I'll explain better, and show and tell next time we get together. But what I am saying is 90 degree angle to a 90 degree angle is square. But a 90 degree angle to a 89.7 degree angle is not square. In PWD life !!! [ .3 of a degree ] miss is all it takes to not a have a perfect rear alignment. That will work easy in a cub scout race, but what I am saying is it won't work when your taking on the big dogs in the NPWDRL league. And also cant is up and down angle of a degree, toe-in and toe-out is the degree angle forwards and towards the back of the car. Forward and back angle is what your looking at on graph paper. I am just saying I don't think I can see .3 degrees on graph paper maybe I can see 1 degree. But of course I wear glasses
...SPIRIT.....by the why Mike that is about how much your alignment on your car "Punisher" was off .
How do you guys
- Thread starter TRE
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+1 to Spirits comments...
I have seen on other sites where they recommend using pins sticking out of the axle holes and graph paper to check for correct drilling and that really tells you nothing. The very smallest amount of misdrilling will make a first place car a last place car. The very most important part of you build is done at the very beginning when you car is drilled. I know a lot of guys here like the drilling jigs because they are easy and don't require a drill press, but any slop in the bushing/drill bit will give you variance.... and you have to have slop for the bit to turn in the bushing.... that being said, any bending of the drill bit, movement, vibration when using the Silver Bullet can also give you variance..... there is no fool proof method for drilling holes. With every method you have to look at the good and bad about the method, practice and try to eliminate the variables that make that method fail.
The only true way to tell if you drilling is good is rolling the car back and forth during building and also running the car down the track.
I have seen on other sites where they recommend using pins sticking out of the axle holes and graph paper to check for correct drilling and that really tells you nothing. The very smallest amount of misdrilling will make a first place car a last place car. The very most important part of you build is done at the very beginning when you car is drilled. I know a lot of guys here like the drilling jigs because they are easy and don't require a drill press, but any slop in the bushing/drill bit will give you variance.... and you have to have slop for the bit to turn in the bushing.... that being said, any bending of the drill bit, movement, vibration when using the Silver Bullet can also give you variance..... there is no fool proof method for drilling holes. With every method you have to look at the good and bad about the method, practice and try to eliminate the variables that make that method fail.
The only true way to tell if you drilling is good is rolling the car back and forth during building and also running the car down the track.
So what you're saying Doug is you can help me fix it right? And so me how I can get it perfect everytime?
Hey guy's I don't know if anyone has even looked at this but. We are talking about wood here, it shrinks it swells it changes every day it's never going to be the same from day to day. therefore the drilled hole are going to change It's my opinion there is no such thing as perfect alignment. But I am new to this but I have almost 30 years building scale r/c and competition C/L planes. wood changes from day to day.
You can drive yourself crazy trying to get perfect alignment I don't think it's going to happen, best we can go for is really good alignment.
I understand what all of you are saying I am just trying to help someone understand why the car will change from the time the roll test to the end of the build. Wood is under stress and when we cut it, it gets relieved therefore it changes when its drilled it changes, when it's painted it changes.
Guess what I am saying we can only do the best we can do.
You can drive yourself crazy trying to get perfect alignment I don't think it's going to happen, best we can go for is really good alignment.
I understand what all of you are saying I am just trying to help someone understand why the car will change from the time the roll test to the end of the build. Wood is under stress and when we cut it, it gets relieved therefore it changes when its drilled it changes, when it's painted it changes.
Guess what I am saying we can only do the best we can do.
Yes and Yes to PDHRacing and ODD's reply's. And as always 5KIDS says things so much better than I can communicate them
....SPIRIT....
PDHRacing said:
You are right, but I would pick a drilling method that has the higher chance of giving me "really good alignment". I wouldn't go out to cut wood with a screw driver, I would bring an axe.
I understand 5KidsRacing all I was trying to do is help someone understand why their car will change during the build. It happens to me all the time just when you think it's good it goes to crap.
You guys are great and I look up to you for advise and to point me in the right direction, just trying to help (with what I can.)
You guys are great and I look up to you for advise and to point me in the right direction, just trying to help (with what I can.)
Everybody helps here PDH! I learn things all the time! Whether a question or answer is right, wrong or unknown it is all helpful to us.... we all learn from each others comments. I am not always right for sure.... there are things I have posted years ago that I cringe when I read now days... lol... thank goodness the PDDR erased my early existence so I don't have to look at too many of those posts! But really we learn from each other and there are no real dumb questions or answers.... and to be honest there probably isn't any right or wrong. Have fun and try to improve from month to month.
I guess all that I was trying to say was to "quickly" check with the graph paper and NOT to eliminate the roll test. Let's say you roll test the car and it doesn't roll correctly. A quick, although not 100% accurate, would be to place is on the graph paper to see if anything is out of square, so to speak.
I agree you cannot tell if the drill is off .3 degrees and yes in the pinewood derby world that is tantamount. .3 degress over 1/2" cannot be seen with the naked eye without precision measuring tools. Now extend those axles to 6 or 8 inches, now you might be able to see it being off square by that .3 degrees. .3 degrees is nothing in a small perspective but keep extending the axle way out and eventually .3 of a degree here on earth could open up to a mile the farther you get away in space.
What it boils down to here is roll test the car!
I agree you cannot tell if the drill is off .3 degrees and yes in the pinewood derby world that is tantamount. .3 degress over 1/2" cannot be seen with the naked eye without precision measuring tools. Now extend those axles to 6 or 8 inches, now you might be able to see it being off square by that .3 degrees. .3 degrees is nothing in a small perspective but keep extending the axle way out and eventually .3 of a degree here on earth could open up to a mile the farther you get away in space.
What it boils down to here is roll test the car!
GravityX said:
Exactly, and I would during it often during the build process... PDH is right that things can shift during the build. I know I am in the minority, but I glue in my weights for that reason. I want the body as rigid and stable as it can be before I drill. I also think that it helps over time keeping the alignment.
I hear what you guys are saying and I agree with it, but I also think using drill rods and graph paper is a quick way to determine if you should even bother sticking wheels on a new body and seeing how it rolls. Here's two pics of a new car I was struggling with before the last race. It was .010 slow. Can you see why?
One side looks pretty close
But this doesn't look right at all
Now, at the same time, using the same setup, I drilled the rear axle holes on this car. It had a noticeable dog tracking. Which was appropriate, since it ran like a dog too.
Just to prove I'm not completely without luck, I had drilled two more cars at the same time also using that same setup. They are close enough that I can go ahead and assemble them and see how they roll.
So what happened? I think along the way I got a bit of sawdust under the parallel I was using to space the body up in the vise. Before the sawdust I was looking pretty good, but all the holes after it got in there are toed. I thought I blew all the dust out, but obviously I missed something. If I had used the graph paper before I put the car together I could have used the time I wasted on the first car on drilling another car. So maybe use it not as a final check but as a QC check along the way.
One side looks pretty close
But this doesn't look right at all
Now, at the same time, using the same setup, I drilled the rear axle holes on this car. It had a noticeable dog tracking. Which was appropriate, since it ran like a dog too.
Just to prove I'm not completely without luck, I had drilled two more cars at the same time also using that same setup. They are close enough that I can go ahead and assemble them and see how they roll.
So what happened? I think along the way I got a bit of sawdust under the parallel I was using to space the body up in the vise. Before the sawdust I was looking pretty good, but all the holes after it got in there are toed. I thought I blew all the dust out, but obviously I missed something. If I had used the graph paper before I put the car together I could have used the time I wasted on the first car on drilling another car. So maybe use it not as a final check but as a QC check along the way.
Oh my gosh, I didn't know a "10 foot pole" was being used. I was thinking along the lines of normal 2 inch gauge pin or less. MY BAD
I guess what matters I guess is double and triple check along the way, as many ways as you can. In my book you can't over do the process of getting the best alignment as possible, and PDHRacing is right nothing is perfect, you just have to strive for getting it perfect as you can. Thank's Bracketracer I like show and tell
....SPIRIT.....
Bracket great item to bring to the forum... From your question alone I have picked up several key factors to work on my next build... I appreciate your pictures.. I can see where you are on this and now I know from your thread...
Sorry this happened to this car and hope things get better as you continue...
Sorry this happened to this car and hope things get better as you continue...
Exactly! Thanks for displaying those pictures.
bracketracer said:I hear what you guys are saying and I agree with it, but I also think using drill rods and graph paper is a quick way to determine if you should even bother sticking wheels on a new body and seeing how it rolls. Here's two pics of a new car I was struggling with before the last race. It was .010 slow. Can you see why?
One side looks pretty close
But this doesn't look right at all
Now, at the same time, using the same setup, I drilled the rear axle holes on this car. It had a noticeable dog tracking. Which was appropriate, since it ran like a dog too.
Just to prove I'm not completely without luck, I had drilled two more cars at the same time also using that same setup. They are close enough that I can go ahead and assemble them and see how they roll.
So what happened? I think along the way I got a bit of sawdust under the parallel I was using to space the body up in the vise. Before the sawdust I was looking pretty good, but all the holes after it got in there are toed. I thought I blew all the dust out, but obviously I missed something. If I had used the graph paper before I put the car together I could have used the time I wasted on the first car on drilling another car. So maybe use it not as a final check but as a QC check along the way.
I don't mind posting my mistakes. Heck, I named two cars after them so far!
If I ever get one right, I'll post it too!
If I ever get one right, I'll post it too!
Gee weez, if everyone posted all their mistakes on this board, there will not be any room to post anything anymore. SO LETS KEEP OUR MISTAKES TO A MINIMUM SHALL WE
.....SPIRIT......
Cool thinking there Bracketracer!! Pictures are worth a thousand words and that there is proof. Where did u find the long drill blanks? if you don't mind me asking. If so don't worry about it.
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