first build thread: lessons and learning to follow...

[Motopreserve]

My bar looks to be pretty straight. Rolls ok and looks good to the eye next to the straight edge I used. I think I would just copy the design of the original - but don't on the lathe, it would be pretty perfectly balanced. I could actually make them out of Delrin as well. I have some at the shop. Might be better for weight.

I dont know know that anything else needs to be balanced.

 

[COMike93yj]

Scott...>GET THE LATHE OUT<

The way I "adjust" the heights of the two sides of the DuBro is to place an ITEM under the moveable top portion (adjustable portion). I didn't want to use blocks of wood so I ran into the reloading room and pulled out some Winchester 300 Win Mag cartridges and used them. As always I took out the Micrometer and the "mini lathe" to ensure that the cartridges were EXACTLY the same length. I then put them under the "adjustable" portion of the DuBro to make damn certain they were at the same height for balancing. Works like a charm and re-purposed a couple of casings that were "off Spec" for my use.

THIS WAY I am POSITIVE they are at the exact same heights! I also took a TON of time making certain my workspace was LEVEL! This is also CRITICAL. Once THOSE steps are done (and NO AIR CURRENTS) I am certain the balancer is level. I also took the time with a straight edge to be positive the shaft is STRAIGHT.

My next step was to watch the mounting hubs (that's what I call em) were as accurate as I could tell and did several "spin" tests on the level balancer. I used a sharpie to mark a similar position on each "mounting hub" and spun them. After 30 or so times and then "flipping" the shaft with hubs on them I found that there was NO difference between the sides so I think I am good to go.

I also get the "issues" of standing up or moving around.....I just make sure I am doing the balancing process the exact same way EACH time.....it is a pain in the butt but it works.

 

[Motopreserve]

It's a little odd that this apparently precise machine is made with molded plastic stops. I think the new cones/stops would be much better. If I make them - I will send a couple to jay for testing as well. People have complained about these before - so they are obviously a weak point on what does appear to be a decent system for balancing.

 

[COMike93yj]

Scott.....the FINAL way that I made certain to have the shaft straight was to roll it across a piece of plate glass.....I would think any flat glass surface would work. This makes sure your shaft is true.

As far as the cones go.....that is above MY ability and the only way I could make certain of them working was to do what I mentioned above.

Funny how we get so ANAL about the balancing stuff but to ME this is an INTEGRAL part to making sure our crafts work precisely.

 

[jbrumberg]

I'll take anything free- I am just a retired ex-human services professional :monkey: living on my good looks and fixed income. I checked the casing length of those Winchester 300 Magnum cartridges- almost 3" long and that's just the casing length. Lot's of potential kinetic energy there. I leveled everything and then I checked the level of that ferrous rod with a level laser level.

"My next step was to watch the mounting hubs (that's what I call em) were as accurate as I could tell and did several "spin" tests on the level balancer. I used a sharpie to mark a similar position on each "mounting hub" and spun them. After 30 or so times and then "flipping" the shaft with hubs on them I found that there was NO difference between the sides so I think I am good to go." Nice idea.

 

[Motopreserve]

Everyone feels it's super important for smooth video, efficient flight and more. So I have no problem making sure this is right.

I have a piece of level granite I use at the shop for things like this. It's not a proper store bought piece meant to be perfect (which exists but is VERY expensive), but for these purposes should be fine.

If I make them on the lathe, I'll know they are as perfect as they can be - I'm not going to get into the possible inconsistencies in the aluminum pour itself. That for chemists

 

[mbowser]

I'm pretty happy with the way my quad is flying right now, but I really should get up to speed on the whole prop balancing thing, what do you guys recommend that is cheap (I know, you get what you pay for, but my wallet is bleeding badly)? I saw a video that balanced the props between 2 torpedo levels, is this a reasonable approach or should I buy one?

On another note, did you guys get anything out of this storm or was it all wasted on people and places that don't want and can't handle snow? We didn't even get a flurry.

-matt

 

[jbrumberg]

it all wasted on people and places that don't want and can't handle snow. Southern coastal areas and coastal areas got a pretty good hit. I got nothing at all but -5F/-15WC cold. This is a strong system when I look at my weather geek stuff. It tracked too far east for us to get snow:dejection: This is not good.:blue:


The 2 torpedo balance level prop balancer trick worked rather nicely for my X1's. They are 5.25" props. As long as the balance bar is and can be kept level and it and/or the prop can spin rather freely, one can achieve some degree of balancing. The key is to allow the prop to spin freely.

 

[Motopreserve]

We got a few inches - but we ALWAYS get a few inches. . I love the snow, and don't mind the cold either (although being prevented from getting this quad outside has me bummed a bit). It's -5 here right now. That'll get to you after a while...

I would say the Top Flite at $20 doesn't hit the wallet too hard, and seems to work well. I'm going to make the stops for an even better balance, but it probably does just fine as-is. You just need to weight the $20 vs the hassle+parts of building your own. Either way, the quad will benefit from balanced props.

I need to to get into balancing the motors. There is a program you can use within multiwii - but it's a beta program, and some people have had issues. I'm going to try the iPhone technique which I'll post here if I can pull it off.

It stands to reason that it's best to have the props/motors balanced before digging into the PID tuning etc. any tuning will just have to fight against the off-balance parts, and is rather take care of getting the mechanical/physical parts right instead of having the software have to work harder.

 

[jbrumberg]

"It stands to reason that it's best to have the props/motors balanced before digging into the PID tuning etc. any tuning will just have to fight against the off-balance parts, and is rather take care of getting the mechanical/physical parts right instead of having the software have to work harder." In theory I agree completely for one motor and balance and the more things one can balance the better, but then one has to throw in the little unbalanced collet gasket and the imperfectly balanced nacelle, etc. and then throw in 4 of the same with all their unique complex imbalances. I have to assume that statistically it all will balance out.

I drank waaay too much coffee this AM. Wifey has been out of town with family matters for over a week now and we anticipate that she will be away for another three. There are +'s and -'s to this. Hopefully I will not kill myself by cholesterol and housecleaning ordered by the DEP and done through HAZMAT.

I am amazed with the speed with which the HK USA warehouse handled my last two orders. I should be getting both orders within a week of order. I will be impressed if this really happens.

 

[Motopreserve]

Jay,

I think if you survive the cholesterol coma you'll find that checking any of these improvements will only make the end results better in the end. If the collets are going to add imbalance to the system, I'd rather have that be the only imbalance, as opposed to adding to the already imbalanced props and motors. It's all cumulative, so the more variables that can be removed, the better the end result.

There has always been a bad mindset with audio recording (I made my living as an audio engineer for the past 18 years) which was: "fix it in the mix." This manifested itself as musicians hearing something wrong while recording, but pushing off correcting it until the final step of the process - mixing. The problem is: no matter how skilled the engineer, I was never going to be able to make the guitar be in tune when we have moved many steps past that, to the mix. Better to take the time to fix it now - so by the time you get to the mix, you can spend your energy making it sound great - as opposed to trying to chase down problems from past mistakes....

i think of this while spending the time now to check issues off the list of this quad. There will always be weak links in this chain, might as well make the rest as tight as possible, when possible.

 

[jbrumberg]

Scott I do agree with you BTW, and the more imbalances one can remove the better. You have taken this to a more micro level of perception which is a really good thing and the way an engineering mind would look at it which again is a good thing (just remember my background :monkey. I am fascinated and amazed that your FC is that much more refined than the KK board. Pretty amazing board you have there. Someday maybe.

I have to seriously watch my sugars too... a "benefit" of treatment that saved my life.

""fix it in the mix."" I never heard that expression, but that's the reasoning behind the "hands off hover no S-L test"- I really want a "clean" Tx program; no trim adjustments. If I can achieve that by manipulating physical, PID, stuff I am happy. I pay really, really close attention to how everything "levels out" to the various "perpendiculars" with how mine is structurally set up. I did not think about "round" vs "flat" when I first started this build. I had not considered that, but it is something that I addressed.

 

[Motopreserve]

I could tell we were on the same page - and as you know, it's the little things that count at this stage of the game. You are exactly right, the idea of getting your quad to level without the aid of trim etc makes the most sense. That way, when you NEED to use the trim for some very fine adjustments, they can be just that - fine!

This multiwii board is extrmeemly capable, but that capability comes at a price, in terms of both research and time. The beauty of the KK is that it offers a quicker path to flight - and there is something to say for that. I often wonder whether it would have been smarter to 'take it slow' and not dive directly into the rabbit hole that is Multiwii. Part of that decision was because at the time I was chomping at the bit to get this build started, there were no KKs available (I think it was the gap between releasing the KK2.1). So I went for a fairly inexpensive board that offered more features than I will probably ever understand.

But diving into the deep end has forced me to wrap my head around some of these foreign concepts, and I feel that ultimately, I will benefit from the knowledge.

I have been looking at the XAircraft SuperX FC. It seems to offer just about all the advanced features you would want - with less of the bells and whistles that Multiwii may offer. It's expensive, but it's the Cadillac of the KK2.1 type simplicity (if you can call ANY FC simple!!!!). That would be for the custom H-Quad frame I want to build - so plenty of time for that...

 

[jbrumberg]

I look at these different boards close enough to know what their features are and enough to know enough to stay away for awhile at this point. I do read the occasional "chatter" amongst all the "experts" touting their respective "product" and the "food fights".:highly_amused: I learn a lot through their BS. It can be both entertaining and educational at the same time.

I look forward to your very own quad frame build.

In the near term, I look forward to those two packages fro HK/USA. I would love to at least get my quad back together and operational. And I do have that area that I cleared for hover test purposes. So maybe I might get it hovering if weather conditions allow in a couple of days.

 

[Motopreserve]

Looking forward to the results. I don't know if I will get much testing done until the weather gets at least up to the 30 degree mark - just not sure how adversely this board woould be effected by it being this cold. I know that most people skip using the barometer (altitude hold) in this type of cold. There are some other things I can do though - and I think I'll take advantage of this time to start mocking up a cardboard version of the custom frame I'd like to build.

 

[jbrumberg]

Well I got the first of the two packages- the zippy battery and that balance lead low voltage alarm voltage meter which is pretty cool. No more multimeter in the field stuff. So I should see the replacement motors before the weekend.

 

[Motopreserve]

Nice! You will definitely find that the USA warehouse is fairly quick - as long as the products are in stock.

Finally picked up some clear nail polish (quick dry) at the pharmacy. Much nicer to be dealing with a substance that won't dry permanently on your hands! I have purposely put superglue on my calluses for playing guitar - but for some reason it bothers me when I do it by accident

I'm finding the need to put a large amount of material on the light side of the hub to balance it out - which makes me think that it may be time to step up to some higher quality props. Nothing crazy expensive - but at least a better quality control???

I'm also wonderng if we may be able to eliminate some of our concerns regarding the collet prop adapters by balancing the motors with them installed. Maybe getting the best reading with the adapters on might make for the most thorough balance between adapter, motor and prop????

I'm going to post up a question to see if the collective finds this idea sound...

 

[jbrumberg]

:mask:"The Collective":mask:.......:hororr:... Just remember- I have my ST card if you need someone to bail you out :highly_amused:

 

[Motopreserve]

Cool gadgets....

I have always been one to be attracted to cool gadgets. Hell, I'm even attracted to uncool gadgets! I have been getting a bunch of small things for my quad from Paul (Witespy) at Ready to Fly Quads. I first became aware of his online shop because of the work he does with Multiwii, and the FCs he releases with pre-programmed software. As far as Multiwii goes, this is the closest you get to "plug-n-play."

But Paul stock a bunch of other cool stuff (gadgets), often things that when you see them - you think "why didn't I think of that???!!!"

One of the latest gadgets I bought is a small plastic "grip" that goes on the battery balance lead. Those small, white plastic connectors that are so difficult to remove when they are plugged into your charger for balancing, or the cheap HK Lipo alarm I use on-board. I am always in fear of yanking the wires completely out of the plug - and with Lipos, I already feel I am treading on thin ice...



These little things clamp over the balance connector, with spaces notched out for the wires. With a small channel to grip the raised part of the plug, these give you the grip you need to safely, and confidently pull the plugs apart. Great gadget!

 

[jbrumberg]

I got a couple of those as freebie's of different sizes with something "RC" that I purchased. They are pretty neat and work as you described. Where I could use them most (inside my Tx case) they do not fit due to their size.