A Typical Day, in a Pellenc 8590…

It was a cold morning, crisp but with the promise of a warm and still day.  I arrive when it’s still dark in my winter pants and a warm pullover, but I stripped to my day outfit once I had completed the pre-check of my Pellenc 8590.

The shaker arms and axles mounts seemed in good condition, and their was no missing or misaligned collector plates.

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Nightshift, McKean Estates,Waipara.

The harvester had been washed well after the previous shift, and the various grease nipples showed evidence of at least having received some grease.  As I climbed up onto the top of the picking head, I inspected each area, and closed the access hatches which had been left open. Everything was clear, the main belts looked central and the mirrors were clean.

I climb down off the harvester and checked my watch – I’d been here for 1/2 an hour already – but then I had walked around and checked the rest of the harvester.

It was time to go. I climb up into the cab, folded away the ladder, turned on the headlights and rotating beacon, raised the rev’s to about 2000 and crept out of our base. Onto the highway, I raise the revs to the maximum, and I am on my way – to your place.

That coffee I receive once I arrive at the vineyard has just been spooned into the mug, and the jug filled and turned on.  I can smell it already.

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Cab view, Broomfield.

I arrive at the vineyard 5 minutes late.  No one was there waiting for me, but I knew where to go, and as I line myself up to the first row, I switch on the stepping function raising the machine at the same time, then come up to my start point dropping down on the stepped stop-height.

Dropping the rev’s to idle, I check no one is standing outside, then open out the ladder and hope out.

Firstly I check the vine. I check the height of the fruiting zone against that of shaker arms in the machine, and then I check the pinch – over the fruiting zone area. A final walk-around the harvester  to confirm everything is in position, before I introduce myself to my client, who has just arrived.

The discussion is simple, after pleasantries are done with, when we discuss what I can and can’t do, but specifically the difficulties regarding removing fruit around posts and the risks in doing so.  Without getting too heavy in the discussion, I promise to perform a few rows, stop in-row, and get out and discuss progress.

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McArthur Ridge, Central Otago.

I start off at 3.5km/hr on fairly mild settings for about 3 bays, and stop and get out. We note the smaller berries not being picked, but some canes being broken, and too much berries still remain on the rachis on the ground.  There’s no evidence on the posts that the bottom fans are too high.

I climb back into the cab, lower the amplitude from 95 to 90, increase the frequency from 490 to 500, but add acceleration to 15.  I increase the mini-shakers from 750 to 850, and then quickly undertake another 3 bays but this time at 4km/hr.

Most clients would recognise the improvement, and I would counter that after a couple of rows the harvester will warm and will “come to” the task.  After finishing the return row, I turn and stop and seek the clients opinion again.  The client wants a little more off around the posts, but makes the point he doesn’t want to break any, and is generally happy the rest of the process.

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Helen & Joey Estate, Yarra.

With the easy part done, I then start to focus on post parameters.  I start with ensuring the amplitude is at least 5 to 10 lower – the simple reality is that with a post jammed up the middle of the shaker arms their effectiveness is somewhat compromised.  I increase the frequency up to 20 to 25 higher, but then I match the increase in pinch around the post with the setting around the canopy.   If I can get this right, then theoretically the post sensor switches to the post parameters, by increasing to the correct width of the post, reducing the actual shaking movement and whilst it has no acceleration (ever), it quickly increases the frequency to try and wrap around the back of the post.  Because the frequency is higher around the post, then I ensure the post parameters are active for slightly longer than their length (110% usually) to ensure fruit is quickly picked directly after the post, in that dead area where the shaker arms can’t operate because of the restriction. Conversely, if the amplitude is quite low, the picking length is usually 90% to 100%.

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McArthur Ridge, Central Otago.

By this stage, the client is happy, and I have completed 4 rows.

After emptying, it is now just mileage, and I get into rhythm quickly.  The next 4 rows happen in the blink of the eye, but now I’m constantly checking the row beside me and how well the harvester is picking.  I’m frequently checking the rear mirror, looking for rachis that may be broken or any fruit remaining on it.  The harvester is warming and the picking head is developing the sweet spot, so now I’m pushing the speed, first up to 4.5km/hr, and if the result looks alright, then up to 5.0 and maybe 5.5km/hr, but not without a minute increase to frequency.

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Emptying straight into fermenting bin…

Sooner or later, the truck is full and after completing another 4 rows, it has not returned in time for me to empty.  This gives me a good chance to give the machine a rest and I lower the rev’s to idle and get out and survey the harvester.  Once I am happy with everything there, then I check where I’ve been, looking for what fruit I’ve missed and what is happening around the post…

I remind myself that as the day gets warmer, I am able to travel a little faster, and sometimes can reduce the frequency and amplitude – this is the first thing I forget to reinstate at the end of the day when temperatures get cooler.

That truck is taking it’s time… I want to finish and get going to the next job.  Besides, even at this time of the year, my wife still has organised friends coming around for dinner and I don’t want to miss out!

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The Finishing Department

The finishing department, covers the area from the discharge of the main drag belt (at the top), through the top fans, the leaf sorting belt, the mini-shakers, down the discharge chute and the tables.

Harvest_side comau

The destemmer above.
Courtesy: http://www.pellenc.com

All of these processes have related functions, not the least being the bottom fans, drag belt speed, and ground speed.

I have discussed the top fans before. Essentially they operate at a very delicate moment – that is when the fruit and juice is transferred to the leaf sorting belt – as it is being catapulted off the belt and free-falls onto the leaf sorting belt.

As it travels over this gap between these two processes, the top fan pressure determines exactly how much of the MOG is removed – including also how much juice and grape berry is removed. If this setting is not 80-90% of the top fans, or is simply just too high, the discharge duct from the fans will be awash with juice and MOG and will be making a considerable mess.

Once the matter is on the leaf sorting belt (in conveyor technology terms it is just a transfer belt), individual berries and juice drops through this belt onto the discharge tray, which drops it all through the rollers and into the bin. Bunches are transferred through a second set of shakers (much smaller and much faster), where the berries and juice drops through, while remaining MOG runs off the end of the belt onto the discharge tray.

All fruit, juice and MOG land on the tables (rollers) and drops through into the collection bins, where (hopefully) all MOG and petioles are run off the side of the sorting tables and drop onto the ground.

Fruit & MOG process.
Courtesy: http://www.pellenc.com

If you ever get a chance, get up on top of the harvester whilst it is working, and open the top hatch where the fruit is thrown off the drag belt and onto the leaf sorting belt. It comes off at such a speed that  fruit can fly out above the hatch onto the top of the top fan casing. The drag belt is going through a 180-degree turn – it isn’t any wonder the driver can lose a lot of fruit at the bottom fans area, where the drag belt goes through a similar movement.

At this point, the fruit, juice and MOG is mid-air and with the covers closed, the fan can lift out more than just leaf, but juice as well. A dead giveaway for this is taking note of the amount of juice discharging from the exhaust ducts at the back. If they are excessively wet and running with juice, you know the fans are too high.

Fruit and juice then falls through the leaf sorting belt, runs down the discharge chute onto the sorting tables.

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Mini shaker unit & leaf sorting belt.
Courtesy: http://www.pellenc.com

Fruit bunches and MOG is unable to fall through the leaf sorting belt, and so travels along the belt through a mini-shaker. This is a similar but much smaller shaker unit to the main shakers but one the operates at twice the rate, anywhere from 750c/min to 1200c/min. These shakers, or destemmers, sit very close to the top of the leaf sorting belt, and are much closer together so any bunches that are still present and shaken violently and the juice and fruit is removed, and drops through.

Mini_shakers

Mini Shakers.
Courtesy: http://www.pellenc.com

The mini-shaker frequency is determined by none other than watching the rear of the discharge tray for any fruit still attached to the rachis (some call it the wrack). The correct setting will result in a pile of empty rachis crossing the sorting table which is dumped on the ground, easily found when the harvester has stopped as the driver conducts his visual check of the vine in the first row. If the rachis is broken, then it is generally viewed that the setting is too high. Exact guidelines are 1-2 rachis with 3-4 berries remaining per bay (vine panel) is a good setting.

The sorting tables sit above the collection bins and are shaped appropriately to perform two roles. The first set of rollers the fruit and MOG comes in contact with allows for the passing of juice but their main role is to re-align MOG and trash such as petioles perpendicular to themselves. Once this is done, they tend to run off the side of the second set of rollers, whereas the fruit drops through and into the collection bins.

Generally speaking, the tables are run at the maximum speed possible, backed off slightly to ensure fruit is covering the rollers evenly, but 1 or 2 rollers back from the outside edge.

Whether the mini shakers cycle setting is set high enough or not, is determined by how much fruit is still on the rachis when they drop off the side. The best time to note this is when the machine has stopped whilst in it’s first setup row, or when it slows down once coming out of the row to turn around. Additionally, what you also do not want to see is wads of leaf and juice running off the side as well. This is the telltale sign of the fans set too low, and the mini shakers pack leaf and juice together  in a pancake. One can also take a ride on the harvester, to view the discharge tray and note the quantity of trash collecting and running across the rollers.

Remember? Ground speed is practically related to everything that could be wrong.

The leaf sorting belt speed is proportional to the main drag belt speed, which is determined by ground speed. If you think something is wrong, first thing is to slow down which makes the whole process more manageable.

Other features include a magnetised discharge tray. The winemaker should demand this is present, as this removes all metal manner from entering the bins (nails, staples and so on). A bin level indicator is available on some models and as an add-on. This too should be demanded by the vineyard owner, to ensure driver forgetfulness does not allow fruit or juice to overflow the bin.

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The SMART Controller – More on Parameters

There are a couple of other parameters that I haven’t mentioned previously, that being proportional shaking (which doesn’t need any further explanation) and the active distance.

Active Distance is the zone for which the post shaking parameters take effect.

In other words, if this is set to 50%, then the post parameters will only be active over half of the shaking zone (the length of the shaking bars). Set at 150% and this activates them for one-and-a-half times the zone.

Essentially, if your post parameters are higher acceleration and frequency, then the active distance should be greater than 100%.  If they are lower, then the active distance should be equal to or less than 100%.

The argument I make here (also refers to the post parameter discussion in the last post) is that if the choice is to make every effort to remove fruit around the post, then maintaining those higher settings just after the post will ensure a better harvest in that “dead zone.”

If this is not the goal (ie post protection is paramount) then it doesn’t matter, and the setting can be 100% or lower.

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The SMART System parameters can vary much between crops.

Whilst late season amplitude settings of 65-80% can allow frequencies up to 540 cycles/min, being late season would not need frequencies this high.

I have harvested 5 hectares of Pinot Noir, of which 3 hectares were “stressed” vines. This allowed parameter settings of 25-80-00-485 (Pinch-Amplitude-acceleration-Frequency) at a speed between 5.0km/hr and 5.7km/hr. The suggestion that I could lower the settings further due to being able to stretch the speed to 5.7km/hr is negated by the fact that these were 50-75 metre rows with only 6 metre headlands.

At the same time, the remaining 2 hectares were quite dissimilar, with a very active canopy. Consequently the parameters required were 25-95-10-510 at 4.8km/hr, with some of the small berries and raisins still remaining.

Speed is very relevant.

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Once, after taking over the machine from a dry-hire job, I felt the picking arms being a little more “loose” by an increase in the shaking effect (which you can feel in the small of your back). I look to my right, to find the SMART parameters are 15-105-15-540. What speed this was being undertaken at I do not know, but this highlights the actions of a rather ignorant driver. He was obviously thinking that as all the fruit was being removed, he therefore was doing the right thing. It just so happens to be someone who did not turn up for driver training arranged prior to the season. With a little adjustment, I managed to lower the amplitude from 105 to 95, and lower the frequency from 540 to 495, and completely cut out acceleration altogether – even though I was doing 5.5kph.

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The season of 2012/2013, we have instigated a policy for ourselves of reducing the post amplitude by 15-20%. No matter what the thinking, having a post momentarily between the picking arms physically reduces the amplitude – trying to maintain or increase the amplitude achieves little. We are experiencing no significant harmful effect, other than a little more fruit remaining around the post. This is countered by keeping our speed to a maximum of 5.0-5.7km/hr. Most vineyard operators agree that to hand pick around the posts doesn’t net much advantage, so this doesn’t seem like too much of an issue.

The short period we ran with an increased amplitude of 95-100% around posts gained little in extra fruit, but did result in a significant increase in post breakages. It is difficult to maintain these settings, even when the pinch is increased, as the post sensor quickly recognises a post and increases the settings sharply – at the same time when travelling in a forward motion. In this case, posts tend to be broken and pushed forward in the row.

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Again, I have had three opportunities this season to ask an observer (winemaker or vineyard owner or their assistant) to visually compare the binned sample, after I have taken over part-way through a particular job. The first and immediate change I make is to lower the fan pressures. Dropping them from the common setting range of 100-140 bar, down to 75-85 bar (top) and 90-100 (bottom) results in a significant increase in the collectible grape juice, something many miss out on. With the presence of petioles, the tendency is for the driver to increase this setting to remove them, but more often than not, grape juice is removed just as easily.

Whilst it is a little more difficult to get the balance between fan pressure and petioles remaining (particularly for Pinot) in the sample, one very good indicator is simply that fact that when harvesting mid-season onward, there should be a considerable amount of juice running out from below the leaf sorting belt, as it drops down and onto the discharge tray. This area is well exposed and can be seen clearly by both driver and observer on the ground.

Petioles are better handled by an INCREASED speed in the sorting tables.

∞∞

The continual adjusting of speed, fan pressure and table speed, throughout any particular harvesting job, has taken me 3-4 years experience to become comfortable to do so. It requires the uncomfortable seating position of frequently peering behind you in cab, frequent checking the Finishing Department for potential jams, and frequent speed vs shaker parameter setting changes to understand their relationship and looking for their ‘sweet spot.’

It takes time, and a focus on the deliverable benefit to who benefits – the vineyard owner or the winemaker. It is the responsible operator that understands who he is working for, somebody who sometimes doesn’t understand every detail, but nonetheless that is who the operator should be looking out for.

The Finishing Department is the destemmer, and the final chapter ion the processes of this machine.

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The SMART Controller

The SMART System is the patented term given to the control of the picking rod arms, of the shaker active head. The head is active in the sense that it moves sideways independently to the tractor unit (MAV), to compensate for the position of the vine and superstructure.

SMART_contrHow the SMART System achieves this is quite complex, and yet the four main parameters that control the shaker arms are set individually by the driver simply altering each one as he or she seems fit.

And this is where things can get out of step.

Having a logical and engineering mindset helps a driver to match their input requests to the controller, with what he or she is attempting to do.

Good practice requires starting ground speed of 4.0-4.5km/hr. This is particularly important at the beginning of the season, when it usually takes a couple of days for drivers to get into the swing, and re-acquaint themselves with the vibrations and noises of the harvester unit.

Lets make a few assumptions here, noting that they are based on my experience (in the Waipara Valley in Canterbury, the Awatere Valley in Marlborough and the Bannockburn-Bendigo-Lowburn-Alexandra-Clyde regions of Central Otago, and around Yea and Alexandra in the Yarra Valley, Melbourne).

  • Red varieties tend to be on vines with smaller canopies, picked mostly when the canopy is starting to shut down, or as in some instances non-existent, hence low MOG levels. Petioles are always an issue.
  • White varieties tend to be on vines with larger canopies, are often the heavier crops, with quite weighty MOG. Petioles are an issue with late harvests.
  • Varieties picked for champagne are usually early picks, resulting in slower ground speeds, higher settings and DECREASED shaker arm centres.

I’ve harvested Sauvignon where the crop is so heavy that a maximum ground speed was 3.5km/hr, simply because the high quantity of fruit was over-running the mechanical processes. In another scenario, a 350m Scott Henry trained row yielded over 2 tonne of fruit, spilling over the sides of the bins.  I have also harvested Pinot so late in the season, there was no point in using the main or upper fans, relying completely on The Finishing Department to remove the petioles.

SMART_whitePinch settings (left) show an arbitrary value but notice that as the season progresses, the tendency is for this figure to reduce, as the vines begin to drop their canopy. The adverse effect then is an increase in MOG.

Amplitude shown is set to maximum (or near to it) at the beginning of the season, and reduces much as the season progresses. I have run this setting as low as 45% for late harvest varieties.

Acceleration is of more use at the beginning of the season, as it is usually more difficult at this time to remove fruit from the vine. After this early period, acceleration is generally not a requirement.

Frequency (or cycles) is set to the upper band in the early season (500-525), and rapidly drops as the season progresses. The bulk of the harvesting season should be able to be done around 480 to 495 cycles.

But it is not as simple as this. What is most important is the relationship between amplitude and frequency. Whilst it is mechanically possible to set the machine to an amplitude of 120% (20% longer than its standard 150mm stroke) – at that increased distance it would be excessive to have the frequency around 500 or higher. High cycling the machine picking arms over a long distance would be akin to driving to work in first gear, but at high revs so as to get there.

SMART_rangeThe relationship should be low amplitude – high frequency, and vice versa.

The relationship between frequency and acceleration is important too. For a given set of cycles, when you accelerate any part of that cycle, another part of that cycle has to slow down, or pause. For example, if you add acceleration to the cycle, because the shaker arms are still cycling at the same measure PER MINUTE, then between each stroke there is a pause. This is why acceleration is sometimes called ‘punch.’ Combine an increase in acceleration with a pinch setting that is too wide, the shaker arms will slap or punch the vines to oblivion.

The more vigorous the canopy agitation, then more MOG is present – which has to be dealt with by the other processes. Consequently, ALL settings work together, to give the finished sample. At times, particularly late harvest, one can’t avoid removing the remaining canopy from the vines. This increases the role of the fans and The Finishing Department, and the operator needs to constantly watch all areas and make continual changes to make sure a good sample is provided.

Speed is directly proportional to the frequency. The chart below shows this. At a speed of 4km//hr, the harvesting unit is travelling along the vine, at 1.11 metres per second. If the frequency is set at 490 beats per minute, then for every metre of travel the vines are shaken 7.4 times.

SpeedvsCyclesAt the same number of cycles, doubling the speed halves the frequency for EVERY METRE of vine.

An experienced operator will begin harvesting at 4.0-4.5km/hr. As the machine warms, as the oils come up to temperature, as the shaker arms settle into their natural harmonic rhythm, so its effectiveness in picking fruit increases. This results in the need to reduce certain settings (particularly amplitude and frequency). Alternatively, it also allows a corresponding increase in ground speed.

An increase in ground speed with no change in frequency correlates to a significant decrease in the cycles per metre (Cps/m). The decrease is shown as a percentage in the above table (from the original starting speed). Where the interests of the winemaker/vineyard owner are being looked after, an operator will start at a low speed and work upwards towards 5.0-5.5km/hr, whilst at the same time REDUCING his shaker arm settings. It is about matching the machine’s settings with the environmental conditions.

An inexperienced or lazy operator will start at the speed he or she is comfortable at, set relatively high shaker parameters, and maintain this for the rest of the day, thinking he or she is performing well based on the fruit being removed from the vines. This is needless, as making the machine work harder than necessary increases its wear, and potentially damages vines and canes.

Racing along at 6-8km/hr can be fun, but things go wrong much more quickly than is sometimes expected. At this speed in heavy crops, it will take only a few minutes to fill the bins, and that is all it takes to collect a whole heap of petioles or other undesirables.

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Post settings are much simpler to understand when you understand how the shaker arms work. But there are two schools of thought, and the decision of which theory to use, is left squarely in the hands of the winemaker / vineyard owner – without fully understanding the disadvantages of either of them.

The vineyard owner wants to make sure all the fruit is removed from around the posts. This requires more vigorous parameters around the posts. This can dramatically increase problems, especially if the settings are not chosen correctly, or are too severe. That is the disadvantage.

The winemaker sometimes isn’t too concerned whether the fruit is fully picked around posts. Winemakers typically only pay for the fruit by weight at the winery. They may also understand that it is often difficult to remove all fruit around the post, and may be happy that no attempt is made to do so.

SMART_postThe harvesting parameters shown left (top line) are typically for a early season harvesting. The second line shows a typical matching setting (which correlate to the main harvesting parameters shown), and reflects the winemaker’s stance.

Here the pinch increases to 90mm, about the size of standard post, although it could be anywhere between 80 to 140mm. This assists with reducing the wear on the nylon shaker arms. By opening up when a post is detected, it allows a post to pass freely.

Now picture the arms, with a post separating and dividing them. Physically, the stroke (amplitude) is restricted, so a REDUCTION in this setting should be the need. The reduction needs to be carefully considered, as there is some movement of the arms around the post.

Accelerating at this time could be considered only because we have DECREASED the amplitude, however  the restrictive nature of the post doesn’t necessarily limit the effectiveness of a small amount of acceleration. I rarely choose this option.

Frequency is typically increased here, sometimes up to 540, to increase the shaking rhythm to offset the other limitations.

But some believe the solution is to INCREASE the amplitude, because the post is restricting the movement (amplitude) and the effectiveness of the action. I find this somewhat counter-productive as nothing can overcome the fact that the post is physically restricting the shaker arms. Violently shaking the post rarely removes all 100% of fruit, but may break rotten, soft, knotty and wet posts. It also causes significant wearing of  the shaker arm mounting axles. The argument that the arms ‘wrap around’ the back of the post I find is somewhat flawed, in the sense that it would require the perfect setting – pinch (to give the flexibility), amplitude (balance between ‘wrap-around effect’ and post damage), and the cycles.

It takes some years in mastering the settings of the SMART System controller, even longer when your experience is built on a lot more variables – such as smaller and more variable vineyard locations, mixed in with different varieties.

There is most definitely a sweet-spot where a group of settings matched with the correct ground speed will perform an almost perfect result. Sometimes this is easily found, other times not so. But the over-riding cause when the machine  is struggling to harvest grapes with vines reluctant to let go their fruit – is an inappropriate ground speed.

An operator struggling to meet the desired result, first needs to slow down.

Then the operator must take a considered approach to each and every individual process the machine is undertaking. But here’s a little more on the Smart Controller parameters.

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The Picking Head Shaker Bars

The main feature of the picking head is the stacked shaker picking rods inside. I call them rods or bars, but technically they are shaped with a taper at the front and a full return curve at the rear, and are better described as arms.

These arms have the greatest effect on the vines and the resulting quality of the fruit sample. With an inexperienced driver, they can be partly responsible for the breaking of posts, tearing out strainer posts, ripping out vines, and damaging the machine itself.

A picking arm axle can break lose, resulting in the arm swinging around and beating the lower fan casing so hard that it will compress it to the point where the fan will jam solid in its housing.

If it can do that amount of damage to itself, spare a thought for your vines.

The preference is for only 3 to 4 picking arms per side, but the height and position of the fruiting zone will determine this. Using a lower number of picking arms pairs results in the shaking force applied over a smaller area, and increasing them in this force being applied over a greater area. Pellenc recommend the arms centered at 130mm, but this can vary if required. Difficult early season crops would require arms centred from as low as 90mm to 110mm, whereas later in the season could see an increase from 120mm to 150mm.

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Shaker system & picking arms.
Courtesy: http://www.pellenc.com

The shaker arms are mounted via rubber-isolated axles to a pair of shaker poles. If the shaker axles are not of a similar age or condition, then the newer one will not only wear out faster, but the effectiveness of the whole arm is somewhat compromised. If there is one or more arms that have loose axles, the picking process is compromised further and this may result in the driver needlessly increasing his settings to offset this.

Not only does low picking arm centres significantly increase the pressure on the vine (used on early or difficult crops), it may also allow lower shaking parameters. An aside, an increase in the height of the lower arms to the bottom tray reduces fruit loses through the collector plates. It is not generally advisable to alter these heights for every individual vineyard, but an awareness of this increase your knowledge of everything that can be altered of adjusted here.

The action of the picking arms are controlled in-cab by 5 settings. These are as follows:

  • Pinch, controls the ‘press’ or ‘squeeze’ on the canopy.
  • Amplitude, controls the stroke or distance of the shaker bars.
  • Acceleration, controls the speed² or the acceleration of the shakers towards the canopy.
  • Frequency, controls the cycles per minute.

To begin, setting the pinch is the easy part. It’s an estimate and usually only requires altering one way or the other depending on the width of the canopy. It is measured in millimetres, and essentially is the space allowed for the vine to pass through. I usually have it set somewhere between 20-40 (for young vines) and 60-80 (for more mature vines).  This setting can go up to a maximum of 240, although for heavy mature Scott Henry vines I’ve harvested, this has not needed to be higher than 120. If the pinch is too wide, the picking arms will slap the vines causing significant damage. If it is too narrow, you will notice the canes being dragged forward, in the direction of the harvester. Rookies would frequently set this to the canopy width, instead of the width of the fruit zone – which can include the cordon area.

Amplitude is the nasty one. In hydraulic ram terminology it is the stroke. An operator on a setting higher than 100% could very well be out of control and if inexperienced, could be causing damage to machine and vines. I usually prefer a setting anywhere from 65% to 95%, although this depends on the variety and time of the season. For example, pinot at the beginning of the season is difficult to get off at times, and may require a setting close to 100% (I usually never go over 100%). Mid-season, amplitude can drop to 75-80%. Sauvignon and chardonnay should be set at about 80-95%, dropping to 55-75% later in the season. Late harvest varieties can be picked with settings as low as 45%. For reference, 100% amplitude results in a 150mm movement of the arms.

Acceleration controls the speed at which the arms come in to the vines. It is used to change the dynamic shape of the shaking rhythm, and only should be used when an operator understands the full implications of the amplitude versus the frequency (or cycles, discussed later). A mechanically driven picking arm / shaker mechanism that relies on an offset pulley and chain drive has a built-in acceleration of 15, corresponding to the Pellenc SMART System as 100%. It is therefore assumed that using this feature within the 0-15 range only has a minute discernible effect on the picking result. Settings above 15 begin to have a more significant effect. The more accurate description of acceleration would be ‘the punch’.

The frequency setting controls the number of cycles per minute the picking arms move from their start position to the full stroke of their amplitude and return. Early season settings may be around 500-510, but after a few weeks and depending on the variety, these values can be lowered to 475-490 and sometimes even lower.

Shaker_arms_2

Shaker picking arms.
Courtesy: http://www.pellenc.com

Those are the four main picking arm settings that are used to control the picking head via the controller.

The fifth setting I referred to earlier, is actually the ground speed. This has a direct influence on the frequency setting, and a skilled operator can often use speed as a method to control the frequency setting, in addition to altering the SMART controller. Many times I increase or decrease my speed to influence the frequency setting. Combined with the effect of the ambient temperatures, speed and frequency will and can vary throughout the day.

In addition to these, post detection is another feature whereby the operator can make adjustments to the picking arm settings, such as when a post is detected. There are various settings to achieve this, including altering  the aforementioned four main settings, to a range of sensitivity and the zone or range whereby the changes are made – from 50% of the picking rod area to 150% of the same.

It should be pointed out here that the shaker arms very rarely break posts. There are some specific conditions where this can happen, but in most cases – post breakages are generally the fault of the driver. Old posts can become both brittle and rotten (dry or wet), can be from inferior timber quality, or the remains of forest fires – common in Australia. The operator needs to be aware of this.

This introduces the discussion of the SMART controller, and typical settings.

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The Rear Visual Effects

Rear visual-effects is what you (the vineyard owner/winemaker) can see from the back of the harvester  machine as it trundles off down the row.

It is the easiest and the least of situations to make sure the I am doing the job correctly.

Conveyor rear panel & flap.

Conveyor rear panel & flap.

From the rear of the machine, you can see a number of things. These are; the bottom fan discharge, the top fan discharge, the shaker exit area, and the drag belt tray (shown left). From the picture below of the picking head, you can see the movement of the fruit & MOG.

Essentially, fruit and MOG falls from the shaker area onto black collector plates at the bottom of the picking head, and then slides over outwards and drops onto the main drag belt. Once on the drag belt, the fruit and MOG travels rearwards toward the rear fans, raising upwards to the fan intake area before undertaking a 180-degree reversal in direction, where the fruit and remaining MOG is dragged along the belt tray before being collected again at the front and delivered to the top of the machine.

When the machine’s picking head is first started, each stage starts independently one after the other. First are the fans, then the sorting tables, mini-shakers and the drag belt, then the shaker arms.

The fans make a very distinctive roaring hum, high in pitch at first, then lower as the hydraulic pressures settle down to their even flows. These are the first things to note, both bottom and top fans.

The MOG discharged from the bottom fans can be painful if it hits you. Canes are chopped by the cutters, then catapulted out at a rather high speed. A setting which is too high, has the effects of throwing out more than MOG – fruit and juice will spray out and this can be seen when a post comes through and it becomes coated in juice and grape skins. With the top fans, this is a little more difficult but if you place yourself between the discharge point and the sun, you will see a cloud or mist of juice if the fans are too high.

For those that prefer the numbers, the main bottom fan pressure range should be between 80-100 bar. The top fans should be no more than 80% of the bottom fan’s setting, hence 60-80 bar.

Being a driver and familiar with the sounds, I can tell whether the settings are too high or not by singing the fan tone… Doh, rae, mee! Mee is too high, doh is just right!

If you closely follow the machine down the row, you will be able to pick the sound of the shakers working on the vines. It unfortunately sounds too much like a chopping sound, but if you match the effects on the vine with the sounds in the shaker area, you will be able to quickly match the two once you are happy with the resulting effects on the vines. If there were a handful of grape berries remaining on each vine, then the shaker settings and its sound match should be about perfect, and slight adjustments only need to be made.

Fruit & MOG process.

Fruit & MOG process.
Courtesy: http://www.pellenc.com

The rear drag belt roller is the point where the fruit and MOG make a 180-degree reversal – at no reduction in speed. The only thing that stops the fruit being thrown out at the rear, is a removable baffle plate behind the rubber flaps. If this plate is either removed or not in place correctly, a steady stream of fruit will be laid out on the ground behind.

In addition to this, any fruit that collects between the rubber flaps and the baffle plate (and builds up here in a mash of fruit and MOG) is a sure sign of the drag belt tracking speed set too high. And because the drag belt tracking speed is set relative to the machine’s ground speed, ground speed is something you will read often here.

Ground speed is practically related to everything that could go wrong.

These are a few pointers that the vineyard grower/winemaker should note when he or she engages a grape harvester contractor. I call it the Rear Visual-Effects simply because at this point these quick visual assessments made from the rear of the machine as it embarks down the row, very quickly determine who is looking out for who.

Specifically, they are the least checkpoints one should notice and check, to make sure the driver is working for YOU.

  • Main (bottom) fan pressure: check juice trail on trunks/posts.
  • Top fan pressure: check juice cloud/mist against sunlight.
  • Sing the fan tone: Doh, rae, mee!
  • Belt speed: check for fruit discharge from rear end.
  • Ground speed:  4.0-4.5km/h maximum starting speed, 5.0-5.5km/h maximum speed overall.

What is preferable, is that harvesting begins at a reduced speed, frequently checking settings versus on-vine results over the first row, and confirm these in the second row. Essentially the first 4 rows are the setup rows, and there would be nothing wrong with re-harvesting the first row if required.

As machine-driver rhythm settles, and working temperatures are reached, and the shakers in the picking head acquire their motion and energy, then speed can be increased. But speed is singularly the most responsible for errors such as vine damage, poor fruit samples, and loss of juice.

Best practice is achieved when the operator makes the correct judgements over the choices of which settings to adjust and when, and usually takes years of practice.

This is particularly so for the main Picking Head area of the Shaker Bars.

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Just a Phone Call Away…

I’m just one phone call way.

And there’s no mistaking when you see me coming.

Pellencs

Being a vineyard grower or winemaker, you’ve work hard all year to get to this point. And you will be up nice and early,  waiting in your vineyard, standing beside the post where you want me to start harvesting, coffee in hand – for me!

On arrival, I line up to the row, increase the harvester machine’s height, and then drop back down to its pre-set ride-height position. I’ll drop my engine revs to idle, pop out the ladder and say hello…

And, yes – It’s double-black, no sugar (the coffee, that is!).

Next is the walk-around. Sounds silly, but for the  driver, this highlights a number of key indicators and determines the set up, including the status of some features of the machine, especially if a personnel change-of-shift has just been undertaken.

First is a check inside the shaker body. A quick visual will determine the number of shaker bars, their height, and once you physically grab them, the condition of the elastic joints. The black bottom collector plates can be seen, including those that are missing.

Then there is a walk along the vine row, mainly for the purpose of determining the height of the fruit zone. This is measured against the drivers body, say between the knee-to-waist or waist-to-chest, and then a comparison is made with the machine. Sometimes, adjustments are made to the ride-height stop position, altered on both sides of the harvester. This is also double-checked mid-row.

Then, I get back into the cab, engine set to full revs, nudge the machine into the row carefully, and I’m off!

It is at this moment, YOU, the grower (read here also the winemaker), have almost completely lost any control on what happens further from here on.

And apart from the usual last-minute instructions of “I want everything off around the posts” or “you are still leaving some fruit behind,” your only determination whether a good job is being done or not, is in fact whether all the fruit is coming off the vine.

Strainer

Yet there is so much else you should have a say on and even more that you could be aware of, that will add to your perception of what the machine is actually doing, thereby helping your previous year-long effort in ensuring that you collect all of your quality crop, providing a clean and mog-free sample, with no damage to vines and their supports.

There are three main areas that you need to be concerned with. Firstly, what I call the rear visual effects, then the shaker or harvesting area, and finally the finishing department.

Having an understanding on what you should see and hear, and what you shouldn’t, will go a long way to improving your  picked sample, and getting the very best from your crop.

So, get to know the Rear Visual-Effects.

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