Length of level needed

[Chuck Keysor]

Hello, last fall, I bought a used PRT 144 (5 x 12 working area) that has been upgraded to an alpha. The unit is fully disassembled.

What is the minimum length of level is needed to align this size of unit? Is there any advantage in having a level which is longer than the required minimum?

Levels, up to 8 feet long are on sale locally through the end of the week. So I thought I had better buy this, even though I am still not ready to put my unit together.

Thank you for your suggestions and advice, Chuck

[signtist]

That 8' level seem like a little over kill to me.
A 4' level is what I used.
I would not use a torpedo level for something this big and important.

[bcondon]

The larger the level, the more accurate you will get. I did use a 8' because it was on sale. I happen to use it on a couple of building projects but in this case, longer (IMHO) is better. The 8' also will span the rails side to side where the 4' may be shot.

Bob

[garyb]

A Straight edge and a 4' level will do the same ;)

[blackhawk]

If you do decide to buy a new level, you might want to consider a 6' level. The 6 foot level comes in a little more handy for building projects that you may have in the future. If you hang any doors, the 6' level is perfect for setting and shimming your jambs. Especially indoors, the 8' level is a little cumbersome.

[Chuck Keysor]

Thanks for the feedback. It is all useful and appreciated. Perhaps I should have asked what is the most desirable length of level to use for aligning my 5' x 12' PRT alpha? IE, what will be the most convenient and reliable size of level? Thanks again, Chuck

[cabindoors]

I would suggest a self leveling laser level. They are dead on accurate. If you know a building contractor buddy, borrow his.

[Gary Campbell]

I am with Gary B. on this one. I use a 4' digital level and an aluminum straight edge long enough to reach cross corner.

[rb99]

I think the laser level would be a must, and a 4' level with an 8' extrusion as a checking level would be best.

RIB

[michael_schwartz]

I used a 6' stabila level and a 50" aluminum straight edge from Lee Valley. To extend the level to check diagonals I used a piece of lumber straightened out on the jointer.

Buy a good level, you will thank yourself.

[ssflyer]

I used a 6' level, among others, but noted that every level I tried was a bit off, itself. They aren't the newest, but not garbage quality, either. Instead of taking the time to adjust the levels (too much in a hurry to get it setup!) I simply checked with the levels running in both directions, and split the small difference. The small variance wouldn't matter in most projects, but I wanted my table dead on the money.

[toych]

A very good 4 foot level and a digital inclinometer or a dial guage for the spindle.

[navigator7]

There is an app for that!
I have several 'level' programs on my iPhone.
Provided you have a suitable straight edge and no bulky enclosure over the iphone....its my tool of choice when being anal isn't a waste of time.
It usually rings when you are getting ready to attach something exactly.

[Chuck Keysor]

Hello everyone. I finally got around to re-assembling my used PRT alpha 144 x 60. I can now say that I needed an 8 foot level!

I started out with a 6 foot level, but found that was NOT long enough to reach from side to side. I did make a good straight board for my level to rest on, but because I was trying to get gaps to be .003" or less, I really couldn't count on my straight board. With the 8 foot level, I could move the side C channels until I got them exactly level and on the same plane.

Then, when I started to level out the lengths of the x rails, which are 14 feet long, I really wished that I had a 14 foot long level! But by starting at one end with the 8 foot level, and then moving the level down the rail, I think I was able to very well shim things to be flat within .003 down each entire x rail.

Thanks, Chuck

Notes:

a) I have a laser level, with a rotating head on a surveyor's transit. I tried that, but the beam width is about 1/8" wide, so there is no way I could use that when I was trying to get gaps to be less than .003"

b) I bought a Wixey angle gauge, and that was invaluable! That allowed me to check the level out on the edge of the machine, when the vial was in the middle of the machine.

c) Warning, I had my Wixey angle gauge on a vertical face of the X gantry, and tapped the iron. Boing! The Wixey popped off, and onto the cement below. That killed it....... (Ironically, while I had the Wixey resting on top of my aluminum level, I was so scared the Wixey would fall off, that of course, it didn't. But I didn't think it would pop off the iron when I tapped the iron, so it did.)

I have attached some photos.

[bleeth]

I use a very good stiff straightedge and put my digital level on top of that.
Works fine.

[dstacey]

This may sound funny, but I used a piece of strong white thread. Just rolled the carriage over one end so it held the thread over the very peak of the rail and my wife held the other end very tight about .25" above the same point on the other end of the rail. Seemed to work really well. Kind of ruins your excuse to buy a new level however.

Dave

[myxpykalix]

Dave, I agree. I think this has less to do with fixing the bot and just a "good excuse" to go buy a new tool!:rolleyes::) lol

But it sounds like a good enough reason to me!
I have used a straight 2x4 with a 4 ft level on it for my rails. To get my indexer leveled and plumb I used a string line and string level.

[frank134]

I have a 60 x 120 and I used both a digital level and a very good transit. I think the transit did better them the level and I could also check all parts of the stand. only thing with a transit you need two people to do it right.