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Toms_42
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Re: Design

Post by Toms_42 » January 25th, 2015, 9:34 pm

DoctaDave wrote:
Toms_42 wrote:
DoctaDave wrote:I've noticed that Armor all has been frequently recommended for lubricating motors. I looked for it on amazon and found this http://www.amazon.com/Armor-All-10228-O ... =armor+all
Is this the armor all that you guys are talking about? It says its a protectant not a lubricant in the description so I just wanted to make sure.
That looks right. But we've been using the same bottle for years, so I'm not sure if it's still the same formula. A couple amazon reviews like this one:
http://www.amazon.com/review/R1J0C6UP15 ... automotive
say that they changed their formula, so I don't know if it's still the same. one said it's more viscous.
Are there any other good alternatives? Or has anyone tried the new formula?
here's a thread from a year ago discussing this topic:
http://www.hippocketaeronautics.com/hpa ... ic=15595.0

Someone suggested this:
http://www.amazon.com/Equate-Lubricatin ... 81&sr=1-22

I also found some older armorall on ebay: (this is what we use)
http://www.ebay.com/itm/Armor-All-ORIGI ... ls&vxp=mtr

Someone in that thread mentioned mixing these two lubricants together, for a slightly thicker lubricant that "works better and doesn't splatter." Someone else mentioned evaporating armorall in a dish to be left only with the silicon base. They also recommend castor oil if you have it.
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Re: Design

Post by DoctaDave » January 26th, 2015, 9:19 pm

Thanks Toms_42!

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Re: Design

Post by InfiniCuber » January 26th, 2015, 9:23 pm

This may be a dumb question, but if I have a dihedral, will the ES measure my wingspan by measuring across from one tip to the other? (like measuring the distance across the top of a "v") or will they measure the total length of each panel (as in measuring the total length of both arms of a "v")?
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Re: Design

Post by Toms_42 » January 26th, 2015, 9:58 pm

InfiniCuber wrote:This may be a dumb question, but if I have a dihedral, will the ES measure my wingspan by measuring across from one tip to the other? (like measuring the distance across the top of a "v") or will they measure the total length of each panel (as in measuring the total length of both arms of a "v")?
I'm fairly certain they measure across the top. If they did it otherwise, vertical wingtips would be added to the wingspan and that just doesn't make sense. There is certainly somewhat of a debate about the necessity of a dihedral, as it offers stability at the possible cost of some lift.
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Re: Design

Post by InfiniCuber » January 27th, 2015, 5:18 am

Toms_42 wrote:I'm fairly certain they measure across the top. If they did it otherwise, vertical wingtips would be added to the wingspan and that just doesn't make sense. There is certainly somewhat of a debate about the necessity of a dihedral, as it offers stability at the possible cost of some lift.
Yeah, you make a good point about the wing tips. And from my experience, they have worked pretty well for me!
Thanks for the help!
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Re: Design

Post by jander14indoor » January 27th, 2015, 12:17 pm

Unofficial, not the place for clarifications, etc.

The ES certainly SHOULD measure from tip to tip. The key word in the rule is PROJECTED span which means pretty much as you said it.

Note, there is NO debate about the need for dihedral. It is required for stability. Vertical wing tips are simply one extreme version of double break dihedral. they provide stability the same way every other version of dihedral does. The "ideal" dihedral would be an eliptical shaped wing (when viewed from front or rear). Single break, double break or multiple break are just approximations of that and are more driven by ease of construction than anything else.

Nor should you think of dihedral in terms of lost lift. Its more correct to think of it in terms of increased drag. that's what drives that ideal eliptical dihedral distribution. That's the other consideration when you chose how to implement dihedral. Vertical wing tips are fine for dihedral, but if you have to be careful building. Any tow in or out increases drag very fast. That sharp break is also a source of drag, offsetting it MAY be the tip effect of the end plate. All things that make this an interesting event with a lot of design tradeoffs.

Note, other than the toed in or out tip plates rapidly increasing drag (which is really just poor construction which is ALWAYS bad) dihedral is not a major driver of duration.

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Re: Design

Post by TC-SciOly » January 31st, 2015, 9:38 pm

Where can you buy Mylar clear covering? We've looked everywhere but have only found the silver types. Thank you all!

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Re: Design

Post by torqueburner » February 1st, 2015, 5:15 am

TC-SciOly wrote:Where can you buy Mylar clear covering? We've looked everywhere but have only found the silver types. Thank you all!
We got ours from Ray Harlan: http://indoorspecialties.com/index1.html

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Re: Design

Post by jander14indoor » February 1st, 2015, 7:11 am

Roy White has offered good deals to SO students in the past for Pennyplane Film, but I can't find a recent e-mail contact, only an address that is several years old.
ROY WHITE
1025 CEDAR ST.
CATAWISSA MO. 63015

But keep in mind, that you don't need to use advanced mylar films (which take practice and skill to work successfully) to hit the 8 gm minimum. You can find store bags that are light enough (I've had success with Home Depot, Quizno's, Canadian Tire & produce bags. But be careful, since they don't buy for weight, you find a lot of variance and you need to weigh the bags to make sure you have nice lite ones.

Regards,

Jeff Anderson
Livonia, MI

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Re: Design

Post by bernard » February 1st, 2015, 9:26 am

jander14indoor wrote:Roy White has offered good deals to SO students in the past for Pennyplane Film, but I can't find a recent e-mail contact, only an address that is several years old.
ROY WHITE
1025 CEDAR ST.
CATAWISSA MO. 63015

But keep in mind, that you don't need to use advanced mylar films (which take practice and skill to work successfully) to hit the 8 gm minimum. You can find store bags that are light enough (I've had success with Home Depot, Quizno's, Canadian Tire & produce bags. But be careful, since they don't buy for weight, you find a lot of variance and you need to weigh the bags to make sure you have nice lite ones.

Regards,

Jeff Anderson
Livonia, MI
Here's a link to a pdf with some information on many other films that can be used as well as contacts/links to vendors at the end of the document. It also included a phone number for Roy White: 636 271-2243.
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