precisision tools in rocketry

[RadManCF]

Has anyone ever felt it necessary to use precision tools, such as micrometers, dial indicators etc. when building rockets? I'd imagine that they'd be indispensible for EX, but I wonder if they could be useful in HPR also. Only thing I can think of would be to check the accuracy of a fin jig. If anyone else has ideas, I'd like to hear them.

[cwbullet]

I use a micrometer for fin thickness.

[RadManCF]

I use a micrometer for fin thickness.

A 0-1inch I'm assuming? Also, what brand?

[cwbullet]

I bought ti from McMaster Carr. I do not know the brand. It is exact enough for me.

[JPVegh]

I use my digital calipers almost daily.

[RadManCF]

So, I know that dial indicators are useful for checking the eccentricity of a cylinder or other round shape, and for alligning cylinders end to end. I could imagine that this would be done in EX, but could it come up in HPR also?

[dave carver]

Digital calipers at Harbor Freight for under $10. Part#93293

[luke strawwalker]

Digital calipers at Harbor Freight for under $10. Part#93293

Yep +1. I use them in scale work on LPR/MPR and they're very helpful. Indispensible is probably a better word.

Later! OL JR

[stantonjtroy]

Yep +1. I use them in scale work on LPR/MPR and they're very helpful. Indispensible is probably a better word.

Later! OL JR

Me as well (Dial Caliper, .001", and a 18" steel rule incremented to .01"). For Scale and general builds. I useally build scratch so it helps me keep everything nice and tight.

[cwbullet]

Mine is electronic.

[Zack Lau]

I use dial calipers all the time. I do have a micrometer that adds another digit of precision--0.0001 as opposed to 0.001 inches, but have never needed the extra precision for model rockets,.

[cavecentral]

So, I know that dial indicators are useful for checking the eccentricity of a cylinder or other round shape, and for alligning cylinders end to end. I could imagine that this would be done in EX, but could it come up in HPR also?

Maybe turning a nosecone? I don't use them except a digital caliper for EX - making nozzles and closures.

[Eric1]

I think everyone should own a 6inch dial caliper as a minimum.

But then, I are a Machinist! LOL

[cwbullet]

I think everyone should own a 6inch dial caliper as a minimum.

But then, I are a Machinist! LOL

And a very talented one. I agree Eric. Most of use need fair to good precision. I am sure your set world measure the width of a hair.

[RadManCF]

Maybe turning a nosecone? I don't use them except a digital caliper for EX - making nozzles and closures.

Makes sense. Are you using the caliper just to measure diameters, or do you have a means of checking roundness with the caliper? If you want to know if somethings out of round, a dial indicator would be a much easier way to find out. The main reason I started this thread is that in my job, I'll end up with a pile of Starrett tools, and I was wondering if they could be useful for building rockets as well.

[RadManCF]

I think everyone should own a 6inch dial caliper as a minimum.

But then, I are a Machinist! LOL

Like my signature suggests, I'm a Millwright. For us, I'd say the minimum is a 0-1 inch micrometer, and a dial indicator. I can't imagine aligning machinery with a dial caliper. On some machines, you need a theodolite.

[Eric1]

RadmanCF,

I might could use a coupler. Prefer .0001" increment, White face. Just bought a Fowler Electronic .00005"
I assume you do repair on these??

PS. Thanks for the compliment CWBullet!

ERic

[RadManCF]

RadmanCF,

I might could use a coupler. Prefer .0001" increment, White face. Just bought a Fowler Electronic .00005"
I assume you do repair on these??

PS. Thanks for the compliment CWBullet!

ERic

I'm just a first year apprentice, I haven't done any shaft alignments yet. The closest I've gotten to that has been to instal the grid in a grid coupling. Most of the precicision work I've done so far has been aligning web line rolls. I've done stick tramming on a couple occasions, but haven't done any optical alignment yet. I have been the guy who moves the scale around for the guy behind the theodolite though. I found stick tramming to be quite relaxing.

[Eric1]

Best of Luck with it!

[cavecentral]

Makes sense. Are you using the caliper just to measure diameters, or do you have a means of checking roundness with the caliper? If you want to know if somethings out of round, a dial indicator would be a much easier way to find out. The main reason I started this thread is that in my job, I'll end up with a pile of Starrett tools, and I was wondering if they could be useful for building rockets as well.

I use calipers to try to duplicate parts. Not perfect, but close enough not to CATO the motor.

I was thinking dial indicator on a lathe for doing the nosecones. Especially longer ones. If the lathe is true, it might help getting the stock centered properly. Just a guess. I am not a machinist, and do not even own a dial indicator.

[chadrog]

Dial caliper is indispensable, I use an O.D. mic here and there. A dial indicator is useless unless you have a concentric spindle of some sort (or bench centers) to mount your workpiece in. First year apprentice? Slow your roll.

[RadManCF]

Dial caliper is indispensable, I use an O.D. mic here and there. A dial indicator is useless unless you have a concentric spindle of some sort (or bench centers) to mount your workpiece in. First year apprentice? Slow your roll.

By bench centers, do you mean v blocks? I've seen those being used to hold peices being checked with dial indicators.

[chadrog]

By bench centers, do you mean v blocks? I've seen those being used to hold peices being checked with dial indicators.

No, by "bench centers" I mean bench centers. A device that resembles a lathe bed with a tailstock on either end. A standard piece of inspection equipment, generally used with centered shafts.

[RadManCF]

No, by "bench centers" I mean bench centers. A device that resembles a lathe bed with a tailstock on either end. A standard piece of inspection equipment, generally used with centered shafts.

Hadn't seen one of those before, thanks for showing the picture. How much would bench centers typically sell for?

[chadrog]

Hadn't seen one of those before, thanks for showing the picture. How much would bench centers typically sell for?

It's one of those things that can be as much or as little as you want to spend. Like any precision equipment, quality=dollars.

[BEAR]

I use a set of Mitutoyo 6" and 12" digital calipers. (The six inch are solar powered and work really well as long as there is adequate lighting. I have a set of 6 micrometers, 0 -1" through 5-6", they are all Starrett. I find those are handy. I also have some 1-2-3 blocks and some adjustable parallels that are really handy. If you got into it deeper, you could go to auctions that have machine tools and pick up a good height gage and even a granite surface plate. Then you could have a good surface for using your indicators to give you greater precision. In my own opinion and with my experience, I have found that Fowler was not the best and could be more readily found to be out of calibration. Sometimes you can also pick up some cheap gage blocks or jo blocks or thickness gages that can be useful. These tools can be very useful in other endeavors than HPR and they are great in scale work and for anything else you desire to engineer and make. You can find a lot of these tools at MSC. My preferred brands are Starret, Brown & Sharpe, and Mitutoyo. And do not forget the scales. Mine are normally manufactured to .010 and then I get optic magnifiers to see real close. I have metal scales in 6", 12", 18", and 24". I also have a piece of tool steel that is 1/2" X 1" X 24" that I use as a weight or straight edge, or for alignment, or anything else I want it for. Check them out.

[BABAR]

I can't imagine aligning machinery with a dial caliper. On some machines, you need a theodolite.

I thought theodolite was a gemstone.

Man, I thought I was going high tech when I bought the 6 inch metal ruler with the little bitty markings---what are the called? oh yeah, millimeters.....

Of course, since my major building materials include dental floss and duct tape, maybe millimeters are okay.

[RadManCF]

I thought theodolite was a gemstone.

Man, I thought I was going high tech when I bought the 6 inch metal ruler with the little bitty markings---what are the called? oh yeah, millimeters.....

Of course, since my major building materials include dental floss and duct tape, maybe millimeters are okay.

Their use is essential when setting up weblines, when you have a pair of rolls, 10-20 feet apart, that need to be within 0.002in of parallel to each other, the only way to align them is with a theodolite. If they aren't within 0.002in, you could end up with wrinkly sandpaper.

[BABAR]

Their use is essential when setting up weblines, when you have a pair of rolls, 10-20 feet apart, that need to be within 0.002in of parallel to each other, the only way to align them is with a theodolite. If they aren't within 0.002in, you could end up with wrinkly sandpaper.

Oh wonderful, now I really feel neophytic. I don't even know what a webline is! And the only time I have rolls 20 feet apart, they are generally in separate restrooms

Please don't take my attempts at humor in any way as negative. You guys are what I would call rocket Craftsman. I fall somewhere between Dilettante and Dabbler.

[cavecentral]

I have no idea what a webline is, what he is talking about, or the dangers of wrinkly sand paper. Everyone here has their areas of expertise. This is well outside mine.