How would you alter the chop length on self-propelled forage harvester?

[edward reilly]

How would you altar the chop length on self-propelled forage harvester?

 

[Chae1]

Don't sharpen the blades.

We had a contractor used to do ours that didn't know how to sharpen blades in field.

Forward speed was about half by end of day. Chop length double.

 

[KB6930]

Some are a gearbox most are variable from the cab but also crop size and forward speed can affect it along with blunt and missing blades and a blunt shear bar

 

[Right-arm fast]

Can't you adjust the speed of the feed rollers to the drum these days?

 

[KB6930]

Can't you adjust the speed of the feed rollers to the drum these days?

Yes as above either a gearbox or variable from the cab but a lot of other factors come into play as well

 

[jondear]

Someone's going to say it!
Sell it for a wagon!

 

[davidroberts30]

either speed up feed rollers or take half the knives out to make chop longer

 

[Chae1]

Do claas not have shredlage option?

Guys on pit used to get annoyed as chop length increased.

 

[hintonroadhero]

Some are a gearbox most are variable from the cab but also crop size and forward speed can affect it along with blunt and missing blades and a blunt shear bar

Please explain to me how crop size and forward speed can affect chop length?.........feed rollers will run at the chosen speed so deliver a specific chop length, as will removing blades.....the other factors you list can only affect chop quality !!!!

 

[njneer]

How would you altar the chop length on self-propelled forage harvester?

Speed of feedrollers .
Slow the intake speed shortens the chop and vice versa also some run with half set knives to lengthen chop.

 

[njneer]

Please explain to me how crop size and forward speed can affect chop length?.........feed rollers will run at the chosen speed so deliver a specific chop length, as will removing blades.....the other factors you list can only affect chop quality !!!!

Crop size ie row size and forward speed will affect chop length as unless the drum is full at the shear bar you get longer chop length as the crop can turn and pass through the knives if not held in a tight flow.
Just look at the difference in chop length coming out the spout at the very end of a row and the difference in lifting three or four into one and lifting a single swath.
If you can’t get enough crop flowing through you get uneven chop length.

 

[KB6930]

Crop size ie row size and forward speed will affect chop length as unless the drum is full at the shear bar you get longer chop length as the crop can turn and pass through the knives if not held in a tight flow.
Just look at the difference in chop length coming out the spout at the very end of a row and the difference in lifting three or four into one and lifting a single swath.
If you can’t get enough crop flowing through you get uneven chop length.

Exactly this

 

[ProDrive]

Leave the harrows in the shed and the roller rusting in the corner of the field........soon lengthen your chop!! [emoji38]

 

[fiat 9090]

Also be carefully if your chopping too long you will wreck the blower,

 

[hintonroadhero]

Crop size ie row size and forward speed will affect chop length as unless the drum is full at the shear bar you get longer chop length as the crop can turn and pass through the knives if not held in a tight flow.
Just look at the difference in chop length coming out the spout at the very end of a row and the difference in lifting three or four into one and lifting a single swath.
If you can’t get enough crop flowing through you get uneven chop length.

I accept that this might be the case at the end of the row...but the overall effect is minimal. If you don't believe this get some shaker boxes. Using your logic, it would be more economical for manufacturers to not bother fitting feed rollers to their machines...just drive faster or slower .. or make thinner or thicker swaths to adjust chop length.. that's not the case... The feed roller housing meters crop to the shearbar at a fixed rate, that in turn is chopped by a number of knives to deliver a theoretical chop length..remember the roots of the term Precision Chop... the fact that the shearbar is rounded or the knives blunt....or change forward speed... is an effect..... not a recognised method to adjust chop length as asked in the title

 

[njneer]

I accept that this might be the case at the end of the row...but the overall effect is minimal. If you don't believe this get some shaker boxes. Using your logic, it would be more economical for manufacturers to not bother fitting feed rollers to their machines...just drive faster or slower .. or make thinner or thicker swaths to adjust chop length.. that's not the case... The feed roller housing meters crop to the shearbar at a fixed rate, that in turn is chopped by a number of knives to deliver a theoretical chop length..remember the roots of the term Precision Chop... the fact that the shearbar is rounded or the knives blunt....or change forward speed... is an effect..... not a recognised method to adjust chop length as asked in the title

I specifically gave the answer to your original question , the main methods of altering chop length, ie knife number and speed of feedrollers then answered your subsequent question as to how speed and crop size can affect shop length.
At no time did I suggest that crop size or forward speed were methods of altering chop length.

 

[holywell farmer]

Also be carefully if your chopping too long you will wreck the blower,

Haven't most modern choppers got long chop settings

 

[thesilentone]

In simple terms.

The feed-rollers have a capacity, which is maximised by the springs compressing them together, so, width x height = feed-roller m3 capacity.

For throughput (tons/min/hour) is relevant to the speed of the rollers (m/sec) and power available.

Chop length is determined by the number of cuts per sec/min (lots of knives, slow feed rollers = short, less knives faster feed rollers = long)

So, if we have lots of knives, and slow feed-rollers (short chop) you need more power AND/OR a slower forward speed (due to slower feed-rollers and power limitations) as we have more chops of the incoming crop per sec/min/hour= more energy needed.

The question of what chop length, is a whole other debate about digestibility, clamp space and pit (crop) compression (silage quality).

So, as has been said above, the number of knives and/or the speed of the feed-rollers (which can be altered in multiple different ways depending on brand/make of machine) is how you alter the chop length.

 

[fiat 9090]

Haven't most modern choppers got long chop settings

I would say 50 ml is the longest

 

[holywell farmer]

I would say 50 ml is the longest

It's an argument older than time about chop length