Scale Blackhawk

[rgallant]

Hello all,

I am about the try my hand at building a Blackhawk, darthdrk body around a T-Rex 450 SE. So in the sprirt of ask questions 1st then break things with reasonable knowledge I have a few questions.

My plan for the tail is to use 2 belts, the stock belt to get aft and then a second belt to get to the top of the tail. This should :) allow me to also angle the tail by the 15 to 20 degrees for the right look, without putting undue stress on a single long belt.

I would like a 4 bladed tail, does anyone know of a unit that can be adapted or is it a build it myself deal ? I have some ideas on how it could be accomplished, but I really do not want to re-invent the wheel if it has been done. It will also save me a whack time doing sturdiness and reliability testing.

Second I plan on a k variant, so I will be adding a refueling boom and a few other bits. Will the stock motor (430 BL) do or should I invest in a more powerful unit ?

That is it for today, I will keep this post up to date as I go.

[rgallant]

Ok here we go:

1st off a few points, I am writing this as both a build log and notes on working on the body itself, those notes that are about issues or points on the body will be treated as quoted material. This will allow people to either locate or ignore that material quickly.

I have decided on a 3 part build, the 1st section is building the nose and designing associated parts. As the body is primary light weight plastic and will be opened and closed for repairs and adjustment. The 1st thing I did was cut a 4 inch by 12 inch by 1/8 thickness piece of light weight plywood to act as a mounting surface for the 450's mechanical bits. This board covers 90% of the floor of the main cabin as will as extending for most of the forward section of the cockpit. This board may end up being coated in fiberglass if it is too flexible.

Picture 1 Mounting board (http://www.gallantent.com/helo/blackhawk/Body004.jpg)

In the image below, the blurry section behind the opened top window for the cockpit, will be reinforced to accept a bolt to hold the front of the canopy in place. Ideally I can locate the bolts where a vent exists and hide the bolt heads that way. There is a vent on the engine cover, in approx the correct location.

Nose Section Mounting (http://www.gallantent.com/helo/blackhawk/body005.jpg)


The body of the model will be attached at 4 points representing the original T-Rex landing gear mounting points. A second set of bolts will hold the cockpit to the main cabin, allowing for easy battery access, these will underneath the body and at the front edges of the forward engine cover. The engine cover mounts will be reinforced as with the main body floor, with lightweight plywood or carbon fiber sheet.

This leaves the tail, the current tail is a single piece that attaches to the main cabin. The tail will have to a 2 piece design to allow access to the raised tail box. As this is the most complex portion of the build I am leaving it for last.

Cockpit area front 3rd.

This is my 1st section of the build, and in many ways is as complicated as the tail section. The MH60K which is the version I am modeling, has a large number of bits that are not on the basic model from Darthdrk. This is not a fault of Darthdrk's model, the basic model as supplied can be built to almost any version of the Blackhawk with a little work. See the picture below, from a 35th scale model build of the K version for the general idea. I invested in a squadron book the H60 Blackhawk in action for reference, as well as a large number of internet sites.

Nose Section Image (http://www.gallantent.com/helo/blackhawk/46.jpg)

Original is from the following site : http://www.aircraftresourcecenter.com/Fea1/801-900/Fea893_Mh-60_McEwan/fea893a.htm

To start the build I cut out the windows and located the forward cooling vents. The vents will take a while to locate, but when they are screened in will help with cooling.

When cutting out the windows, you need to start with a smaller cut out than the actual window size then slowly enlarge the opening. As this is relatively thin plastic, use a very sharp knife and carefully score the area 1st, then slowly cut out the excess material. Once you have opened all the windows check to see if any areas need reinforcing, any small areas should get some. Most hobby shops that cater to modelers can get sheet plastic, plastic rod etc that can be used for this task.

At the end of the 1st night, about 3 hours work and a very sore knife finger I have 80% of the cockpit openings roughly opened.
Nose Section Cleaned up (http://www.gallantent.com/helo/blackhawk/body006.jpg)


The refueling probe on these birds is a monster, it works out to the same diameter as the tail boom on the 450, so that is where I am going to start. It works out to about 9 inches long, so it sticks way the heck out there. The image below will give you a general idea of the size on the real bird.

Refueling Probe (http://www.gallantent.com/helo/blackhawk/11.jpg)

Well that is it for day one of the build, more in the next couple of days.

[screwbirds]

rgallant,
Very interested project, keep the post up :thumbup:

[rgallant]

While I figure out some weird reinforcing methods for the inside of the intakes, I have started work on the forward landing gear.

Here is the external prototype, it is all basically to scale, a few millimeters out but nothing too serious.

Here is the 1st test fit prior to cutting the hole for the vertical landing leg. If you look at the engine intake you can just see the fiberglass that will be used to reinforce that area.

http://www.gallantent.com/helo/blackhawk/wheelboom001.jpg

Here we have the hole cut and the gear test fitted, note the material raising the body does raise the body to the correct height. The forward leg (the angled one) will be cut and a tube placed inside to allow the front cabin to removed for battery and other access. Need to pickup the right tube stock for that job. A single carbon fiber tube will join the right and left landing gear at the front.

http://www.gallantent.com/helo/blackhawk/wheelboom002.jpg

Here we have problem child #1, the refueling boom. The boom is currently made from a spare tail boom as it is almost the perfect diameter. Should be fun balancing this out :). The length is 9 inches in total. Conveniently the servo mounting bracket is about right size and general shape for the forward boom support. And no, the blue tape will not be used to attach the boom :), after all it is not duct tape.

http://www.gallantent.com/helo/blackhawk/wheelboom003.jpg

This is the same basic shot with the tail case in the image for a sense of size,and bit further back. The boom ends just at the end of the image. It is actually a little low, the boom should sit just below the door edge. I hope to have a semi-permanent mount completed this evening if all goes right. For the final product I will most likely use CF unless I can find something even lighter.

http://www.gallantent.com/helo/blackhawk/wheelboom004.jpg


Landing gear will not be fitted for a couple of days, I want to add a shock tube to the upright to allow for some give on hard landings.

[rgallant]

Hi all,

As mentioned above the body was purchased from Darthdrk. It is a special order item, due to some the more complex parts. As delivered the kit represents a basic UH 60 with the HIRSS updates and the roof mount IR suppressor. A great many different variants can be built out of this basic kit, if you have the patience and so basic plastic modeling skills. In the 450 range this kit is the best option available.

When I received the kit it was pre-assembled which is to say all the joining flanges, were attached and the forward cockpit sections joined and the tail assembled. As well he took the time to attach the engine intakes and HIRSS baffles, All told this saved me at least 4 to 5 hours work out of the box, and allowed me to get right into the conversion portion of the build. All in all excellent service from Darthdrk.

The plastic is very thin ranging from .040 to .020 in thickness, which is pretty decent for a vacuformed kit of this size. This requires some reinforcement, whereever you are going to attach items such as the landing gear and T-rex mechanicals etc. I found that lightweight 1/8th in plywood works really well , and currently I am testing a fiberglass resin on some spare bits for curved areas. As well if you have a craft or hobby shop that carries hobby plywood you can get even thinner wood.

The body is so light that you can add the reinforcement without being too worried about weight, as long as you keep the sizes down to the minimum for the job. Of course you have to make sure the CG and balance are kept in the front of your brain.

As for my build, large amounts of time on the net and 2 Squadron and signal books on the Blackhawk, are making this a little easier.

[luvmykids2]

anything new on your build?? i am interested in this one!

[rgallant]

Not much right now, I have working on some fiberglass reinforcement for the nose. There is a bunch of stuff to be mounted and the lightweight plastic will not be up to the job.

The fiberglass test is complete and the good news is that it worked perfectly with no heat distortion. I used a bondo product :).

Now I just need to find a way to insure it bonds to plastic correctly, but that should be some simple sanding with 60 or 80 grit sand paper. A good rough surface should hold it all together. Hope to have the boom mounted by Monday night.

In the mean time here is a shot of the nose of a Pavehawk with refueling boom

http://www.gallantent.com/helo/blackhawk/02.jpg

The site this image is taken from, not to mention being very helpful site.

Blackhawk walkaround (http://www.aircraftresourcecenter.com/AWA1/601-700/walk609_HH-60_Provenzano/walk609.htm)

And my test fit from the same general angle

http://www.gallantent.com/helo/blackhawk/refprobe1.jpg

As you can see the tail boom as a refueling probe stand in is extremely close in scale size to the real thing.

[rgallant]

Hi all,

Well things are going along great, just ordered that a 4 blade head and my tail raiser is on the way. The nose is coming along very well, the fiberglass test was completed successfully and I am off to the races.



To use fiberglass to reinforce these kits you need to insure it does not create a lot of heat during the curing process. I used a Bondo car repair product, that works really well. Next you need to mask off everything fiberglass is not going to be applied to this is a very messy job, see the photos below. If you don't mask you will be sanding just like I am going to do.

Then take a 50 grit sand paper and rough up the area, go both length wise and sideways, you want a nice rough surface. Once that is complete, clean throughly and cut two pieces of fiberglass to size. Prepare your resin as per instructions dip and place.

Let dry for at least 24 hours, regardless of the directions. You want a good solid bond, then trim, add some super glue anywhere the bond seems iffy and you are good to go.



Here is my test fit of the fiberglass

http://www.gallantent.com/helo/blackhawk/nosewrk001.jpg

The finished installation front and back, notice the excess that will need to be trimmed. A dremel multi tool is the best bet, with a cutting wheel. The small pieces of plywood are for the attachment of the wheels and refueling probe.

http://www.gallantent.com/helo/blackhawk/nosewrk002.jpg

http://www.gallantent.com/helo/blackhawk/nosewrk003.jpg

And all cleaned up

http://www.gallantent.com/helo/blackhawk/nosewrk006.jpg

Just to remind you of the size here are the 450 mechanicals beside the body. They are roughly in the location the will be placed on the interior.

http://www.gallantent.com/helo/blackhawk/nosewrk004.jpg

Finally 2 shots of the nose with the refueling probe and FLIR dome attached. Both of these are temporary attachments. The boom for location and distance from the body, it is a little close, but I am happy with the look so it may stay there. The boom just needs the stepping platform added under the the door and some work on the bracing. The front of the boom will likely be an old airbrush nozzle that is no longer serviceable, just got to find it and test fit.

The FLIR dome is too long, but close to the right diameter. A nice Cuban cigar tube was sacrificed to make the dome. Some rough shaping and white glue attached it while I figure out how much shorter it should, I figure about 1/2 it's current length but need to get some measurements. A small plastic collar will hold it in place once it is complete. The forward radar dome is still being worked on, that should be the next project you see posted here.

http://www.gallantent.com/helo/blackhawk/nosewrk007.jpg

http://www.gallantent.com/helo/blackhawk/nosewrk008.jpg

[lrogers]

You are doing an awesome job on this one. Very interested in seeing your solution to the elevated tail! I'm currently (very slow bell) working on a 222 body from Darth for my 'Rex. I'm going to watch your build closely for tips/tricks I can apply to mine.

[rgallant]

That is going to be the fun part, I have ordered a unit from a German maker that will turn the belt and get the bits up top. The trick will be getting the 20 degree angle at the top. Hopefully a small pipe bender I have will do the trick. Leaving that until all the bits arrive.

[rgallant]

Well nothing too exciting to report, mostly planning and dry testing ideas for the tail and working on the nose radars.


I did however take the time to build out the main gear for the port side. I need to add a couple of stops but other than that it looks good. Here is the basic build idea dry fitted, more in the next few days.

Here is the internal slider in the landed position, so the bird would be on the ground. The tubes are light weight aluminum stock. The surrounding tube will be mounted to the piece of plywood, the internal tube will have two pins inserted as upper and lower movement stops. The 1st image is the inside view, the second the outside.

http://www.gallantent.com/helo/blackhawk/maingear 002.jpg

http://www.gallantent.com/helo/blackhawk/maingear 003.jpg

These two views are of the gear in the flight position, dropped down and basically hanging, the tubes are close enough in size that this works fairly well. I will likely drop a small spring inside to act as a bit of a shock absorber, between the stops. The travel is about 1/2 an inch. I have not fitted the gear covers yet but have a prototype ready, that is for the next update.

http://www.gallantent.com/helo/blackhawk/maingear 004.jpg

http://www.gallantent.com/helo/blackhawk/maingear 005.jpg

[bcritch]

So far it looks great. I work on H-60's so I love to see this kind of build. Keep up the good work.

PS- Also are going to make your landing gear struts extend? I do not know how you would, but I am sure it could be done, and on take off and landings it would be a great effect.

[lrogers]

This bird just keeps getting better and better!

[rgallant]

Well, things have quieted down enough for me to complete some more work. The main gear is complete and mounted, it will need some adjustment but it is complete. As well I have complete the fitting of the plywood floor, for mounting the T-Rex mechanicals.

In response to bcritch, the gear is setup so it should just drop as I lift then compress as I land. It is an idiot system just a small tube that the is the vertical riser, going through the larger tube mounted on the side of the main cabin. I need a small weak spring (ballpoint pen spring might work) to act a a bit of shock absorber for those hard landings.

The two nose radar domes are mounted and the re-fueling probe re-fitted for the pics. I am seriously considering plastic rather than the tail boom material I am currently using. With plastic I could route a short deans antenna inside the tube and keep it completely hidden. The weight difference will be the deciding factor on this one.

Most of the work right now is insuring I can change a battery easily and making sure all the joints will hold together while in the air.

As well I need to figure out the 4 blade head I have sitting in Canada Customs.

Here we are with the gear attached, on both sides, with a the start of the fitting of the gear pods. The ugly yellow stuff is carpenters glue which will hold plastic while I work, but can easily be removed and cleaned up for final fitting with epoxy. If you try this trick on fiberglass test a scrap piece 1st just in case.

http://www.gallantent.com/helo/blackhawk/gear008.jpg

And from the front, the tape dispenser is just there to support the back end. You can also see the high tech materials used to create the radar domes, I knew those Cuban cigar tubes would come in handy. As well the plywood inner floor is visible as is the starboard gear tube.

http://www.gallantent.com/helo/blackhawk/gear007.jpg

Lastly the starboard side with the refueling probe mounted and the tail gear laying there abandoned for now. There is a slight toe out to the the main gear wheels that will need to be resolved, but it is not a serious issue. The level on roof is to check and insure I get the gear set to the bird is level from left to right.

http://www.gallantent.com/helo/blackhawk/gear004.jpg

The main portion of the radar installation is series of cardboard cut outs right now. That allows me to figure out the curves and how I am going to build it out of permanent materials. I will most likely build and attach it to the heli than create a mold I can use to cast new ones when I crash and need to fix it.

[bcritch]

You may bable use a R/C car spring, I know they come in all shaped and sizes, but with that extention of the strut that should have a very nice affect.

[rgallant]

I have not given up, just working on the flying bits. I have added a Lightning 4 blade head, currently I am spending my available flying time getting that setup.

Still working on the Blackhawk, here is the game plan:


get my 4 blade head sorted, getting closer.
Then I have the raised tail to add it is in hand and waiting
Add the 4 blade tail rotor, parts have been ordered (Maxir 4 head)
Finish the mounts to tilt the tail rotor 20 deg.
Finish detailing the body, and mount mechanicals
Test fly / crash fix and continue :)
Oh yeah fit in Christmas and keep the wife happy

[screwbirds]

rgallant,
Sound very interesting, I bet it will be owesome bird when it is completed. Post the 4 blades tail rotor photo when it arrived also the link to get it.

[AndreasM]

As others already have said: Inspiring, and awesome. Looking forward to further updates.

[TCAS]

Anything new to report on the Blackhawk?

[rgallant]

Hi all,

Sorry about the long pause in reporting, all is going well.

The mounting plank has been installed in the body, so I am basically ready to install the mechanicals. However, I have been setting up & practicing with the 4 blade head, very interesting experience. Next up is to add the raised tail, that may slow down production as I may need a longer belt than the raised tail comes with.

I will post some images in the next few days, with the mechanicals test fitted.

[rgallant]

Just a few quick images to let you know I have not vanished

Here is the tail with riser as supplied :

http://www.gallantent.com/helo/bhtail001.jpg

Here is the actual height,actually about 1/2 inch too high but it stays that way until things are mounted

http://www.gallantent.com/helo/bhtail002.jpg

Note the difference in height :)

You get a fully assembled and painted black shot in the next few days, not flight ready but with all the attachment points done and everything painted basic black.

[JayAAllen]

Just joined the Freak and your's is the only thread I've found so far warranting my subscription.

Just waiting for the results before convincing the pocketbook to start building my USCG HH-60J replica.

Baited breath.

Inspiration:

http://www.youtube.com/watch?v=8cBlHCnmL0M

[rgallant]

Hi and welcome,

So far it has been worth the effort. Xmas and a bathroom reno have slowed me down but I am happily getting back to work on this bird.

[Darthdrk]

Heres mine (keep inspired)

[h60]

rgallant,

Any updates?

I too am looking at builing a scale HH-60J/ MH-60T (the latter is the new modded Coast Guard H-60 preliminarily dubbed the Thunder Hawk (aka thunder chicken).