Reasonable Entry Cost

[Robert Youens]

I just want to share my story. I have wanted to get into Giant Scale 3D for some time with an electric. Entry cost was a limiting factor. I have had good luck with Hobby City products on smaller planes but had not given them a try with anything big.

A couple of weeks ago I picked up a used 3DHS 85" Katana airframe and now the task of loading it with equipment. Here is what I ended up purchasing from Hobby City:

Motor: Turnigy HXT 6374-200 (approx 3000watt) $55.35
ESC: Turnigy Sentilon 100HV (100 amp, up to 12S) $99.99
Motor Mount: LC-FWM 2530 $9.85
Prop: TGS 22X12E $13.00
Main Batteries: Flight Max 5000mah 5S 20C $67.50
Reciever Battery: Zippy 1300mah 2S 25C $7.32
Voltage Regulator: Turnigy Mega 8 (with low voltage alert) $11.05
Rudder Servo: HD9150MG (digital, metal gear, 220 oz/in) $31.98
Other Servos: HD9110MG (digital, metal gear, 146 oz/in) $28.29

FYI Futaba Servo Arms will fit on these servos.

Minus the reciever and plane all up cost was $476.70 + freight

Freight will typically add 20% or less to the order.

I have 12 flights on the Katana and everthing is going well so far. I did open up the front of the cowl around the motor shaft about 1/4 inch to allow more air flow over the motor and use a small spinner. Many of the 12 flights have been flown at temp in the 90 to 100 degree range in Texas. The motor and battery combination is strong and runs cool on this 15.7 lb all up weight plane. (Not all of the Hobby City large motors have given this good a result, I recommend doing some research before purchase, the one I chose had pretty good reviews) I use two of the 5000 mah 5S packs to equal a total 10S. The servos are strong, quick and center amazingly well. The electronic speed control is very smooth and runs cool. The remote low voltage warning light is a nice feature on the voltage regulator.

My cost may reflect a couple of dollars lower per item since I purchase from Hobby City with a group of pilots and the cost goes down with volume. I use the EMS Express option and I usually get my order in 4 to 7 days. I use pay pal for increased security on my payment.

This made 3D with a giant scale electric affordable for me!

Robert

[learnedinuk]

Nice timing on your post. I have a 30% YAK I want to switch to electric and have been looking for similar setups.

What size prop are you running?

[Robert Youens]

Nice timing on your post. I have a 30% YAK I want to switch to electric and have been looking for similar setups.

What size prop are you running?

Good luck with your Yak and enjoy.

Prop size 22X12 it is included in my list of components ordered from Hobby City. On the bench it is drawing about 90 amps on 10s and produces about 3300 watt or 4.4 hp, about the same as a 50cc gas.

I purchased a 22X10 this afternoon and will report as I get a chance to test. Flew two more flights this morning with motor thrust angle adjusted back to factory specs. Hovered much better and held a vertical line much better with little tail feather input. Guess the guys at 3DHS knew what they were up to when designing the plane. Though I have little experience flying Giant Scale, the Katana is reacting well as I get to know it.

Pack, ESC and Motor still running cool in extreme heat of Texas summer. I am keeping my flights to 6 minutes with a mix of aerobatic and 3D. Static voltage after flight is about 3.8 volts per cell. Very happy with components so far.

Robert

[ekotil]

Robert, good job with your plane and set-up. You did your homework and did it for way less than I thought was possible. Even with HC. Have fun and when you do another I hope you get an 87'' Extra SHP from 3DHS. I would love to see your cost breakdown on one. :)

[smelyal8r]

Hey Robert, it was good to see you and my old Kat fly today! The plane looked to fly just as smooth as any other GS electric I have ever seen. Great job.

Brett

[Robert Youens]

Hey Robert, it was good to see you and my old Kat fly today! The plane looked to fly just as smooth as any other GS electric I have ever seen. Great job.

Brett

Thanks Brett,

I appreciate the deal you made me on the plane. It may be a couple of years behind the curve as related to design technology, but it is providing a great platform for dipping my toes into giant scale. At this time I am a long way from maxing out it's potential.

Look forward to hooking up again with the Titanium group next Saturday, maybe I can pick up the extra parts them.

Thanks again,

Robert

[Robert Youens]

Now have 16 flights on my Giant Scale - Hobby City components. Everthing running smooth and cool.

Did an static amp check with the Hobby City 22 X12 prop again. Now pulling a max 99 amps at WOT where initially pulled max 92 amps. Don't know why, just reporting.

Tried a Zinger 22x6-10 wooden prop. Max amp draw was 74 amps. The motor winds up much more quickly. Adequate pull out of hover, but not nearly as good as the 22X12. Got increased flight time from 6 min to 7 min. This setup is producing about 2,800 watts as compared to 3,300 watts. There was no noticable heating of the motor, not even warm. Same with the batteries.

Might try a 22 X 10 or 22 x 8-12 next. One of these may be the perfect prop for this setup although both of the existing props are adequate.

I have included photos of how I increased the opening to allow full airflow across the motor and a glamor shot or two.

I believe that keeping all motors cool is desirable by keeping amps down, and air flow across motor high. In addition, I believe keeping the prop balanced on a regular basis is important. Break in is also a good ideal, because the steel in the bearings work harden over time and a couple of light run throughs probably is a great way to break in a new electric motor. This may be much more important on the low cost Hobby City motors. What ever, I love my motor and complete setup so far. It is providing everything I hoped for at about 1/4 the cost of most name brand setups for similar sized giant scale planes.

Robert

[Xpress..]

Wow, nice setup :)

I'll keep this one in mind, except run 2 10s 5000 packs for a 10s 10000 pack- i like flight time :)

[staggerwing]

Appreciated your cost savings thread.
Some tunnel vision people here will say if you're not spending enough money on an elec giant system, it must be junk--I know as I've submitted several cost saving successfull set ups I've used to threads here inquiring about same .
I realize there will always be those who cannot imagine peeking outside of thier high $ comfort boxes--- probably lined w/ easy $ .

[Robert Youens]

Appreciated your cost savings thread.
Some tunnel vision people here will say if you're not spending enough money on an elec giant system, it must be junk--I know as I've submitted several cost saving successfull set ups I've used to threads here inquiring about same .
I realize there will always be those who cannot imagine peeking outside of thier no-adventure mental boxes--- probably lined w/ easy $ .

In my opion, there is room for all suppliers. Some people like the comfort and support that they get by purchasing from a local hobby shop. By the way, I still spend a lot of money with my local shop on convience items.

Some of the United States distributors, do a great job of supporting thier products and seeking out the best products possible to sell over the internet to end users or through a dealer structure.

The fact is that little of the products we use in RC are made in the United States. The cost of great service and proven great products must be built into the cost of what you purchase from US Distributors and local hobby stores. It is like purchasing insurance when you purchase from them. Unfortunately with a US distributor and dealer. The cost of services and freight have to be built in twice, once for the distributor and once for the dealer. This increases the cost significantly, but some are willing to spend it to get the support of a dealer / US Distributor.

I have a friend that is an electrical engineer of the highest order and he has taken apart many of the products that he has purchased from HC and finds the components to be of very high quality. With the internet we can read about specific results that people have had regarding a product and direct our purchases accordingly.

I personally have had a great experience with HC products that I have purchased. But again I am aware that I may get a dud from time to time. Heck I have recieved more than my share of dud products that I have purchased from premium vendors and have got rotten service from premium vendors. The key is buyer beware, educate yourself before making a purchase.

If comfort is what you want, buy premium from companies that you know support thier products. I choose to pay 1/3 to 1/4 the price for the same items and take the risk that I may have to eat something every now and then. So far with the 12 -14 guys in my group we have bought around 150 batteries and numerous motors, esc, voltage regulators, and servos without a single problem.

So buy what and from who makes you comfortable, but let me take comfort in my up front savings.

Robert

[jsc]

I am in the process of coverting a H9 Ultra Stick Lite 120 using HC components. I use the local shops for convience items, but HC prices are hard to beat and get it in 7-9 days from the time I order...

[Robert Youens]

Now have 22 flights on my "reasonably priced" giant scale electric components from Hobby City and still going strong. I like the plane and setup so much that I have decided to buy more batteries from Hobby City to get in more flights. In the Turnigy brand they now have a 5s 5000 mah 15C for $49.95. In reading reviews, one fellow said that he was drawing 20 - 25C from the battery with no problem. This is consistant with what I have found, I believe Hobby City tends to under rate thier batteries. I am currently using the FlightMax 20C packs which cost $20 more per cell, I will report the results of the new batteries. If you want to take a look at the batteries, here they are:

http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=9174

I also added SFG's of my on design to the wing tips. I will include some photos next time. The SFG's totally changed the feel of the plane. Rolling circles much easier and straight line axial roll are much easier. The 3DHS 85" Katana lacked the side force area that thier new 89" Slick and SHP offer, so what the heck, just add it.

I have also been working with CG and some mixing to keep my knife edge passes, straight without a lot of elevator input. It has been an interesting journey.

Robert

[G.P.]

I read in one of the HC forums that apparently those 15c lipos were badged incorrectly and are actually 20-25c lipos.

Thanks for the updates and keeping us informed. I am looking to do a 40cc conversion this winter and think I may go the HC route. I just wish that they made some 4000mah lipos as a 5000mah setup is a bit heavy for a plane that size.

PS - Is that the pre-production plane? I remember seeing that color scheme in the prototype stages.

[Robert Youens]

I read in one of the HC forums that apparently those 15c lipos were badged incorrectly and are actually 20-25c lipos.

Thanks for the updates and keeping us informed. I am looking to do a 40cc conversion this winter and think I may go the HC route. I just wish that they made some 4000mah lipos as a 5000mah setup is a bit heavy for a plane that size.

PS - Is that the pre-production plane? I remember seeing that color scheme in the prototype stages.

Yes, as I understand it this was Ben's prototype plane. It is very light, but is missing some of the fit and finish of the production runs. What is really nice, is when Ben sold it to the previous owner, he gave away all of the parts he had remaining in stock. I have 5 wings for the plane. 1 pair is in the production colors. The previous owner actually got a spare fuse. Unfortunately that was already sold before I puchased the plane.

Regarding 4000 mah, they have one in zippy for around $53 at 20C 5S. They have the new Turnigy in 4000 mah, just not in 5s yet. I suspect they will wait till they run out of the Zippy before introducing the Turnigy in 4000 mah 5S.

Robert

[markepilot]

Hey Robert,

Nice setup, I did about the same thing as you did. I'm flying a proto Extra 260 from Ben. On 10S with a CC85HV and a power 160. I'm using Hobby City Rhino 5S 4900 packs and am at 2904 watts on my wattmeter. My AUW is 14lbs 6oz. If you want to save some weight you could go to CF tube as standoffs to mount the motor. I did this and saved about 4.5 oz.

Cheers, Mark

[Robert Youens]

The Turnigy 5000 mah, 5S 15-20C ($49.95) ordered Monday, came in today (4days from time ordered). They appear to be the same size a the Flightmax 5000 mah 5S 20C I already have had great success with. I compared weight with the Flightmax packs and the Turnigy weigh about 40 grams heavier. Generally I have found that higher C batteries are a little heavier than others of the same mah. This may indicate that they will perform well. I will attempt to test fly this afternoon and report back.

[Robert Youens]

Got in 3 more flights Yester afternoon and 3 more this morning. Now 28 flights. My new Turnigy 5000 mah battery performed well, could tell no difference from my other Hobby City 5000 mah packs, but my wallet like them a lot better at $20 less a pack..

Picked up bearing noise in the motor yesterday. Did research on the internet regarding lubricating Large RC Outrunners. Some manufactures recommend lubricating the bearings every 10 flights. Some sell thier own bearing lube.

It seems that Tri-Flow Lubricant which is usually available at bike shops, gun shop, and lock shops works well for the purpose of lubricating bearings. Many recommended 3 in 1 oil, commonly available at sewing shops and hardware stores.

I stood my plane straight up and lubed the front bearing with 3 in 1 oil and let it set for about an hour. I stood the plane on its nose and lubed the back bearing and let it set for several hours. I spun the motor several times during the process. This mornign I ran it for a while with no prop before heading out to the field. I wanted to heat the motor up and spread lubrication in bearing under no load. Hopefully I have not damaged the bearing too bad. Noise appeared to be in the back bearing. Seem natural since this would be the thrust bearing?

I am going to purchase some Tri-Flow and start lubrication the bearing every ten flights.

The motor felt and sounded good as new this morning. Will report more later.

Robert

[staggerwing]

[/QUOTE]

It seems that Tri-Flow Lubricant which is usually available at bike shops, gun shop, and lock shops works well for the purpose of lubricating bearings. Many recommended 3 in 1 oil, commonly available at sewing shops and hardware stores.

Robert

Hello Robert,
Awhile back I purchased a C6364 Welgard BL (formally sold by BP Hobbies who dropped the line) used here in RCG for a back up to same I have in my 85" H9 T Craft turning a 20/10 on 8s.
I was not warned it had a rough bearing in it --don't remember which as there are two shielded 10 X 15 x 4 mm in front & one 10 X 19 sealed in rear, however I was able to get all three brgs thru ;

NationSkander Calif. Corp in Anaheim Ca 92806,

which I found on line for about $17 total . (Do a search for miniature ball brgs)
Don't know about Tri Flow, but 3 in 1 has been around forever & is one of the earliest forms of a penetrating oils having a large content of kerosene (IE its smell) & not the greatest lube for heat or ball bearings under load--ok for a squeaky hinge though. A good quality motor oil works if the brg has just run dry & is open or shielded (not sealed).
Usually when a ball bearing fails or gets rough (pitted from metal or lube failure or corosion), there is no saving it.
One of the pitfalls of bearings nowdays is thier mfg origin---usually Japanese brgs are exc quality--all other off shore w/ no ABEC or Military specs--beware !
Technology constantly changes--especially off shore--so who knows really what you're getting ? Youse take your chances.

Bob

[edoc]

Robert,
I have had great success with the Turnigy SK motors up to the 50-65-380. The SKs run cooler and have very good bearings. However, the larger 63 series SK motors have been reported to have their Magnets pull loose under heavy load. The other large Turnigy motors often have Bearing problems.... So you can either by an SK and reglue the magnets or a regular Turnigy and replace the bearings. I have been waiting for the Fix to come on the stock motors.

Have you considered replacing your bearings?

Tim

[Robert Youens]

Robert,
I have had great success with the Turnigy SK motors up to the 50-65-380. The SKs run cooler and have very good bearings. However, the larger 63 series SK motors have been reported to have their Magnets pull loose under heavy load. The other large Turnigy motors often have Bearing problems.... So you can either by an SK and reglue the magnets or a regular Turnigy and replace the bearings. I have been waiting for the Fix to come on the stock motors.

Have you considered replacing your bearings?

Tim

Tim,

Yes I am looking into doing that. I wrote emails to several companies that sell the HXT 63-74 200 under various brand names to see if they might sell a bearing upgrade or might mind sharing the bearing size or part number. Only heard back from one company and they said that it would be best to remove the bearing and measure myself since it is possible that the manufacture may use different size bearings in different production runs.

I have been given several recommendation of good places to purchase bearings, but have not wanted to tear down my motor since it is running quite and cool at this time.

Hopefully someone will come forward with specs on the bearing needed for the HXT 64-74 200's currently sold by Hobby City. I will go ahead and purchase the bearings hoping they will fit when I get a new one in hand.

Currently I have been flying almost every morning and evening and having a blast. Now have 40 flight on the Hobby City components.

Robert