HAwks Hobby BOMARC

[Fred22]

Well folks this is my first stab at a real build thread especially in MPR. My chosen victum is the HAWKS HOBBY BOMARC. Please do not judge the value of this fine kit by my efforts. The nosecone is superb. The ramkets speek for themselves. You actuaaly make cuts in the mbt to recess the wing. The cut out bits are the used to make the body aerodynamic again :) My cuts need work :)

[Fred22]

In case anybodys surprised Gordon I have already contacted excelsior about custom decals :)
Cheers
fred

[sandman]

In case anybodys surprised Gordon I have already contacted excelsior about custom decals :)
Cheers
fred

Doesn't the kit come with decals?

OH, you probably want the John Diefenbaker version. eh..:rolleyes:

[Fred22]

Doesn't the kit come with decals?

OH, you probably want the John Diefenbaker version. eh..:rolleyes:

Of course eh :) Ya it does Gordon and I will have shot of them later :)
Cheers
fred

[dpower]

...You actually make cuts in the bt to recess the wing....And that makes this the best kit I've seen of the Bomarc; I look forward to your review. How much nose weight is included for this beast?

[dcastle]

So where do I find one of these kits? Not to bring up a very sore subject but I wouldn't mind building something on the scale of the large Bomarc I'd ordered from Empire a few years ago that never appeared in the mail....this looks to be about right...

[Fred22]

And that makes this the best kit I've seen of the Bomarc; I look forward to your review. How much nose weight is included for this beast?

About 180 grams on my rather cheap postal scale :)

[Fred22]

So where do I find one of these kits? Not to bring up a very sore subject but I wouldn't mind building something on the scale of the large Bomarc I'd ordered from Empire a few years ago that never appeared in the mail....this looks to be about right...
Try Red Arrow
http://www.redarrowhobbies.com/
It's where I got mine :) I have always found their service to be outstanding :)
Cheers
fred

[Fred22]

Well guys did a number of things tonight. First off I marked and cut the conduit tube. basically using one of the handy dandy guides provided I marked and cut it in half :) The nosecones which form conduit ends were also cut in half. I had to notch one for the tail and I put my tamiya putty next to it as I suspect I will need some :) Also they leave the method of engine retention up to the builder. I have a hook which maight be big enough but I would apreciate some aopinions. Also can you friction fit a 29mm motor?
Cheers
fred

[Fred22]

Heres a few more pictures :) Is the hook long enough fellas and if it is how much overhang do I need from the bottom of the tube ?
Cheers
fred

[Pantherjon]

Looking good! The hook you have is too short for the 29mm hobby line case(29/40-120) which is 5 inches long..Looks to be an Estes 'E' hook..Yeah you can do friction fitting on 29mm motors..Personally I would put in some PMR(Positive Motor Retention) if you plan on flying it on reloads..It's a real bummer to have a perfect flight only to find when you retrieve the rocket you have lost the motor casing..

[Fred22]

Thanks John I will look into getting a hook and an engine block :)
Thanks
Fred

[Fred22]

Guys who sells motor hooks and engine blocks for 29mm?
Thanks
Fred

[Fred22]

Well guys I just had a look at a great book I got at apogee called "Model Rocket Design and Construction". To my chragrin I found out hooks aint used on the MPR's and they dont need an engine block because they have a lip that potrudes arond the bottom of the motor mount tube. Instead one way to retain the motor is to use two pieces of hardwood and a couple of screws to kep the motor in the tube. brilliant idea :)
Cheers
fred

[cjl]

Yep, or if you like a really solid solution, you can get an Aeropack engine retainer. They're somewhat expensive, but the quality is worth it.

You don't need an engine block though - you can use motors of varying lengths in 29mm for everything from a smallish F motor (or even a large E) to a smallish I motor.

[Fred22]

Yep, or if you like a really solid solution, you can get an Aeropack engine retainer. They're somewhat expensive, but the quality is worth it.

You don't need an engine block though - you can use motors of varying lengths in 29mm for everything from a smallish F motor (or even a large E) to a smallish I motor.

My biggest problem with mpr is the fields I use up here are small for LPR let alone MPR so I have to figure out an optimal size somehow :)
Cheers
Fred

[Fred22]

Well two steps forward and one backwards today :) First I have a picture of the motor moubt tube before it was put in. Notice the centre wing has a a flat side for the wing to sit on. That becomes more important as we move on:) I also notched a centreing ring and put a kevlar string on for recovery :)

[Fred22]

Next came inserting the motor mount tube into the main body tube and notice the forward ring was not flush with the forward end of the opening :(

[Fred22]

I obviously had made a mistake with the opening I had created. After all the motor mount tube was flush with the end of the main body tube. If the wing was to sit flush with the openning something would have to be done. I proceeded to enlarge the opening at the opposite end and use the piece as a patch to seal the other. Hope I got this right and thank goodness for putty :)

[Pantherjon]

Nice recovery! And I am sure with the putty, as the finish gets closer, that patch won't even be visible! ;)
Maybe even a wrap of light(3oz?) fiberglass to further strengthen it a bit too...

[Fred22]

Nice recovery! And I am sure with the putty, as the finish gets closer, that patch won't even be visible! ;)
Maybe even a wrap of light(3oz?) fiberglass to further strengthen it a bit too...
Thanks :) The fibreglass sounds good as I have never worked with that before either :) John how big a screw do you need to retain the engine if you use dowels to keep the engine secure ?
Cheers
fred

[Fred22]

Well on another forum I am also doing this thread. They were kind to us and let us use their space so to speak so I put in my build thread to give them a laugh :) Anyways the maker of this kit came on and said the instructions in the kit were in error and told me the rear edge of the wing needed to be 8 1/4 inches from the end of the tube and the wing opening needed to be 91/4inches long. With the fix I used the measurements worked out fine. It was amazing this person came onto the board and gave me vital info so quickly and offered me a new body tube. I believe that the true test of class is how you deal with difficulty and Hawks Hobby passed with flying colours. Do not let this stop you from buying this kit :)
Anyways I put together the ramjets ,right wing and rear stab components. The balsa was nice,smooth and thick just like the way I like my coffee :) heres some pictures :)

[Pantherjon]

Thanks :) The fibreglass sounds good as I have never worked with that before either :) John how big a screw do you need to retain the engine if you use dowels to keep the engine secure ?
Cheers
fred

Dowels? Just curious where you would be putting the dowels..

Anyways, most of the motor retention I have on my High Power rockets involves 2 6-32 blind nuts, 2 6-32 (1.5-2" long) screws and 2 washers..Drill 2 3/16" holes almost 1/4" away on each side of the motor tube opening. Then hammer the blind nut in and set with CA or epoxy...As you have the motor mount completely assembled, there is another way to do something similar..Instead of using blind nuts you can use threaded inserts..Drill 2 holes, thread them in, then you have threaded inserts for your screws to go in..

Pictures 1 and 2 show the motor retention used on my 3" Thor..Blind nuts, the screws and washers..I used an additional 3 nuts as I couldn't find screws with thread all the way to the head and needed a 'spacer'..1 is without motor and 2 is with a motor in the tube..
Piture 3 shows a threaded insert with a screw..You will of course want a screw a bit longer then the one in the picture because of the aft closure on the RMS or thrust ring on a single use motor..

[Handeman]

Another type of fastener I've used to add or enhance retention on a built rocket, when there is enough room, is the molly bolt like these (http://www.amazon.com/40-Piece-Molly-Bolt-Anchor-Assortment/dp/B000K7GRJG). They won't pull out because of stripped threads or thin centering ring.

A second method I've used on minimum dia rockets was to take a large paper clip, about 1/16" dia. wire, and cut it up and make a two deep U shapes out of it. Don't worry if the legs are straight, it's actually better if they're a little wavy. I epoxy these to the outside of the BT opposite of each other.
If the rocket has four fins, you can lay them along a fin root when adding fillets. If it has three fins, put one by a fin root and the other opposite, where the lug or rail button might go. I use thin copper wire through the loops to retain the motor.

[Fred22]

Dowels? Just curious where you would be putting the dowels..

Anyways, most of the motor retention I have on my High Power rockets involves 2 6-32 blind nuts, 2 6-32 (1.5-2" long) screws and 2 washers..Drill 2 3/16" holes almost 1/4" away on each side of the motor tube opening. Then hammer the blind nut in and set with CA or epoxy...As you have the motor mount completely assembled, there is another way to do something similar..Instead of using blind nuts you can use threaded inserts..Drill 2 holes, thread them in, then you have threaded inserts for your screws to go in..

Pictures 1 and 2 show the motor retention used on my 3" Thor..Blind nuts, the screws and washers..I used an additional 3 nuts as I couldn't find screws with thread all the way to the head and needed a 'spacer'..1 is without motor and 2 is with a motor in the tube..
Piture 3 shows a threaded insert with a screw..You will of course want a screw a bit longer then the one in the picture because of the aft closure on the RMS or thrust ring on a single use motor..
Wow that looks great John :)
Cheers
fred

[Fred22]

Another type of fastener I've used to add or enhance retention on a built rocket, when there is enough room, is the molly bolt like these (http://www.amazon.com/40-Piece-Molly-Bolt-Anchor-Assortment/dp/B000K7GRJG). They won't pull out because of stripped threads or thin centering ring.

A second method I've used on minimum dia rockets was to take a large paper clip, about 1/16" dia. wire, and cut it up and make a two deep U shapes out of it. Don't worry if the legs are straight, it's actually better if they're a little wavy. I epoxy these to the outside of the BT opposite of each other.
If the rocket has four fins, you can lay them along a fin root when adding fillets. If it has three fins, put one by a fin root and the other opposite, where the lug or rail button might go. I use thin copper wire through the loops to retain the motor.

Another great set of ideas. Darn bald spot going to get bigger from all the head rubbin I do trying to figure out what would work best :) Those retaining rings are mightey pricey although no doubt great value at the price :)
Cheer
fred

[Fred22]

Well upwards and onwards :)
Well guys the wing span on this bird is mighty impressive :) I also enjoyed the book and now it generates good vibes as a fine weight :)

[Fred22]

Well the rear stab involved first putting in a centre line at about 65 millimeters:) This is for me a big rear stab :)

[Fred22]

Well Loretta at Hawks Hobby pointed out I had not assembled the tail properly as the grain was lined up wrong. I used the form the tail pieces were cut out of to draw out then cut a single piece tail from light ply. I lined up the fuselage as level on a work bench with a torpedo level. I then checked the tail and did a little grinding then put on the tail stab assembly. Man this rocket is a real cooker and hard to put away. Thanks again to loretta :)
Cheers
fred

[MysticalRockets]

Guys who sells motor hooks and engine blocks for 29mm?
Thanks
Fred

Hanger 11 usually has them.

Hooks are normally what I use, but you can also use the screen clips method as well. It works quite well.

[MysticalRockets]

My biggest problem with mpr is the fields I use up here are small for LPR let alone MPR so I have to figure out an optimal size somehow :)
Cheers
Fred

In that case, you might want to consider a 24mm adapter and use an F-12 or something similar. Depending on the weight, of course.

[Fred22]

In that case, you might want to consider a 24mm adapter and use an F-12 or something similar. Depending on the weight, of course.
That's sound advice. I have not really thought about what to fire it up with. I will have to balnce it so what I stick in the tail end definately makes a differance.. Swing testing this puppy should be fun :)
Cheers
Fred

[MysticalRockets]

I've never built a Bomarc, and this thread kinda makes me want to. But I promised the wifey no more kits until I knock the build pile down some. And this is a big build pile.

[Fred22]

Well off we go again :) I put on the upper conduit. The two ends are made by splitting two nose cone in half. I put sand paper on the body tube and rubbed the two halfs on it to make then conform to the body tube. I also noticed my conduit was had a gap between the wing and the tube so I cut a thin strip of paper and attached it to the conduit. I then used tamiya putty to cover what was left of the gap and my rather rough cut on the read conduit end.

[Fred22]

I have to mount the ramjets which involves shaping two piece of balsa wood supplied as rectangular blocks. My problem comes in in that if I shape them as long rectangular supports the grain will run parallel to the main body tube. Will this mean a significant risk of the ramjets tearing off or do I need the to change the balsa log under my hat?:confused:

[rokitflite]

Sheet them with 1/64" plywood afterwards;)

[Fred22]

Sheet them with 1/64" plywood afterwards;)
A good idea and I was toying with the idea of making my own but Gordon suggested paper so maybe that and epoxy as a covering I think :)
Cheers
fred

[Pantherjon]

Or maybe the dowel 'rebars' suggestion I posted over on YORF? ;)

[Fred22]

Or maybe the dowel 'rebars' suggestion I posted over on YORF? ;)

John my apolgies for not mentionning your clever and well thought out suggestion. Much to my chagrin I dont think I could carry off you dowel soloution so I went with paper but it is worth seeing so with your permission:

"Does seem to be a little bit of a predicament..However, I don't think there is all that much stress on those so the grain direction shouldn't pose a problem..I think..Not much you can do to get around it tho unless you go get some thick balsa and make your own..
Wild idea and not sure how much strength it might add: After shaping, drill 3 evenly spaced 1/8" holes thru the struts and insert dowels.Make three receiver 'holes' on the underside of the wings and on the top side of the pods for the dowels to 'nest' into..Make the 'holes' or 'divots' for the dowels in the wings like 1/16-1/8" deep and then have say 1/4" of the dowels going into the pod tubes.."
Johns excellant suggestion whic I was scared to try :)

Also Loretta from hawks Hobby made the following observation which she politely sent as a PM but I asked her to put in a post. I am putting this build up on YORF as well since they were kind enough to help us a while ago i thought I would give them a laugh :)

"Don't fret the standoffs for the ramjets will give you no problem if cut as suggested.

From what we could see from your latest pictures the more pressing problem that you have is that .... oops.... it looks like you forgot to put the cutouts back onto the main body tube before the conduit and nosecones were put on ..... this will answer the question about there being spaces between them and the wing. Also couldn't tell clearly by pics but did you remember to add the 1 inch extention to the conduit tube, didn't look like it was there.

Sorry to keep pointing things out, I just want you to be happy with the finished product.

Let us know if there is anything we can do to help.

Always watching

Lady Hawk / Loretta"

As you can see kind and polite. I am doing this thread not so much to showcase my skills but to get help and suggestions. Frankly this kit is a bit over my head but given the subject matter I wanted to try it. I also believe it is only by challenging myself that I learn :)
Cheers
fred

[Fred22]

Next I worked on the ramjet struts. The kit come with a template to shape your struts. I used it and got one of my sons to use a belt sander to shape it. I also covered the strut in paper because it's less to sand and seal as well. I also marked the ramjet tubes where the end of the strut goes :)

[Fred22]

This comes again from Loretta at hawks Hobby
"Just another note for you on the ramjet standoffs ..... after Mark shaped them that was the only part that he used epoxy to attach. He attached them to the ramjet first then gave the sides of the standoffs a lite coat of epoxy before attaching to the main tube. and they survived this.

Loretta / Lady Hawk""
The photo was supplied by Loretta from hawks Hobby and should be considerred their property for any and all purposes :) Thanks again loretta for your help with my build :)
Cheers
fred

[Fred22]

By the way at the hawks hobby website they have a nice little series of photos on how this bad boy should be built by someone who has great skills :)
Heres a link to how it should be done :)
http://photos.hawkshobby.com/GallerySlideshow.aspx?gallery=61546
Cheers
fred

[Fred22]

Well heres the finished product :) Still a few more touches and then swing testing with an engine :)
Cheers
Fred

[sandman]

Well heres the finished product :) Still a few more touches and then swing testing with an engine :)
Cheers
Fred

That looks amazing!

[Pantherjon]

Looks OUTSTANDING Fred!:D..And you can['t even see where you put that patch on the tube for the wing inset! ;) Super nice...

Have you decided on motor retention method?
That would look way cool going up on a G53FJ! :D

[Fred22]

That looks amazing!
Gordon that is praise indeed :) My thanks sir :)
Cheers
fred

[Fred22]

Looks OUTSTANDING Fred!:D..And you can['t even see where you put that patch on the tube for the wing inset! ;) Super nice...

Have you decided on motor retention method?
That would look way cool going up on a G53FJ! :D
Thanks John. I am still ponderring buying those engine retaining cap system. I have never fired a G before but thats what I am going to swing test this badboy with :) It looked a little rough at first but it turned out not too bad :)
Cheers
fred

[Mike Di Venti]

So where do I find one of these kits? Not to bring up a very sore subject but I wouldn't mind building something on the scale of the large Bomarc I'd ordered from Empire a few years ago that never appeared in the mail....this looks to be about right...


Don't worry . You're not missing a thing..
I built one as per instructions and added a little more nose weight because it didn't do well on the swing test.
Flew it twice and both times I was ducking for cover after it cleared the rod.

Empire's kit is an unstable kit to fly. Great for shelf decoration though.

my 2 cents though...