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Titanium eye bolts/U-bolts

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TonyL

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Hi Fred,
I am not sure that this is a true statement: "RF signal absorption is directly proportional to conductivity" without some specific definitions, really we are talking about impedance, energy transfer and energy loss to heat. Antennas inherently absorb RF energy [transfer in] and then re-radiate [transfer out], at the same time resistive losses absorb some of it. High conductivity/low resistance elements have higher efficiency transferring energy in and out so yes, they will interact. A 'lossy' element of the same physical dimension will see the same voltage field and will still interact but with a different effective impedance. To claim that it will "interact" more or less [and that 'more' is worse than 'less'] one would need to establish the actual effect [ideally with measured data]. One could easily be making an effective absorber that attenuates the signal more and redistributes the radiation pattern less. Which one is better kind of depends.

This article <https://ieeexplore.ieee.org/document/8261793> suggests that your titanium hardware will 'interact' more over a wider frequency band than a higher conductivity material that will be 'peakier', which is consistent with filter design theory [higher resistance means lower Q and wider bandwidth].

Regardless, the merits of titanium being discussed are relative to carbon steels and stainless steels. All are pretty close together in electrical properties, with stainless edging out the others, making stainless a theoretically better choice [unless it is not].

I would be very interested in any published work you can point me to on the merits of different antenna element materials, as I am still finding very little on the subject.

br/

Tony
 

Richard Dierking

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And, please get back to us on what you find out about the Ti U-bolts. I'm still trying to get past the $90 for a 3' 1/4"-20 all-thread, but I might jump in.
BTW, I made threaded rods (like 10" long and threaded on both ends) and tried making U-bolts with 6061 aluminum and it was a big pain. So, unless you had some real good equipment, making stuff like U-bolts with Ti rod would probably be a no-go.
 

dhbarr

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Regardless, the merits of titanium being discussed are relative to carbon steels and stainless steels. All are pretty close together in electrical properties, with stainless edging out the others, making stainless a theoretically better choice [unless it is not].

I would be very interested in any published work you can point me to on the merits of different antenna element materials, as I am still finding very little on the subject.
Hrmm, absorption-per-tensile-strength-per-gram is a fun metric to try and reason about.
 

jderimig

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From all my ground tests all thread has no measurable effect on range. I am certain that there is a theoretical pattern distortion. There may be even antenna detuning if antennas were tuned to begin with.
 

pbahorich

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And, please get back to us on what you find out about the Ti U-bolts. I'm still trying to get past the $90 for a 3' 1/4"-20 all-thread, but I might jump in.
BTW, I made threaded rods (like 10" long and threaded on both ends) and tried making U-bolts with 6061 aluminum and it was a big pain. So, unless you had some real good equipment, making stuff like U-bolts with Ti rod would probably be a no-go.
Issues about signal propagation aside, strength data suggests that titanium all-threads would not provide a USABLE strength advantage over aluminum allthreads. What I mean by that is the aluminum is more than strong enough for the allthreads to still be the strongest link in the deployment chain, and are almost as strong as steel allthreads. Here is why I make that strength claim. I contacted the reputable rocketry vendor who supplied steel allthreads as part of a 4" fiberglass kit rocket which is almost 8' long. Here is what they said about their allthreads: "The last batch we bought was grade 2 steel - zinc coated", which is low strength steel. This is basically what you'll get, a 50,000 psi strength:

Steel allthreads or bolts are overkill even in grade 2, with a tensile load strength of 2350 lbs:
With two of them, you would need 4700 lbs to pull your AvBay apart.

The titanium allthreads get you to the same 50k psi as the grade 2 steel:
But at a lighter weight.

The aluminum allthreads I am going to use have a tensile strength of 40,000 psi:
(I ordered aluminum washers from McMaster-Carr along with the aluminum allthreads. I was able to pick up some aluminum 1/4-20 nuts at my local Ace Hardware.)

So the aluminum althreads should give you about 2350*40k/50k = 1880 lbs. For two that's 3,760 lbs per AvBay. That still makes it much, much stronger than anything else in the deployment chain, including the Kevlar, nylon, stainless quick links, swivels, forged eyebolts etc.

So the titanium gives you a 20% strength advantage over aluminum, but is 60% heavier than aluminum, so not as strong per pound.

So why pay for titanium when you can get lighter aluminum?

""
 
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steveh.jae

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I called McMaster-Carr and found that they offer grade 5 Ti all-thread rod in 12” & 36” lengths of 1/4” 20 tpi, 5/16” 18, and 3/8” 16. They also offer Ti stock (e.g., rod, sheet, ball, etc.) but I’m not looking at machining parts.

No joy on finding other reputable sources of grade 5 Ti hardware. Sorry I don’t have better news.
 

steveh.jae

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I am also concerned about rf interference generated by using dissimilar metals (e.g., Fe, Al) in recovery hardware because of the unavoidable current induced in the thermocouple. If I end up using Al bolts, are Al nuts available?
 

Richard Dierking

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It's cool. Yeah, all I found in stock were larger U-bolts from a specialty metals place. And, of course very expensive. Perhaps you are just like me, more curious than anything else. I've never worked with Titanium. You hear a lot about it, but it would be kind of fun using it.
Keeping in mind that it was probably curiosity more than anything else that made me try aluminum hardware. I saw many raised eyebrows when I said I was trying aluminum U-bolts and nuts.
 

Richard Dierking

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Just saw your post; guess we are both typing about the same time.
I get the aluminum nuts, nylon insert nuts, split washers, coupling nuts, and washers all from McMaster. Using 1/4"-20 mostly now. But, I have used 10-24 for smaller rockets and even 5/16" aluminum hardware on my L3 project. I conducted drop tests for my L3 to assure the U-bolts and all the other Aluminum could withstand shock. I deformed U-bolts and cracked bulkheads but no thread ever failed.
Also, I suggest checking out Nord-Lock vibration resistant washers. They are stainless steel and come in pairs.
 

pbahorich

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I am also concerned about rf interference generated by using dissimilar metals (e.g., Fe, Al) in recovery hardware because of the unavoidable current induced in the thermocouple. If I end up using Al bolts, are Al nuts available?
I got my aluminum nuts from the local Ace Hardware so I could buy in small quantities. McMaster-Carr has them though, as well as aluminum washers.
 

FMarvinS

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And, please get back to us on what you find out about the Ti U-bolts. I'm still trying to get past the $90 for a 3' 1/4"-20 all-thread, but I might jump in.
BTW, I made threaded rods (like 10" long and threaded on both ends) and tried making U-bolts with 6061 aluminum and it was a big pain. So, unless you had some real good equipment, making stuff like U-bolts with Ti rod would probably be a no-go.
Richard-the Grade 2 titanium all thread is only a little over $30-see my previous post in this thread with the Amazon online ad with price.
 

FMarvinS

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Tony,
The following reference states that the three major metals that are used for EMF shielding (i.e. rf attenuation) are copper, steel and aluminum (see: https://leadertechinc.com/blog/the-...g-metals-and-what-you-should-know-about-them/). If I had more free time, I'd gladly find further references. But suffice it to say, from "anecdotal" trials, I get better performance and S signal readings on my HT when ground testing my 2 meter GPS transmitter using the titanium all thread in comparison to stainless steel. However, they both work and over reasonable distances either would probably do well.
Fred
 

jderimig

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I am also concerned about rf interference generated by using dissimilar metals (e.g., Fe, Al) in recovery hardware because of the unavoidable current induced in the thermocouple. If I end up using Al bolts, are Al nuts available?
Do not be concerned about that.
 

Richard Dierking

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Thank you FMarvinS. I misread that post from Amazon at per foot, not 3'.

Still not sure about getting from Amazon. It's from their Small Parts department so, probably not much traceability there. Nuts would be $4.25 each from Amazon. McMaster shows $2.57 each for grade 2. So, I'm thinking of getting both from McMaster. What do you think?

One of the posts on Amazon suggests you can't cut Titanium all-thread with a hack saw. Don't believe that. I just got to put some of this through my band saw and torture the all-thread and nuts a bit.

And, I could point at my rocket and say "yeah, I use Titanium hardware" Of course as it's being shredded.
Has anyone made an airframe and fin can from Inconel? ;-)
 

0011001100

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I've machined titanium before and it is a pain to work with. If you want to cut the all thread you will want an angle grinder, lathe, or metal chop saw. Unless you got an hour to use a hacksaw. I've got some grade 9 and grade 5 on hand for a special project. Personally I see the titanium in this case as being way overkill. As pointed out already aluminum is plenty strong enough, though steel tends to be easier to find at local hardware stores.

If someone wants to use titanium, go with grade 5 and then go with a smaller size. Then you will get the benefit of the extra strength while reducing weight.

If someone really wants some custom threaded rods or titanium hardware I could make someone once I've moved and gotten set back up, but that likely won't be till September or late August.
 

FMarvinS

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Thank you FMarvinS. I misread that post from Amazon at per foot, not 3'.

Still not sure about getting from Amazon. It's from their Small Parts department so, probably not much traceability there. Nuts would be $4.25 each from Amazon. McMaster shows $2.57 each for grade 2. So, I'm thinking of getting both from McMaster. What do you think?

One of the posts on Amazon suggests you can't cut Titanium all-thread with a hack saw. Don't believe that. I just got to put some of this through my band saw and torture the all-thread and nuts a bit.

And, I could point at my rocket and say "yeah, I use Titanium hardware" Of course as it's being shredded.
Has anyone made an airframe and fin can from Inconel? ;-)
Richard,

I cut my titanium all thread with a dremel with the usual cutting disc with no problems at all. I'm quite sure, if you use the right blade, your hack saw will work well. Just remember to grind the cut edges (dremel works well again) so that the nut easily screws on and off. You can call your next scratch built
Titan (ium)!
Fred
 

jderimig

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Threaded rod in an av-bay is unnecessary. If you want to reduce weight do not use a conventional space and weight inefficient traditional av-bay. If you want bling, then of course use titanium, but don't rationalize any real benefit of using it. Of course it is all my humble opinion.
 

rocket_troy

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I cut my titanium all thread with a dremel with the usual cutting disc with no problems at all. I'm quite sure, if you use the right blade, your hack saw will work well. Just remember to grind the cut edges (dremel works well again) so that the nut easily screws on and off. You can call your next scratch built
Titan (ium)!
Hacksaw blades (not your $2 shop varieties) should theoretically cut through most grades of Ti alloy. IIRC grade 4 (a popular grade for performance engineering) is somewhere in the 36 HRC hardness range - which is very hard for a non hardened metal. A good saw blade should be in the 60-65 HRC range, so providing you stroke it slow (avoiding heating up the blade and teeth), it should cut through. Bi-Metal flavours (with a small percentage of Co) would be preferable.
 
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Richard Dierking

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So John, you don't think I should spend part of my social security check buying Titanium all-thread and nuts? LOL
This has been a good topic for me to follow for several reasons. First, I questioned the efficiency of using Titanium hardware. Then, went out in the garage to continue working on the retractable legs for my rocket. I don't want to reveal how much I've spent working on that! I realized that I was being a hypocrite.
Amateur rocketry is a bit of an extreme hobby. It brings us joy - but at a cost. I feel so fortunate, so grateful to be able to pursue something that is so challenging and often amusing.
I wish all other rocketry people were beautiful women, but you can't have everything.

I recently had a conversation with my neighbor that plays golf that mentioned that they spent a couple hundred dollars on a club and whether that was a good idea. I didn't laugh at the time, but did after we parted. OMG, I thought, what if you spent that to hit that ball once! But, oh man, that ball went really fast!

So bottom line, I'm getting 10-24 Ti all-thread, washers, and nuts and would like to get some coupling nuts and U-bolts too.
 

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You can get custom length titanium bike spokes made at some bike shops. Not very expensive at all. They make really nice long skinny bolts and have a breaking load of around 280kg each. Not bad for a 2mm diameter spoke. Because they are so skinny they can save a lot of space in tight avionics bays.

I also used them on my Apache: https://forum.ausrocketry.com/viewtopic.php?f=6&t=5019&start=45
 

steveh.jae

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So John, you don't think I should spend part of my social security check buying Titanium all-thread and nuts? LOL
This has been a good topic for me to follow for several reasons. First, I questioned the efficiency of using Titanium hardware. Then, went out in the garage to continue working on the retractable legs for my rocket. I don't want to reveal how much I've spent working on that! I realized that I was being a hypocrite.
Amateur rocketry is a bit of an extreme hobby. It brings us joy - but at a cost. I feel so fortunate, so grateful to be able to pursue something that is so challenging and often amusing.
I wish all other rocketry people were beautiful women, but you can't have everything.

I recently had a conversation with my neighbor that plays golf that mentioned that they spent a couple hundred dollars on a club and whether that was a good idea. I didn't laugh at the time, but did after we parted. OMG, I thought, what if you spent that to hit that ball once! But, oh man, that ball went really fast!

So bottom line, I'm getting 10-24 Ti all-thread, washers, and nuts and would like to get some coupling nuts and U-bolts too.
Richard, and everyone else contributing to this thread ... thank you for indulging my curiosity and silly questions. If you continue to find out more, please continue to update this thread for as long as the topic interests you all. I’ve learned a fair bit, and will probably end up using Ti in ways that are applicable and reasonably economical when appropriate, and Al for most other fasteners and hardware such as eye bolts or U-bolts (but may take up the offer of the kind gentleman offering to machine a couple parts out of Ti stock (e.g., perhaps a small exhaust nozzle, etc) in the future. Once again, thank you all, and please keep posting to this thread as you learn new things about how Ti might fit in with our hobby. Happy building and flying to you all! Best Regards!

Steve
 

jderimig

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So John, you don't think I should spend part of my social security check buying Titanium all-thread and nuts? LOL
This has been a good topic for me to follow for several reasons. First, I questioned the efficiency of using Titanium hardware. Then, went out in the garage to continue working on the retractable legs for my rocket. I don't want to reveal how much I've spent working on that! I realized that I was being a hypocrite.
Amateur rocketry is a bit of an extreme hobby. It brings us joy - but at a cost. I feel so fortunate, so grateful to be able to pursue something that is so challenging and often amusing.
I wish all other rocketry people were beautiful women, but you can't have everything.

I recently had a conversation with my neighbor that plays golf that mentioned that they spent a couple hundred dollars on a club and whether that was a good idea. I didn't laugh at the time, but did after we parted. OMG, I thought, what if you spent that to hit that ball once! But, oh man, that ball went really fast!

So bottom line, I'm getting 10-24 Ti all-thread, washers, and nuts and would like to get some coupling nuts and U-bolts too.
Richard, I regret my naysaying party pooper post on Ti hardware. This hobby is one of fun and variety and often we do things out of fun and experimention and not necessarily out of necessity or benefit to derive enjoyment. I should know that more than anyone. (One who bought a TIG welder so I can make aluminum fin cans....)
 

0011001100

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You can get custom length titanium bike spokes made at some bike shops. Not very expensive at all. They make really nice long skinny bolts and have a breaking load of around 280kg each. Not bad for a 2mm diameter spoke. Because they are so skinny they can save a lot of space in tight avionics bays.

I also used them on my Apache: https://forum.ausrocketry.com/viewtopic.php?f=6&t=5019&start=45
This is how titanium can be beneficial. Using a smaller diameter than normal will end up at a reduced weight, but I never thought of bike spokes... I guess I should visit a local bike shop.
 

Richard Dierking

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On the Amazon site, it's curious that the 1/4"-20 3' long Titanium all-thread ($29) is so much less than the 1' length ($50).
I was going to reduce size on all-thread from 1/4" to 3/16" until I saw the prices. Plus, I would need to get adapter coupling nuts for all the stuff I already have, like the 1/4"-20 aluminum U-bolts. Guess I'm just going to have to build bigger rockets. ;-)

I noticed that some Titanium has a high heat resistance, like 600 C. Might be useful on thrust vane structural components. TVC on larger-longer solid rocket motors would be difficult. Imagine trying to gimbal a 6 grain 54 mm motor. But, with thrust vanes, you could do it and even control roll. But, what would you use for the vane itself?

Anyway, being introduced to stuff like this gets you thinking about new possibilities.
 

Richard Dierking

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Received the 1/4"-20 nuts and 1/4" washers from McMaster. Waiting to hear about shipment on the Ti rod from Amazon and hope they don't change their mind on the price. Ordered 2 of the 3 foot rods.
The Titanium nuts are 1.8 grams vs 1.0 grams for the aluminum I've been using. Hum... how much stronger? :-|
But, at least I can say I have Titanium nuts! Even learning how to play Titanium on my guitar.
 

steveh.jae

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Received the 1/4"-20 nuts and 1/4" washers from McMaster. Waiting to hear about shipment on the Ti rod from Amazon and hope they don't change their mind on the price. Ordered 2 of the 3 foot rods.
The Titanium nuts are 1.8 grams vs 1.0 grams for the aluminum I've been using. Hum... how much stronger? :-|
But, at least I can say I have Titanium nuts! Even learning how to play Titanium on my guitar.
Richard, et al, I believe I have found a supplier for reasonably priced titanium fasteners. I just posted a new thread with a title to gain MAXIMUM interest in the shortest time possible: “Affordable TITANIUM hardware”. Please visit this thread and make a comment. Maximum input will yield the most optimum results! I am also posting to the NAR and TRA Facebook sites and directing them to the “Affordable TITANIUM hardware” thread to maximize exposure. Please invite your compadres to comment and contribute. Best!
Steve
 

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Richard Dierking

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Received the 1/4"-20 Titanium class 2 all-thread today through Amazon. Cut it with a used 12" Dewalt bi-metal hacksaw blade and it was about as difficult as cutting a steel all-thread of the same size. Also, finished the end with a disk and belt sander, same as I've done with 6061 aluminum all-thread. Looks pretty much the same but a bit heavier than 6061 aluminum.

Looking forward to using this new all-thread and hardware on a future project.
Just because I can.
 

steveh.jae

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Received the 1/4"-20 Titanium class 2 all-thread today through Amazon. Cut it with a used 12" Dewalt bi-metal hacksaw blade and it was about as difficult as cutting a steel all-thread of the same size. Also, finished the end with a disk and belt sander, same as I've done with 6061 aluminum all-thread. Looks pretty much the same but a bit heavier than 6061 aluminum.

Looking forward to using this new all-thread and hardware on a future project.
Just because I can.
Got ubolts yesterday. Super light!
 

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