Who Backdrags?

[Construct'O]

A couple things that i backdrag for is when working in mud which has been mentioned. Trying to smooth up without foot deep ruts to hold water.

When having to working in muddy conditions sometimes it is faster,easier,and the only way that you can finish the job.

Also if clearing small and scattered brush and trees after i corner one out i will push pass the hole a little then just back drag loose dirt back in the hole and move on to others.Big trees is a different story.:usa

 

[grunk36]

Hello, Grunk36.
So what you are saying is that there were no REAL dozers until the Cat D10 came out in 1978? I faintly suspect that there might be some who would disagree with you on that one. Me, I'm only curious so I'd just like to ask a question, if I may. May I enquire what built or cleared so many roads and airfields during WW2, what destroyed so many pillboxes and other fortifications in the same war, what built so many highways, railways, dams, etc., and cleared so much farmland in the years leading up to the release of the first REAL dozer in 1978?

Personally, I don't think we have strayed very far from the topic at all because we are still talking about back-blading/back-dragging. We have simply extended the topic scope to cover the effects of this practice on the machine itself which, for anyone who is familar with this forum, was always a foreseeable event.

can i then ask you why do you think they made the dozers with elevated drive i am sure its not because it made the machine worse,, i have never said that the old dozers didnt do anything good but the progress have made the dozers a hell of a lot better i cant imagine anyone today that would rather sit in an D6 from 1965 than in an D6T from 2008 i have tryed driving the old one to even though it is older than me and that is the worst pain ive ever tryed:Banghead:Banghead
which dozer is must productive/effective of those two???i will surely bet my money on the newest model i am not into the older models at all better off melting the metal from them down to use in the newer ones

 

[dieseldave]

If I am bulk pushing and not slot dozing,that is I am trying to build a berm etc I will collect my windrows as I go.You can doze at an angle to windrows and pick them up in such a way as to have a bladeful at the end of your push.You can't get much more efficient than that.If you have material rolling off of your blade that is wasteful technically.I also will not be backblading in this case unless there is a special reason to.
When backblading with a PAT blade you will angle the blade to create a windrow in the direction you are moving your material which means that you will roll the material in that direction going forward then reverse the angle to cast it the same way backing up.
The float position should not be used while backblading as you have no control of the finished product,all you will have is windrows which look worse than not backblading at all.
You can still do nice looking work without backblading but there are times that you need that extra touch and as was said earlier,you might just need to move some material for whatever reason and that is the most obvious and efficient way to do it.Ron G

The "special reason" in my case is that I'm working for the govt.:usa It was explained to me from the get-go that there's "the right way, the wrong way, and the govt. way. We're gonna do things the govt. way". I agree that having dirt rolling off the blade is wasteful, but the corps likes to see dirt rolling, the more the better, hence the big windrows. When in Rome...ointhead Actually, the pic I posted isn't a good example for what I was trying to explain, anyway- those big windrows would be pushed to the dike in the next pass. I was referring to the small windrows left at the end, in which case I would work the machine in both directions, as you stated in an earlier post.

 

[AtlasRob]

Wow ( wheres the smiley thats ducking ) I have operated dozers and can put one to work BUT do not class myself a dozer operator ( some would say duck operator either )
When I read the original question, Yes I backblade, but if I do then only in float to wipe out a windrow. BUT yes I back blade to get material away from a face or corner, as stated its a tool to use not abuse. :drinkup

 

[SKOAL]

lol theres novice blade sharpeners and dil bags that say they never back drag thats poop! you have to use the machine whatever way you have to use it with that said i ve never had to smooth my forward path by dragging dirt back your just not getting it right the first time ,"at least until i learned how" and not putting pressure on the blade and floating it while you still have to cut a grade is a waste of time, iam balls out in r passing that dumb f sharpening his blade hmm wilst we are on the subject I constanly move the blade when grading and pushing yet ive had heated arguments with those who dont ???

 

[Iron Horse]

Just a bit of common sense from the "RUBBISH" poster . No matter how tight the tracks are on a low sprocket machine , when pulling in reverse the sprockets are PUSHING the the lower length of track chain AWAY from themselves , and NOT pulling the chain towards themselves . grunk36 it is easier to pull a chain than push one .............

 

[Deas Plant]

Real Dozers Back-blading/Back-dragging.

Hello, Grunk36.
I will not argue the point with you about productivity because it is patently obvious that the newer dozers are bigger, heavier and more powerful that their predecessors and it is size, weight, balance and horsepower that gets earth moved most efficiently. They also have more electronic gadgetry to go wrong, give trouble and cause the fitters and management severe headaches trying to cure the problems.

What I AM saying is that there WERE real dozers before the Cat high sprocket drives, that they did REAL work really well and DID bunch up slack track chain between the sprocket and the rear track roller when travelling in reverse and that it had nothing to with operator slackness. It was simply a fact of life and the only way to avoid it was to have the tracks adjusted way over tight.

A lot of people were dead against back-blading in any way, shape or form because it was believed that the blade base could be damaged and/or that it was a sign of a bad or incompetent operator or both. I'd happily bet that there were more dollars worth of damage done to tracks through back-blading/back-dragging than was ever done to blades and yet very few mentioned it as a reason for not working in reverse.

One thing that is not well known is that high sprocket drives actually accelerate pin and bushing wear because the track chains have to bend around 3 radii instead of 2 in a full circuit of the track and all of those radii are smaller than the same radii in the equivalent oval track machines. It wasn't until sealed and lubricated track (SALT) was developed that high sprocket drives became viable because SALT so dramatically reduced pin and bushing wear.

Just for chuckles, would you please tell me when the first high sprocket drive production crawler tractor was made.

Quote from Grunk36:
"better off melting the metal from them down to use in the newer ones '
Unquote.

Boy, that comment is going to get you just a tad offside with a few folks on this forum and a lot of other vintage machinery forums around the 'net. You are entitled to your opinion. Just don't expect a lot of agreement with it.

 

[95zIV]

in my opinion oval drive is not a real dozer

I guess the 575 doesn't count as a "real dozer"? I don't have much time on bulldozers but like any piece of equipment there are certain things that apply here. Yeah the new dozers are nicer, smoother, faster, but even with all of those new gadgets and gimicks I'd like to see some of these people who won't get on an older machine keep up with those same older machines. Size does count but put your average operator with that narrow mindset on a machine and all you've got is a guy sitting there moving controls and some material. Take one of those other operators who WILL get on ANY machine and OPERATE it and it won't matter what size or age machine they're on they'll walk all over the first kind all day long.

 

[grunk36]

I guess the 575 doesn't count as a "real dozer"? I don't have much time on bulldozers but like any piece of equipment there are certain things that apply here. Yeah the new dozers are nicer, smoother, faster, but even with all of those new gadgets and gimicks I'd like to see some of these people who won't get on an older machine keep up with those same older machines. Size does count but put your average operator with that narrow mindset on a machine and all you've got is a guy sitting there moving controls and some material. Take one of those other operators who WILL get on ANY machine and OPERATE it and it won't matter what size or age machine they're on they'll walk all over the first kind all day long.

i do not like the low drive dozers at all and not the komatsus either if i should drive an komatsu dozer my legs would have to get an extra knee i CANT get my legs in those japanese size machines but that is the worst i can say about them they can push allmost the same as there cousin cats

 

[grunk36]

Just a bit of common sense from the "RUBBISH" poster . No matter how tight the tracks are on a low sprocket machine , when pulling in reverse the sprockets are PUSHING the the lower length of track chain AWAY from themselves , and NOT pulling the chain towards themselves . grunk36 it is easier to pull a chain than push one .............

i agree with that but i was talking about the highdrives didnt think about the lowdrives

 

[grunk36]

One thing that is not well known is that high sprocket drives actually accelerate pin and bushing wear because the track chains have to bend around 3 radii instead of 2 in a full circuit of the track and all of those radii are smaller than the same radii in the equivalent oval track machines. It wasn't until sealed and lubricated track (SALT) was developed that high sprocket drives became viable because SALT so dramatically reduced pin and bushing wear

this i am with you on deas i agree with that

 

[Sparffo]

I never do, I like the looks of the tracks in the dirt

Thats true!


I think Dozer575 is right on spot when it come to blade wear! of course there is some more wear on the blade when backdraging, but the dirt packed behind the blade acts as a bearing wich prevents wear to some point.

usually i only push forward, only when preparing the motocross track i use to backdrag the jump faces to make a nice and smooth finnish!

Here in Finland there is almosta always quite a lot of head size stones in the sand, so when backdraging the finnish is really bad...

 

[F-1.08-F.G.]

.One thing that is not well known is that high sprocket drives actually accelerate pin and bushing wear because the track chains have to bend around 3 radii instead of 2 in a full circuit of the track and all of those radii are smaller than the same radii in the equivalent oval track machines.

Dear Mr. Plant:notworthy,
Just to clarify your post about track wear on elevated sprocket machines... Are you saying that the track chain experiences more wear because the chain has to go around three bends instead of the 'standard' two? Or are you saying that, because of the severity of angles produced by smaller sprockets/idlers AND the fact that the chain actually spends more time 'becoming' bent and subsequently straightened to and from a more severe angle?
I see the light in either side of the statement... just trying clarify. Thanks

 

[CatSkinner77V]

highdrives are ****. we have a D8N and numerous D8K's... the K's out push the N no matter the conditions. and the undercarriage wears out twice as fast on the N. It takes more horse power to pull the rails around 2 idlers than it does just 1......
after having taken my first D8 transmission apart many years ago... i soon realized that the reverse directional clutch is smaller than the forward directional clutch... ever since i have not once back dragged. if a cat was designed to back drag it would have a blade on the back of it.

 

[Deas Plant]

Did I say THAT??????????????????

Hi, F-1.08-F.G.
Welkum two ther 4um.

Ackshully, I meant both. They travel around 3 bends instead of 2 and all bends are of a smaller radius than those in similar-sized oval track machines.

To some extent, I can understand the reason for the smaller idlers in D7 and up because of the rocker arrangement with the adjacent roller bogies. I can also to some extent understand why the sprockets are a smaller diameter than the previous oval track models, to fit in above the track frame with overly increasing the height of the jigger. Not for love or money can I figure out why they went for smaller idlers on the D6's and down where there is no rocker assembly being shared with any roller bogies.

On top of that, Catskinner77V (I do like a man of conviction.) is right when he says that it is harder to drag the track chain around 2 idlers than one. He didn't mention that the smaller radius of the high sprocket tractor's idlers make it even harder still.

Having said all of the above, I'd still take a high sprocket drive machine. D8R and above, for a hard day's work ripping or pushing rock over an earlier oval track dozer any day 'cos, IMHO, they DO ride smoother than the older machines due to the idlers being on rocker assemblies with their adjacent roller bogies. The D6's and down don't have that and the D7's are just a little light for much serious ripping in rock. Gotta consider my pore ol' bones these days. LOL.

 

[Iron Horse]

Is sprocket wear less on a high track machine , as most of the abrasives would fall from the chain before it gets to the sprocket ? A high track machine also looks like the chain could jump a tooth or two when they get a bit of wear as they seem to only have several teeth in contact . Can this happen , especially when hard clay packs in the chains ?

 

[trackfanatic]

my $0.02

One of the factors affecting wear on the high vs low debate is the number of links of the chain that the sproket is bearing on, ie that on a high drive the sproket is only fully engaging on under a third of it's teeth, on a conventional half the sproket is engaged. My expereience is that undercarriage life is not much different in either, and has more to do with other factors than this.

On the new versus old debate i say this: Grunk 36, in my shed is a D6R. In my neighbours shed is a D7E 47a. The D7 was built way back when, and has 160 HP. I will absolutely guarantee that the 7 could push the 6 backwards, and probably do it in 2nd gear. I can absolutly guarantee that I can repair the 7, I can't say the same for the 6. So which is better????

Oh and I'm 6'2" and have no trouble fitting into the one komatsu I own.

 

[OCR]

Hurry up Deas.

 

[Deas Plant]

Track wear on high sprocket machines.

Hi, Iron Horse.
Contrary to what some people would have you believe, Cat did not design and build the high sprocket drive to annoy D8Bob/Dozer 575 or Grunk36. The original idea was to get the contact between sprocket teeth and bushes up out of the dirt, mud, sand, rock, whatever. It worked. The fact that only 3 or 4 teeth are taking the load of driving each track at any one time does not matter. In spite of appearances, there are only 3 or 4 teeth on an oval track machine taking any real load at any one time too. Even though there are many more teeth actually 'meshing' with the chain, they are not taking any real load.

I suspect that hard-packed clay could cause the teeth to fail to mesh properly and 'jump' but I have yet to have it happen on any high sprocket machine that I have operated. It seems that if it is soft enough to be picked up by the tracks, it is usually soft enough to also fall out again as the track goes on its merry way up to the sprocket. Remember that the track chain is partially inverted on its climb up to the sprocket.

The first 2 D10X experimental dozers had top carrier rollers similar to the 'R' and 'T' series high sprocket drive machines. Then Cat decided to delete the top carrier rollers from D10X3 and D10X4. They also chose not to fit top carrier rollers to the first production run D10's, the D8L's, D9L's, D8N's, D9N's, D10N's or D11N's. I suspect that the idea behind this was to get more weight of chain hanging down from the front of the sprocket to improve the 'bite' of the teeth. What it really achieved was to leave a great long stretch of track chain whipping furiously up and down with the potential for huge amounts of needless wear and impact for no great gain in tooth grip.

They remedied this defect with the 'R' series and I believe they made an optional retro-fit carrier roller kit for earlier machines.

Hi, Trackfanatic.
I suspect that you may be right about that old 160hp 47A D7E pushing the D6R backwards. I have no doubt at all that a 180hp D7E would do it, even though the D6R is pretty much the same weight. I also wouldn't mind putting a 2U/13A D8 at 130-140 hp up against a D6R, just for interest's sake and to try to remedy that 'cat-poison'.

I'm also with you on the repairability bit. Whizz-bang electronic gadgetry does not necessarily make for a better machine. It does make them more complicated and gives more things to go wrong that are often a LOT harder to correctly diagnose.

The same thought occurred to me about people not fitting into 'Kummagutsa' dozers when Grunk36 mentioned it. Is he 6' 14" tall or something? I know I'm only a runt at 4' 21" but I NEVER had any problem with leg room or operator space in any of the 'Kummagutsa' machines that I have operated, even down to a D41S track loader.

Grunk36, I notice that you have not yet tried to answer my question about the first high sprocket drive crawler.

Hi, OCR.
Quick enuff?????????????????????????????????????

 

[Deas Plant]

Wunn Wilde Beeste

Hi, Sparffo.
That D6C of yours is certainly 'wunn wilde beeste' with the fuel tank on the side like that and the other 'little extras' that it has. Would you still have a photo of the steering set-up to post here so that people can see what wonders have been wrought within the cabin? I suspect that some eyebrows might disappear into some hairlines. LOL.

Thanks for sharing.