Rumfal on 4S A123
09-30-2007, 10:06 AM
#1
Thread Starter
Join Date: Jul 2003
Location: alexandria, VA
Posts: 63
Likes: 0
Received 0 Likes
on
0 Posts
Rumfal on 4S A123
Hey everyone,
I got no love on another website, so I thought I'd add my experiences with the A123 cells. A few years ago, I bought an ARC JR Rumfal from Esprit Model. At the time there was not many 8-10 cell/3s pattern-type plane and this was the only one there was. It stayed in my basement for about a year and then I began to assemble it. I cant tell you what a pain in the [:@] it was to modify and fix defects to the fuse ( nose ring installed crooked, wing chord longer than opening in hatch/canopy, etc.), but it finally took to the air two weekends ago. I can get 8minutes of mixed throttle, if I'm careful and 6-7 minutes of more agressive flying. At 23 oz. per foot, it doesn't float, but niether does it violently tipstall. I also found out I have an incidence issue, but I ordered a Hnagar 9 incidence meter and will fix it.
I have followed Dick Hansen's and Turbine 50's posts and thought I would contribute.
Specs:
42.5 oz (down from original 49 oz. with 17 oz. 8 3600NiMH & 6oz. motor- never flew with this arrangement.)
4S A123 in stick configuration
Hyperion 3019 1070kv outrunner
MGM TMM 4016 controller w/ BEC (bought before lipos existed)
2 Dymond D90's in the wing
2 Hitec HS 85's in the fuse
FMA extreme 5 receiver.
about 420 watts at 36 amps with full pack.
I had someone else hand lauch and with full power it went straight up after launch. So far it has 7 flights and I need to fix a wing incidence issue (too much positive). Still sorting it out, but the real challange was fitting A123's in to a sub-c wide fuse. The pics below show how I did it.
Terry
Edit: sorry about the attachment files. First time positng pics here. If anyone could give me a pointer on it I'd appreciate it.
2d Edit- fixed it.
I got no love on another website, so I thought I'd add my experiences with the A123 cells. A few years ago, I bought an ARC JR Rumfal from Esprit Model. At the time there was not many 8-10 cell/3s pattern-type plane and this was the only one there was. It stayed in my basement for about a year and then I began to assemble it. I cant tell you what a pain in the [:@] it was to modify and fix defects to the fuse ( nose ring installed crooked, wing chord longer than opening in hatch/canopy, etc.), but it finally took to the air two weekends ago. I can get 8minutes of mixed throttle, if I'm careful and 6-7 minutes of more agressive flying. At 23 oz. per foot, it doesn't float, but niether does it violently tipstall. I also found out I have an incidence issue, but I ordered a Hnagar 9 incidence meter and will fix it.
I have followed Dick Hansen's and Turbine 50's posts and thought I would contribute.
Specs:
42.5 oz (down from original 49 oz. with 17 oz. 8 3600NiMH & 6oz. motor- never flew with this arrangement.)
4S A123 in stick configuration
Hyperion 3019 1070kv outrunner
MGM TMM 4016 controller w/ BEC (bought before lipos existed)
2 Dymond D90's in the wing
2 Hitec HS 85's in the fuse
FMA extreme 5 receiver.
about 420 watts at 36 amps with full pack.
I had someone else hand lauch and with full power it went straight up after launch. So far it has 7 flights and I need to fix a wing incidence issue (too much positive). Still sorting it out, but the real challange was fitting A123's in to a sub-c wide fuse. The pics below show how I did it.
Terry
Edit: sorry about the attachment files. First time positng pics here. If anyone could give me a pointer on it I'd appreciate it.
2d Edit- fixed it.
10-01-2007, 08:20 PM
#3
Thread Starter
Join Date: Jul 2003
Location: alexandria, VA
Posts: 63
Likes: 0
Received 0 Likes
on
0 Posts
RE: Rumfal on 4S A123
A post! A post!
Anthony, I can't tell you specifically how many mah I put back in after a flight as I have 5 4S A123 packs and 5 3S 2200 lipo packs (for other A/C). Basically for the time I'm at the field, I don't need to recharge. I can tell you that after doing a lot of verticals, I had ran it flat at about 6:45 and had to dump it (no damage). I think 8 minutes with diligent throttle control is possible
I'm using a Graupner 11x6 folder on a 42mm spinner.
Right now the airplane's all over the sky due mostly from me and it needs to be trimmed better so I haven't done a series of maneuvers to figure out how many mah a set pattern pulls. As it flies now, it's a bit frustrating- but I'll get it fixed.
I really believe that these are best for .40-.60 size conversions and voltage is your friend. Instead of 5S lipo, use 7-8S A123.
I have read your A123-Vanquish thread. Flight times are going to be a little shorter than other lipo for equivalent weight, but you can just fly, land, carry out another pack, swap packs and fly.
Terry
Anthony, I can't tell you specifically how many mah I put back in after a flight as I have 5 4S A123 packs and 5 3S 2200 lipo packs (for other A/C). Basically for the time I'm at the field, I don't need to recharge. I can tell you that after doing a lot of verticals, I had ran it flat at about 6:45 and had to dump it (no damage). I think 8 minutes with diligent throttle control is possible
I'm using a Graupner 11x6 folder on a 42mm spinner.
Right now the airplane's all over the sky due mostly from me and it needs to be trimmed better so I haven't done a series of maneuvers to figure out how many mah a set pattern pulls. As it flies now, it's a bit frustrating- but I'll get it fixed.
I really believe that these are best for .40-.60 size conversions and voltage is your friend. Instead of 5S lipo, use 7-8S A123.
I have read your A123-Vanquish thread. Flight times are going to be a little shorter than other lipo for equivalent weight, but you can just fly, land, carry out another pack, swap packs and fly.
Terry
07-10-2008, 09:05 PM
#4
Junior Member
Join Date: Oct 2003
Location: Rio Rico,
AZ
Posts: 14
Likes: 0
Received 0 Likes
on
0 Posts
RE: Rumfal on 4S A123
Terry,
Strange question, but your Rumfal-in-backyard pics look very much like the backyard of a Herndon, VA home I owned 1995-2004 (1036 Jeff Ryan Dr.) It would be almost impossibly rare if true, but I just have to ask. Please say no so I can finally believe age has gotten to me...(smile.)
Thanks,
Tom Mitchell (aka Herndonguy on eBay)
Strange question, but your Rumfal-in-backyard pics look very much like the backyard of a Herndon, VA home I owned 1995-2004 (1036 Jeff Ryan Dr.) It would be almost impossibly rare if true, but I just have to ask. Please say no so I can finally believe age has gotten to me...(smile.)
Thanks,
Tom Mitchell (aka Herndonguy on eBay)
07-11-2008, 09:43 AM
#5
Thread Starter
Join Date: Jul 2003
Location: alexandria, VA
Posts: 63
Likes: 0
Received 0 Likes
on
0 Posts
RE: Rumfal on 4S A123
Tom,
I live in Alexandria, south of Old Town, where the home is and the picture taken. I live near Fort Hunt park.
I haven't flown the plane in a while so I need to as I have fixed the incidence issue (I hope).
Terry
I live in Alexandria, south of Old Town, where the home is and the picture taken. I live near Fort Hunt park.
I haven't flown the plane in a while so I need to as I have fixed the incidence issue (I hope).
Terry
07-17-2008, 03:36 PM
#6
RE: Rumfal on 4S A123
Glad to see someone flying the Rumfal ... I've had my eye on it FOREVER ('99 or so when I quite glow and went electric only)
besides the issues mentioned, what are your thoughts of the kit ?? is it a heavy glass lay-up ?
besides the issues mentioned, what are your thoughts of the kit ?? is it a heavy glass lay-up ?
07-21-2008, 08:43 AM
#7
Thread Starter
Join Date: Jul 2003
Location: alexandria, VA
Posts: 63
Likes: 0
Received 0 Likes
on
0 Posts
RE: Rumfal on 4S A123
Alan,
Given what is currently available, I would not have bought this. The glass work is a little heavy and the parts fit is not good at all. I wanted an 8-cell (round cell) pattern plane and this was the only game in town at the time.
I would MUCH RATHER have an Aspera, as it can ROG, has more wing area, is build straight and flies superbly. I don't have an Aspera as I will work with this for a while. Right now, it is a little lighter than an Aspera, but an Aspera is a larger plane. I will be at NEAT this year and will be bringing it, if it survives until then.
Given what is currently available, I would not have bought this. The glass work is a little heavy and the parts fit is not good at all. I wanted an 8-cell (round cell) pattern plane and this was the only game in town at the time.
I would MUCH RATHER have an Aspera, as it can ROG, has more wing area, is build straight and flies superbly. I don't have an Aspera as I will work with this for a while. Right now, it is a little lighter than an Aspera, but an Aspera is a larger plane. I will be at NEAT this year and will be bringing it, if it survives until then.
07-23-2008, 03:14 PM
#8
RE: Rumfal on 4S A123
Thanks for the response Terry ...
I will be at NEAT this year and will be bringing it, if it survives until then.
... I was working to have something quite big and patternish for this years event but a major house renovation has cut both my wallet and time to shreds
