44" Resin Spine with weight test

**Dakota_in_the_sky** · 13-05-2012, 11:26 PM

Hello Everyone,

The resin spine will be available by the end of the week pending the success of the strength test.

Brass runners and steel inserts are not included. Although not shown in the photos, the angled rods are included and are made in resin.

Any blemishes you see on the parts are only on the test cast. The production parts may have minor pinholes or airbubbles, but not to the extent as seen in these pics. Clean up is required.

Casting will be done by Jim Key. His website is here:
http://www.customreplicas.com/specialevents.html

The cost is $200 USD plus actual shipping. I need a minimum of 5 orders (I have one so far). If interested, please email me (spaces are added so I don't get spam) at
robert (no Space) burns (no space) jr101 (at symbol) yahoo (dot) com.

The zinc metal spine will be available later in the year. Prices are unknown, but I hope to have them in the $400-$500 range. Lower if there are more orders. If interested, please post here

Photos

Hosted on Fotki

**Dakota_in_the_sky** · 13-05-2012, 11:34 PM

Spine hung from a closet dowel

Hosted on Fotki

10 pound dumb bell added

Hosted on Fotki

Second 10 pounder added

Hosted on Fotki

Another 15 added for a total of 35 pounds

Hosted on Fotki

I'll give this a few days, then a week to see if there is any breakage, warping, or sagging.

By the way, a question for those of you building Eagles. What is the weight so far of the parts? I wondering if I should add another 15 lb dumb bell.

**Dakota_in_the_sky** · 14-05-2012, 01:45 AM

Couldn't resist added more. The two green ones are 3lbs each for a total of 41 pounds

Hosted on Fotki

**Captain Sci-Fi** · 14-05-2012, 06:11 AM

Do you get the brass and resin parts for $200 or just the resin connectors?

What adhesive was used in this test rigs construction and is it possible to see an image of one singe resin part?

Lastly, could you quote for shipping to the UK?

**29390** · 14-05-2012, 06:27 AM

Impressive demonstration, but can you stand on it?

I think A Zinc metal version would still be my choice of preference. The weight of Eagle 1 was around 30 lbs IIRC.

richardlamer · 14-05-2012, 06:49 AM

Hey Bernie

Quote:

Originally Posted by Dakota_in_the_sky

Hello Everyone,

Brass runners and steel inserts are not included. Although not shown in the photos, the angled rods are included and are made in resin.

D.I.T.S, these look FANTASTIC,
I think it's a great option for a build and it would take much less time to put together too. Your weight test is simply amazing!

**Captain Sci-Fi** · 14-05-2012, 07:20 AM

Hi Richard,

I shouldn't post so early in the morning, head and eyes not awake. That is actually the answer I wanted, so I can use carbon fibre tubes in place of brass, that's excellent.

I am sure the weight test will be a success and so long as the parts are allowed a full cure they should stay round in profile too meaning that the longeron tubes will fit correctly.

Robert,
Have you seen any issues with shrinkage or do you suggest reaming the holes for the tubes first?

And are you working on a set of cage parts?

**MADsen** · 14-05-2012, 08:37 AM

Hi Robert...

It looks great...

It´s very tempting... Looking forward too see the test result...

**rockwellcm** · 14-05-2012, 11:44 AM

Just one thing to remember,when you drill the spine to accept the cages it weakens the spine quite a bit (16 holes in Total)

**Captain Sci-Fi** · 14-05-2012, 01:57 PM

I would be tempted to perhaps slightly alter the clamp design so that didn't happen, at the risk of serious trouble later I think it's a compromise worth making. Something else to bear in mind, if you make it a light weight model using modern carbon fibre materials all the associated problems with stress destroying the frames or other parts is totally mute.

Reducing the weight by 50 - 70% is perfectly possible, I am following the "use metal where you can see it's metal" method.

**Dakota_in_the_sky** · 15-05-2012, 12:28 AM

Quote:

Originally Posted by rockwellcm

Just one thing to remember,when you drill the spine to accept the cages it weakens the spine quite a bit (16 holes in Total)

Should be fine. In this test model, there are steel rods inside the brass tubes.

Quote:

Originally Posted by MADsen

Hi Robert...

It looks great...

It´s very tempting... Looking forward too see the test result...

Thank you Lars

Quote:

Originally Posted by Captain Sci-Fi

Hi Richard,

I shouldn't post so early in the morning, head and eyes not awake. That is actually the answer I wanted, so I can use carbon fibre tubes in place of brass, that's excellent.

I am sure the weight test will be a success and so long as the parts are allowed a full cure they should stay round in profile too meaning that the longeron tubes will fit correctly.

Robert,
Have you seen any issues with shrinkage or do you suggest reaming the holes for the tubes first?

And are you working on a set of cage parts?

No issues with shrinkage. A standard tube will fit.

Quote:

Originally Posted by richardlamer

Hey Bernie

D.I.T.S, these look FANTASTIC,
I think it's a great option for a build and it would take much less time to put together too. Your weight test is simply amazing!

Thank you Richard

Quote:

Originally Posted by 29390

Impressive demonstration, but can you stand on it?

I think A Zinc metal version would still be my choice of preference. The weight of Eagle 1 was around 30 lbs IIRC.

Noted, one for metal. Copy the weight. Thank you Nigel.

Quote:

Originally Posted by Captain Sci-Fi

Do you get the brass and resin parts for $200 or just the resin connectors?

What adhesive was used in this test rigs construction and is it possible to see an image of one singe resin part?

Lastly, could you quote for shipping to the UK?

No adhesive was used in the test, but I would recommend epoxy for the actual build,

I'll post a single truss photo tomorrow.

Shipping should be very low since the resin parts don't weigh very much. I'll find out when I pull the parts apart.

jockdeboer · 15-05-2012, 08:40 AM

Robert, that is looking great! Come on guys!

Lamboman · 18-05-2012, 10:45 PM

Currently building 9 44" eagles with uncle bills resin parts and carbon fiber rods, and to date had no problems

**Dakota_in_the_sky** · 20-05-2012, 08:04 PM

Quote:

Originally Posted by Lamboman

Currently building 9 44" eagles with uncle bills resin parts and carbon fiber rods, and to date had no problems

Thank you for adding Lamboman. Would love to see some buildup photos.

Someone suggested I do a new test with the weight hanging from both ends. Here are the pics:

10 pounds each

Hosted on Fotki

15 pounds each

Hosted on Fotki

10+15x2 for a total of 50 lbs

Hosted on Fotki

Lamboman · 20-05-2012, 08:49 PM

Hi,
You need to support the frame at either end with nothing in the middle, rather than supported all the way along as you have at present. then hang some weight in the center of the frame, again not all the way along it !!

**stingray48442** · 20-05-2012, 10:21 PM

no you have to imagine picking the eagle up at the middle of the spine only work out the weight of the side pods and legs then hang the eagle of equil weight at both ends you have this frame compleatly suported

**Dakota_in_the_sky** · 20-05-2012, 10:28 PM

You two should make a drawing of what you're talking about. It's easier to see in pictures rather than have it described to you

**Captain Sci-Fi** · 21-05-2012, 08:31 AM

Hi Robert,

I think they mean like this:

Lamboman's configuration:

Stingray48442's configuration:

Personally I think they both have merit as the load, leverages and turning moments will change depending on how an Eagle is handled, one illustrates the "at rest" state when the model is on it's own feet, the other covers more "flight display" mode.

The more of either of these configurations the less the stress at each point and the greater the load that can be carried. Your configuration is one extreme, these are the other but they represent a more accurate loading of the framework at any given time.

A good lesson here is if you are hanging a model for display do the model a favour, support it as close to Robert's configuration as possible, ideally supporting the passenger pod separately through the framework to relieve torsional loads to the frame. It's the twisting action that will cause the resin components to fail with cracks. Thinking about what has been said about frame attachments I would do as Robert suggests and use a section of solid bar where the clamp holes are drilled perhaps an inch either side of the drilled holes in length to spread the load

This should show what I mean:

I will use this method when building mine but will also tap a thread through the steel bar that the bolt will screw into and lock with a nut at the back.

**healvis** · 21-05-2012, 11:02 AM

Hi Dakota, I'm no engineer but if you look at the spine as being a bridge then you are testing it as a suspension bridge where all the load is being transferred up the cables to the pipe above. You need to test it as a trestle type bridge where the loading is transferred to the ends of the spine.

John.

Lamboman · 21-05-2012, 07:41 PM

I could not have said it better myself.

Captain Sci fi and healvis, have grasped what i was trying to point out.

You do need to support at either end and test lateral movement both up and down.

I have built well over 30 top spines in both full brass and carbon resin and have played with this a lot now.

Having said that i am NOT saying that it will be a problem, but the way you are testing currently does not show the strength of the frame.

13-05-2012, 11:26 PM	#1
Dakota_in_the_sky Eagle Pilot Join Date: Dec 2005 Location: San Diego, California Posts: 510	44" Resin Spine with weight test Hello Everyone, The resin spine will be available by the end of the week pending the success of the strength test. Brass runners and steel inserts are not included. Although not shown in the photos, the angled rods are included and are made in resin. Any blemishes you see on the parts are only on the test cast. The production parts may have minor pinholes or airbubbles, but not to the extent as seen in these pics. Clean up is required. Casting will be done by Jim Key. His website is here: http://www.customreplicas.com/specialevents.html The cost is $200 USD plus actual shipping. I need a minimum of 5 orders (I have one so far). If interested, please email me (spaces are added so I don't get spam) at robert (no Space) burns (no space) jr101 (at symbol) yahoo (dot) com. The zinc metal spine will be available later in the year. Prices are unknown, but I hope to have them in the $400-$500 range. Lower if there are more orders. If interested, please post here Photos Hosted on Fotki Hosted on Fotki Hosted on Fotki Hosted on Fotki Hosted on Fotki

14-05-2012, 06:27 AM	#5
29390 Communications Officer Join Date: Dec 2007 Location: Kent, United Kingdom. Posts: 1,329	Impressive demonstration, but can you stand on it? I think A Zinc metal version would still be my choice of preference. The weight of Eagle 1 was around 30 lbs IIRC. __________________ "It's good, but it's not right" - Roy Walker To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. Last edited by 29390; 14-05-2012 at 07:00 AM.

14-05-2012, 08:37 AM	#8
MADsen Eagle Pilot Join Date: Mar 2011 Location: Ebeltoft, Denmark Posts: 632	44" Resin Spine with weight test Hi Robert... It looks great... It´s very tempting... Looking forward too see the test result... __________________ Once a Eagle pilot, always a Eagle pilot... To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. Fly safe and happy landings... To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

21-05-2012, 11:02 AM	#19
healvis Communications Officer Join Date: Aug 2008 Location: London Posts: 894	Hi Dakota, I'm no engineer but if you look at the spine as being a bridge then you are testing it as a suspension bridge where all the load is being transferred up the cables to the pipe above. You need to test it as a trestle type bridge where the loading is transferred to the ends of the spine. John. Last edited by healvis; 21-05-2012 at 11:06 AM.

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13-05-2012, 11:34 PM	#2
Dakota_in_the_sky Eagle Pilot Join Date: Dec 2005 Location: San Diego, California Posts: 510	Spine hung from a closet dowel Hosted on Fotki 10 pound dumb bell added Hosted on Fotki Second 10 pounder added Hosted on Fotki Another 15 added for a total of 35 pounds Hosted on Fotki I'll give this a few days, then a week to see if there is any breakage, warping, or sagging. By the way, a question for those of you building Eagles. What is the weight so far of the parts? I wondering if I should add another 15 lb dumb bell.

14-05-2012, 01:45 AM	#3
Dakota_in_the_sky Eagle Pilot Join Date: Dec 2005 Location: San Diego, California Posts: 510	Couldn't resist added more. The two green ones are 3lbs each for a total of 41 pounds Hosted on Fotki

14-05-2012, 06:11 AM	#4
Captain Sci-Fi Commander Join Date: Sep 2005 Location: South Glos, UK Posts: 4,341	Do you get the brass and resin parts for $200 or just the resin connectors? What adhesive was used in this test rigs construction and is it possible to see an image of one singe resin part? Lastly, could you quote for shipping to the UK?

14-05-2012, 07:20 AM	#7
Captain Sci-Fi Commander Join Date: Sep 2005 Location: South Glos, UK Posts: 4,341	Hi Richard, I shouldn't post so early in the morning, head and eyes not awake. That is actually the answer I wanted, so I can use carbon fibre tubes in place of brass, that's excellent. I am sure the weight test will be a success and so long as the parts are allowed a full cure they should stay round in profile too meaning that the longeron tubes will fit correctly. Robert, Have you seen any issues with shrinkage or do you suggest reaming the holes for the tubes first? And are you working on a set of cage parts?

14-05-2012, 11:44 AM	#9
rockwellcm Communications Officer Join Date: Sep 2009 Location: Dundee,Scotland Posts: 1,079	Just one thing to remember,when you drill the spine to accept the cages it weakens the spine quite a bit (16 holes in Total)

14-05-2012, 01:57 PM	#10
Captain Sci-Fi Commander Join Date: Sep 2005 Location: South Glos, UK Posts: 4,341	I would be tempted to perhaps slightly alter the clamp design so that didn't happen, at the risk of serious trouble later I think it's a compromise worth making. Something else to bear in mind, if you make it a light weight model using modern carbon fibre materials all the associated problems with stress destroying the frames or other parts is totally mute. Reducing the weight by 50 - 70% is perfectly possible, I am following the "use metal where you can see it's metal" method.

15-05-2012, 08:40 AM	#12
jockdeboer Weapons Technician Join Date: Apr 2009 Location: Staten Island, NY Posts: 147	Robert, that is looking great! Come on guys!

18-05-2012, 10:45 PM	#13
Lamboman Hydroponics Technician Join Date: Oct 2011 Posts: 39	Currently building 9 44" eagles with uncle bills resin parts and carbon fiber rods, and to date had no problems

20-05-2012, 08:49 PM	#15
Lamboman Hydroponics Technician Join Date: Oct 2011 Posts: 39	Hi, You need to support the frame at either end with nothing in the middle, rather than supported all the way along as you have at present. then hang some weight in the center of the frame, again not all the way along it !!

20-05-2012, 10:21 PM	#16
stingray48442 Eagle Pilot Join Date: Sep 2007 Location: united states michigan Posts: 631	no you have to imagine picking the eagle up at the middle of the spine only work out the weight of the side pods and legs then hang the eagle of equil weight at both ends you have this frame compleatly suported

20-05-2012, 10:28 PM	#17
Dakota_in_the_sky Eagle Pilot Join Date: Dec 2005 Location: San Diego, California Posts: 510	You two should make a drawing of what you're talking about. It's easier to see in pictures rather than have it described to you

21-05-2012, 08:31 AM	#18
Captain Sci-Fi Commander Join Date: Sep 2005 Location: South Glos, UK Posts: 4,341	Hi Robert, I think they mean like this: Lamboman's configuration: Stingray48442's configuration: Personally I think they both have merit as the load, leverages and turning moments will change depending on how an Eagle is handled, one illustrates the "at rest" state when the model is on it's own feet, the other covers more "flight display" mode. The more of either of these configurations the less the stress at each point and the greater the load that can be carried. Your configuration is one extreme, these are the other but they represent a more accurate loading of the framework at any given time. A good lesson here is if you are hanging a model for display do the model a favour, support it as close to Robert's configuration as possible, ideally supporting the passenger pod separately through the framework to relieve torsional loads to the frame. It's the twisting action that will cause the resin components to fail with cracks. Thinking about what has been said about frame attachments I would do as Robert suggests and use a section of solid bar where the clamp holes are drilled perhaps an inch either side of the drilled holes in length to spread the load This should show what I mean: I will use this method when building mine but will also tap a thread through the steel bar that the bolt will screw into and lock with a nut at the back.

21-05-2012, 07:41 PM	#20
Lamboman Hydroponics Technician Join Date: Oct 2011 Posts: 39	I could not have said it better myself. Captain Sci fi and healvis, have grasped what i was trying to point out. You do need to support at either end and test lateral movement both up and down. I have built well over 30 top spines in both full brass and carbon resin and have played with this a lot now. Having said that i am NOT saying that it will be a problem, but the way you are testing currently does not show the strength of the frame.