BUSHWACKER, MARK'S MODELS, 1970s
#26
Senior Member
Thread Starter
RE: BUSHWACKER, MARK'S MODELS, 1970s
Maiden flight(s) today. Five times into the air with no real issues. The airplane sits very flat(nose nearly level) on its gear. This creates two issues with the plane. One, the prop is very close to the ground and a very small amount of nose down(i.e. level attitude) can cause the prop to start hitting the ground. Secondly, the very flat attitude on the gear means that a typical nose high landing attitude is not possible. It must be flown onto the ground and then controlled as it loses speed. Other than that, a very nice bird.
#27
RE: BUSHWACKER, MARK'S MODELS, 1970s
I've just read through your build. Nice job on the plane!
How aerobatic is it? If it is slowed down does it fly anything like a glider? I'm wondering if Mark Smith's glider heritage shows up in the way the Bushwacker flies. Is there any source for plans (I realize all the parts aren't shown)?
Jim
How aerobatic is it? If it is slowed down does it fly anything like a glider? I'm wondering if Mark Smith's glider heritage shows up in the way the Bushwacker flies. Is there any source for plans (I realize all the parts aren't shown)?
Jim
#28
Senior Member
Thread Starter
RE: BUSHWACKER, MARK'S MODELS, 1970s
It does all basic acro just fine. I don't fly knife edge maneuvers but I doubt it would do those very well. It glides well but is probably not sail plane material. The more I have flown it, the better I am able to land and takeoff with its fairly constant nose attitude. There is not enough ground clearance with the prop to bring the tail up on take off(short grass). Also, the gear is relatively short so slower, near full stall landings are out. But a good little plane overall. I'm glad I bought and built it.
Oh, plans, I don't know of a source that would have all the parts depicted.
Oh, plans, I don't know of a source that would have all the parts depicted.
#29
RE: BUSHWACKER, MARK'S MODELS, 1970s
Thanks for the info. The April 1970 Flying Models had a somewhat similar plane by Gene Rogers called the Invader. It had a 73 inch span, 19-25 power, rounded crutch body, and a bit more glider-like appearance. 576 sq in. I've always liked both planes and should build one or the other one of these days.
Jim
Jim
#30
My Feedback: (9)
Join Date: Jan 2002
Location: Copperas Cove, Tx.
Posts: 552
Likes: 0
Received 0 Likes
on
0 Posts
RE: BUSHWACKER, MARK'S MODELS, 1970s
Jim,
Any chance you could scan the Invader article so we could see the plane?
I've got a line on a kit and will try to get it copied (plans, parts or both) somehow so others can have a crack at it. Wish I could give a time frame but I have no idea how soon I can get it accomplished.
Mike
Any chance you could scan the Invader article so we could see the plane?
I've got a line on a kit and will try to get it copied (plans, parts or both) somehow so others can have a crack at it. Wish I could give a time frame but I have no idea how soon I can get it accomplished.
Mike
#32
RE: BUSHWACKER, MARK'S MODELS, 1970s
When I load multiple pictures, they load across the page in one line. This is the second thread where this has happened. I'll load one pic per post. Sorry, but I don't know how else to fix.
#36
Senior Member
Thread Starter
RE: BUSHWACKER, MARK'S MODELS, 1970s
jjscott, no apologies needed. I have just skipped through reading the ariticle but will finish it tonight. One thing that just caught my attention was the wing building board. It was one of those "DUH" moments when you say, "Why didn't I ever think of that?" The wing building board is hinged in the middle to give the desired dihedral. I'm going to think about this for a while, but it could be a neat idea to that age old problem of mating two wing halves and trying to get them properly aligned.
#37
RE: BUSHWACKER, MARK'S MODELS, 1970s
Thanks for posting the Invader article. It must be the same guy who designed the Desperado, which was very similar, but larger, for a Ross .60 twin. Nice to have the smaller one. Perfect for my new ASP .21.
I did the folding building board, and I like it, but really took my time installing the hinges because it only aligns your wing well if it is aligned itself! I used a hollow sliding door panel. It folds up nicely for storage too.
Jim
I did the folding building board, and I like it, but really took my time installing the hinges because it only aligns your wing well if it is aligned itself! I used a hollow sliding door panel. It folds up nicely for storage too.
Jim
#39
RE: BUSHWACKER, MARK'S MODELS, 1970s
The Bushwacker sure has nice lines and I am not surprised it is a good flying ship. Is anyone kitting or partial-kitting this these days? Just getting the wing ribs would make this a fun project.
#40
Junior Member
Join Date: Sep 2003
Location: Lincoln,
NE
Posts: 21
Likes: 0
Received 0 Likes
on
0 Posts
Don't know if anyone is still watching this thread. I built 2 Bushwacker kits in the 70s and early 80s and I've scratch-built several almost identical planes in the years since, of various sizes. I also corresponded some with Mark Smith in the early 80s about the kit, so I guess I'm as close as you'll come to a "Bushwacker Expert", hah.
I noticed a number of questions while reading this thread that I can answer if anyone is still interested. If so, re-ask them, and I'll do my best.
The original kits that I built would knife-edge just fine, in fact would climb in a knife edge, using a Max .25 (non-schneule). My two original kits were re-engined a number of times. The engines included the original Enya .19, a Cox Conquest .15, the Max .25 and finally a Max .40 (again, non-schneurle). Had to watch it with the .40, but it flew fine, unlimited vertical. The second original kit started with an OS .25 FSR, then had an Enya .46 4-cycle, and when that broke (at a pattern contest that I took second in, with the Bushwacker no less!!), I went to Hobby Barn in Tucson, and bought a brand new Enya .53 4-cycle from Bill Hemple (Senior) to finish the contest.
Mine never weighed 3 lbs dry, because the only radio I had was a Kraft with (heavy) KPS-15s, and a 450 MaH battery pack, and a huge receiver. They were more like 3 1/2 lbs dry, but flew fine
They also glided fine, and I managed to catch thermals with mine several times. They were more akin to a slope soaring glider than a thermal soarer, but they were very clean aerodynamically, and glided very flat (which made them a real challenge to land). I even had spoilers on one of my scratch-built versions, which made it a lot easier to land.
I would love to see someone scan this in for Laser cutting. I have an original kit that I bought for $45 on an up-and-coming website called "AuctionWeb" in 1997. Later that year, AuctionWeb changed their name to Ebay.
If anyone knows a company that would like to scan the kit and plans in, I would loan my kit, as long as I get it back. I know the plane well enough that I can probably sit down and draw one in my amateur CAD program and have it be a virtual duplicate. I drew (or built without plans) all the subsequent Bushwacker "clones" that I've had over the years without benefit of a CAD.
When I finally build my kit (possibly this winter or next), I plan to use possibly a 480 brushless, or possibly a .10 brushless. That's a lot less power than the glo-engines I've used, but with today's super light radios, and the fact that I will replace a lot of the original sheet balsa with contest grade balsa, I imagine that 40 ounces (2 1/2 lbs) will be very possible. I'll bet it will glide even better! I might even put in a tiny bit more dihedral to help with the gliding, since with computer radios, it's easy to mix the coupling effects out for aerobatics.
As you can tell, almost 40 years of history with this beautiful design has not diminished my enthusiasm for it.
I noticed a number of questions while reading this thread that I can answer if anyone is still interested. If so, re-ask them, and I'll do my best.
The original kits that I built would knife-edge just fine, in fact would climb in a knife edge, using a Max .25 (non-schneule). My two original kits were re-engined a number of times. The engines included the original Enya .19, a Cox Conquest .15, the Max .25 and finally a Max .40 (again, non-schneurle). Had to watch it with the .40, but it flew fine, unlimited vertical. The second original kit started with an OS .25 FSR, then had an Enya .46 4-cycle, and when that broke (at a pattern contest that I took second in, with the Bushwacker no less!!), I went to Hobby Barn in Tucson, and bought a brand new Enya .53 4-cycle from Bill Hemple (Senior) to finish the contest.
Mine never weighed 3 lbs dry, because the only radio I had was a Kraft with (heavy) KPS-15s, and a 450 MaH battery pack, and a huge receiver. They were more like 3 1/2 lbs dry, but flew fine
They also glided fine, and I managed to catch thermals with mine several times. They were more akin to a slope soaring glider than a thermal soarer, but they were very clean aerodynamically, and glided very flat (which made them a real challenge to land). I even had spoilers on one of my scratch-built versions, which made it a lot easier to land.
I would love to see someone scan this in for Laser cutting. I have an original kit that I bought for $45 on an up-and-coming website called "AuctionWeb" in 1997. Later that year, AuctionWeb changed their name to Ebay.
If anyone knows a company that would like to scan the kit and plans in, I would loan my kit, as long as I get it back. I know the plane well enough that I can probably sit down and draw one in my amateur CAD program and have it be a virtual duplicate. I drew (or built without plans) all the subsequent Bushwacker "clones" that I've had over the years without benefit of a CAD.
When I finally build my kit (possibly this winter or next), I plan to use possibly a 480 brushless, or possibly a .10 brushless. That's a lot less power than the glo-engines I've used, but with today's super light radios, and the fact that I will replace a lot of the original sheet balsa with contest grade balsa, I imagine that 40 ounces (2 1/2 lbs) will be very possible. I'll bet it will glide even better! I might even put in a tiny bit more dihedral to help with the gliding, since with computer radios, it's easy to mix the coupling effects out for aerobatics.
As you can tell, almost 40 years of history with this beautiful design has not diminished my enthusiasm for it.
#41
Junior Member
Join Date: Sep 2003
Location: Lincoln,
NE
Posts: 21
Likes: 0
Received 0 Likes
on
0 Posts
Oh, an addition to my last post. I have scanned in the entire instruction manual, and I had to photocopy the original plans because they "self-unrolled" when I took them out of the ancient kit and tore themselves right down the middle, so I imagine I could photocopy them again, if anybody would like copies.
Somewhere, I have plywood templates that I used to gang-sand wing ribs that were close enough to the original that you could build the kit around them, with almost no changes to the wing saddle. If you're an experienced builder, you could do the same, because it does show the root rib on the plans,
Somewhere, I have plywood templates that I used to gang-sand wing ribs that were close enough to the original that you could build the kit around them, with almost no changes to the wing saddle. If you're an experienced builder, you could do the same, because it does show the root rib on the plans,
#42
Good posts, thanks. I wound up with a kit that is a real mess and most likely incomplete (but does have the plans), along with two sets of foam cores, from an estate. This makes me think I should keep it and build from it. Any opinion on the foam wing cores?
Jim
Jim
#43
Junior Member
Join Date: Sep 2003
Location: Lincoln,
NE
Posts: 21
Likes: 0
Received 0 Likes
on
0 Posts
I'm neither pro or con on foam cores. If they seem to be a reasonable copy of the airfoils and taper from the original Bushwhacker, go for it.
I built a slope soaring model by Bill Evans (of Simitar fame) which had foam cores and the long winged version was actually a similar planform to the Bushwhacker. If you've ever built anything by him, he doesn't fully sheet the cores. He sheets the leading edge and trailing edge, and then glues cap strips between, so when you cover it, it actually looks like a built up wing, and is probably 95% as strong as a fully sheeted wing.
If your foam cores ARE taken directly from the Bushwhacker rib templates, then the wing is quite thin, I believe it's only an 8 or 9% thick semi-symmetrical section. You might consider laying in some "sparlets" of carbon fiber. If you get the .007 thick stuff, you can just stand it on edge in an exacto knife slot right under the spar, or even put it in a slot even with the back of the L/E sheeting after sheeting the leading edge, and leave it sticking out of the top of the core just enough to glue it to the back edge of the L/E sheeting. You can glue the c/f in with either white glue (or carpenter's glue) or slow set epoxy, and that will stiffen the foam wing up greatly, for very little extra work.
Also, it's very easy to cut out the unsheeted foam in the rib bays I've found. What I've done in the past is just take a large piece of brass or alum. tubing with the end sharpened to make a hole saw: then just make a hole at one corner of each rib bay, and use a hacksaw blade (or any thin saw blade, I imagine a coping saw would work equally well), and just carefully saw around the outline of each rib bay. On a wing the size of the Bushwacker's, this will probably take between 1 & 2 ounces of weight off. It takes a little time, but it's relatively mindless work...you can do it while watching TV.
The 'Wacker has enough wing area that it will fly fine at 4 lbs, but to really get the performance (and lessen the risk of folding a wing), keep it as light as possible. I'm a big fan of contest grade balsa. When you mail order it, it's usually as cheap or cheaper than normal weight balsa at a hobby shop, and can save a LOT of weight when you replace large sheeted areas with it. With a little care, there's no reason for a foam core wing to be any heavier than a built up one.
You mentioned that you had the plans. Did you also get the construction manual with it? That manual for the Bushwhacker is a veritable bible of construction tips. When I built my first one, I think I was about 16, and completely self-taught (which explains why I was such a hack builder for so long, heh heh), but I learned a LOT from that manual. If you don't have it, I have the entire thing scanned in (because mine was so beat up, I decided to take the time). Just let me know. I'm about 2 computers newer than I was when I scanned it in, I'm sure I can find it (yup, just checked).
I built a slope soaring model by Bill Evans (of Simitar fame) which had foam cores and the long winged version was actually a similar planform to the Bushwhacker. If you've ever built anything by him, he doesn't fully sheet the cores. He sheets the leading edge and trailing edge, and then glues cap strips between, so when you cover it, it actually looks like a built up wing, and is probably 95% as strong as a fully sheeted wing.
If your foam cores ARE taken directly from the Bushwhacker rib templates, then the wing is quite thin, I believe it's only an 8 or 9% thick semi-symmetrical section. You might consider laying in some "sparlets" of carbon fiber. If you get the .007 thick stuff, you can just stand it on edge in an exacto knife slot right under the spar, or even put it in a slot even with the back of the L/E sheeting after sheeting the leading edge, and leave it sticking out of the top of the core just enough to glue it to the back edge of the L/E sheeting. You can glue the c/f in with either white glue (or carpenter's glue) or slow set epoxy, and that will stiffen the foam wing up greatly, for very little extra work.
Also, it's very easy to cut out the unsheeted foam in the rib bays I've found. What I've done in the past is just take a large piece of brass or alum. tubing with the end sharpened to make a hole saw: then just make a hole at one corner of each rib bay, and use a hacksaw blade (or any thin saw blade, I imagine a coping saw would work equally well), and just carefully saw around the outline of each rib bay. On a wing the size of the Bushwacker's, this will probably take between 1 & 2 ounces of weight off. It takes a little time, but it's relatively mindless work...you can do it while watching TV.
The 'Wacker has enough wing area that it will fly fine at 4 lbs, but to really get the performance (and lessen the risk of folding a wing), keep it as light as possible. I'm a big fan of contest grade balsa. When you mail order it, it's usually as cheap or cheaper than normal weight balsa at a hobby shop, and can save a LOT of weight when you replace large sheeted areas with it. With a little care, there's no reason for a foam core wing to be any heavier than a built up one.
You mentioned that you had the plans. Did you also get the construction manual with it? That manual for the Bushwhacker is a veritable bible of construction tips. When I built my first one, I think I was about 16, and completely self-taught (which explains why I was such a hack builder for so long, heh heh), but I learned a LOT from that manual. If you don't have it, I have the entire thing scanned in (because mine was so beat up, I decided to take the time). Just let me know. I'm about 2 computers newer than I was when I scanned it in, I'm sure I can find it (yup, just checked).
#44
Junior Member
Join Date: Sep 2003
Location: Lincoln,
NE
Posts: 21
Likes: 0
Received 0 Likes
on
0 Posts
Oh, an addendum. I mentioned that I had a Bushwhacker with spoilers. I forgot that I also had one with Prettner-style airbrake/flaps. These are also used on some full size and model gliders as spoilers. If you're not familiar with them, I went and found a diagram (turns out is was from some other RC Universe thread, lol). If I can figure out how to attach it, I will (I read a lot of stuff here, but never take the time to post, as is obvious).
Okay, I THINK I might have successfully attached a sketch of the airbrake I mentioned. If you want to try 'em, they don't have to be very big (3 inches per side would be plenty for the Bushwacker). The nice thing about this kind of airbrake/spoiler is, if you size the airbrake portion so it is exactly 1/2 of the flap portion, there is virtually no trim change. The airplane will just slow down, and put it's nose down and find a new gliding equilibrium, albeit much steeper, but stable.
On the other hand, if you do like I did, and make the airbrakes fill the entire area between the ailerons and the fuse on the Bushwhacker, you can do your final approach in a vertical dive, and start a pull-up at about 20-30 feet up, and by the time you get it level, it has bled off all of it's speed. It's kind of a kick to be able to do that.
Okay, I THINK I might have successfully attached a sketch of the airbrake I mentioned. If you want to try 'em, they don't have to be very big (3 inches per side would be plenty for the Bushwacker). The nice thing about this kind of airbrake/spoiler is, if you size the airbrake portion so it is exactly 1/2 of the flap portion, there is virtually no trim change. The airplane will just slow down, and put it's nose down and find a new gliding equilibrium, albeit much steeper, but stable.
On the other hand, if you do like I did, and make the airbrakes fill the entire area between the ailerons and the fuse on the Bushwhacker, you can do your final approach in a vertical dive, and start a pull-up at about 20-30 feet up, and by the time you get it level, it has bled off all of it's speed. It's kind of a kick to be able to do that.
#45
Good stuff, thanks! Not sure about the manual...the kit's in the attic. If you've already found the file I'd be happy to receive it from you. The air brake makes sense to me. Just wondering about the effect on the stab/elevator and the rudder control. Seems like there'd be a lot of turbulent air hitting the tail feathers.
Jim
Jim
#46
Junior Member
Join Date: Sep 2003
Location: Lincoln,
NE
Posts: 21
Likes: 0
Received 0 Likes
on
0 Posts
Yep, I found the file(s). There are actually 28 files, LOL. I formatted them so that each file is one side of a double (foldable) page. In other words, If you print file 1A, then turn the page over and print 1B on the other side, and then do the same thing for files 2-28A, and 2-28B, you can stack them all, and fold them in half and voila! You have a manual that is identical to the 5 1/2 x 8 1/2 inch, 56 page original. And, since the original was also a photocopy (albeit, on glossy paper), the quality is almost exactly the same.
Is there some way to post the files on this forum? I have to run out and rescue my car from the evil mechanic just now, but if there's a way to post the files for the manual to the forum, that might be a nice resource for others.
Otherwise, I guess an e-mail would be useful to send them to. I've never posted enough on this forum to know how to send private messages, although I'm sure there's a way. I need to get in the habit of posting more, since I'm one of those people who seem to like to hear themselves talk, hah.
Is there some way to post the files on this forum? I have to run out and rescue my car from the evil mechanic just now, but if there's a way to post the files for the manual to the forum, that might be a nice resource for others.
Otherwise, I guess an e-mail would be useful to send them to. I've never posted enough on this forum to know how to send private messages, although I'm sure there's a way. I need to get in the habit of posting more, since I'm one of those people who seem to like to hear themselves talk, hah.
Last edited by Pattern Junkie; 12-21-2013 at 10:24 AM.
#47
PJ, you can post files by clicking on "Go Advanced". Then you go to the paper clip for attachments. Click on Add Files and then go to Select Files. That should allow you to go to your own folders on your computer. But 28 sounds like a lot, but it will depend on how big the files are.
#48
Junior Member
Join Date: Mar 2014
Posts: 1
Likes: 0
Received 0 Likes
on
0 Posts
Super Tiger 23 with a pipe. Dead stick, flies like a glider. Above half power it flies like a pattern ship. My son has a kit and I am trying to get him update it and cut me a few kits on his laser(maybe add flaps). The muffler part of the kit was scraped.
My all time favorite model!
My all time favorite model!
#50
Junior Member
Join Date: Sep 2003
Location: Lincoln,
NE
Posts: 21
Likes: 0
Received 0 Likes
on
0 Posts
One of my early versions (from an actual kit) had Prettner style airbrake/flaps covering the entire trailing edge (not including the aileron area), and a Max .25 (non-schnuerle). I could make vertical landing approaches, start the pull-up at about 30 feet, and make about a 20 foot landing roll. I used to fly it out of a basketball-court size parking lot with (tall!) streetlights all around the edge, heh. One of these days I'll post some pics of my (scratch-built) variations over the years. Personally, I think the airbrakes were more useful than pure flaps would be. There's plenty of wing there already.
Also my all time favorite (sport-type) model. I speak as an old time pattern flyer. I've built 3 (I think) from actual kits, and probably 4-5 others that were rip-offs of the design. Low wing with a T-tail, .40 sized (88 inch span) with a V-tail and a couple that were just stock, except drawn from memory. I knew the span and area, so it's not hard to get the planform right. My very first one (in college, about '76) started with an Enya .19, and ended up with a Max .40 (my biggest engine ever, to that point!) that my uncle sold me for $5. The .40 dropped right in, and didn't even look oversized, and even though it wasn't a schneurle, the vertical was breathtaking, for the day.
Anybody that wants a copy of the original manual, drop me an e-mail, and I'll mail it to you. I have it scanned in in proper order so if you print it out two-sided, you can staple and fold it and make an exact duplicate of the original manual. It has an MS Word file for each double-sided page, so it might take several e-mails, but, oh, well, eh? Actually, I think the original manuals were made exactly that way, except with photocopies.
Also my all time favorite (sport-type) model. I speak as an old time pattern flyer. I've built 3 (I think) from actual kits, and probably 4-5 others that were rip-offs of the design. Low wing with a T-tail, .40 sized (88 inch span) with a V-tail and a couple that were just stock, except drawn from memory. I knew the span and area, so it's not hard to get the planform right. My very first one (in college, about '76) started with an Enya .19, and ended up with a Max .40 (my biggest engine ever, to that point!) that my uncle sold me for $5. The .40 dropped right in, and didn't even look oversized, and even though it wasn't a schneurle, the vertical was breathtaking, for the day.
Anybody that wants a copy of the original manual, drop me an e-mail, and I'll mail it to you. I have it scanned in in proper order so if you print it out two-sided, you can staple and fold it and make an exact duplicate of the original manual. It has an MS Word file for each double-sided page, so it might take several e-mails, but, oh, well, eh? Actually, I think the original manuals were made exactly that way, except with photocopies.