Now to the main working mechanisms of the machine. Starting at the front, inspect the pick-up for bent or broken tines and bands. Straighten or replace them to ensure a smooth flow of material from the ground into the machine.
If you have changed the tractor from last year's model check whether the drawbar needs adjusting to get the baler sitting level; as one of the few straight edges on a modern baler, an upright parking jack is a good indicator.
With the correct setting, the baler's pick-up will be able to drop low enough to get a smooth flow of crop to the intake rotor and lift high enough for adequate ground clearance when turning on the headland and travelling between yard and field.
The pick-up drive chain needs to be checked for excessive wear to the links; if there is wear and the baler has not done a lot of work, be sure to tension it correctly and check that the lubrication system is working as it should. As a precaution, some manufacturers recommend replacing this relatively inexpensive chain as a matter of course each season.
A lot of the Krone and Welger balers now have pick-up reels with no cam tracks, which will be a blessing to operators who find them troublesome. Where they are fitted, remove and inspect the cam track for wear or damage and then check that each of the cam wheels rotates freely without wobbling.
Further back, take a look at the flights on stub augers and put right any damage from stones or other debris that might cause crop material to snag. Check for adequate clearance all round and that the augers rotate freely with the drive chain removed. The same goes for the feed rotor, where it is also worth applying a bit of leverage at each end for early signs of bearing wear.
On to the crop slicing system if fitted: blunt knives will dull the baler's performance and make a significant difference to power and fuel consumption. Discard knives worn back such that there is little or no serration left and be sure to give knives that do have some life in them a good edge before the new season starts.
Balers with a good control unit or terminal in the cab will advise the operator when some attention is required - Welger's E-Link controller, for example, shows a fading 'scissors' emblem.
Typically, knives need sharpening every 500 to 1000 bales, depending on the material baled, and it is important to sharpen them correctly if they are to stay the course.
Dealers will often have a sharpening tool or jig to set a power grinder to the correct angle for doing the job properly. Agriknives Direct based in Westmeath specialise in baler knife sharpening. But if DIY sharpening is the only option, work on the flat side of the blade only.
Where the blade tip remains exposed even when the knives are retracted it is better to remove the knives when baling hay or straw to avoid unnecessary wear. And if they are not going to be used for a length of time, install blanking inserts to prevent crop material being packed into the slots.
On to the bale-forming mechanism next; on New Holland and Krone balers with a chain and bar mechanism check that all the bars are straight and run true around the track and over sprockets to avoid excessive wear. Likewise, check that the small rollers on each end rotate freely but are not obviously loose.
With the drive chains slackened - and the belts where these are used to form bales - the bearings on which the rollers run can be checked. On roll balers, pay particular attention to the base roller and the one behind it as they are the hardest-working of the lot.
Here you are looking for rollers that rotate freely on firm bearing assemblies, the condition of which can also be assessed by applying gentle leverage with a long bar near the end of each roller.
This should reveal a fraction of sideways movement, which is normal to compensate for flexing as the baler passes over an uneven field surface. But anything more than a fraction should be investigated further to avoid having to replace bearings when it is least convenient.
Leave the job of fitting new bearings to a dealer's expertise, if for no other reason than high torque settings are needed and it is important that they are spot on, especially for the main drive sprocket.
Where the belts are slack on a variable chamber baler, take a stout scraping tool to the drive and idler rollers to give them a good clean because an irregular build-up of material will likely cause the belts to be thrown out of alignment. Where the baler has its own scrapers to help prevent this build-up, give them a good clean too and make any adjustments needed to compensate for wear.
Doing this painful job pre-season may be enough of a reminder to do it next time at the end of the season when the material is still nice and soft!
On some balers, 'escape holes' are cut or punched into side panels so that paddles on both ends of every roller can keep material away from the bearings. Have a good poke about to make sure these holes and the area behind them are clear of debris.
Inspecting the steel roller surfaces for stone damage and the belts on a variable chamber baler for tears and punctures is next on the check list.
To minimise the risk of snagging the net wrap it is better to clean a belt edge tear by cutting the loose material away to a rounded shape; likewise, remove the 'flap' from a puncture and leave a clean hole.
Trim any trailing fabric threads to prevent them being pulled further.
Unless serious damage has been incurred, it is usually better to clean up the belt and leave it intact rather than risk weakening it by inserting a replacement section using joiners.
Next, check that all drive chain tensioning mechanisms function as intended and that spring tension is set correctly according to the operator's manual for the specific make and model of baler.
Different settings can apply, even on balers of the same make but different ages using a similar tensioning system. Badly worn chains or sprockets with teeth worn to a hook shape should be replaced.
On balers with hook latches to keep the tailgate closed, manufacturers recommend re-calibrating the proximity sensors every couple of seasons.
The sensors are used to detect movement in the latch slots, which is converted into a bale density reading on the controller.
Correct calibration will ensure the baler works to the correct density without over-loading or making bales that are 'thinner' than optimum.
Into the net wrapping system next, where before doing anything else it is important to safely trip the spring-loaded net cutting knife.
Net roll brake pads should be adjusted so that the brake disc can be rotated with a little resistance to keep the net correctly tensioned; likewise any tensioning spring mechanism on the net feed-in roller.
The loose fitting grey foam roller on Welger balers should be replaced if it is damaged to prevent the net from snagging - but resist any temptation to straighten the curved bar inside because it is shaped purposely to spread the net across its width.
Similarly, do not be tempted to scrape any debris from the rubber feed-in roller with a knife or other sharp implement because the slightest cut can result in the net becoming snagged. Instead, wash debris away with warm, soapy water and a sponge.
Any lubrication issues should have been revealed by inspection of drive chains and sprockets; but double check all auto-lube components to ensure the correct volume of oil is dispensed to brushes that are in firm contact with the chains.
The auto lube reservoir will need topping up halfway through a busy summer - but be sure to use the correct oil, which will have anti-fling characteristics to keep it on fast-moving chains and sprockets where it can do some good.
Pour in anything else and accelerated chain and sprocket wear - and a very messy baler - will be the inevitable consequence.
Finally, grease nipples should get no more than a single shot to avoid popping bearing seals. If the baler is lucky enough to get a good clean down with a power washer, give a shot of grease first, wash, run the machine briefly, then grease again to expel any moisture.