big difference to the neatness of the cut. With a PTO speed of 540 revs per minute, the blades will turn at 85m/sec. THE MACHINE IS DESIGNED FOR 540 RPM FROM THE TRACTOR. ANY SPEED HIGHER THAN THIS FALLS OUTSIDE THE MACHINE'S GUARANTEE. SPEED HIGHER THAN 540 RPM IS ALSO DANGEROUS. The gear in which the tractor moves forward depends on the crop being cut. The more dense the crop, the slower the tractor will move. Fifth or sixth gear is good to start off with. If a higher cutting height is required, the top arm of the three-point connection can be adjusted to make it longer. If a lower cutting height is required, the machine can be adjusted to lean a bit forwards by making the top arm of the three-point connection shorter. The cutting height is +- 50mm if the machine runs horizontally.

 

ROUTINE INSPECTIONS:

  1. Add 4 squeezes of grease after every 20 Ha. of grass cut. Make sure that the grease holes aren't blocked up. Each bearing on the machine has its own grease point. Thus, on each shaft there are 2 main bearings in the beam (Fig 3) and 2 bearing in between the discs with their own grease points (Fig 1). An extension pipe is supplied in the tool box of the machine in order to make the grease pump's pipe longer to reach in between the discs. The draw bar has two grease points. Use grease as supplied in the back of the manual.

  2. Make sure the belts are always tight. Loose belts can slip and the belts can damage. The gearbox has a adjusting bolt to tighten the belts. The other belts are kept tight by a tensioners. New belts tend to expand, so check the tension after cutting for a day.

  3. If the machine vibrates, don't use it. The vibration causes a lot of damage. Look for the cause of the vibration straightaway and fix it as soon as possible. The most common cause of vibration is when one of the blades fell off. Replace immediately.

  4. Check the margin on the lower dish. If the margin on the outside is more than 4mm, adjust it. This procedure is discussed on page 3.

  5. The blades are inserted and removes with at special tool supplied. Turn the blades around when they get blunt. The blade sheets are fastened with a soft and a hard bolt so that the soft bolt gives way when a rock hits the blade directly. In this way both bolts doesn't break off and the blade is still in place. Replace the bolts correctly. ( Fig 2 ). When the pins of the blade sheets wear away, they can be made stronger with hard facing welding rods. Don't weld on the sheets - spring steel!

  6. The top dish that turns with the shaft is fastened with a 52mm nut. Ensure that this disc is always tightly fastened. Never cut with a loose cutting disc.

  7. The gear box has to oil plugs or a rod for the oil levels. (SAE 90 oil)

 

ADJUSTING THE MARGIN ON THE LOWER ROLLER BEARINGS

(See special tools at the bottom of the page)

See fig. 1 and 4.

If the margin on the lower dish is more than 4mm on the outside, it must be adjusted as follows: remove the lower dish by loosening the 5 bolts. An extended 19mm spanner works well because the nuts are a bit difficult to reach. Now lift the plug at the bottom of the flange. Remove the split pin and take out the nut completely. Put a pipe over the inside ring of the bearing and hit with a hammer until 95% of the play is gone. The 30306 bearing fits tightly on the shaft and can't be pulled in by the nut. Now turn the nut by hand tightly against the bearing. Turn the nut back to line up with the first hole and put the split pin back. Never turn these two bearing tightly together. The shaft turns very fast, and can cause the bearing to get stuck. It is safer to leave a bit of a margin on the lower dish. Put back the plug and the lower disc. Tighten the 5 nuts. Nylock nuts will ensure that the lower discs don't loosen.

 

HOW TO REMOVE THE MAIN SHAFT:

(See special tools at the bottom of the page) 

See fig. 3 and 5.

Follow the steps below to remove the main shaft from the frame:

  1. Remove the canvas with its frame and the 4 bolts connecting it to the main frame.

  2. Remove the V-belt pulley and the oil seal lid at the top of the shaft.

  3. Remove the sir clip on the shaft just above the21309 bearing (Item 30).

  4. The shaft can now be pressed out with the help of a jack. Put the jack on top of the shaft and put a beam on top of the jack. Support the 2 ends of the beam with 2 chains on opposite ends of the jack onto the main frame. Use the jack to press the shaft down and out. If you don't have a jack, you can use a hammer. Put a tyre tube or soft material between the hammer and the shaft. A jack is recommended in order to protect the bearing.

  5. The steps in reverse can now be followed to put the shaft back in place. The jack is now placed underneath the lower disc. Use the correct bearings and seals when you replace them. Make sure all the grease nipples are open! A blocked nipple can cause as lot of damage! Consult the specifications at the end of this manual.

  6. At the bottom of the beam first attach the bearings, then the seals, then the steel rings to protect the seals, and then the sir clip. (Fig. 3). Be very careful not to damage the 22211 and 21309 bearing when inserting them - they are very sensitive to any kind of damage. Move the shaft centred through the bearings without damaging them.

  7. It is important to treat the axles with the bearing in the same way as a motor engine. The bearing move at very high speed – everything must be perfect, otherwise problems will occur.

 

PARTS

Table refers to pictures below:

Picture Item No

Description

Part Order No

Comments

     

 # 1

Plough share bolt

M12 x 30 C/sunk Sq.

Bolt below disc on casing

# 2

Lower disc

OR 0002

 

 # 3

Grease cap below

Lower seal plug

Seal lower bearings

# 4

 O Ring

 'O' Ring 68 x 3mm

Rubber O ring for lid

# 5

Split-pin

4 x 40mm Split pin

Locks castle nut

# 6

M30  (Castle nut)

Castle nut M30 x 1.5

Screw on shaft

# 7

Bearing

30306

 

# 8

Grease point

M6 Grease nipple

 

# 9

Bearing casing between discs.

Lower bearing casing

House the lower bearings

# 10

Bearing

32008

 

# 11

Dust seal

487012 or 446510

 

# 12

Main shaft

OR 0004

 

# 13

Plaatjies (M52 nut)

M52 sluitplaatjies

Locks M52 nut

 # 14

M52 x 3 nut

OR M52

Connects cutting disc to main shaft

# 15

Waster for M52 nut

OR 0092

 

# 16

Bout plaatjie vir lemplaat.

Blade sheet spacer

 

# 17

Cutting blade

18mmØ x 107mm

Use only anti-clockwise blades

#18A

Lemplaat klinkpen

 

Pin for blade on sheet

# 18

Blade sheet

Blade sheet

Spring steel blade

# 19

Cutting disc

OR 0001

Balanced in workshop

# 20

Bolt soft steel

M12 x 40 

Breakage bolt for blade

# 21

Cap screw

M12 x 40 Cap

Hard bolt

# 22

Flat iron

160 x 40 x 8 plat

Flat iron

# 23

 Sir clip

100mm Int.

Locks seal, bearing and ring

# 24

Ringplaat

Ringplaat

Steel ring to protect seal

# 25

Seal

7010010

Main seal for lower bearings

# 26

Spherical bearing

22211 E C3

Main bearing frame (below)

# 27

Main frame

   

# 28

Grease point

M 6 Grease nipple

 

# 29

Spherical bearing

21309 E C3  

Main bearing frame top

# 29

Spherical bearing

22211 E C3 (before 2004)

Main bearing frame top

# 30

Sir clip

45mm Ext.

Locks shaft top

# 31

Seals

456808 or 556808 (old)

2 Seals in top plug.

# 32

O Ring

O Ring 95 x 3mm

To seal top plugs

# 33

Lid

Locks lid (top)

2 top seals

# 34

Bearing casing in main beam

 

House main bearings and seals

Pictures:

 

Specifications for Items Not in the Pictures:

Grease

High temp. (120 ºC). Shell Retinax LX or equivalent. Use grease with a Lithium base.

Jockey wheel bearings

6205   2RS. (SM1500 and SM2200)

Wheel turntable bearing

6307   2RS

V-band jockey pulley bearing

6304   2RS

Cutting blades

ORBACH CUTTING BLADES 111 x 45mm or KUHNE 55903213 or any cutting blade with a  18mm hole and 110 max. mm length. Fig. 2 item 17.

Belts

  • SM1500 and SM2200:  Gearbox to shaft no 1 = SPB16N3550

  • SM2200: Shaft 1 to shaft 3 = SPB16N3800.

  • SM1500 and SM2200: Between axles = SPB16N2150.

  • SM3000: SPB16N1590, SPB16N3170, SPB16N2150.

 

Special Tools:

 

With a 12mm sheet, 3 long 12mm bolts and a hydraulic jack, the lower bearing casing can easily be removed.

A simple piece of equipment that will help to remove the cutting unit from the main frame. The photo shows how, with the help of a beam, hydraulic jack and a chain, you can remove the shaft. The tolerance on the shaft and the bearings is critically important for maximum performance. Therefore, this method is strongly recommended. All the bearings and seals come standard and are available for your local bearing agents. The main bearings are designed for 5000 working hours before they need to be replaced.

After the old bearing have been replaced with new one, the same method can be used to put back the cutting unit in place. Use a 175mm thick wall pipe with 95mmØ diameter to keep the jack and the top bearing in place when putting the cutting unit back.