Toughest encoder!

Hey all.

I'm looking for possible encoders to use on my Tree Harvesting machine. its a stroke harvester that slides in and out to basically climb a tree once its been cut. Currently I count pulses from a proximity switch that is mounted in an 8MM housing on the machine body.
I'm controlling it with a Micro850 and I would love to get to an encoder for measuring log length instead of the proximity switch.
The environment is the worst. It gets banged around all day and is commonly wet. I'm not sure if there is even an encoder out there that can take this kind of abuse of not.

It is common though for the switch to get destroyed from debris entering the boom area and even water getting in there and freezing in the sensor well, then the sensor gets busted as soon as the machine moves.


Any thoughts on a tough encoder to measure a telescopic type of movement between two heavy steel tubes. I'm looking at approx 40 inches of travel. ??

I'm even thinking about some type of distance measuring, analog sensor that could handle the abuse.

Anybody working on forestry equipment out there??

So you go by length up north? here in the south we go by diameter, so it gets cut where the diameter is the next size... the only length is how long it can hang off the end of the truck

Diameter is important to a degree. Here a load of logs for lumber goes by weight oddly enough. If its not of a certain diameter, its pulp wood anyway and if you put it in your log pile its a penalty. Pulp wood is measured by the cord but scaled at the mill yard so it doesn't matter to me how much is there so long as its a truck full.
Diameter is a measurement that I intend on adding in the future. Just for my own data collection purposes. For now, I use length to determine where to stop stroking and where to cut. The preset can be entered as any value desired. This allows me to cut a particular species and size as an 8 foot log for pulp wood or firewood, then other lengths, 10 foot 4, 12 foot 4 and even a 16" firewood mode for junking.

I bought an older 15 ton Daewoo excavator to run this machine. Its been an uphill battle learning, troubleshooting and repairing all the worn out hydraulic components on the excavator but I'm getting there. Finally to a point where the excavator works very nice and debugging my fancy control system for the harvester is about to start.

I replaced the Stroke Harvesters old text based computer with a Micro 850 and and a Weintek HMI.

I added some temperature measurement to the engine and hydraulic systems for some indication of whats going on inside.

Everything seems great but I'm not happy with the recent experiences with the proximity switch getting broken and I would love a more accurate measurement than counting the pulses from the switch. It works but.... could be better. I know a few guys with this same variation of this machine that have the same problem with proxys.

I have used AMCI resolvers that were virtually indesctructible. They don't (yet) make a plug in module for the Micro 800 series, but they do have these:

https://www.amci.com/plc-automation-products/position-sensing/rotary-sensors/rotary-encoders/

I suspect, (but I am not sure) that the heart of those sensors is a resolver and the built in electronics convert that signal to suit your needs.

I was not thinking about firewood... here its all about what the mills will take so its only diameter and what you can fit on the trucks, I have 90% pine, I like to leave the hardwoods for the life living off of them

I just thinned 50 acres here and got, Pulp 7.50/Ton, CNS $15.00/Ton and Ply logs $23.00/Ton

OkiePC said:

They don't (yet) make a plug in module for the Micro 800 series, but they do have these:

https://www.amci.com/plc-automation-products/position-sensing/rotary-sensors/rotary-encoders/

Click to expand...

They look good and modbus or Ethernet/IP I would think would work

I think if I were you I would stay with the prox switch
depending on the resolution you need
use a chain sprocket and let the prox switch to pick up the points on the sprocket
or use a 5mm prox on gear for better resolution
simple and cheep to replace if damaged with an encoder you ate looking at $1,000 for each replacement when you look at the heavy duty encoders
I would also build a guard around the switch to protect it

GaryS said:

I think if I were you I would stay with the prox switch
depending on the resolution you need
use a chain sprocket and let the prox switch to pick up the points on the sprocket
or use a 5mm prox on gear for better resolution
simple and cheep to replace if damaged with an encoder you ate looking at $1,000 for each replacement when you look at the heavy duty encoders
I would also build a guard around the switch to protect it

Click to expand...

Interesting..... I had not thought about this... cheap, and I can use my existing prox. I need to go look at it again.

geniusintraining said:

I was not thinking about firewood... here its all about what the mills will take so its only diameter and what you can fit on the trucks, I have 90% pine, I like to leave the hardwoods for the life living off of them

I just thinned 50 acres here and got, Pulp 7.50/Ton, CNS $15.00/Ton and Ply logs $23.00/Ton




They look good and modbus or Ethernet/IP I would think would work

Click to expand...

Good prices..... Here firewood is becoming king. I have a lot of it to. Odd times I find big straight hardwood logs. Ash and yellow birch, sometimes maple logs and get a good $ just for a couple particular logs. People that make floors, tables ect..... mostly though, it all goes for pulp or firewood. I don't have lot of nice softwood on the piece I'm working in now.

I'm saving my honey hole land for down the road, its about 300 acres of healthy and untouched Acadian forest with a river through it. $$$ Retirement plan !!!

PLC Pie Guy said:

I'm saving my honey hole land for down the road, its about 300 acres of healthy and untouched Acadian forest with a river through it. $$$ Retirement plan !!!

Click to expand...

Now your talking!! retire and fish in the river most of the people dont burn wood down here, it does not get cold enough, the fire places are propane

One good market down here is wood for BBQ's one guy down the road from me supplies about 5 restaurants, he has great hardwoods and gets 5 times over market value but when the restaurants cook with it it needs to be a good quality

geniusintraining said:

Now your talking!! retire and fish in the river most of the people dont burn wood down here, it does not get cold enough, the fire places are propane

One good market down here is wood for BBQ's one guy down the road from me supplies about 5 restaurants, he has great hardwoods and gets 5 times over market value but when the restaurants cook with it it needs to be a good quality

Click to expand...

I defiantly never thought of that one! I do make my own chips for grilling, I never thought about selling them though.

PLC Pie Guy said:

I defiantly never thought of that one! I do make my own chips for grilling, I never thought about selling them though.

Click to expand...

Its weird they are not chips, they are logs and all about 6 inches in dia and 36" long and most are not split, they are round... down here we have a ton of BBQ smokers and its like a religion

This one is in the town next door https://www.shealysbbq.com/ on Friday and Saturday they have a line down the block, I think that maybe one of his customers, its a good niche.