I have been getting a little time in on the blade lately, but still learning all I can. I was asking an old time operator for advice or anything he could give me some pointers on. Mostly grading shot rock roads that have eventually become washboarded/potholed and are due for a "Smooth up". The guy told me that whenever trying to get penetration on a stubborn surface, to ALWAYS roll the moldboard FORWARD, so the top edge is 3-4'' forward of the cutting edge. He explained this was for cutting and not carrying, once I needed to carry, then I would roll the blade backwards, not damaging the moldboard itself, but enough to carry material. So a few days later, I was grading one of the fills, blade angled sharp, moldboard forward and spilling material out the heel. It was working fine for me and I thought it looked good afterwards. Another operator saw this and later told me to ALWAYS roll the moldboard BACK to CUT material. I explained how I was previously told and now each other calls the other an Idiot and says he dont know what he is talking about. So I asked some more people and it seemed I got both answers and others said it depends on the material, which makes sense, but what I want to know is... What is the PROPER way to cut/penetrate a stubborn road surface. It seemed more of the "Old skool" guys said forward pitch also. :beatsme Thanks.
G'day Sharky, I certainly don't want to get in to an argument with the "Old School" guys but our grader cuts a whole lot better with the moldboard rolled forward. New blades cut even better again. When you are trying to cut a hard surface next, put pressure on the moldboard in the upright position the roll it forward and you will see the difference straight away. Rn'R.
The only grader I operate is the grader attachment on my Bobcat. Construction Equipment Magazine had an article titled Use all of a Motor Graders Features to Build Roads Better . It had the attached graphic that describes moldboard positioning.
X3Unless your using the rippers your not going to cut much hardpan with the blade pitched back, but you want to keep it back as much as posable and still make your cuts.
blade position I don't think there's a definite answer to this. Too many variables such as material type, compaction, etc., etc. I will though, make a couple points. First, if you have ran your blade in a specific position for a period of time cutting hard packed surface you have ground a particular degree of edge on the cutter. Once that degree of edge is ground into the cutter if you roll the blade back you come off the point of the edge and start using the heel part of the edge and it won't want to cut. If you roll forward you will be using only the point of the edge or the toe of the edge and it will cut better. But if you leave the blade tilted forward in that position within an hour or so (again depending on conditions) you will have ground a different degree of edge on the cutter and lose the effect. Second, a lot of operators will say "put your blade at a specific pitch, start cutting, then roll the blade forward and see what happens, you will immediately start cutting better". They offer that as proof that the blade cuts better rolled forward. I know one oldtimer that will get redfaced and argue that point endlessly. That explanation has no merit at all. The same affect could have been had by simply pushing the moldboard into the ground more with the lift cylinders. The way the blade tilt is designed you automatically lower the cutting edge when you roll your blade forward. Whether you improve the blades ability to cut hard packed surfaces or not is secondary to the fact that you just lowered your cutting edge, adding more pounds of downward pressure on the edge. I normally graded crushed stone roadbeds with my moldboard tilted forward with the top edge about six inches in front of the cutting edge. I'm going to say 80% of the grader's tilt ability forward. So I grind my cutter to certain degree edge after a couple hours. At that time if I come to washboards that I want to cut a simple forward roll of the blade will stand my cutter edge up until I'm cutting on that razor edge only. It will shave the washboards very nicely. Then I roll the blade back to where I was and continue working. That way I always have the ability to roll forward further and get up on that razor edge for a brief time. :cool2 Now let the arguments begin!!!! :drinkup
I might as well add my 02 cents into this. First, I agree with most of what ovrszd has to say. When I grade a road that is very hard or rocky I tilt the moldboard ahead to about 80 percent of the way. This allows my to get a cut and it slides better over the rocks. Now if I'm looking for a heavy cut in looser material I will lay my blade back so that my material will roll off the heel of my blade. Keep in mind that with the moldboard rolled ahead all the way your material is going to carry along with you more so than with the blade rolled back. Ditching for example...try doing this with your blade rolled all the way ahead. Try leveling gravel with the blade rolled ahead. You won't get much accomplished. As said, great for making a cut (not a huge cut) on a hard packed road.
G'day ovrszd, You raise some very good points but for me you also raise a couple of queries. 1. I agree, every situation is different, so there is no standard rule. 2.This is correct and even more so when the blade is getting worn because the heel is wider and will not penetrate unless you roll the blade forward. 3. Here I do differ with you slightly (and I'm certainly not going to get red faced about it) because I have had situations where I can lift the front wheels off the ground trying to cut a hard pan, but as soon as I roll the blade forward, it will pentrate and this is partly due to, like you say, the angle of the heel is altered and the sharp edge is in contact with the ground. 4. My query here is what happens if you have to leave the road after running the blade forward at 80% and you have to cut & grade wet sticky material or cut wet grass where you need the blade right back to be able to slide the material away? The blade would then be riding up on the heel that has been shaped by the gravel road and you would have a very hard time cutting, especially grass. No arguments from me, hopefully I'll come away a bit better operator. Rn'R.
blade tilt Yep, that's a problem alright. I mostly notice that when moving from grading gravel to cutting hard packed clay. When I roll the blade back to better move the cut material I lose the sharp edge at the surface. That's just an affect that can't be avoided. And, it will take a long, long time to grind a new edge angle in dirt!!! I rotate my blades regularly to get better life out of them so it doesn't bother me to change blades. I use a 14ft moldboard with two 7ftx8" cutting edges. They are heavy for sure, but I will still change them if needed. So if I was going into a big dirt job for an extended time, I'd change to new cutting edges to get a sharp tip. I also like to go into winter with new cutting edges to gain back the height I've lost from wear down.
Thanks for the reply's (and tips). I need more time on the blade to strengthen my skills. Always seems there is the "Blade guy" that always gets to do it. Ours is out of town on a highway paving job, so therefore I took advantage of it and just got on it and went. Just looking for the right way to do things. Also A little ammo is always nice to have. I have worn out a few new cutting edges on diffferent dozers, but have yet to wear one out on the blade.
TriHonu, your diagram sez it all, a vital point not often explained enough or pointed out to blade hands new and old. As well my take on it is this, when you are shifting material always have the board tilted back and make a habit of it. The reason is that, this way your edge is continually being sharpened and kept sharp. When you need to cut compacted, hard material to trim to levels, or just generally cutting hard material, the operator ALWAYS has a sharp edge to call upon to do this work by tilting the board slightly forward as required. Believe me, this a blade hand fundamental rule- look after that edge at your peril! Although I prefer not to do it, I often see guys with the board tilted right forward so they can see the back of the cutting edge on the ground as they are trimming, their choice entirely to help them do their job and one could debate it till cows come home.
Well said, pabear52, you make a very good point.:thumbsup Rn'R.
Moldboard Tilt or Pitch Position Hello Sharky, Just got home from Anvik on the Yukon. I also worked at the Pogo Mine for awhile. Post #3 has the General rules for grading. Hard rock surfaced roads that develope chuck holes , need , lots of grader work. This is what I did at Pogo. It took 6 passes with a Cat 16H to grind up the surface. Lean the moldboard forward , if it is really hard, then all the way forward. Put enough down pressure , to cut, but not so much to make the grader spin out, or skid sideways, or lug the engine down. The 1st couple passes generate little material, as it is harder or more compacted near the surface. The succeeding passes get softer and generate more material. Do the whole roadway width, when you have a nice windrow of material , bring it back in with lifts,water and compaction. For your own information, just try the various moldboard tilt or pitch positions, and you will discover very quickly for yourself the position that works best.
Do you work for AIC? Know a few guys who worked for them at Pogo, amongst other places. We did a bunch of clearing/logging for them at the Kensington project. Big Dave and his crew. We just hired a new "Blade guy" on this job. A California dirt/Gps operator. 28 yrs exp. Not so sure he has ever graded rock before. After 2 days on the cat, he had it #*%&$ up. Boss let him loose on finish grade today with the blade, from what I seen this evening, I could have done a better job (Thats not saying much). I will give him the benefit of the doubt and wait a day or two and see how it looks. Cant understand how people BS their way into a job half the time claiming to be "Finish" hand's, when in reality there aint woth dog#$%*.
Work ? Hello Sharky, I worked for AIC at Pogo, and the Dalton, then moved on to other projects. I wasn't excited enough to go Kensington and work in the rain. Don't like the rain after VietNam and the Monsoons. Later, Northart
whatever works for u i normally run the moldboard standing straight up and down for just because seems to me to carry much more material easier.. seems to me that new operators are always running with blade leaned all the way forward probably just because u can see the cutting edge..i do roll the blade forward and back but just slightly to keep a sharp edge as you are always dulling the blade and barely changing the angle of the blade makes it where u can always keep the blade sharp ... seems to me that finishing with blade leaned all the way forward on the caliche and sand and gravel we have around here just pops up rocks in the finish and just makes the blade feel ackward because it pushes the material down into the uncut surfacde instead of letting it flow freely .. and for drifting material from a cut to a fill u can push MUCH more with the blade standing straight up and down.. but every one is different and i am no expert just learning as i go been running 140 g's and h's for the past 11 yrs. learn new things about the blade all the time...
I always like an ace in the hole. I try to maintain the best edge with the best results. Although it is a rare event that I roll it all the way over. If I was to keep my blade in the same position all the time, up, i'd never cut any dirt. You end up just pressing and rubbing a flat piece of steel over the earth but not maniputlating the surface. A motor grader man must know when to, and not, apply his edge. ..as with most operating, just another aspect of the art and skill.
Right on Brother!!!!!!!!!!!!!!!