Advice for New Boomerang XL
03-26-2023, 08:06 AM
#1
Advice for New Boomerang XL
I found a new old stock Boomerang XL 2 which will be my first experience with a turbine. I have been reading some old threads and it seems it was designed around a 120, but can fit larger engines as well with throttle management. With the options available in 2023, what would be the best turbine size that would be compatible with future sport jets? Are there more options in the 120-140 class, or should I go the next size up to a 160-180 to have the most options for future stuff? From my reading the boomer's tended to be on the tail heavy side in a good amount of builds so going bigger may hurt there.
I have also read that there were some issues with the booms fitting loosely and allowing some play when assembled and needing to be pinned, as well as some instances of wing failing in flight. I have seen posts saying to add come covering on the leading edge seams as covering delaminating may have caused issues there, as well as some saying to go as far as to glass the wings, center section, and stabilizer.
Is there a thread/s anyone can point me to with common modifications I should do? I plan to go over the fuse formers and potentially add some hysol reinforcement and hit whatever I can with CA as with any arf. Speaking of CA, I'm surprised to see CA hinges used on a jet, I may opt for something more substantial there.
I got this jet with a set of heavy duty robart retracts (635's I think?) and will be my first experience with air retracts and brakes. Are there any options still available for electric retracts for the XL? The current boomerang options are too small or too big for the XL, I think electrics would be a lot easier to install and more trouble free if I can find any. If not, I have a bvm smooth stop and a few tiny air manifolds, without a variable rate manifold will the retracts activate too harshly? Would more modern electric air controllers be more worth it over these old servo actuated style?
I'm very excited to get this thing going, thanks for any help you guys have.
I have also read that there were some issues with the booms fitting loosely and allowing some play when assembled and needing to be pinned, as well as some instances of wing failing in flight. I have seen posts saying to add come covering on the leading edge seams as covering delaminating may have caused issues there, as well as some saying to go as far as to glass the wings, center section, and stabilizer.
Is there a thread/s anyone can point me to with common modifications I should do? I plan to go over the fuse formers and potentially add some hysol reinforcement and hit whatever I can with CA as with any arf. Speaking of CA, I'm surprised to see CA hinges used on a jet, I may opt for something more substantial there.
I got this jet with a set of heavy duty robart retracts (635's I think?) and will be my first experience with air retracts and brakes. Are there any options still available for electric retracts for the XL? The current boomerang options are too small or too big for the XL, I think electrics would be a lot easier to install and more trouble free if I can find any. If not, I have a bvm smooth stop and a few tiny air manifolds, without a variable rate manifold will the retracts activate too harshly? Would more modern electric air controllers be more worth it over these old servo actuated style?
I'm very excited to get this thing going, thanks for any help you guys have.
03-26-2023, 11:16 AM
#2
Why start a new thread when so many users are already subbed to previous threads? You’re losing potential answers from users subbed to those thread who may not see this new one.
As to your question:
The Boomer XL is a terrific flying airplane ad is capable of flying on as little as 80N, depending on the length of your field etc…Yes, the XL requires some nose weight, but not gross amounts when compared to the overall weight and wing area. (Elans do none). Yes, modern engines make the same thrust for less weight or more thrust for the same weight, which helps. Imo you’re on the right track to plan for future use of the engine and not fal into the “just enough” trap which leads to a later purchase in pursuit of more thrust.
Many of us flew the XL on 160N with appropriate throttle management. Overkill off of a hard surface but handy from grass on hot days. IF (IF) you’re thinking of heavier jets later then consider the Xicoy 180 and electronically (it’s an easy procedure) reduce it to no more than 160N. Otherwise, the Xicoy 120 will prove a light and reliable power plant, especially if you’re not flying from a high/hot/short grass field.
Do a google search for “RCU Boomerang XL” and read absolutely every post. There are no fuse former issues that I recall but it is VITAL to take note of flaws we found in some horizontal stabs, which lead to dangerous separations and total losses. (I barely caught mine in time, thank goodness). Also VITAL is to throw away the crap Chinese wing/stab mounting bolts and buy quality hardware, lest you one day require a saws-all to remove a wing one day because the retaining bolt head snapped off. (Ask how I know)
Use a cover to keep the fuse and booms out of the sun at the field. They yellow otherwise.
Yes, electric gear is much simple. Buy quality or buy twice, imo. Electron seems on of the better options, but idk if they sell anything specific for the XL. Get trailing link legs. Mine air air-driven and I used 120 PSI. No, “harshness” was never a problem. In fact, I loved the rapid “bang” up and especially the “bang” down. No issues. KISS, with no fancy electronic controllers etc. The BVM unit you already have is reliable and effective.
Trust me when I say that the gear should be mounted with (long-ish) servo screws. Yes, servo screws. They are more than strong enough for normal abuse, but act as a “fuse” and will let go on those truly awful landings rather than ripping out the internal wing structure. Some will be tempted to argue the point, but the method 100% works AND was the suggestion of Alana Cardash (designer).
The only wing failures I am aware of were due to the covering issue you mention and were not limited to Boomers, so yes, put a strip of clear packing tape along the leading edge. No, I do not believe that glassing is required or even desired. (But do find the post about defective internal stab mount glue joints and reinforce those points)
Yes, do hard-mount (screws) the booms to the center section.
CA hinges are NOT a problem. They just aren’t. CA hinge issues in this installation are more superstition than fact, imo, but to each their own.
Gary from Jet Tech makes an excellent 1gallon tank for the XL. More than enough fuel.
Congrats on your find, best wishes for the build. The Boomer XL was a mildly flawed kit but terrific flyer. Feel free to PM me as desired.
As to your question:
The Boomer XL is a terrific flying airplane ad is capable of flying on as little as 80N, depending on the length of your field etc…Yes, the XL requires some nose weight, but not gross amounts when compared to the overall weight and wing area. (Elans do none). Yes, modern engines make the same thrust for less weight or more thrust for the same weight, which helps. Imo you’re on the right track to plan for future use of the engine and not fal into the “just enough” trap which leads to a later purchase in pursuit of more thrust.
Many of us flew the XL on 160N with appropriate throttle management. Overkill off of a hard surface but handy from grass on hot days. IF (IF) you’re thinking of heavier jets later then consider the Xicoy 180 and electronically (it’s an easy procedure) reduce it to no more than 160N. Otherwise, the Xicoy 120 will prove a light and reliable power plant, especially if you’re not flying from a high/hot/short grass field.
Do a google search for “RCU Boomerang XL” and read absolutely every post. There are no fuse former issues that I recall but it is VITAL to take note of flaws we found in some horizontal stabs, which lead to dangerous separations and total losses. (I barely caught mine in time, thank goodness). Also VITAL is to throw away the crap Chinese wing/stab mounting bolts and buy quality hardware, lest you one day require a saws-all to remove a wing one day because the retaining bolt head snapped off. (Ask how I know)
Use a cover to keep the fuse and booms out of the sun at the field. They yellow otherwise.
Yes, electric gear is much simple. Buy quality or buy twice, imo. Electron seems on of the better options, but idk if they sell anything specific for the XL. Get trailing link legs. Mine air air-driven and I used 120 PSI. No, “harshness” was never a problem. In fact, I loved the rapid “bang” up and especially the “bang” down. No issues. KISS, with no fancy electronic controllers etc. The BVM unit you already have is reliable and effective.
Trust me when I say that the gear should be mounted with (long-ish) servo screws. Yes, servo screws. They are more than strong enough for normal abuse, but act as a “fuse” and will let go on those truly awful landings rather than ripping out the internal wing structure. Some will be tempted to argue the point, but the method 100% works AND was the suggestion of Alana Cardash (designer).
The only wing failures I am aware of were due to the covering issue you mention and were not limited to Boomers, so yes, put a strip of clear packing tape along the leading edge. No, I do not believe that glassing is required or even desired. (But do find the post about defective internal stab mount glue joints and reinforce those points)
Yes, do hard-mount (screws) the booms to the center section.
CA hinges are NOT a problem. They just aren’t. CA hinge issues in this installation are more superstition than fact, imo, but to each their own.
Gary from Jet Tech makes an excellent 1gallon tank for the XL. More than enough fuel.
Congrats on your find, best wishes for the build. The Boomer XL was a mildly flawed kit but terrific flyer. Feel free to PM me as desired.
Last edited by highhorse; 03-26-2023 at 11:19 AM.
03-26-2023, 12:26 PM
#3
Thank you that was very informative. I found the 2012 thread about the stab mounting blocks, I'll be sure to reinforce that. The retracts I got with the arf have straight legs, so maybe I'll get a set of trailing link style if I can for them. I thought the adjustable valves were necessary, if not I'll just try what I have to start. What kind of flight times did you get with the 125oz tank?
For securing the booms did you use any glue or just screws? Would it be worth having them removeable or did you mount them permanently?
For securing the booms did you use any glue or just screws? Would it be worth having them removeable or did you mount them permanently?
03-26-2023, 01:26 PM
#4
Straight legs are ok if you’re more talented than me :-) but well worth the $ imo.
I screwed on the booms. Semi-removable, but if i needed to break the booms down for transport I would have pinned them.
I had a 10-minute timer which left at least 2-3 mins in reserve for my style of flying, but due to so many variables, I don’t think my flight times are useful info for you other than to say that my XL was too doo-dad complicated, too heavy, and my 2006 era Jetcat 160 was comparatively thirsty. Ergo, your overall times are likely to be better than mine. You won’t go wrong with the 1 gallon tank since you certainly won’t need more and you needn’t fill it completely if the extra capacity is not required.
See pic of my Jet-Tech tank (painted cus at the time I thought it would look cool) installed in the XL…
If this is your first turbine, please do avail yourself of local experienced help for the installation. Turbines aren’t rocket surgery, but there are some hints that will save you a lot of grief.
I screwed on the booms. Semi-removable, but if i needed to break the booms down for transport I would have pinned them.
I had a 10-minute timer which left at least 2-3 mins in reserve for my style of flying, but due to so many variables, I don’t think my flight times are useful info for you other than to say that my XL was too doo-dad complicated, too heavy, and my 2006 era Jetcat 160 was comparatively thirsty. Ergo, your overall times are likely to be better than mine. You won’t go wrong with the 1 gallon tank since you certainly won’t need more and you needn’t fill it completely if the extra capacity is not required.
See pic of my Jet-Tech tank (painted cus at the time I thought it would look cool) installed in the XL…
If this is your first turbine, please do avail yourself of local experienced help for the installation. Turbines aren’t rocket surgery, but there are some hints that will save you a lot of grief.
Last edited by highhorse; 03-26-2023 at 01:43 PM.
03-27-2023, 10:02 PM
#5
see my old topicBOOMERANG XL Navy scheme - Page 6 - Forum KéroStart (kerostart.com)
with a TJ74 (160N)
unfortunately it was destroyed following the implosion of a wing, probably following too great a speed,
it had more than 500 flights!
for this reason, you have to be very careful with this jet, no need to overpower, a 120 is enough even to take off from a grass runway.
I liked this jet so much, that currently I am renovating to another one.
with a TJ74 (160N)
unfortunately it was destroyed following the implosion of a wing, probably following too great a speed,
it had more than 500 flights!
for this reason, you have to be very careful with this jet, no need to overpower, a 120 is enough even to take off from a grass runway.
I liked this jet so much, that currently I am renovating to another one.
Last edited by harpoonrs; 03-27-2023 at 10:04 PM.
03-29-2023, 01:33 PM
#6
My Feedback: (53)
On mine I had a k140, if I was to build another one I would go with a K142 same size as a K100, just be careful it’s not a yank and bank jet and speed have kill a few of these in the past. I had smoke in mine….
