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Posted

Sorry, I've been off line for a while. I will be using carbon fiber for the rails the ramp retract on and the rest of the upper hull structure. I just hinged the first segment and have to do the other half. I've been working on the mechanics of the retract and folding mechanisms. I've got to keep it ultralight, but very robust, Tough combo! - MT

  • 2 weeks later...
Posted

UPDATE 14 OCT 07

First off, my apologies for taking so long to post. I ordered geared drives for the articulation of the ramp two weeks ago and the stupid Royal Mail strike is holding up the parts. Normal delivery time is 2 days! I even had extra time to install them! First off, both hinged joints were built twice. The first fastening method of the brass hinges didn't work out. So I took sewing pins, filed the heads thinner than paper and counter sunk them into the hinges so the hinge movement would not be hindered. A gearhead and threaded rod will articulate this section for speed and strength at a lighter weight. The styrene hinges froze up when glue ran into them. That was a blessing since I found better fitting plastic tubing.

The styrene hinged parts are large so the doors fold back (180 degrees) with a large gap to make room for the machinery and side details. This is the section that the ramp folds down for in the Daeadlus Attack Mode (Assualt Mode is a beach landing). A gearhead will turn a clutched gear (for safety) that runs through the hinged parts and actuates the folding of the parts.

I made brass clutch parts that worked fine, but the weight was higher than I wanted. So I went with an old clutch form a toy tank (always save cool looking spare parts). The weight of the whole hinged assembly was still lighter than just the clutch parts!

I'm almost done building the hydraulic looking brace that goes perpendicular to the ramp. It will just free fall into place as the ramp lowers down. More pictures later.

When the ramp folds, it will travel along a gear driven threaded rod to extend and retract from the hanger deck.

post-2518-1192387144_thumb.jpg Brass and styrene hinged joints. The brass hinges are 1.5mm wide (very small, but strong).

post-2518-1192387225_thumb.jpg Machined brass parts (not used after all).

post-2518-1192387270_thumb.jpg Brass and styrene hinged joints.

post-2518-1192387324_thumb.jpg Assembled brass clutch (not used).

post-2518-1192387386_thumb.jpg Acetal plastic geared clutch (ratchets if too much pressure is applied or forced upon it).

post-2518-1192387491_thumb.jpg The 180 degree folding joint assembled and reinforced.

post-2518-1192387567_thumb.jpg The frame (as it will hopefully look) folding up.

The frames are light and the corners reinforced with epoxy for strength and styrene adhesion. Total length extended is about 25" or 63.5 cm long by 11" or 28cm wide. With something so big that folds up high into the top of the hull, weight is more critical than ever! That's it for now. C'mon Royal Mail, where's my gearheads! - MT

Posted

Great work, Mechtech, and an inspiring display of discipline and interpretation. Have you givin any though as to how and where you will display this creation? I for one would love to visit an air & space or naval museum and find your work there. At the Santa Monica Airport museam in California a 6 to 8 foot (not sure of exact dimensions) miniature of a Starship Trooper spacecraft sits not to far from a authentic full scale F-4 Corsair. Just puttin it out there....

Fortitude,

Rick

Posted

Thanks guys! And welcome Ahab and Juan Jovv! I think after all this work, I'm going to make a special shelf for it to sit on and occasionally play with it. And when my children turn about 35 (in thirty years), I'll let them play with it too :lol:. For now it's in about four pieces on every shelf! I probably will take it with me to modeling shows and stuff. They're always fun!

Royal Mail FINALLY finished all of it's strikes in all areas so I'm hoping to get my gear cases soon! I'll post videos. Thanks again! - MT

Posted

UPDATE 21 OCT 07

Thank God Royal Mail finally finished ALL of it's strikes. Yesterday I got the gearcase so I'm starting in on the folding mechanisms. The included photos cover the hydraulic support that's supposed to go down "perpendicular to the ramp" as described in the drawings and notes. Nothing really works on this (of course). The foot actually sits VERY loosely on the hydraulic cylinders and just hangs or swerves into position. When the ramp goes down (as shown), the foot swings out and the cylinders just sway wherever the foot goes. When everything moves,it actually looks real.

post-2518-1192970916_thumb.jpg Machined Tamiya ball joints (brass).

post-2518-1192970969_thumb.jpg One of the joints snapped into place and the other joints shown.

post-2518-1192971047_thumb.jpgpost-2518-1192971069_thumb.jpg In the end the brass parts went because they occasionally bound up. I replaced them with hinged ball joint-looking joints. Those work 100% every time and are lighter (there's the at word again). On to the actuators... - MT

Posted

Thanks guys! Sorry, I've been off line awhile. The gearhead is not strong enough that I got for the rear, so it will fold the short front piece and a larger gearhead for the rear two pieces. I'm having fun engineering it all though! - MT

  • 3 weeks later...
Posted (edited)

Update 11 November 07

Hey everyone, those stupid laws of physics have been getting in the way again! Long story short, there is not a powerful enough and small enough gear motor that I could find on the market to drive the folding mechanism and still keep a realistically low profile (and do it fast enough). Here's what I built and am not using (...again) and the updated version.

post-2518-1194764781_thumb.jpg Here's that beautiful gear motor (these little things rock!) and the clutched linkage I made for it. It's just not strong enough (with the voltage doubled and a bigger motor put on it too!).

post-2518-1194764870_thumb.jpg Here's the folding linkage with custom crafted ball joints. They worked great at least!

post-2518-1194764970_thumb.jpg Here's the whole assembly. A length of threaded (and machined) rod drives the arm to retract the joint. There's a problem with the fulcrum and power of a small profile motor. It works great at any angle OTHER than at 90 degrees when the ramp is fully open. Other than that, it works great!

post-2518-1194765150_thumb.jpg Another shot overhead.

post-2518-1194765214_thumb.jpg The fix... I took a 1/4" square brass tube and machined a slot all the way down it. The threaded rod will be inside and the nut will ride inside that too. Then a regular sized gear motor (hidden in the side of the ship) will drive the whole thing. The back segment of the ramp will ride that whole thing forward and backward with standard tracks on the other side for support. A lever will then catch and fold the middle segment within the same movement. The final segment will fold on it's own with a modified servo. Hitech recently came out with a metal geared low profile servo that should work (HS-82MG). It's tiny with the same torque as a standard servo. That's it for now. - MT

Edited by MechTech
Posted
OT, and sorry if it's been brought up before, but on a slightly similar vein:

20 foot long LEGO Yamato: http://gizmodo.com/photogallery/Yamato/ (incomplete, but still amazing)

He's got a site documenting the earlier stages of building it here:

http://www.geocities.jp/jun_brick/projectyamato.html

Wow, that is awesome. Love the Doreoman in the background.

Posted

Thanks guys for the comments and a HUGE thanks Dave for sharing that link! I love both the IJN and Space Battleship Yamatos! Someday I'll build my 52" long Nichimo kit!

UPDATE 24 November 07

I've finally got most of the problems worked out and I'm back on track (and short a little more money too :rolleyes: ). The retract and fold mechanisms work great. I've made everything kinda on the slow side for dramatic effect and realism. A giant ramp that size would not just flop down and quickly fold shut with any technology so that's what I'm shooting for. No video yet, but the whole sequence would take longer than what we can upload here so I'm trying to figure out what would be the best solution.

First the biggest problem; getting the ramp to fold over 180 degrees on itself (with a small / thin gear case and motor). post-2518-1195943847_thumb.jpg post-2518-1195943873_thumb.jpg post-2518-1195943911_thumb.jpg

First I took an awesome ultra thin servo (dual ball bearings-metal gears: see the box) and took one of those awesome tiny geared motors, a lot of machining and stuck them together! I got a smooth, slow and POWERFUL drive to fold the ramp. Don't ask how much it cost - I stopped counting :mellow: .

Next is the linear drive for the ramp. It's that "C" section of tube from my last post with ball bearings at either end. The recycled clutch from my previously made fold mechanism was reused.

post-2518-1195944227_thumb.jpg An overall view of the whole drive minus the gear case, motor and ramp.

post-2518-1195944260_thumb.jpg The reinforced front end and mounting bracket (grips CF framework).

post-2518-1195944355_thumb.jpg And the gearcase "interface." Everything works great and a little 30:1 ratio gear drive with only a RE-280 motor on it works great!

post-2518-1195944436_thumb.jpg That pole sticking out of the drive slips into the ramp hinge point. I just have to make the rail for the other side. It will move only to support the ramp and hinges, it will not be powered; only the side you see. The trick was making this all work and still look like it belonged on the model; not a toy. Everything works together, I just have to put it together permanently and record it on tape. Some ball bearings will probably be put under the ramp to help it glide over the edge of the hull better. An arm on the ramp will catch as it goes back and make the middle part fold upward. That is the next engineering step before it all works like it should. Talk to you all later. - MT

Posted

Amazing precision work MechTech! :blink: That boat is going to be awesome!

Posted

Thanks guys! So far so good with the other stuff. Posts later on in the week. - MT

Posted

Looks fantastic..! Can't wait to see the video.

Quick question, what diameter are, and where did you get your final-stage gears for the ramp-folder?

~Luke

Posted

I am following very close this topic because the way you are doing all mechanism are simple desings and very efficient, just like engineer must be... in addition to that I am a robotic engineer, I am really enjoy this process

Congratulations

Posted

First off, thank you guys for ALL the compliments. My regular job has little to do with this stuff; so it's a lot of fun for me to figure stuff out like this and make it work. Even my wife got in on the project with interpreting the drawings. The good and the bad of Miyatake's Daedalus drawings are that the mechanical parts are vague in how they work. That lets me make stuff up to a degree.

Isamu, if I get stuck, I'll PM you for help! ^_^

LL Cool VF1J, I told my wife what you wrote. She and I busted up laughing! All I can say is take stuff apart when you're a kid to figure out how it works. When you grow up (and your parents stop yelling at you for breaking their toaster), then you begin to start making your own stuff. Of course you're probably already grown up (is that you're toaster squirming in the background?). I'm still always taking stuff apart (some of it you've seen pictures of B)) ). Seriously, challenge yourself to build something new; you never know until you try!

IAD, the servo is a Hightech HS-125MG. It's awesome. 3Kg of torque (4.8v), dual bearings on the spline gear. All that for 10mm thin (see calipers in photo)! You can buy them all over. Just Google it. I bought mine at the local hobby shop. The smaller gearcases (also 10mm thin were from Solarbotics.com (Canada). In the UK, Technobots.co.uk sells them. Servocity.com is also an excellent source for ALL KINDS of servos (U.S. I believe)!

Chrono, The top will open up with either a servo or another type of screw and lead mechanism. It's on the very top of the hanger so weight will be the biggest issue; especially with the door construction.

I'll update with photos Sunday hopefully. - MT

Posted
First off, thank you guys for ALL the compliments. My regular job has little to do with this stuff; so it's a lot of fun for me to figure stuff out like this and make it work. Even my wife got in on the project with interpreting the drawings. The good and the bad of Miyatake's Daedalus drawings are that the mechanical parts are vague in how they work. That lets me make stuff up to a degree.

Isamu, if I get stuck, I'll PM you for help! ^_^

LL Cool VF1J, I told my wife what you wrote. She and I busted up laughing! All I can say is take stuff apart when you're a kid to figure out how it works. When you grow up (and your parents stop yelling at you for breaking their toaster), then you begin to start making your own stuff. Of course you're probably already grown up (is that you're toaster squirming in the background?). I'm still always taking stuff apart (some of it you've seen pictures of B)) ). Seriously, challenge yourself to build something new; you never know until you try!

IAD, the servo is a Hightech HS-125MG. It's awesome. 3Kg of torque (4.8v), dual bearings on the spline gear. All that for 10mm thin (see calipers in photo)! You can buy them all over. Just Google it. I bought mine at the local hobby shop. The smaller gearcases (also 10mm thin were from Solarbotics.com (Canada). In the UK, Technobots.co.uk sells them. Servocity.com is also an excellent source for ALL KINDS of servos (U.S. I believe)!

Chrono, The top will open up with either a servo or another type of screw and lead mechanism. It's on the very top of the hanger so weight will be the biggest issue; especially with the door construction.

I'll update with photos Sunday hopefully. - MT

OK, Mech Tech, you work on this project is really great, but if I can help you in anyway it will be my pleasure ^_^ my firend

Awaiting your update, take care

Posted
IAD, the servo is a Hightech HS-125MG. It's awesome. 3Kg of torque (4.8v), dual bearings on the spline gear. All that for 10mm thin (see calipers in photo)! You can buy them all over. Just Google it. I bought mine at the local hobby shop. The smaller gearcases (also 10mm thin were from Solarbotics.com (Canada). In the UK, Technobots.co.uk sells them. Servocity.com is also an excellent source for ALL KINDS of servos (U.S. I believe)!

ahhh, hitec, gotta love 'em. tough servos and a great price, what's not to love? i use one of their servos for steering my t-maxx and it's awesome. the original servo couldn't even turn the tires when the truck was not moving, but the hitec has absolutely no trouble at all.

on a side note, not sure if it would apply to your situation, but have you thought of using a screw drive for opening and closing? it's a great way to get a lot of torque from a small device, and the length of travel is only limited by the length of the threaded rod.

greg

Posted (edited)

Thanks everyone for your support!

IAD, sorry, I thought you meant the final drive gear chain. The final drive gear is a Hitech servo arm with the arm cut off and the core epoxied into an old Tamiya car gear. However, Servocity has these: http://www.servocity.com/html/servo_mount_gears.html. I made another one last year to rotate the drive motor pods on the lower hull.

Rotorhead, thank you for the help. I posted this earlier: "Chrono, The top will open up with either a servo or another type of screw and lead mechanism. It's on the very top of the hanger so weight will be the biggest issue; especially with the door construction." You are right. The screw drive is the way to go. Helping someone fix a flat tire gave me inspiration after using a jack with a screw drive.

Thanks Isamu for the offer!

UPDATE 12 December 07

Well, at least a small one anyhow. Good news and bad news. The bad news is that when I put a rail on the other end to support the ramp, there was too much drag and the ramp kept going back at an angle causing the drive to drag badly. I thought from the start I'd put the drive down the center (one drive, one motor, less weight). I tried to put the drive on the side for better appearance and now another setback. The good news is that I am putting the drive in the center with two light weight rails on the ship sides as guides. With the drive in the middle, it will always pull/push from the center solving my problem and keeping the weight and complexity down.

post-2518-1196628174_thumb.jpg Where the drive will go (blank tube showing location).

post-2518-1196628220_thumb.jpg I cut off the angled supports and soldered two square tubes on either side. The tubes are almost flush with the edge, but not fully to allow the edge of the deck to rest on them. The drive will sit flush with the floor in the center of the hanger deck. I didn't want anything in the middle of the floor; but oh well! Note the modified gear case in the photo (flattened end). The motor is a rewound Mabuchi 280 with added ball bearings. I think I will go with a Mabuchi RS-555 (12v) motor instead. Lots of quiet torque and no gears at only 3v! It just weighs more! Now I gotta go make it fit in the deck nicely and cut carefully! - MT

Edited by MechTech
Posted

no prob, mechtech! i'd not seen the earlier post, but a car jack is exactly what i had in mind when i posted. if i come up with another good idea that you'd already thought of, i'll let you know! ^_^

~greg

Posted

I love the sense of normality you give your pictures, You know the large boat on the kitchen worktop next to the plates with your Daughters bike in the background. Makes us all think we should have one.

Posted

Thanks rotorhead. I'm ALWAYS open to ideas. You guys have given me some great ones that I've used!

BigF, yes I think we should all have a "My Little Pony Bike." Those of us that are older though can remove the training wheels/stabilizers :lol: Seriously though, thanks! A sense of normalcy is a good thing! - MT

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