ironJaw

Greg,

To make sure I understand your answer, I am referring to the prop shaft hole not the prop drill pattern.

I have tried drills (Sharp ones), reamers, etc.  All seam to drift off center from the original hole.  Most
promenently in wood props.

The larger the prop shaft  hole is the worse the problem.

I have tried lining up drill press with a piece of drill rod first and then clamping down the prop.
;Then put the tool in.  It still doesn't get the job done right.

Tom

LDHFlyguy

Hi Tom,
If you are talking about enlarging a 1/4" prop hole to a 10mm hole, I have a drill bit that was manufactured (or altered) just for that purpose. The first part of the drill bit is 1/4" for hole centering and the remainder of the bit is 10mm. If that's what you need, let me know and I'll check mine out to see who made it. If there are six other bolt holes in the prop that you need help with, and they happen to match a Desert Aircraft or a 3W gas engine, you can get a drill guide from DA, probably 3W and a company called PSP.

I checked on the bit. Look here: http://www.bennettbuilt.com/page9.htm
Here are PSP drill guides: http://www.pspmfg.com/PropDrillJigsGuides.html

I hope this helps. If not, I'm pretty sure Greg will have your answer.

Larry

Greg Covey

Tom,

It looks like Larry has the right idea. Let me know if this is not what you were looking for. Perhaps there is some sort of slop factor in your drill press.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
For about $10 at Home Depot, I picked up some #6 x 1" screws and a 1/2"x6"x4' piece of Poplar. After a few hand cuts, I was ready to make my test box. Poplar isn't a hard wood but it is fun to work with and becomes plenty strong if you put enough screws in it.

The idea here is to clamp and tie the box to my WorkMate and then move my portable station outside for testing. No sign of the prop yet so my next step will be to finish the setup on the WorkMate and do a quick test on 6s at low RPMs without a prop. The CC ICE HV 160 ESC will mount on the side of the test box. I still need to solder the 8mm bullet connectors onto the ESC.

ironJaw

Larry, Greg

Thanks for the reply.

The Props I have been getting,  I.E. Mejzlik,, Vess, Xoar etc.  all come with a 10mm prop shaft hole dia.

If I have to enlarge them to a larger dia. to fit an adapter thats when the trouble starts.

Bennetts prop drills all have a 1/4 in. pilot drill so it would require a special order.

Greg, thanks for the dimension info.  I have put it into my CAD drawing and your right-
it does look like a washing machine motor.

Tom

Thanks Again

LDHFlyguy

Tom,
What prop adapter are you using that is larger than 10mm?
Neu has a 14mm. That's the only one I recal being larger than 10mm. "Bone Doc" has had experience with the Neu adapter.
Perhaps the manufacturer of the adapter can give you some ideas on how to successfully go about enlarging a 10 mm hole.
Larry

Greg Covey

My Xoar [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXZJA7&P=7]30x10[/link] PJA Series Beechwood prop arrived from Tower Hobbies. I also bought the [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&P=8&I=LXZTJ0]Xoar Prop Covers[/link] that work up to 34" props.

I was surprised with the quality of this prop. It was perfectly manufactured and painted with a clear coat enamel. I should be able to get it drilled between Christmas and New Year's Day.

ironJaw

Larry,

The adapter that comes on the AXI 5330/20 Dual Tandem is 12 mm but it also
has a 17 mm boss that the Prop and spinner back plate have to fit over.
The motor shaft is 8 mm!!!

I no longer use it.  I had Tru-Turn make me one with a 10 mm OD but I still had
to retain the 17 mm boss.  It contains two of the four set screws that retain the adapter
on the motor shaft.   So I need a good drill to do the 17 mm portion of the hole.

Tom

LDHFlyguy

Sorry Tom, but I'm out of ideas except to special order a drill bit from Bennet or find a machinest that can reduce the point on a 17mm bit down to 10mm and drill just enough of the hole in the prop to 17mm.


I had one additional thought for you Tom.
Please be very careful in everything you do with the propeller, adapter, etc.
You are dealing with a lot of torque, power, RPMs, etc. and neither I, nor would anyone else, want you to be injured.
Any vibration due to an improperly drilled or balanced propeller, in my mind, is completely unacceptable in your setup.
Set screws on collets are a concern to me, also.

Best Wishes,
Larry

ironJaw

Larry

Thanks for the info, and the warning, if you look at a photo of the AXI 5330/20 Dual
you will see that the adapter is bolted to the front motor with 4 bolts.  The set screws
are in pairs.  They are located 1 pair on the small boss and 1 pair on the outer dia. boss

The shaft comes through from the rear motor and the two motors then are tied together
by the set screws.  All is proper and relatively safe.

This arrangement is such that you could run two propellers in a counter rotation mode.

One prop tied to the shaft (rear motor), and one prop tied to the front moter via the adapter.

Tom

Greg Covey

I picked up a Heavy Duty Battery Cutoff Switch ([link=http://www.harborfreight.com/heavy-duty-battery-cutoff-switch-66789.html]66789[/link]) for $10 at Harbor Freight Tools to use as my safety arming switch outside the plane. The low-cost switch locks in both the On and Off positions and is rated for 500 amps at 24v which should be good for around 250 amps at 48v. The switch weighs 7.7oz but I consider it a requirement for safety and convenience on a giant-scale electric conversion that approaches 10KW of power. I'll detail use of this switch along with a momentary push button anti-spark setup when I video my prop testing outside.

The motor passed its first test. Not only does it run but it appears to be vibration-free. I tested it on my work table using a 6s LiPo pack and was very happy that it appeared to run flawlessly at a range of throttle settings. The Spektrum [link=http://www.horizonhobby.com/Products/RelatedParts.aspx?ProdId=SPMAR9100&Category=Optional%20Accessories#quickOverview]AR9100[/link] DSM2 9-Channel PowerSafe Receiver and Hobbico [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXYAT1&P=ML]LiFe 6.6v 3200mAh[/link] pack are inside the box.

I started assembling my portable Work Bench to be used in the outdoor prop testing. You can see my technique of clamping and strapping the motor test box. The 12s3p LiPo packs will sit on the left side and I will mount the arming switch to the motor test box.

slevin1

My Feedback: (23)

Looking great Greg. I am very curious to see if that battery arming switch works. I remember you using one on your review of the World's Models J3 Cub.

Saul

LDHFlyguy

Congratulations Greg.
So far, so good
I'm assuming the towel in the center picture
is for perspiration immediately before and
after the test run

Greg Covey

Thanks, guys. There may be some apprehension on the first power-ups but I won't admit to any perspiration.

Saul,

Good memory. Same idea but this HD switch has much higher ratings.

I mounted the HD Battery Disconnect Switch and the momentary push button to my test box. In this setup, the operator presses the button first, then pulls and twists the battery switch for a spark-free arming of the power system. The momentary push button connects a 100 ohm 1w resistor across the battery switch to charge up the capacitors on the ESC within a second.

slevin1

My Feedback: (23)

I feel there is a need in the market place for an airplane specific arming switch for all size aircraft. I believe it would increase the element of safety with electrics.

Saul

LDHFlyguy

+1 for Saul

In my 89" Slick with 12S 5000mAh I had a little over 100 amps running through this occasionaly: #6972 Arming Switch, with Ultra Dean Plugs & AWG12 wires and a power pole connector to plug in for arming by MPI...(I couldn't paste the picture
Mounted directly adjacent to the power pole connector on the fuselage was a miniature pushbutton that placed a 47 ohm 5W resistor in parallel with the power pole. There was never a spark ! It was about identical to what you have Greg.

I'm considering trying something like that with my Predator and using a larger power pole OR one set of power pole arming plugs for each battery set. I think the power pole ratings are based on the amount of current they can safely start and stop rather that their continuous current. With the pushbutton and the fact the motor isn't running when I unplug the power pole, I think I can get buy safely with a fairly small power pole.

But back to Saul's idea.... I too wish manufacturers would come up with a couple different sizes based on what's being armed.

OK GREG..... lets make that puppy go

Greg Covey

By buddy slipped on some black ice and injured himself so my prop drilling is delayed for a few weeks. I almost finished wiring my 12s3p LiPo pack so I'll post some photos on that setup soon.

I decided to start retaking my back family room as my assembly area since all the holiday festivities were over.

- - - - - - - - - - - - - - - - - - - - - - - - - - - -
The Ultimate was brought from my filled plane room to the back room where I can complete the assembly. I decided to work on the gear mains next. After the metal brackets (for the flying wires) are installed into recessed slots, the main gear bar is screwed into place with the supplied cap head screws. Notice that the t-nuts are offset so that you cannot install the mains backwards.

I replaced the stock air-filled wheels with Dubro 5" Treaded Lightweight ([link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXD785&P=ML]500TL[/link]) solid rubber wheels. The World Model air-filled wheels tend to leak. The wheels are held in position on the axle with a collar on each side.

I discarded the supplied hardware for the pants and used my own small cap head screws and t-nuts. After checking the alignment of the pant, I drilled two holes through the metal gear mains and through the pants. The pants are well designed and have an indentation on both sides to mark where to drill the axle hole. Since both of the inner sides have plywood plates fiber-glassed into place, either pant can be used as either a left or right pant. I used a Dremel tool to sand a Dime-sized recess on the outer side where the pant meets the welded nut on the axle.

All the parts seemed solid when finished. I plan to add some extra V-poxy to the hardwood mounts inside the plane that secure the gear mains. This should help hold things together in the event of a rough landing.

Once finished, I held the cowl in place with a single piece of tape. The Ultimate was starting to shape up!
- - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Has anyone ever seen giant scale wheels with bearings in the axle? I wouldn't mind upgrading my axles to have bearings if it doesn't require custom fitting.

LDHFlyguy

My Pilot RC Decathlon came with some really nice looking 5" wheels with shiny aluminum hubs with brass sleeve bearings. Maybe Pilot RC or Chief Aircraft sells them.
With my flying skills I'll probably consistently roll off the end of the runway with these bearings !

I wanted to recommend another supplier whose plane I'll be assembling; but, when I looked at the axle holes in the aluminum hubs, they were obviously drilled off-center and there was no sleeve in them. But, I'm sure they will get the job done. The rest of the plane is beautiful.

Your Dubros look good. When I used a drill press to enlarge the holes in my 5" Dubros, one of the holes went in perfectly centered on one side and came out pretty far off center on the other side. Other than that wheel wobling a little, it still gets the job done.

With the apropriate drill guide/jig for props on DA and 3W engines, I've seen guys use a hand held battery powered drill to drill accurate holes. I still do mine with a drill guide on a drill press. I don't know if there is drill guide manufactured for props for your motor. PSP makes these: http://www.pspmfg.com/HolidaySpecialDLE30DrillJig.html

Happy New Year!

Greg Covey

When you assemble a super battery pack like this 12s3p 15AH configuration, you must keep safety your first priority. I use safety goggles when soldering and sanding with the Dremel tool. I also have three fire extinguishers nearby.

The packs I used here for testing are similar but not matched cells. I will likely purchase six 6s packs of the same type in the springtime.

I soldered Castle Creations 6.5mm bullet connectors to all the 6s packs. These connectors are rated to 200 amps. The red wire gets the male connector so that when using a single pack, the last connection to the ESC can easily touch the anti-spark resistor (soldered to the ESC female bullet) just before being inserted. On this application, I am using a separate arming switch and resistor so the male/female orientation is meant for other smaller applications.

Each set of 6s packs are first balanced charged separately and then connected in series to make a 12s pack. The resultant three 12s packs are then connected in parallel to create the super battery pack.

I made my own 3:1 adapters using #10 Castle Creations "wet noodle" silver wire. I don't know what the rating of the HK 8mm bullet connectors is but they are more like 10mm connectors so I expect them to be sufficient.

I have one #10 gauge wire coming from the arming switch to the battery packs that I will eventually replace with an #8 wire. For testing purposes, the #10 wire should be sufficient.

The [link=http://www.robotmarketplace.com/products/wire_and_accessories.html]Robot MarketPlace[/link] sells high quality wire by the foot in many gauges including #8.

I charged the packs last week. No matter when they are charged, you should measure each 12s configuration before connecting them in parallel. I measured 49.8v, 50.0v and 49.9v so I knew that I would have no issues when connecting them in parallel. The resultant super pack voltage was 49.9v. The super pack sits on a piece of 1/4" aircraft grade plywood and is held by two Velcro (p/n 90700) One-Wrap straps. A similar configuration will be used in the plane once I assemble the motor box.

Each connection of the bullet connectors is covered with a 1.5" piece of masking tape. This is done for safety since there is often a small ring of metal showing that the shrink tubing doesn't cover. I also found a piece of EPS foam with the perfect density to make some end caps for both the battery leads (when separated) and the final two 8mm connectors. The red cap has the EPS foam inside. The advantage of using the EPS foam is that it will not press the male connector pins during storage and has no memory for being slightly forced onto the connector. They can be made in seconds with a razor knife and ruler and will not fall off or be shaken off.

LDHFlyguy

Very Interesting Greg.
Thanks for sharing your ideas and efforts with the world.

When I finally get around to assembling my plane, I'll be trying to decide whether 12S-2P, 12S-3P, or 14S-2P fits my flying style/needs. One of the reasons I went with the big Predator and Schulze is to keep many options available.
My hopefull setup will be 12S-2P or else 14S-2P. I already own 12 matching 6S-5000mAh batteries. It would be easy for me to add some 2S-5000mAh batteries.
There are sooo many variables and things to take into consideration, besides the battery arrangements, that I think flying the different setups will be the only way to finally decide. [sm=spinnyeyes.gif]

I really think it's going to be fun figuring it all out! [sm=idea.gif]
So are these smily faces

Greg Covey

I did some research and discovered that the [link=http://www.sullivanproducts.com/WheelsMainFrame.htm]Sullivan Skylite Wheels[/link] come with a Delrin (Dupont) bearing when you get the aluminum hubs. The wheels are available in sizes from 3-1/2" to 7" diameter. The bearing fits a 3/16" axle except for the 6" and 7" wheels that use a 1/4" axle.

Sullivan Skylite Wheels are made by a unique process that makes them both light and durable. They have a urethane outer skin and a foam core, so they can support heavy loads without going flat. The hubs are all over-designed and can be drilled out to larger axle sizes. Also, all of the larger sizes (3-1/2" and up) are made with two piece Nylon or Aluminum hubs to ensure that the tire cannot come off the rim on heavier aircraft.

Horizon Hobbies sells them [link=http://www.horizonhobby.com/Products/Default.aspx?ProdID=SUL854]here[/link].

Tower Hobbies sells them [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXHML6&P=7]here[/link].

I ordered an upgrade for my 42% Ultimate.

ironJaw

Greg,

Be careful when you assemble the sullivan wheels.  The aluminum hub plates must be
exactly lined up on each side or the hub will not be perpendicular to the wheel and wobble!!!

Tom

Greg Covey

Tom,

I assumed that the wheels came pre-assembled since I bought them with the aluminum hubs. Since my main focus is to eliminate wobble and have a smoother roll, I will certainly be checking that out.

The Dubro wheels would probably work just fine. I was a bit dismayed by the wobble and wanted to find a relatively inexpensive wheel that used a bearing. The Sullivan Skylite Wheels seem to fit this solution.

I'll let you know my findings when they arrive.

Happy New Year!

Greg Covey

All four wing halves are completed. Each wing was built like the first one and had the aileron sealed on the bottom side with clear Monokote. The supplied linkage hardware worked well here.

Since I am using only 8 servos total for the entire plane, instead of 16, I realize about a pound in weight savings.

On to the horizontal stabilizers...

Greg Covey

FYI - My prop is scheduled to be drilled on Sunday January 9th so I should be able to run my power test on the following weekend.

Greg Covey

It looks like Tom was right as my Sullivan 5" wheels arrived un-assembled. I was a bit disappointed that the Delrin bearings turned out to be what I call a Nylon bushing. However, it does fit nicely on the Dubro 3/16" axle shaft.

Since the "upgrade" wasn't really what I had envisioned, I will likely leave my Dubro 5" wheels on the plane and save these if I have any problems.