tachometer problems dynamic dc50

[sugarbear]

Hi im new to the site. we have a dynamic dc50 chipper that has a lor programable tachometer. the tachometer reads 8888 all the time whenever theres power to it doesnt matter if the engines running or not and the autofeed doesnt work. im thinking that the tach is defective. was wouldering if anyone has any experience with these that could point me in the right direction. the local dealer wount help they just want to fix it for us. the tach is a LOR programable digital controller pdc-1 thanks any help would be appriciated.

 

[Eq Broker]

Sugarbear,

I have 10 years experience with LOR tachs. Tell me how old is the chipper?

 

[Eq Broker]

Sugarbear,

I know your most probably out working. Please let me know if your LOR has a speed sensor in the bell housing of the clutch or does the tach have a wire going to the altenator? You may want to remove the speed sensor out of the bell housing and make sure the flywheel didn't chew it up. I don't think it's a speed sensor with your symptoms but it will only take a few minutes to check it out. Also, please let me know if the face of the tach is black or white. Do you have the operating instructions of the LOR? If not, I should have them here tomorrow and I could email them to you as the tach may need re-calibrating.

Let me know what I can do to help.

Eq Broker

 

[sugarbear]

Hi eq broker, the signal wire for the engine speed comes off the alternator. we have had issues before with the alternator but it would show the no signal on the tach display. it also used to read no signal if the key was turned on and the engine wasn't running. now it shows8888 whenever there is power to the tach. when the autofeed is on the feed rollers wount start until the engine almost gets to full throttle but when the machine boggs down it wont shut off the feed. we do have the book on how to program the tach but the display reads 8888 all the time so nothing can be programed. i have checked all the fuses,wires, connections, and the ground connections to make sure everything is correct and found nothing wrong. i dont have the paperwork for the chipper with me now but i think its a 2003 or 2004 thanks for your time.

 

[sugarbear]

according to our paperwork the chipper is a 2004. on the back of the tachometer it has 4/04 which i assume is when it was manufactured and has rev.3 on back also. thank you for your time.

 

[Eq Broker]

Usually a no signal means that the wire going to the altenator isn't reading the rpm's or the tach could be defective. It seems that the tach is working on the low end of the settings of the rpm's. When a chipper has the auto-feed off the feed rollers start turning the minute you start it. Turn off the auto-feed and see if the feed rollers start turning at any rpm. I would turn off the auto-feed because it will bog down on a large tree. This will reduce the clogging of the machine and it isn't good for the engine to just come to a stop. You'll have to work the feed bar on larger material. I would try re-calibrating the tach as the settings should be on the instructions. I would also check the auto-feed valves and make sure they're not rusted up and they move freely as they're controlled by magnets. Usually a light oil will help these move freely unless they're contaminated. Let me know what happens after these tests.

 

[sugarbear]

Hi, the tachometer reads 8888 in the display so i cant check anything thats programed into it. the feed rollers will come on as soon as the engine is started with the autofeed switch in the off position, it has a seperate switch in the wire that runs to the dump valve. the feed will operate properly in manual but someone has to work the bar manualy otherwise it will stall itself on bigger material. im thinking the tach has issues internally but its a guess and for $670.00 i dont want to be guessing.the local dealer has a part # of 350501-3007 i dont know ifthats a dynamic # or if its a LOR # if that helps any.

 

[Eq Broker]

Okay. Some portions of the tach are working then, however, since you're get nothing but 8888's I think it's bad. You don't have to have a LOR tach to correct the problem. I know the pricing is outrageous for a LOR tach. I have a tach that will work for $300 plus freight and it does come with a wiring harness as well. You will simple replace the wiring harness on the machine side and calibrate the tach (instructions included) and now your auto-feed system will work. You can adjust the low side rpm's and the high side rpm's to your liking. The low side rpm's will stop the feed rollers when a large piece of material is pulling down the rpm's on the engine and the high side rpm's will start the feed rollers again. You usually want a 200 to 300 rpm spread between the low and high rpm settings. After you install a new tach you never want to push two buttons at the same time as this is how you set the calibrations and unless you carry the settings with you, will render your chipper useless until you can re-calibrate.

I hope this helps.

Let me know what I can do to help.

 

[sugarbear]

thank you for all your help. no matter what tach is installed i think i will have to make it so no one can touch the buttons almost all of the problems we have had with this machine have been feed related and either because someone touch the tach that shouldnt have or because they think they know everthing and turned the autofeed off.i will find out what the boss wants to do and let you know concerning the tach. thank you for taking the time to help me with this problem. steve.

 

[Eq Broker]

Hi Steve,

I always inform the crew when I sell a chipper with auto-feed never to touch the tach. I've had some customers have their mechanic install something over the buttons to stop the problem. As we both know the only thing you should touch is the auto-feed on/off and leave it at that.

No problem helping.

Dave

 

[Brian B]

Sugarbear,

I have 10 years experience with LOR tachs. Tell me how old is the chipper?

You ever have a lor PDC-X on a bandit 250 where the low rpm will reverse as programmed and immediately following reverse feed wheel goes to forward. If rpm’s rise to high setting then feed wheel stop until low rpm setting is hit again, reverse for 0.4 sec then full feed up rpm until the motor rpm gets up to high setting?

To me it seems like the controller is not activating dump valve a low rpm setting point after the reverse period, and instead activating only a the the high rpm point.
Thanks for thoughts. I’m a day in and completely lost.