Well, I got around to putting the scale under the auger with the weights on and got 800# which is what I had originally calculated that it would be. It was too hot and I was too tired to take the weights off and measure without them today but I expect it to be around 200# or so. I will try to get this done on Thursday. The second Wednesday of each month I meet up with a crew of IBM retirees for BBQ in Elgin, TX so tomorrow in not a work day for me. I am picking up a Belltec Puff drill and toothbar for my loader bucket tomorrow on the way to Elgin.
Digging post holes
- Thread starter centex
- Start date
- Views: 25382
knucklehead
Platinum Member
I'd be interested in what the unweighted rig weighs at the auger. If it's 200#, as Don says, then there's 600# being applied by the 336# weights at the auger. 600/336=1.8, and if his top link is 15" long, or 1.25', then L1 = 11.25', and L2 = 6.25', and L1/L2 = 1.8.
Hopefully the numbers will balance out, and help show things more clearly. I'm fully prepared to argue for a localized change in gravity between Tuesday and Thursday, if they don't.
By the way, nice notcher pictures, guys.
Hopefully the numbers will balance out, and help show things more clearly. I'm fully prepared to argue for a localized change in gravity between Tuesday and Thursday, if they don't.
By the way, nice notcher pictures, guys.
I got around to measuring the unweighted rig today. It was 200# as I expected. I measured the lever arms on the tractor also. The long arm from the top link pivot point where the boom is attached is 117.5" and the distance from the top link pivot pin to the pivot pin on the PHD gear box is 64" so the ratio of these two arms is 1.83. The ratio of the weight added to the auger to the weights added to the boom is 1.78. I attribute the discrepancy in the ratios to the accuracy of the the weight measurements. My scale uses a 2.5" 1500# pressure gauge that is divided into 50# increments on the scale and I don't know it's accuracy but it is no better than 10%.
knucklehead
Platinum Member
Don
Just for the fun of it, how long is the top link? This may end up as one of those "close enough" deals, but if you want to know, then let's find out.
Just for the fun of it, how long is the top link? This may end up as one of those "close enough" deals, but if you want to know, then let's find out.
knucklehead, I am not sure what you mean by "how long is the top link?". The boom of the auger is attached to the bracket at the back of the tractor where the top link attaches so the top link is not being used. I have attached a picture of the unit in operation. The boom extention is painted yellow in this picture.
The key thing here is that the unit is working away digging a hole in this picture and I am just standing around taking pictures. Before I bought this auger and built the boom extention, I would have been standing there at the side of the hole beating on rocks with a bar and breathing diesel fumes while the tractor idled away waiting to clear out the rock chips that I made with the bar. Now I just start the machine and it does all the work. It is slow to be sure. It took over an hour to finish the hole in the picture to a depth of 4'. If I were doing it the old way I would have ended up with a post like the old one in the foreground of the picture. When they put these posts in they dug down as far as they could which was maybe a foot or so and then wired a large rock to the post to keep it in the ground. My posts are not going anywhere. Rhino sells a hydraulic down pressure kit for their largest auger for $300. My digger has the same boom as the larger one but if I bought it I would have voided the warranty on the gear box and besides I can appliy more weight with this setup and it only cost me about $20 for the scrap metal. I already had the weights. Everyone around here (the local dealers and the auger manufacturer)told me this auger would not work with a 3PT PDH but they were wrong. In fact they told me I would have to spend a minimum of $2000 for a hydraulic PHD to be able to use the auger.
The key thing here is that the unit is working away digging a hole in this picture and I am just standing around taking pictures. Before I bought this auger and built the boom extention, I would have been standing there at the side of the hole beating on rocks with a bar and breathing diesel fumes while the tractor idled away waiting to clear out the rock chips that I made with the bar. Now I just start the machine and it does all the work. It is slow to be sure. It took over an hour to finish the hole in the picture to a depth of 4'. If I were doing it the old way I would have ended up with a post like the old one in the foreground of the picture. When they put these posts in they dug down as far as they could which was maybe a foot or so and then wired a large rock to the post to keep it in the ground. My posts are not going anywhere. Rhino sells a hydraulic down pressure kit for their largest auger for $300. My digger has the same boom as the larger one but if I bought it I would have voided the warranty on the gear box and besides I can appliy more weight with this setup and it only cost me about $20 for the scrap metal. I already had the weights. Everyone around here (the local dealers and the auger manufacturer)told me this auger would not work with a 3PT PDH but they were wrong. In fact they told me I would have to spend a minimum of $2000 for a hydraulic PHD to be able to use the auger.
Attachments
knucklehead
Platinum Member
Centex, you're right to start that post with "knucklehead" for more than one reason /w3tcompact/icons/smile.gif. Not having a tractor (actually, I bought a '79 Ford 1710 today), I did not know that the PHD's pin directly to the top link bracket on the tractor. The person I bought the tractor from had a PHD, and I saw it, but it did not register that there was no need for a top link.
In looking at your picture with my highly accurate, adjustable eyelash calipers, it seems that if you measured right along the ground, or up level with the PHD top connection to the tractor (where the top link would be), that you would get a slightly shorter length from the PHD to the end of the weight bracket than from the PHD back to the tractor. That's the way to simplify the force diagram; because we are talking about forces in relation to gravity (weights are tending to drop straight down), and lever arms are measured perpendicular to the force (so horizontally in the case, and not along the bracket/PHD). It seems we are coming to the same thing from two directions. I was keeping this discussion going because I don't think measuring from the bottom lift ends (where the PHD attaches at the bottom) is accurate, and would make you think the pressure was greater than it really was, if you only calculated it. As I said, this is really a case of close enough, but a while back we started getting interested in the "math n' science" of it, so I thought I'd toss in my two cents.
The real thing I'm interested in is how is the earth you can stand what must be one hellacious racket while that bit chews through the rock. I'd also be interested in if you guys had any experience or thoughts about running that bit wet; whether it would aid or hinder cutting.
In looking at your picture with my highly accurate, adjustable eyelash calipers, it seems that if you measured right along the ground, or up level with the PHD top connection to the tractor (where the top link would be), that you would get a slightly shorter length from the PHD to the end of the weight bracket than from the PHD back to the tractor. That's the way to simplify the force diagram; because we are talking about forces in relation to gravity (weights are tending to drop straight down), and lever arms are measured perpendicular to the force (so horizontally in the case, and not along the bracket/PHD). It seems we are coming to the same thing from two directions. I was keeping this discussion going because I don't think measuring from the bottom lift ends (where the PHD attaches at the bottom) is accurate, and would make you think the pressure was greater than it really was, if you only calculated it. As I said, this is really a case of close enough, but a while back we started getting interested in the "math n' science" of it, so I thought I'd toss in my two cents.
The real thing I'm interested in is how is the earth you can stand what must be one hellacious racket while that bit chews through the rock. I'd also be interested in if you guys had any experience or thoughts about running that bit wet; whether it would aid or hinder cutting.
wroughtn_harv
Super Member
Don,
Are you using any water? Sometimes a little, not a lot helps in the limestone.
What I'm trying to do here in my own mind is figure out how to take the information you've provided and apply it to my situation.
This picture is of Iris gettin' after it. After it is sometimes harder to get than others.
Are you using any water? Sometimes a little, not a lot helps in the limestone.
What I'm trying to do here in my own mind is figure out how to take the information you've provided and apply it to my situation.
This picture is of Iris gettin' after it. After it is sometimes harder to get than others.
Attachments
wroughtn_harv
Super Member
wroughtn_harv
Super Member
After It was in the bottom of a hole eight feet deep and two feet across.
But that was in regular old black clay, nothing special, just ugly dirt that that's harder than a bad girl's heart when it's dry and like roofing tar when it's wet.
What I'm thinking about now is how and where to attach some weight for those days when I need to fulfill the engineer's request for two feet into rock.
I can't run a boom like you have because the angle of the dangle changes with the position of the boom on Iris. She swings in an arc where the auger motor is closer at the top of her reach.
Yeah, to keep the hole straight I have to move in and out with Iris as I'm going up or down.
She (Iris is a girl, I checked) will only pick up about fifteen hundred pounds. So if I have two hundred and fifty pounds of auger motor and auger and a block of steel for weight of say six hundred that means I could only get it out a little bit from the front of the tractor before I'd have the auger stuck when you add the weight of the tailings from the hole.
So what I'm thinking about is how to have a weight of about four hundred pounds that I could rotate hydraulically (sp). That way I could have it between the tractor and the auger and it would only weigh four hundred, maybe a tad less. Then when I need the down force I could rotate it where it would hang out beyond the auger say four feet which would give me about twelve hundred pounds of down pressure since the auger point is only about thirty inches from the front tires.
Of course if I built the weight right I could have it supplying ballast on the back of the tractor when it's rotated back to rest position which would give me more lifting capability............the thicken plots..........
But that was in regular old black clay, nothing special, just ugly dirt that that's harder than a bad girl's heart when it's dry and like roofing tar when it's wet.
What I'm thinking about now is how and where to attach some weight for those days when I need to fulfill the engineer's request for two feet into rock.
I can't run a boom like you have because the angle of the dangle changes with the position of the boom on Iris. She swings in an arc where the auger motor is closer at the top of her reach.
Yeah, to keep the hole straight I have to move in and out with Iris as I'm going up or down.
She (Iris is a girl, I checked) will only pick up about fifteen hundred pounds. So if I have two hundred and fifty pounds of auger motor and auger and a block of steel for weight of say six hundred that means I could only get it out a little bit from the front of the tractor before I'd have the auger stuck when you add the weight of the tailings from the hole.
So what I'm thinking about is how to have a weight of about four hundred pounds that I could rotate hydraulically (sp). That way I could have it between the tractor and the auger and it would only weigh four hundred, maybe a tad less. Then when I need the down force I could rotate it where it would hang out beyond the auger say four feet which would give me about twelve hundred pounds of down pressure since the auger point is only about thirty inches from the front tires.
Of course if I built the weight right I could have it supplying ballast on the back of the tractor when it's rotated back to rest position which would give me more lifting capability............the thicken plots..........
Mark, sorry about the "knucklehead". I did not mean it that way. I measured the straight line distances from the top link pin to the pivot pin on the PHD gear box and from the top link pin to the center of the weights. I assume the lift pins play no part in this because when the PHD is in use digging the lift is not used except to pick the PHD up when the hole is finished. I don't claim that the weight measurements are very accurate because the scale I am using is very small and uses a 1 sq inch piston to create a reading on a pressure gauge. That way 1 pound on the scale equates to 1 a 1 psi reading on a pressure guage. It is very hard or I should say impossible for me to get the auger exactly centered on the scale and exactly perpendicular to the ground and if either of these conditions is not met then the reading will be off some. Also the granularity of the the guage readings is not small either.
The noise is horific especially if I keep the hole cleaned out. I did that on the first few holes I dug with the auger but now I don't do that as much and the noise is muffled some but it is still enough to be damaging to one's ears so I wear ear plugs and get off the tractor and stand back aways so the noise is not so loud. I put something between the interlock switch and the seat so the PTO still operates.
I don't think water would help with this bit since I am drilling solid rock. The bit just grinds the rock into a powder. It is so fine that it is sometimes hard to get out of the hole. I pick a load up with a manual PHD and it just falls out when I lift it. As suggested by Harv, I sometimes put a little water in the hole to help with this. The bits on the auger are bullet shaped carbide and they are supposed to rotate in their sockets sockets so that they wear evenly. I would be afraid that water would create a grinding paste that would get into the sockets and grind them away so that the bits would not stay in. The dealer told me I should put oil in the sockets periodically so that they stay free to rotate but I have not done so for the same reason. I check that they are free to rotate every time I remove the auger from a hole.
The noise is horific especially if I keep the hole cleaned out. I did that on the first few holes I dug with the auger but now I don't do that as much and the noise is muffled some but it is still enough to be damaging to one's ears so I wear ear plugs and get off the tractor and stand back aways so the noise is not so loud. I put something between the interlock switch and the seat so the PTO still operates.
I don't think water would help with this bit since I am drilling solid rock. The bit just grinds the rock into a powder. It is so fine that it is sometimes hard to get out of the hole. I pick a load up with a manual PHD and it just falls out when I lift it. As suggested by Harv, I sometimes put a little water in the hole to help with this. The bits on the auger are bullet shaped carbide and they are supposed to rotate in their sockets sockets so that they wear evenly. I would be afraid that water would create a grinding paste that would get into the sockets and grind them away so that the bits would not stay in. The dealer told me I should put oil in the sockets periodically so that they stay free to rotate but I have not done so for the same reason. I check that they are free to rotate every time I remove the auger from a hole.
