Arcie II help

[aerostadt]

I've only flown the Edmond's Arcie II once on a D12-3. It was flown stock except that I forgot to put on the nose cone fairing that surrounds the receiver and battery. Also, I put small cardboard tubes on the control horns to better engage the servo arms. After the motor pod ejected, the Arcie II glider part went into a steep dive. I could turn left or right slightly, but the dive persisted. The balsa housing for the receiver and battery was broken and missing. I am thinking that the part broke on impact. I'm surprised that the nose cone fairing could make so much difference. I probably can repair this model. I still have the outline of the broken and missing part from the left over laser cutting. The remains are shown in the attached photos.

[billspad]

Any one who knows me will tell you that by no means am I a glider expert. However, I have flown a couple of Arcie II's and I recall from building them that there are a couple of marks on the wings for the CG and it's really important to make sure it's right on the marks. I looked at mine to see where they are but that part burned off when the wings caught on fire. It did glide really nice until they fell off.

[aerostadt]

Thanks, Bill,

It has been awhile since I built the Arcie II, but I remember the instructions discussing the balance point. I did follow those instructions. The thought occurred to me later today after starting this thread that perhaps the battery might have come loose from the balsa housing and without the nose cone fairing (body tube) it would have been dangling downward. Perhaps, this was my problem.

[tightwad]

My Arcie II suffered a broken horizontal stabilizer on its maiden flight. It spiraled upwards till the pod ejected, then rolled, rolled and rolled through its glide phase. I was able to bring it under control just before impact. Luckly no damage, except the stabilizer. The stabilizer broke off right where the antenna wires went through. It is all fixed, antenna wire rerouted and ready to fly once I get nice weather. Good luck with yours.

[billspad]

Thanks, Bill,

It has been awhile since I built the Arcie II, but I remember the instructions discussing the balance point. I did follow those instructions. The thought occurred to me later today after starting this thread that perhaps the battery might have come loose from the balsa housing and without the nose cone fairing (body tube) it would have been dangling downward. Perhaps, this was my problem.

That makes sense. Mine broke just like yours after a hard landing. I need to do a little redesign on the receiver and battery mount to make it a little more sturdy since my landings are usually not very gentle.

[iter]

My experience with Arcie is a lot less violent it seems. Arcie is my first foray into rocketry, and as such I recall a lot of anxiety before its first flight. It has now lived through 2 CATOs (apparently defective lot of Estes E9s, others in my club have CATOs with the same date marking), a Red Barron (booster's failure to separate at apogee--hence its conversion to a one-piece RCRG) and is still going strong.

My photo shows CG location markings. They may be hard to see behind CATO charring. I remember my surprise at CG location so far behind the leading edge until I realize that sweepback on the wings moves MAC back from the root cord.

@aerostadt: thank you for posting your photos. The glider looks fine to me. I don't like the aileron setup either, but I leave it as is on my Arcie. It's a training aid for me, and once I learn what I can from it, I move beyond it to more elaborate gliders I design now. Battery coming loose in flight typically moves CG back, not forward, depending on where its wire attaches to the airframe. As a pendulum, a loose-hanging battery tends to amplify whatever attitude the glider is in, so if the glider is pointing nose-down at separation, and the battery is loose on a sufficiently long wire, this may move the GC forward beyond recoverable.

Arcie's original design cals for NiCd batteries, which are heavy. I use a single-cell LiPo in my Arcie, and even with the battery all the way in the nose, I still need a quarter at the base of the nosecone for correct CG.

I would like to see these wounded birds fly again. It's sad to see gliders in such sorry state :=)

Ari.

[aerostadt]

Yes, the proof is in the flying. Since my first flight Arcie II flight is questionable with my bad, I need to refurbish the model to as close to the original condition as possible and try again. Rocketry is slow for me these days. I have too much yard and garden work and other things going on right now. The hot Utah weather is also putting a damper on flying. The club launches for May and June were canceled because of the fire hazard conditions.

[cwbullet]

The fire hazard is putting a damper on rocketry. I sure with you would get some rain.

[Massrokit]

http://forums.rocketshoppe.com/showthread.php?t=11274 message 5 has dims. for balance location.

[aerostadt]

Arcie's original design cals for NiCd batteries, which are heavy. I use a single-cell LiPo in my Arcie, and even with the battery all the way in the nose, I still need a quarter at the base of the nosecone for correct CG.

Ari,
It seems that I lost the NiCd batteries in my crash. Can you tell me about your LiPo battery? (cost, where to get it, connecting it, recharging, etc.) I am not familiar with using LiPo batteries. I wonder if it would be difficult to replace the NiCd batteries.

[iter]

The battery I have is from my battery box. It probably cost $30 when new in 2005 or so. Now you can buy them for about $2:
100mAh: http://hobbyking.com/hobbyking/store...dProduct=11873
138mAh: http://hobbyking.com/hobbyking/store...dProduct=11874
240mAh: http://hobbyking.com/hobbyking/store...dProduct=11870

As I recall, Arcie instructions call for a 50mAh NiCd; any of these are more than sufficient. Neat thing about the ones above is that they come with a JST plug which you can connect directly to a receiver (make sure you plug red into plus, black into minus and leave the signal pin--where white signal wires go--empty).

You can buy a charger from Hobby King as well, though I'm less clear on their chargers than their batteries. This one looks like it does what you need and is relatively cheap: http://hobbyking.com/hobbyking/store..._charger_.html . If you have a local hobby shop you like, you can ask them about single-cell LiPo chargers.

One word of caution: 4-pack of NiCd batteries runs at nominal 4.8V. A single-cell LiPo runs at nominal 3.7V (4.2 on a fresh charge). Modern receivers internally regulate their voltage down to 3.3V and so don't care about lower input voltage. Some older analog receivers may depend on the higher input voltage. I encourage you to do a thorough range check with your receiver and your battery.

Ari.

[aerostadt]

Thanks, Ari, I am ordering the 100mAh Lipo battery and charger. We will see how this works out. I sent an email to one of the two companies that Rob Edmonds suggested in his Arcie II directions for the 50mAh Nicad pack, but I have not heard from them, yet.

I still have the laser-cut outline of the balsa parts from the original kit. From that outline and the instructions I was able to make a pattern for the new part. I cut the new part from soft balsa. It is much softer and lighter than the heavy balsa that comes with the kit. I have given the new part a light CA coating. I am thinking that I will attach it to the original frame with CA, but I will give it some reinforcing with white paper and white glue.

[iter]

Thank you for sharing your process. Unless you have a compelling reason to use NiCds, I recommend against buying them. They are the one-before-last technology, and I can think of no benefit to using them. Incidentally, the large cutout in the forward fuselage is the size of and for this old NiCd battery. If you're ordering a LiPo, replicating the shape of that cutout is optional.

Also, CA works by wicking its way into capillaries in balsa. If you coat a piece of balsa with CA, you seal the capillaries--making it harder for CA to wick into the wood. I prefer to glue parts first, seal them second.

Ari.

[Massrokit]

I use thin aircraft plywood to reinforce some of the areas subject to stress (hard landings). I used plywwod were the servo screwed into the balsa to give the screws something to better bite into and reinforce that area.

[aerostadt]

Also, CA works by wicking its way into capillaries in balsa. If you coat a piece of balsa with CA, you seal the capillaries--making it harder for CA to wick into the wood. I prefer to glue parts first, seal them second.

This is a good point, Ari. I will try to remember this in the future. I think I am a little bit lucky, because it looks like I avoided putting CA at the point of contacts on both parts until I was ready to do the final assembly. I used super glue gel to join them together and it seems like I got a good bond. I also tried the nose cone fairing fit and it seems to work well. I am still planning on putting on some white stationery paper and white (Elmer's) glue.

[iter]

One thing I want you to verify is your wing's angle of attack. I can't tell from the pictures if the leading edge sits lower than the trailing edge. Decreasing AoA decreases the difference in AoA between wing and stabilizer and reduces elevator's nose-up moment.

Ari.

[aerostadt]

I have reinforced the repair with 24 pound stationery (Now that I am retired I don't need this paper for resumes anymore. It's a great feeling and probably a better use for the stationery.) as shown in the attached photo.



I have some pictures in the next post that Ari requested.

[aerostadt]

Ari,

It looks to me like the angle of attack is either zero or slightly negative (The latter doesn't sound good.). It has been several years since I constructed the model, but I thought I followed the directions correctly. In fact I don't remember the directions talking about a of a with regard to the wing construction. I thought the instructions said to put the wing on flush with the main airframe. Perhaps, the attached pictures will answer the question.

[iter]

Flush with the fuselage sounds right.

Ari.

[aerostadt]

I bought the Lipo batteries and charger from Hobby King last summer and several weeks ago tried them out for the first time. It took awhile to get back to this topic. The charger did not work, but Hobby King has refunded the cost. I asked them for a charger that they recommended and I have ordered it. The merchandise comes from Hong Kong, so it takes time to ship and the shipping cost are high. When I found that the charger did not work, I decided to revisit Nicad batteries. The small batteries that Edmund recommended are no longer to be found anywhere, but I did find a substitute from Megabatteries. The Nicad batteries do not have the correct connector, so I cut it off and soldered on the correct connector. The Lipo batteries have some factory charge on them and I measure the voltage at 4 volts. The Nicad batteries have 6 volts.

[Minimum_Wage]

Hi Aerostadt,

You might want to take a look at cheapbatterypacks.com. If you click on the link for "Custom NiMh/NiCd packs" they have a really nice online tool for building custom packs using just about any battery, connector and configuration you can think of. Lots of options for small cells, down to 1/4AAA size. Pretty good prices and quick shipping too. I use them all the time when I need small packs for gliders. (I have no other connection to the company.) It might be too late for this project but hopefully it can help you next time!

Mike Mc.

[TheAviator]

I second CBP. I've used them several times for a collegiate competition that requires NiMH batteries. The small KAN cells are excellent for RX packs. Also, go NiMH instead of NiCd. Drop in replacement for NiCd and easier to work with. Also somewhat lighter.

Hi Aerostadt,

You might want to take a look at cheapbatterypacks.com. If you click on the link for "Custom NiMh/NiCd packs" they have a really nice online tool for building custom packs using just about any battery, connector and configuration you can think of. Lots of options for small cells, down to 1/4AAA size. Pretty good prices and quick shipping too. I use them all the time when I need small packs for gliders. (I have no other connection to the company.) It might be too late for this project but hopefully it can help you next time!

Mike Mc.

[aerostadt]

Lo and behold I found the old battery pack in my workshop. This is another message that I need to clean up the shop. Thank goodness my wife does not visit this forum. Anyways I put the in the old battery pack and balanced the Arcie II according to the directions and launched today. The same thing happened again as in the first flight. I called it a steep dive (no gliding at all). One of my friends called it a spiral dive. The front of the Arcie glider sustained heavy damage just as in the first flight. I am now thinking of turning this model into an unguided boost glider and using the electronics for something else.