How to Precisely Check Alignment

[W8NONU]

This video should probably come with a warning that it may cause violence against drill presses; this test is harsh and unforgiving. I was getting good drills from a cheap bench top drill press (the popular Skill model), then suddenly it was all over the place. Long story short - I bought a Proxxon and it was the best money I ever spent.

I've been looking at the Proxxon Drill and Mill and comparing them to the Micromark. I have lots of experience with the variable speed Micromark. It's a great drill and like the variable speed.

Will definitely add comments to YouTube. Thanks again!

 

[Crash Enburn]

Tom/LightninBoy: Great and informative video.

But one thing bothered me throughout. You are paying such close attention to getting the rear drill dead nutz perfect. But when you add in the DFW, unless you have adjusted the drill to account for it, you'll be adding toe-in or out to your once perfect rear drill.

Curiosity and math got the better of me, and I calculated out height changes (at the DFW) for various net changes in DFW cant angle. I believe that there is even more height added simply because the axle is bent, which then doesn't allow the wheel to be as concentric to the axle hole as it would if the axle was straight. But discounting that small change, these are the height changes you'll see with various degrees of canting:

Degrees	Addt'l Height
5	0.03315"
6	0.03921"
7	0.04508"
8	0.05076"
9	0.05624"
10	0.06152"
11	0.06661"
12	0.07149"
13	0.07617"
14	0.08064"
15	0.08491"

So, at 5° the car is raised a little over 1/32". At 10° , a tiny bit under 1/16" (less than a 256th). At 15°, just shy of 3/32".

This is all using the formula: (COS(°) * 19/32) + (SIN(°) * 13/32) - 19/32

As usual, I'm second guessing myself, and thinking the formula should actually be: ((19/32)/COS(°)) + (SIN(°) * 13/32) - 19/32

And if that's the case, the height changes are even greater, from just over 1/32" at 5°, 5/64" at 10°, to over 1/8" at 15°.

(The rears also end up getting lowered by a very, very small bit (< 1/1024") from their 3° cant, but that really can be tossed out as no change.)

 

[Rat Pack Racing]

Crash, I think LB's video was dedicated to checking your drill only. Getting the axle heights correct so that you don't induce toe in/toe out is another discussion. Your thread gives some good information and would be a great starting point for that article.

 

[HurriCrane Racing]

Hmmmmmm..... Should be an interesting build!

I agree that the blade runner is a great pwd tool!

 

[Quicktimederby]

Incredible Video! Just order me some 1-2-3 blocks. Thanks for sharing!!

 

[microbrush]

Tom/LightninBoy: Great and informative video.

But one thing bothered me throughout. You are paying such close attention to getting the rear drill dead nutz perfect. But when you add in the DFW, unless you have adjusted the drill to account for it, you'll be adding toe-in or out to your once perfect rear drill.

Curiosity and math got the better of me, and I calculated out height changes (at the DFW) for various net changes in DFW cant angle. I believe that there is even more height added simply because the axle is bent, which then doesn't allow the wheel to be as concentric to the axle hole as it would if the axle was straight. But discounting that small change, these are the height changes you'll see with various degrees of canting:

Degrees	Addt'l Height
5	0.03315"
6	0.03921"
7	0.04508"
8	0.05076"
9	0.05624"
10	0.06152"
11	0.06661"
12	0.07149"
13	0.07617"
14	0.08064"
15	0.08491"

So, at 5° the car is raised a little over 1/32". At 10° , a tiny bit under 1/16" (less than a 256th). At 15°, just shy of 3/32".

This is all using the formula: (COS(°) * 19/32) + (SIN(°) * 13/32) - 19/32

As usual, I'm second guessing myself, and thinking the formula should actually be: ((19/32)/COS(°)) + (SIN(°) * 13/32) - 19/32

And if that's the case, the height changes are even greater, from just over 1/32" at 5°, 5/64" at 10°, to over 1/8" at 15°.

(The rears also end up getting lowered by a very, very small bit (< 1/1024") from their 3° cant, but that really can be tossed out as no change.)

This issue has bothered me for a long while. Should be a great discussion.

 

[microbrush]

Incredible Video! Just order me some 1-2-3 blocks. Thanks for sharing!!

What you didn't have them? Everyone watch out! I thought I was the only one with out them. I thought about getting some after Brackets video, but didn't know what they were called.

 

[Mister B Racing]

Tom/LightninBoy: Great and informative video.

But one thing bothered me throughout. You are paying such close attention to getting the rear drill dead nutz perfect. But when you add in the DFW, unless you have adjusted the drill to account for it, you'll be adding toe-in or out to your once perfect rear drill.

Curiosity and math got the better of me, and I calculated out height changes (at the DFW) for various net changes in DFW cant angle. I believe that there is even more height added simply because the axle is bent, which then doesn't allow the wheel to be as concentric to the axle hole as it would if the axle was straight. But discounting that small change, these are the height changes you'll see with various degrees of canting:

Degrees	Addt'l Height
5	0.03315"
6	0.03921"
7	0.04508"
8	0.05076"
9	0.05624"
10	0.06152"
11	0.06661"
12	0.07149"
13	0.07617"
14	0.08064"
15	0.08491"

So, at 5° the car is raised a little over 1/32". At 10° , a tiny bit under 1/16" (less than a 256th). At 15°, just shy of 3/32".

This is all using the formula: (COS(°) * 19/32) + (SIN(°) * 13/32) - 19/32

As usual, I'm second guessing myself, and thinking the formula should actually be: ((19/32)/COS(°)) + (SIN(°) * 13/32) - 19/32

And if that's the case, the height changes are even greater, from just over 1/32" at 5°, 5/64" at 10°, to over 1/8" at 15°.

(The rears also end up getting lowered by a very, very small bit (< 1/1024") from their 3° cant, but that really can be tossed out as no change.)

Yes this was a great video! But I think Crash is onto something here.

As long as the bottom of the car remains flat and parallel to the track, you will have perfect drill. But when you add in the bent axle on the DFW and the bottom of the car is no longer flat and parallel to the track, you technically no longer have a perfect drill.

It would be interesting to see a check done on a body that has a perfect drill, but is set up for racing.

 

[chromegsx]

Crash, I think LB's video was dedicated to checking your drill only. Getting the axle heights correct so that you don't induce toe in/toe out is another discussion. Your thread gives some good information and would be a great starting point for that article.

Agreed, this is for getting your rear as perfect as possible. getting the FDW set and the axle hole at the right height in search of the "perfect" whole car alignment so as to not induce any toe (either in or out) is another discussion...and maybe a path to drive you mad when you factor in that adjusting steer in effect also adjusts your toe on the rear.

Generally it probably doesn't matter as much if you get a little (not excessive) toe out as it will only help migrate the wheels out. Unless you plan to race backward then it might be an issue /images/boards/smilies/wink.gif so as you raise the front end up with the bent front axle you will get some toe out. As you induce more steer via turning the axle it lowers the front of the car and then reduces the toe out.

 

[LightninBoy]

First off - thanks to everyone who added comments on youtube. That's a really, really big help to making sure this information gets consumed versus others (such as those videos involving tread mills).

Regarding the angled DFW raising the body and thus adding toe-out, yeah that's an issue; I just didn't want to address it in that video. As others have alluded to, I was focused on getting the rears holes perfect in complete isolation of all other factors. Maybe in other videos I'll talk about all the different ways you can spoil a good drill.

Once you get these tools in the video, it is pretty easy to see how much certain height difference will affect the toe. Just turn the SB upside down and set the body (with pin gauges installed) on top. Put the 1-2-3 blocks on either side and align the pin gauges to them as shown in the video. Now use something to incrementally raise the front - spacers, feeler gauges, business cards, whatever. In my tests, I have to get around .045 raised (at the front axle location) to see any visual toe change.

 

[GravityX]

Incredible Video! Just order me some 1-2-3 blocks. Thanks for sharing!!

Oh great! Now he's going to get faster... thanks Tom! J/K

Incredible only begins to describe what Tom has provided here. We are racing at a new level folks, hang on to your pants, the competition will be getting stronger! BooYah!

 

[DerbyBoyz]

Thank you Lightnin Boy for the great video! Now I have to order the solid 1-2-3 blocks now. Thanks again, keep the very informative videos coming!

 

[BulldogRacing]

I think Amazon will be getting a flood of orders of 1 2 3 blocks LOL

 

[Vitamin K]

I think Amazon will be getting a flood of orders of 1 2 3 blocks LOL

Ain't gonna lie, was lookin' at 'em myself, earlier. LB should set up one of those things where he gets a kickback if people buy through his link. /images/boards/smilies/wink.gif

 

[Greatred]

I have been trying to emulate the methods demonstrated. I seem to consistently getting a little toe in on both sides. Rechecked my table for level with the drill (Skill/non-praxon), tried a different drill bit, rechucked the drill bit, but I am consistently getting symmetrical toe in on both rears. I must be off somewhere but I am having trouble understanding it. If the table was un-square to the drill, and I flip the block, would not I have toe in on one side and toe out on the other?

I recall you saying something about a feeler gauge and while waiting or them to arrive, I tried placing different amounts of paper first under the drill table to see if I was just wrong about the square of the table, but not effect. Second, I put paper under the block where it hits against the fence on the side with the rear wheels, figuring this would help the toe in on both sides and it did a little but the hole starting being less than the 1/8th" from the bottom I intended.

This got me thinking that I needed to also put a like amount of paper under the pin housed in the block groove on the side with the rear axles. I am getting some long feeler gauges to try this.

Any ideas of what I am doing wrong or how to fix this would be awesome. If pictures are necessary to explain the above, I will have some time likely late on Wednesday night to post some. I have a feeling I am missing something obvious.

Eric Rice

 

[txchemist]

Trying to fix a bad drill.
Got symmetrical bad toe out on both back axles- "A" part of photo.
found problem with my drill press when adding larger base plate. Got good drills out of old process but hard to do some things on a small base- will take a bit more shimming to fix so in the meantime, what if anything can be done to get some use out of the car?

"B" part of photo is drop nose a little. "C" part of photo is drop nose a lot- toe is now perfect, but DFW axle is now above the top of the wood- Fix is to cut car in two and move nose up while letting back of car slope down.

Car is in the "everything is adjustable state" right now. Push to side to set DFW offset to track, twist to make 4 on the floor or 3 wheeler. Infinite drift settings that are repeatable.

Drift tests next ( done with shimming the gap you see-and car will then get epoxy fill in the gap at the middle of car, and then sanded smooth.
We will see if times can show problem fixed.

Yes, I know best fix is burn it and wait for base plate shim fix- but this is real sugar pine and I can't dump it until I do something good with it.

 

[Vitamin K]

txchemist: I like the way you think!

One of the goals I've had in sort of the backburner of my brain is to have a build that is highly tuneable. That is, instead of looking to nail all of the alignment issues in one shot, be able to fine tune the car based on a series of tests, in order to get it to where you want. This is one of the reasons behind my romance with bent axles, but there are other issues regarding that avenue. I have some other ideas in mind, but nothing realized...yet. /images/boards/smilies/smile.gif

 

[jatofau1]

Great video. Thanks for taking the time to share.

I normally go through four to six blocks before I think I have a descent drill job. Now I can really confirm how bad my drill jobs are. I might have to kill a whole pinewood forest to master a good drill job.

 

[bracketracer]

Any ideas of what I am doing wrong or how to fix this would be awesome. If pictures are necessary to explain the above, I will have some time likely late on Wednesday night to post some. I have a feeling I am missing something obvious.

Eric Rice

Eric, I would think your drill press table would have to be cupped to give the results you are seeing?
That is, it's high on the left and right edges as you're facing it and low in the middle. That would cause the nose of the car to be higher each way when you drill and leave you with toe in on both sides. Have you checked the table for flatness?

 

[Maglev]

Also check the play between the column and your table attachment. Two shims of equal size (0.02-0.004" as needed) at the back and front of your drill press table attachment collar on the column will solve your problem!