The ins and outs of milling .

[milling_drum]

Leica mill

:BangheadLeica mill is a GPS based system loaded with schematics of finish grade for this road. The mill is being controled by this Leica mill GPS. All the nitwits running it have to do is steer. The grade is handled by the Leica. As you can see its working great.

The additional picture is us correcting a shoulder paving screwup...I was forced to stop backing up because I was taking down the wire they use to set grade for the pavers....so...why did they screw it up in the first place?

You are ALL welcome to come and join us here if you think you can help or do better.

BTW, I have NO input with the Leica system. After it left a ridge for 20ft and couldn't maintain a simple flush cut I didn't want another second of the BS.

 

[Toegrinder]

I used paveset back in 04 on a pr-1000 at an airport. When it worked it worked great. But when it went screwy it was a nightmare.

 

[Blue Collar]

the best one i think, if you dont like doing maintance you chose the wrong line of work. I get a kick out of newer guys when something major or minor breaks of the mill and they ask what do we do? All i do is smile and say ha now the fun begins-WE FIX IT- i dont know how you guys companies are but when our mill breaks its. it doesnt matter if we dont get any sleep that night if it can get going before the next start time that morning, make it happen.

 

[buddy605]

I would imagine it is like the grader set up that we had and it would not do a good job when the sattilites get low on the horizon. There is a web site that you can go on to tell you when this will happen. Top con has a add on now to add to the gps and it is a rotary laser level and it is surpose to give you millimeter accuracy but it is a 16000 add on to the topcon gps system

 

[Kellogg Report]

Yes, the same rules regarding satellite visibility applies to mills as they do to graders and dozers. However, all machine control systems have a setting referred to as the 'elevation mask' that will exclude low-lying satellites from the GPS position. If, for instance, it is set to 10 degrees, then all satellites lower that 10 degrees from the horizon will not be used by the system. This setting should be evaluated and set according to the geographic location of the job site and the immediate surroundings. The elevation mask can also be used to limit the effect of multipath from nearby objects. (Multipath is when the satellite signals bounce of nearby objects before they are received by the GPS antenna).

As buddy605 said, there are websites available that can tell you the expected satellite availability on any date and most manufacturers of machine control systems offer free programs that will do the same. Some systems also have this functionality on-board the machine.

Additionally, the GPS system can usually detect when the quality of the calculated position becomes questionable and alert the operator. The system should also stop driving the hydraulics if the GPS position becomes altogether unusable.

milling_drum: Did the dealer/manufacturer give you an explanation for this?

 

[milling_drum]

Well they think they have sorted out the Lieca system...THINK they have...

Now The white machine cuts the remainder of lane and takes out white line and FIXES what they can't seem to handle, which are numerous ridges (as pictured) and the holes...can't be fixed...its just a reminder of how great a GPS can be attached to a milling machine.

 

[milling_drum]

Wish I had pictures from today for my friend Kellogg. Within 50 feet of each other in the same pass it goes from 10-12 inches deep back to leaving a 5 inch ridge...

However Kellogg makes the point about GPS controling the machine, I have seen the operators react to the GPS unit and the machine itself seems to be cutting off it manually. Grade is suspect by the product. The cuts look awful and if they pass for a concrete slab over top, I'll be in shock.

Saw a video at Youtube of some Japanese milling with a Saki rubber tire machine. On city work they'd lay an @ss whoopin on pretty much most of the people I've seen milling over here. (including me, of course.)

 

[Kellogg Report]

I am sorry to hear you are still having problems. I'm not sure how to interpret your second paragraph, though. Are you saying the operators could possibly be overriding the automatics?

Leica has been using robotic total stations for machine control applications for many years now and I had almost expected them to use this instead of GPS on a mill. I'm not convinced your problems are due to GPS positioning, but it would be interesting to know if the supplier has suggested running the machine with total stations.

 

[milling_drum]

Its entirely possible my phrasing is incorrect and the system you explain is what they are using. As you can see in the pictures above there are numerous tripods with what I am told are send units. Today they had problems because either they weren't set up right and/or the mill discharge conveyor interfered with the signal from send unti/tripod to the machine.

From what I understand the overall program running the Leica is GPS based IE existing topography. Its the same system that will be used by the concrete paver. Finished plan according to programmed specifications.

The people running the milling machine even without the Leica system are clueless because they have limited experience at all milling. That being what it is, a grade change with operators that don't know what to look for produces a ...

Hilariously bad result as pictured above.

 

[Kellogg Report]

Ah, -that makes more sense. They are using robotic total stations, not GPS. They are using a minimum of two, probably three. They are then leap-frogging them ahead as the mill travels. This principle is borrowed from their paver application.

One wonders if they are reconsidering using this system for paving given they are having so many problems with the mill.

If the crew is inexperienced, I can believe there would be problems. However, the technology works as I have seen it used with Leica, Trimble and Topcon. Leica and Trimble tend to use robotic total stations for this and Topcon prefers a combination of GPS and laser augmentation. -All systems will get the job done IF it is set up and used correctly.

You mentioned the set-up of the total stations. This is by far the biggest potential error source when leap-frogging instruments like they are doing. Each set-up could result in a potential incorrect grade if done incorrectly. There are procedures to check your 'resectioned' position, but they need to be followed, though...

Another potential issue with robotic total stations is that they require line of sight. If an object (such as the conveyor belt, a truck, people, trees, etc.) comes between the total station and the target mounted on the mill/paver, the system can't operate.

I hope they get it running and that the company doesn't get 'burned for life' regarding 3D machine control. It's a great tool, but as with any tool, it is only useful when used correctly.

 

[milling_drum]

Total stations, I've counted as many as four set up on the inside median grassy area usually within a clear sightline of the mill. The groundman has a station as well for apparantly checking grade. There are also a number of pods that do not have a Total station attached too it but rather an unit simular to the antenna on the machine.

The greater difficulty is the crew and operators not knowing what to look for, drastic grade changes mean a correction will be necessary when in fact they could initiate a plan or learn to correct as they go....which they currently do not.

Thank you for your input, I believe the company will stand by the Leica system and continue to use it.

 

[milling_drum]

The Leica Mill has been trying to cut the same ramp for 3 days now. That, after milling 5 miles mainline @ 2% with 2ft crown shift/offset.

 

[milling_drum]

The first buried manhole hit of the year is always refreshing.

While on shoulder widening we whacked a buried manhole. That little treat did something to the W2000 that I've never seen before....the ski is literally broke in half, right at the bell housing. Unfortunatly my PDA is now different and I cannot share a picture.

The manhole ring is broken, the outer part of the drum had a buncha broken teeth and not much more. Thankfully it was in the dirt and not asphalt.

 

[Kellogg Report]

-Ouch!

I hope that was not only the first, but also the last hit of the year.

 

[elimn8r475]

i love the guys who are looking at u right in the mirror as you are waving your arms and yelling stop and the keep going. crcks me up everytime.

 

[milling_drum]

We put a new ski on today....no machine to lift it and very few tools...

 

[csx7006]

the best one i think, if you dont like doing maintance you chose the wrong line of work. I get a kick out of newer guys when something major or minor breaks of the mill and they ask what do we do? All i do is smile and say ha now the fun begins-WE FIX IT- i dont know how you guys companies are but when our mill breaks its. it doesnt matter if we dont get any sleep that night if it can get going before the next start time that morning, make it happen.

sounds like the USMC

 

[Johnc]

Hey Guys, this is my first post on this forum so I hope I'm in the right place. I've been milling for a couple years now and started of with an older w500. As the company I've been working for expanded they purchased a Wirtgen 1200ft. We started getting into smaller road patches and have been getting teared up about the quality of the passes. The right rear track of the 1200 sits right infront of the drum which is the side I can see. Whenever I go over an uneven surfaces so does the machine and I find myself manually adjusting. I've tried pulling out the track which is a great option on the machine and driving it along the gutter of the curb which is usually level and it works. The only problem with this is that it leaves about a foot of unmilled pavement which the boss gives me sh*t for. Is this the right machine for the job or am I just doing it wrong. Would an ultrasonic system work?

 

[milling_drum]

If you go way back in the pictures to share thread you can see me running a 1200F. In my experience with them they hold grade pretty well IF you remember to set the front down a little before cutting the autos on.

I found if you left that rear track folded in for an extended period of time, the grade response and mouldboard get to acting up. Being as I was the solo operator most of the time I would swing the leg back outside the drum to load it onto the Fontaine detach because it wouldn't get up it very well folded in.

They are great machines along a curb line with the leg folded in but they suck trying to manuver because the rear tracks won't steer.

Good luck this season! I learned how to mill in Toronto.

 

[Johnc]

Thanks milling_drum. Im suppose to be going to that wirtgen training center in tennesse this winter. I hope its worth it