Many farmers run their own chopper balers, baling and wrapping second-cut or even first-cut silage themselves. For those baling their own silage, it gives them some control over silage production. It may also utilise existing tractors and machinery on the farm to make the farming enterprise more cost-effective.

To keep a baler going throughout the silage season, it pays to go through your baler and knock any issues on the head rather than in the middle of baling. Here, we take a look at one of the longest-serving machines to enter the Irish marketplace, the Welger RP220 and its newer sibling, the RP235. First though, carefully remove bolted side panels (mid-generation machines) to expose the workings of the machines. The RP235 has gull-wing hoods, which make it a bit easier to access the machine, but panels on the tailgate are still bolted.

Picture one

Driving the entire baler is a pto shaft with a wide-angle joint at the tractor end and an overload clutch at the baler end. The complete shaft is expensive to replace, so it is wise to treat it well and grease accordingly. Pay particular attention to the wide-angle joint, that all points are greased. Check the centre carrier of the wide-angle joint for wear as this will cause a vibration in the machine as the double joint will sag and cause the pto shaft to whip, possibly breaking the tractor’s or baler’s pto shaft. If the pto shaft needs to be shortened, cut the shaft tubing with a hacksaw, not an angle grinder as this will melt the Teflon coating on the tube and cause it to stick. Ensure that the pto guard is complete and functioning. Testing the overload clutch is a job for the dealer.

Picture two

The gearbox on all RP220s – from the late 1990s to the current series – is a power-split gearbox taking the drive to two sides of the machine, driving the chamber rollers from one side and the rotor and pickup from the other. Don’t forget to check the gear oil level and condition – nice clear oil indicates a healthy gearbox.

Picture three

All RP220, RP235 and RP245 balers drive the chamber rollers on the left side. A 20B chain from the gearbox transfers drive to the front and tailgate section 16B chains via a double sprocket front and rear. Drop all chains off, mapping their routes and spin all rollers, tension sprockets and jockey sprockets. Noise or roughness in any will require bearing replacements. With the tailgate open (and locked), check for play between rollers with a lever. Again, play might indicate bearing problems.

Refit the chains according to your ‘‘map’’. If you wipe your map off the side of the baler, the machine’s parts book indicates the chain’s route. There may be a combination of spring and rubber block tensioners. The spring versions have a position indicator to guide tightening, while the guide for the rubber block type is when they start to compress and swell.

Picture four

Early RP220 balers have a jockey sprocket between the baler’s first two rollers behind the pickup to stop the chain from jumping on the sprocket with a heavy, wet bale in the chamber. The tensioner often disappears altogether, leaving the chain to run on the bearing mounting shaft. The jockey sprocket was replaced by a plastic guide block which wears but doesn’t disappear and can be fitted to the earlier jockey sprocket versions.

Picture five

Apply the same logic to the pickup drive as the roller drive – drop all the chains off and spin everything looking for play or noise in bearings. If all is ok, refit chains and tension chains back up. A pawl-type overload clutch protects the pickup drive. It has a grease nipple but grease it sparingly as overgreasing it as can cause it to slip. Pay particular attention to the pickup centre bearings, checking for play and roughness. They are not dear to replace but cost a half-day to change during the busy silage season.

Picture six

One of the cheapest and easiest bearings to replace on the baler are the four cam lever bearings for controlling the tines in the pickup.

Bring each one around to the inspection hole behind the pickup reel drive sprocket and using a screwdriver (not your fingers), carefully check for wear or roughness. If they fail, they can damage the cam track and cam lever, both of which are very expensive to replace/repair. It’s a bit fiddly, but the cam lever bearings can be replaced easily through the inspection hole, particularly if the cam track oiler is working and they are well lubricated.

Picture seven

The oiler is driven off the roller above the mouth of the pickup and should only be filled with proper chain oil, which contains an anti-fling agent (not used engine oil). To check that the oiler is working, remove one of the clear pipes and trap an air bubble in it. Re-attach and run the baler, keeping all body parts and clothing clear of anything that moves. The air bubble will progress steadily along the pipe as each piston in the oiler is operated in sequence.

Oil will never be dripping off the chains, but if you grab any of the chain’s rollers (obviously with the baler off) they should be ‘‘sticky’’ when you move them from side to side. Make sure that all the chain oiler brushes are in contact with the chains.

Picture eight

The oiler drive is taken from the end of the roller via a flexible drive, braided fuel piping or similar; this one has reached the end of its working life.

Picture nine

The net unit’s net knife is reliable but after the winter break, there may be a buildup of rust on the knife edge and anvil that it strikes. Some emery tape or regular sandpaper will clean up both but be careful not to trip the net knife. It’s not sharp, but the springs powering it are strong and nasty for fingers.

Picture 10

Welger use a paired steel and rubber roller to grip the net and feed it into the bale chamber when netting the bale. If the rubber roller gets coated with pollen, certain types of dust or undetermined material, it cannot grip the net and feed it into the chamber properly. Washing the rubber roller with some soapy water cures that problem.

Picture 11

The net brake operates like the front disc brakes of a car. It stops the net roll spinning once the net has been fully applied to the bale and cut. There is adjustment on the brake mechanism to compensate for brake pad wear. This is probably best left alone if the net application is working ok. The knurled brass nut and steel bolt weld together if they haven’t been adjusted for a while.

Picture 12

Replace all broken pickup tines. Many use straight tines on the outsides to stop the reel from getting stuck in the grass on headland runs. This is where the land wheel may stand on the grass while negotiating corners.

Picture 13

The kick-bar on the RP220 and early RP235s are held up with a gas strut. If this becomes weak or fails unnoticed, it can get stuck in the ground on a reverse manoeuvre and cause the bar to bend.

There are a number of grease banks on Welger balers (auto-greaser optional) which simplify maintenance. In addition to the pto shaft, there are a number of extra greasing points underneath the drop floor on the knife mechanism and split-knife bank mechanisms on RP235s, which are often forgotten about.

This article was first published in May 2015

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