Scale UH-1H 450 Class Custom Build Project

[Highspeed1964]

So I've been learning a bit more about the 3D printing. Specifically, batch printing multiple parts in one "plating". This lets me set up several parts to print, monitor the first bit of it to ensure everything is setting up well and then walk away (perhaps to get some sleep!) to come back later and assemble the parts for a test fit.

This next section I completed was done in two print runs as some of the parts were too large to include in the same run with the other parts. I could have added a couple more parts onto the second run but I didn't feel they were ready to be made yet so here is what I've accomplished on this session.



Added in some of the components on the front section of the frame for the main body. This will be the cockpit area of the cabin. And yes, those are zip-ties holding the upper part of the frame to the main support beam. I forgot to add in some screw holes there. But none of this is bolted together yet anyway. It's pretty much holding itself together except the joining of the front and rear halves.



The profile view shows how this is shaping up. I still have to contour the exterior edges on most of the parts but I have a rough shape on the nose section of the main beams.



Here I've placed the battery into the correct location for where it will sit in the final model. The wiring and connectors will be routed through to the proper places through the center console and along the sides of the hull under the floorboards.



And the overhead beams will support the GPS module I'm planning to use. I'll be using the lower half of the case you see in the pictures to mount it under the upper beams so that it becomes the "overhead console" of the finished model. Wire routing is still to be determined but I do have a couple of options in mind. It's just a matter of which one is best.

So I've been having a lot of fun getting this build back on a forward track with this new tool I have at hand. There's still a lot of fine-tuning and detail work to do. I'm especially thinking through how best to do the door tracks. If you look closely at the floorboard in the first picture, you may see a track that is part of the floorboard itself, but it is the rear part of the door track system (the part that is aft of the cabin area) that I'm having some thoughts on how to best implement it.

Well that's it for now. Back to the CAD work and printing more test parts from that. I'll keep you posted.

And again, thanks for following this. I hope to have a finished bird in the air before y'all get too board with reading these updates.

Highspeed

[Highspeed1964]

Just a brief update this time.

Been working on the cockpit area including the seats, center console and instrument panel. Why this level of detail on this area when there's so much else to do (i.e. exterior contours)? Well, these components are key to the routing of the wiring which needs to go from under the floorboards on the sides to the nose in the center. With the battery being in the center channel, the wires have to go up and across then into the nose. Up into the seat pedistal, across into the center console and then forward into the upper nose "electronics tray".

I will be working on the exterior contours next and hope to have some photos up in the next couple of days for that. In the meantime, enjoy these pics.



Cockpit floorboard installed and one seat (co-pilot's seat in this pic) temporarily put in place. The seat is a simple model at this time but will get redone with more detail later. I also made it a bit too wide for the scale and that needs to be fixed. But for now I needed to do a proof of concept for the wire routing. You can see the pass-through hole on the pilot's side.



Here, I've moved the seat to the pilot's side and also put in the center console as well as the instrument panel. Love the way this is looking!



Looking into the electronics bay of the nose section. If you look closely you can see the opening through which the wiring will pass to get here from the center console. Battery cables will run beneath this shelf and the satellite RX will sit on the shelf. I will probably bring the GPS wires through here as well and up to the overhead console through the center post of the windscreen frame that will be added later.

And that's it for now. But next time I hope the have this frame sitting in the fiberglass shell (at least the lower shell) after working on the external contours of the frame.

As always, thanks for watching.

Highspeed

[RCBound]

As always, thanks for the updates!

[Highspeed1964]

So at the outset of this project blog, I promised a few things. In particular for this update was my promise to share the good, the bad and the ugly. In that order...

The good: I've made good progress on the contour of the frame. At least the design work. Unfortunately, there's still the bad and the ugly...

The bad, I printed the first couple of pieces to test fit and found that I had forgotten to subtract the thickness of the fiberglass shell! So I had to adjust the size to compensate. That is when...

The ugly! I adjusted the size of the first test pieces and went to print them. Can you say "Nozzle Jam"? Well it jammed so badly that it ruined the PTFE tube inside the feed barrel. So no more printing at the moment. However, I do have a replacement on order and it should be here in the next couple of days so bear with me on this short delay.

Now back to the good...

I have continued on the CAD work contouring the remaining parts. I'm also working on some of the finer details in the process so I thought I'd share some more screen captures to show you what you can look forward to when I get the printer back on line. No captions this time, so just enjoy what you see. They're pretty self-explanatory anyway.









Always pleased to share the updates with you and again...

Thanks for watching.

Highspeed

[MariaFan]

I love this thread.

[Highspeed1964]

Hey folks,

As you recall from my previous update(s) I had a part failure on my 3D printer. This has caused another delay on the project, but I've received the new parts and I'm back in action on the printer. I've even made a couple improvements on the printer to hopefully avoid a recurrence of this break-down.

So I've spent the last few evenings reprinting several (in fact most all) of the parts for the frame with the new contouring that I've been working on. The goal was to get it fit into the fiberglass shell for the main body of the fuselage. I do not have the upper fuselage cast yet but the lower hull is the key focus at this point. The upper fuselage shell includes pretty straight-forward contours and the nose section.

So after printing these new parts, I have gotten it all assembled and the first test fit into the lower hull shell! It wasn't perfect as you'll see in the photos but it is good to be at this point where I can fine-tune things a bit and get on to the next phases. Follow on with the pictures below for details.



The first test fit of the frame into the lower hull. Pretty good, but not perfect. All-in-all, however, it's looking really good. I do not have the floorboards re-installed on this setup as the floorboards have some contours of their own that need to be done. Still figuring that part out.



As you can see, the main beams running fore and aft do not sit down into the shell all the way. The segment around the rear landing strut support beam is still too deep and so the whole thing "teeters" around this point.



On the up-side, I also added in the proper screw holes and cutouts to mount the GPS module for a test fit. In this case, it's PERFECT!



Finally, I also managed to add an additional part for the mechanical bay. This piece and some of the other frame parts will support and provide mounting points for the mechanical assembly which will be built as a removable module. That module will also have the mount points for the tail boom assembly to be attached onto the main body.

I am thrilled to be back into a forward moving direction with this project and especially excited to see the body coming together as much as it is now. After getting the fitting of the frame into the body (which will include casting the upper fuselage shell) I'll be working on getting that mechanical assembly module at least mocked up so I can check the fit of the motor/transmission unit as well as getting a better visual overall. Then I'll continue on with the tail boom frame and shell.

That's about it for this update, but I hope it's as exciting an update for you as it has been for me. And as usual...

Thanks for watching.

Highspeed

[Highspeed1964]

Hi Folks,

First, I know it's been a little while again. Life seems to have a way of presenting challenges and this time, I'm getting ready to move out of my current residence and have been getting ready for that. In the meantime, I've been working on getting the final touches on getting the frame properly sitting into the shell of the lower hull.

It was a long process because I was having difficulty figuring out why things just weren't working to get a proper fit. After much trial and error (I should have listened to the old carpenter's adage - "Measure twice, cut once.") I finally broke out the calipers and realized that the main beams were 5mm too short! I added that 5mm back in at the aft section and viola! everything is fitting so much better now. These pics might not look much different than the previous set, but believe me there is a big difference in terms of the model itself. The frame now sits down properly into the shell so that the floorboards will be at the right height and line up with the lower door openings.

So here's the pics:



The frame has been redone to fit the shell better. Still have the forward bulkhead to complete...



... but it's sitting at the correct height for the floorboards to sit at the lower edge of the door openings.



If you look closely, you can see that the cross-wise components are contoured with minimal gaps to the shell.



Completed the forward bulkhead. It's a little bit too thick (3D printing is definitely an art and not a science - at least not for me) but it works for now. I'll fine tune it later.



You can also see that the battery will be a bit snug under the floorboards, but it fits. I'll be adding some foam padding later on the sides and rear to cushion the battery for flight conditions.



That forward bulkhead is almost a work of art in itself! The contour fit is almost perfect.

After I took these pictures, I went ahead and put most of the electronic/electro-mechanical parts into the model as it is to see how well it's all going to fit. It also gave me a chance to get a feel for what the weight is going to be like in the finished model. It's probably about 100g (just guessing as I don't have a scale, but I did a comparison holding this in one hand and a 450 Trex clone in the other) heavier than a typical 450 so it's not light. But I think this is going to give it a much more "scale" feel in flight and that's really what I want in this model. So I'm quite happy with where it's at and where it will be when I'm done.

Once I get the top shell in place, I'll work on a mock-up of the mechanical module that will go in the back of the main body so I can do a more accurate test fit, especially to make sure the motor will fit properly under the engine cowl. Then I can begin work on the tail boom! I can't wait to get that in place.

So as always, thanks for watching. I really appreciate y'all following this project through the ups and downs as well as some of the delays that come up at times. I just wish I had more hobby time and less of the day-to-day stresses of life. But it is what it is and I'll keep moving forward on this project. So stay tuned for more.

Highspeed

[Highspeed1964]

Hi folks,

Just a single photo today. But it's a pretty exciting one! I've started doing a mock-up of the electronics/mechanicals module. I wanted to make sure things are going to fit properly before I go too much further with the frame. This is the first chance I've had to mount the motor/gearbox into any sort of frame.

What I did was print all the parts (side plates, bearing blocks, mounting blocks and FC shelf) out of plastic on the 3D printer. Then I glued them together (the final assembly will be carbon fiber side plates and aluminum blocks screwed together) and mounted the motor/gearbox assembly and the flight controller onto this frame that will be a removable module in the finished model. Then I dropped this module into the frame and lower hull for the test fit. It's all looking good and the motor will fit nicely under the engine cowl so I'm quite happy with it.

I also did up a good bit of the wiring too so that I could do a test run-up of the systems to ensure everything would work out ok. I did a quick video of that but haven't gotten it uploaded to YouTube yet so I'll have that for you soon. But for now, I at least want to show you the progress I've made. It's more than just a frame now!!!!!!!!



One thing I discovered is that the ESC is just a mm or so too big to fit as I currently have the floorboard so it's back to the CAD work to see if I can squeeze just that much more space in there for that. I have a plan, I just need to execute it and hope that it'll do the trick. I just wish I had a little more CAD experience so I don't have to do this trial-and-error stuff. So for this pic, there's some wiring hanging out and some that need to be lengthened to reach the areas some of the components are being mounted into.

But here's what I had before doing some of the final wiring I needed to do for the test run-up. (Again, that video will be up soon.)



Like I said, it's more than just a frame now. I still have a lot of detail work to do on the frame such as the overhead door rails, the rear door rails and some of the nose section as well as the floorboards to finish. But it's making good progress this week.

Now, having said that I will be off-line for a few days after getting that video up. I will be moving early next week so I'll be spending a lot of time packing and getting the place "move-out ready" so hope to see y'all shortly after on the other side of the move.

Thanks again for watching and keep an eye out for that video.

Highspeed

[Highspeed1964]

So first, a couple of words about this video.

1. It's a bit dark so you can't see a lot of detail. But the idea was to do a run-up and that's what I accomplished. But I had to do this on my covered patio (yes it was raining out as you can hear in the video) so that the GPS module could lock on to the satellites - something it can't do inside my apartment.

2. You may want to turn your volume down a bit as the motor "whine" can be quite irritating to some.

3. The video was shot with the camera (cell phone) in one hand and the TX in the other, so it's a bit unstable at times.

Having said that, I did forget to mention in the previous post that there is an antenna sticking out the back of the body. This antenna is for the telemetry of the flight controller that provides some pretty cool looking stuff on a computer by way of a pair of wireless modems. I had it hooked up and monitoring during this test run-up, but forgot to turn on the loggin feature of the program!

Oh, well. Next time I'll get that.

Anyway, it;s a short video. Just showing some flashing lights at first. But then I flip the switch to engage the motor. After letting it spool up, I then switch to UI1 for proper governing which is where I will do most of my flying on this model. Then I spool back to Normal and the TH. Finally, I perform a "dis-arming" step where the FC will not spool up the motor no matter what. A cool safety feature of this flight controller. If you watch closely after spooling it down, you'll notice the flashing blue light showing underneath the FC changes to a slower flashing cyan light. This is when the throttle is disarmed.

Have fun and enjoy watch the video. Here is is now:

UH-1H "Huey" Custom RC Build - Test run of the motor and electronic systems (0 min 57 sec)

As always, thanks for watching.

Highspeed

[RCBound]

One step closer!

[atkin]

Really well done thread Highspeed. I'd love to see it in person.

[Highspeed1964]

Originally Posted by atkin

Really well done thread Highspeed. I'd love to see it in person.

I'm sure we can arrange something. Both in the Seattle area. PM me and we'll figure out some details.

Highspeed

P.S. Still getting settled in to my new digs after moving but I've dug up most of the stuff for this project. Still have to remember which box has the original wood airframe.

[MariaFan]

Originally Posted by Highspeed1964

I'm sure we can arrange something. Both in the Seattle area. PM me and we'll figure out some details.

Highspeed

P.S. Still getting settled in to my new digs after moving but I've dug up most of the stuff for this project. Still have to remember which box has the original wood airframe.

And here I am, stuck on Ohio.

[Highspeed1964]

Hi guys,

Been a bit longer than I expected. Still getting settled in to my new dwelling, but I got my priorities straight! Got my office/hobby room done first!!!

So I'm trying to figure which way to go from here. I think I'm going to start in on the tail boom. Going to do the CAD work to figure out the best way to build the frame so I can start printing out the pieces for that. This will also let me start figuring out some of the details for the mechanical linkages, drive systems and rotor hub, etc.

As for the main body of the fuselage, I need to cast the upper shell and fine tune the shape of the bulkheads for fitting into that portion of the fiberglass body. I also need to add a few more parts up top for the frame as well.

I've been messing around with the electronics a bit the last few days and have determined that the location of the GPS (which also provides the magnetometer in my system) is sufficient to keep the MAGs away from high current devices thereby avoiding erroneous readings for the directional signals. I've also found that, at least with the components I have installed (I do not have any shafts, gears, servos, etc. installed yet), vibrations have minimal influence on the FBL systems so it's looking good on that front.

Anyway, got my 3D printer set back up and adjusted so I can start making parts again.

I still need to find a source for CNC milling the bearing and mounting blocks as well as cutting and milling the custom shafts I will need. Still finalizing the design on some of those parts so it'll be a little while yet before I'm ready for those. Gotta fine tune the placement on some of the components and design the mounts for the bell-cranks and other pieces.

Anyway, I am back at it as time permits. I didn't want y'all thinking I had bailed on this project. Just doing it as time permits. I knew from the beginning that this would be a long term project and I don't want to hold myself to unrealistic timelines. It is, after all, my hobby and I want to keep enjoying it.

As always, thanks for watching and I hope to have more to show you soon.

Highspeed

[RCBound]

It'll be a few more months before I purchase a CNC. I have a friend that helps me out with CNC work now but he's also super busy so turn around isn't quick. Wish I could help you out! I feel so held back without machinery.

What final target weight are you shooting for?

Congrats on the new house!

[Highspeed1964]

First, let me answer a couple of questions from RCBound and then I'll get to the update. Read on...

Originally Posted by RCBound

It'll be a few more months before I purchase a CNC. I have a friend that helps me out with CNC work now but he's also super busy so turn around isn't quick. Wish I could help you out! I feel so held back without machinery.

I know the feeling. I wish I had more high-end tools like this myself. I'm pretty sure I could do the work. Just can't afford the machinery!

Originally Posted by RCBound

What final target weight are you shooting for?

Haven't really thought about a target weight. I really couldn't even tell you the weight of my store-bought or kit models as it is. I did do a comparison by hand between my 450 clone and the huey body and I do know it's a slight bit heavier - and I've still got the tail boom and a few more mechanical pieces to put in there.

However, I do want it to be on the heavy side as I'm going for scale flight. Between a heavier body and the main mast being taller (thus a lower CG) I do expect this model to fly more like the real Huey rather than the stunt models everyone's going for these days. My only concern is flight time. I'm hoping to be able to get 5:00 plus (I routinely get 6:30 on my 450 flying scale/sport so keeping my fingers crossed) but I'm doing this project more "on-the-fly" (no pun intended) rather than following engineering processes. So far everything seems to be working out ok, but there have been a few times (as you can see reading earlier in this thread) I have had to go back and re-think how to approach a given challenge.

Originally Posted by RCBound

Congrats on the new house!

Thanks, man. It's actually been my house for a while. Just been going through some of life's challenges and finally getting things back on track in that realm. So moved back in at least for now.

So having answered those questions, I do have a quick update on the actual project! As the title says, I've started work on the tail boom design. I've gotten a pretty good start on the CAD drawings and I thought I'd post a quick screenshot of what I've got at this point.

So here it is:



There's still a lot more to do. I need to cut out the centers and create the passage-ways for the control links and telemetry antenna, add bearing blocks for the articulated horizontal stabilizer, place the components for the tail hook, and possibly wiring channels for the tail lighting if I decide to include fuselage lighting onto the model. (I probably will!)

The vertical stabilizer is also different from the one on the wooden model so I'll have to make two of the frames - one that I can cover and cast a mold from and the other to go into the finished model. I've actually gotten an exact 42 degree angle between the boom and the vertical stabilizer as it is in the real Huey.

Of course, as with all the rest, 90 percent of the work is in the details so we'll see how the progress goes.

And as always, thanks for watching.

Highspeed

[RCBound]

Thanks Highspeed!

[Highspeed1964]

So I've been busy working away at the tail boom design and I've attached a few pics of what I've accomplished to this point. However, I've also gone a bit further and placed all the various modules together into one drawing for the first time! You'll see a few screen shots below of the whole frame and mechanical assemblies put together - minus a few pieces on the tail that I'm still working on the design for.

Not much to expand on in this update so I'll just put the pics up and let you see where I've gotten to this week.



Got a lot more done on the tail boom design.



I even have the mechanism for the articulated horizontal stabilizers completed.



Looks pretty good as it is, but...



...even better when it's attached to the rest of the helicopter.



A lot going on in there but it's all working together pretty well. I've post a video recently that showed the electronics systems functioning properly.



And of course, what would a post about the Huey air frame be without a shot of the famously recognizable profile of the aircraft.

Well that's it for now. I'll be starting to print up the parts for the tail boom so I can get started putting it together on the real model. And of course, as always...

Thanks for watching.

Highspeed

[Highspeed1964]

Firstly, I haven't done much printing on the parts yet. I've printed the first piece but I couldn't get my mind off of the actual design. So I've been continuing my work in CAD and have gotten the power train complete all the way to the tail rotor! (I still have the gear box enclosures to do but the line of power is complete.)

So I just thought I'd share the latest screen shots of the CAD drawings. Here they are:



A good perspective view of the whole model.



Tail rotor system has been added - including the rotor blades themselves. You can see that the gear systems still need to be enclosed, but that gear assembly at the base of the vertical stabilizer is a true 42 degree gear box.



As shown in this profile view, I've been refining the vertical stabilizer and I think this is the final iteration of that section. I really like how it's shaped up now.

Not much more to add at this point, but I hope you're enjoying seeing the CAD work progress. And again, as always...

Thanks for watching.

Highspeed

[RCBound]

Something I've been noticing. "upside down" air foils on the tail horizontal wing. I'm assuming that's standard to help keep the tail down in forward flight?
Even on full scale?