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Old Mar 17, 2010, 05:00 PM
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ender707's Avatar
Sacramento, CA
Joined May 2009
718 Posts
I think that getting the "Right" Thrust angle for Your plane with Gary's mount has to do with your Setup.

I am running a 4s 2650 which makes mine a little nose heavy. Some people here run More cells, at 5000mah/Fiberglass and their planes are MUCH heavier. We will most likely not use the same thrust angle, just like a person running 3s 1800mah lipos will not.

My mount is just tight enough on the forward screws, but I have the 2 rearmost screws much tighter, compressing the foam and lowering my thrust angle. I did this because while eyeballing the mount with my fins off, I wanted it to be pretty much in line with the nose. I will be completely honest and say that I was merely guessing with this thrust angle, but it has worked great! So I have not made any more adjustments.

My point is just to say that you can alter the angle with this mount very easily, and expirimentation may be required to get the "perfect" angle, there is no "One angle fits all" solution.
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Old Mar 17, 2010, 05:07 PM
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customrcparts's Avatar
Renton, WA
Joined May 2009
98 Posts
The goal of the angle is to keep the flaperons out of the jet stream and to be extremely durable. Static alignment tests can be done all day long, but when I'm flying, I want the least drag. I believe that this test was suggested in anther thread or another forum (from a different pilot). I tried it and made a mount that followed this and found that I had to use the elevons to keep going in a straight line. That may be influenced by the weight of the mount, the aerodynamics of it, etc. Doing a static alignment based on someone else's setup may cause some trouble. Just be careful of the advice you follow. What works for my setup will most likely be different for everyone else!

This angle was the best angle IMO to handle a variety of setups from stock 28mm motors to big 36mm setups. We're all into customizing out planes in this forum and that goes for the mount too. If you fly it and feel that the thrust angle is off, you can shim it to get it where you want it. Suggesting that this one setup is going to be what works for everyone would be irresponsible. And, I'm not suggesting that. There are a lot of people out there that are flying with this mount regularly, including myself that are happy with how they work.

But, I'm always open to suggestions for improvements!
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Last edited by customrcparts; Mar 17, 2010 at 08:29 PM. Reason: fixed spelling errors
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Old Mar 17, 2010, 05:19 PM
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United Kingdom, England, Redcar
Joined Jan 2006
3,270 Posts
Hi Gary , could the mount be adjusted so that the part that attaches to the motor sits within a cutout section of the foam , sandwhiched between the two other pieces of the mount, basically bringing the motor to the level of the foam ?



basically like a tube style mount but with a lot more support and strength due to your mount design
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Old Mar 17, 2010, 05:46 PM
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United States, TX, Lubbock
Joined Oct 2007
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EDIT: I posted this before reading Ender and Gary's last two comments, which I agree with completely.
---------------
Before saying something's "WRONG" or "doesn't look right" we need to consider the purposed flight characteristics of the product (CustomRC's mount).

I have no doubt that Gary's mount gives more of a nose up thrust angle than the stock mount setup. Pictures of stock mounts can and will verify this.

I have a feeling that CustomRC's mount really shows its teeth when coupled with a high power setup. These setups usually run with a CG that's forward, or in some cases, FAR forward, of the stock CG dimples. The nose up thrust angle on these mounts compensates for the nose down tendency that would normally accompany the nose heavy CG. If the motor mount didn't provide that nose up angle, the elevons would have to be deflected up to pull the nose up on a nose heavy setup.

I may be incorrect on this, but I would wager than if the mount were installed on a Stryker with the CG in the stock location, there would be a nose-up tendency in flight which would have to be compensated for by flying with the elevons deflected down.

Gary, can you share whether the mounts were tested on a nose-heavy, high power setup, or on a more stock-ish power setup that had stock CG, and the findings with especially the varying CG?

An important thing to keep in mind on this topic is an element of flying wing aerodynamic design. Any flying wing or delta airfoil must have REFLEX, which is an upturning of the airfoil at the trailing edge. This reflex is necessary to provide stability in pitch (elevator axis). A wing without an upward deflected trailing edge will be unstable in flight. When you look at a properly thrusted, trimmed, and balanced Stryker, the elevons appear to be deflected slightly up. This is the reflex of the airfoil that you need. Yes, it does add drag, and it's one of the reason a Delta or flying wing is not the most efficient high speed design.
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Old Mar 17, 2010, 06:17 PM
Why the dirt on the wings?
moparmyway's Avatar
New York
Joined Jan 2009
4,991 Posts
Dudes,
The mount is designed to get the elevons neutral in a basically stock Stryker. All testing was done on a NON CF Stryker with stock verticals, stock elevons, no epoxy, no glass. Motor(s) were 480 size and longer. Battery was a 3s-3850 with the CG just less than 1/2 of an inch forward of the dimples.

I would humbly suggest that anyone who gets the mount to set their elevons to neutral, crush a slight amount of foam evenly all around the upper and lower brackets. Make sure you have all 3 bolts on each side of the motor mount to upper brackets, the center bolt goes from the bottom all of the way through to the top.

Fly it

You should see neutral elevons.

Some applications might need some tweaking, but only slightly and very minimal.

I understand the mounts may seem off, but I am sure that when the Stryker gets thrown up in the air, it will fly fine. NOBODY who has a Stryker that has flown with the mount has complained about it being off, its just the Dudes who are setting it up that have questions.
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Old Mar 17, 2010, 06:34 PM
Why the dirt on the wings?
moparmyway's Avatar
New York
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Quote:
Originally Posted by scousethief View Post
Would the "best" position for keeping the thrust line as close to "perfect " as possible be to follow the seam along the wing ?
IMHO, the BEST position is to install the mount as it is and set the elevons to neutral.

Fly it

Squish some foam to compensate for any trim that might have been needed.

To move elevons down out of the airstream, you need to tighten the front screws

To move the elevons up out of the airstream, you need to tighten the rear screws

The mount was designed to be an UPGRADE from the stock mount, so a MEGA 16/25/2 and an ARC 28x48x1.5 with a 3s3850 (25/50) battery was used (310 grams), and that is where the angle came from.

If you are running a smaller motor and lighter battery, or a larger motor and a heavier battery....................it makes no difference. You need to adjust elevons, thrust angle, CG, etc to your desired flying style.

I fully stand 100% behind this mount, and in every application so far there havent been any problems whatsoever, just questions from Dudes doing their installation, and comments from the peanut gallery.

I second Garys suggestion;
Be wary of who's advice you listen to
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Old Mar 17, 2010, 07:42 PM
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United Kingdom, England, Redcar
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Guys , i dont think anyone is questioning Garys mount in anyway just questions about the thrust angle being so sharp, as everyone already knows that could quite simpy be down to the angle of the picture or the tightness of the screws or as has already been stated the differences in thrust angle for heavy setups vs lighter setups.

On another note "peanut gallery" ? dont know what that term means over there but here that would insinuate that people are asking questions in a derogatory way in order to discredit in this case the product or the supplier i dont see were people are doing that rather just asking questions ???
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Old Mar 17, 2010, 07:45 PM
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Joined Jul 2006
152 Posts
When I got home tonight I took a look at the elevon positions on my two Strykers. The fast, heavy one with wood TE and elevons is straight with the wing, and flies straight and true with no trim. The stock one has a slight bit of up to it.

I also took a closer look at the motor mounts and there is a little more angle to the motors than I thought, but not much.
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Old Mar 17, 2010, 09:55 PM
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murdnunoc's Avatar
United States, TX, Lubbock
Joined Oct 2007
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Quote:
Originally Posted by moparmyway View Post
All testing was done on a NON CF Stryker with stock verticals, stock elevons, no epoxy, no glass. Motor(s) were 480 size and longer. Battery was a 3s-3850 with the CG just less than 1/2 of an inch forward of the dimples.


Fly it

You should see neutral elevons.
Surely, if you know one thing, Mopar, it's how to test something.
Knowing where the CG was for the tests is enough to settle me, and I'll keep my honey roasted peanuts to myself on the issue.

I still have issue with the idea of the elevons being neutral, but it's a personal preference thing based on what I've read on the balance of flight forces and stability. Hard for me to get it out of my head.

If it works, it works. And you've shown that it does.
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Old Mar 18, 2010, 01:30 AM
Why the dirt on the wings?
moparmyway's Avatar
New York
Joined Jan 2009
4,991 Posts
Quote:
Originally Posted by scousethief View Post
guys , i dont think anyone is questioning garys mount in anyway just questions about the thrust angle being so sharp, as everyone already knows that could quite simpy be down to the angle of the picture or the tightness of the screws or as has already been stated the differences in thrust angle for heavy setups vs lighter setups.

On another note "peanut gallery" ? Dont know what that term means over there but here that would insinuate that people are asking questions in a derogatory way in order to discredit in this case the product or the supplier i dont see were people are doing that rather just asking questions ???
Dude,
There is someone who continues to "question" Garys mount and has thrown in his opinion on it just about any time someone asks a question. He/she probably does not even have the thought of ever purchasing one, yet continues to throw dirt on it.

All I ask is for anyone who gets a Custom RC motor mount for the Stryker to do is this;

1. Install it as it is with all hardware and equal foam squish (it shouldnt have to be crushed, just squished a little)
2. Set elevons to neutral
3. FLY IT !!!!!!!!!!
4. Make any adjustments to the thrust angle after you have flown it and trimmed it to set the elevons neutral. (Most applications usually do NOT need any thrust angle adjustments)
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Old Mar 18, 2010, 01:54 AM
Why the dirt on the wings?
moparmyway's Avatar
New York
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Quote:
Originally Posted by murdnunoc View Post
Surely, if you know one thing, Mopar, it's how to test something.
Knowing where the CG was for the tests is enough to settle me, and I'll keep my honey roasted peanuts to myself on the issue.

I still have issue with the idea of the elevons being neutral, but it's a personal preference thing based on what I've read on the balance of flight forces and stability. Hard for me to get it out of my head.

If it works, it works. And you've shown that it does.
Murdo,
I will admit that my testing of that mount was 2 fold.

1. To get the BEST mount possible for ANY application

2. To have the BEST mount for MY application(s)

While the number 1 reason was for the Stryker community, it was established first and foremost on the "lightest" and least advanced Stryker I could come up with. My brain has a huge aversion with ESC's under 60 amps and batteries under 3850's, it wont allow my wallet to open to release the cash for anything smaller on a Stryker. That being said, everything else was intended to make the mount use the Stryker airframe to achieve the LEAST amount of drag while keeping the motor in the stock location.

The number 2 reason was so that I could lay down some serious power without worrying about the well known deficiencies in the stock mount creeping up on me and Mr. Murphy. It seems that Parkzone has paid Mr. Murphy handsomly for his co-operation in higher power applications. This too was intended to reduce drag.

In all applications so far, the Strykers with Garys mount flies just as well as or better than when the stock motor mount is used. Doppler showed speeds increased on identical power setups, Eagletree showed extra unloading above and beyond the stock mounts statistics on identical setups.

Win - win - win................. in my book.

The Stryker's overall reflex gets reduced by having the elevons neutral, yes..........
BUT it does not take anything away from how the Stryker flies or handles.

Also ................ it wouldnt be fun if I let out every detail about my testing of the various prototypes that were invented or upgraded by Gary. It would bore most Dudes and give fuel to "others" for "peanut gallery" comments.

Its easy to watch the game after it is played and say what should have been done, "Monday morning quarterback" if you will.............. I did NOT intend for the "peanut gallery" and "Monday morning quarterback" comment(s) to get settled over your brow, but I do think it was deserved by at least one Dude.
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Old Mar 18, 2010, 04:36 AM
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United Kingdom, England, Redcar
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Well ill leave this subject well alone now , sorry Gary if it appears i was "throwing mud" on your mount that wasnt intentional at all , in fact is far from my mind.
I want to be 100% sure about a product before i buy especially one that costs so much (mount plus international recorded postage plus tax= 3x the price of the airframe itself for me ) my new stryker will be fast and were i have no problems with the stock mount at all with my existing slower setup i understand the need for something more reliable. Please dont forget i am still new to planes so any questions i pose are made in a why ? i dont understand ? fashion, maybe that just doesnt come across in the way i phrase things and maybe it is me that needs to learn more , or rather just sir back and let others ask the questions in the right way and learn from that.

Again apologies , im trying to learn and understand not cause issues.
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Old Mar 18, 2010, 09:48 AM
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customrcparts's Avatar
Renton, WA
Joined May 2009
98 Posts
Quote:
Originally Posted by scousethief View Post
Well ill leave this subject well alone now , sorry Gary if it appears i was "throwing mud" on your mount that wasnt intentional at all , in fact is far from my mind.
I want to be 100% sure about a product before i buy especially one that costs so much (mount plus international recorded postage plus tax= 3x the price of the airframe itself for me ) my new stryker will be fast and were i have no problems with the stock mount at all with my existing slower setup i understand the need for something more reliable. Please dont forget i am still new to planes so any questions i pose are made in a why ? i dont understand ? fashion, maybe that just doesnt come across in the way i phrase things and maybe it is me that needs to learn more , or rather just sir back and let others ask the questions in the right way and learn from that.

Again apologies , im trying to learn and understand not cause issues.
Scousethief,

No apology necessary! Just about everyone was questioning the angle for a good reason, it looks different. I would ask the same question. It's important to know what you are buying. Like I said before, I am always open to comments, criticism, suggestions, etc!

Happy Flying!

Gary
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Old Mar 18, 2010, 01:05 PM
You down with EPP?
johnnyrocco123's Avatar
Houston, Tx
Joined May 2009
6,792 Posts
Quote:
Originally Posted by customrcparts View Post
Scousethief,

No apology necessary! Just about everyone was questioning the angle for a good reason, it looks different. I would ask the same question. It's important to know what you are buying. Like I said before, I am always open to comments, criticism, suggestions, etc!

Happy Flying!

Gary
Maybe I should have just emailed you the question about the thrust angle and not have posted it.

Second time in two weeks I posted something that was taken way too far.

This is why I like Pm's, but everyone always says to me, "post it so others can chime in"

Not always the best idea.
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Old Mar 18, 2010, 01:13 PM
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DoctorAudio's Avatar
Milwaukie , Oregon
Joined Feb 2003
4,441 Posts
Only one question, is the mount adjustable. It would be if we can put what ever thrust angle we want in it.
A friend of mine is running your mount and he loves it!

They look awesome and an adjustable one would make a customer out of me!
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