Greek Bireme by bensid54 - FINISHED - RADIO

[bensid54]

Both oar racks complete next to make the second part of the oar rack, that part will be directly involved with the mechanics.

[bensid54]

The picture with the darker wood on top of the lighter wood is Sepili hardwood glued to hobby grade aviation plywood that is going to become oar ports in the end. The other pictures of the two 1/4 plywood pieces glued together is what the oar rack will be attached to, the next posts will give a better idea of how the mechanics will look.

[bensid54]

The start of the removable oar ports, they will be lined up using dowels glued to the oar port planks and the oar port planks will be  held in place with Velcro pads on the bottom, the removable upper deck will have three sets of Velcro pads per side to hold the top of the oar ports in place and hold the upper deck in place on the ship. The oar port planks will be trimmed to size once the planks have been fitted. The holes you see in the bulkheads are for the upper deck alignment pins or dowels. 

[bensid54]

The new improved plastic oar rack and altered oar eyes. I scrapped the wood oar racks because I don't think they will stand up for long. Still some alterations to do I will explain more at the next posting.

[bensid54]

I have to seal the hull at this point even though the rest of the wood work isn't done because I need to locate the water line when it's fully loaded. The build is plank on frame with the planking side by side so there are gaps or cracks where water could get through so I make up my own filler. I'm sure this is an old trick but I never heard of it before, what I do is produce some sanding from the wood I'm building my boats from mix it with wood glue and then force it into the inside of the hull filling all gaps and cracks the end result is a stained, sealed interior of the hull and little blisters of my mixture on the outside of the hull as you will see in the pictures.

[bensid54]

The first picture is the bottom of the hull sealed, well it turned out a leak was found in the starboard bow of my ship. The second picture is the load it will carry at sea plus two lypo to make up for the missing mast and unfinished staining and painting. The next picture shows the deck in place before placing in my tub to find out how low it will sit in the water so I can gauge the parameters the oars will travel in. The last picture shows my ship in it's first time at sea.

[bensid54]

Time to start making the "racetracks"

[Louie da fly]

This is a fascinating build, particularly the mechanics of getting the oars to actually row. Following this with great interest. Oh, and the ship is beautiful, too.

[Omega1234]

Hi Ben

 

The shot of the ship in the tub gives a good idea of the actual size.

 

She's bigger than I thought. Looks great, nonetheless.

 

All the best

 

Patrick

Edited January 18, 2015 by Omega1234

[bensid54]

Thanks for the compliments! I'm going to change racetrack make the radius of the corners a little bigger, when I woke up this morning it occurred to me the corners may put too much strain on the oar racks.

[bensid54]

Machined the nuts and bolts for the race track followers, they look rough because I used a rough stone in my Dremil while spinning them on the lathe, mounted nuts, bolts, spacers and bearings on oar racks.  I machined the nuts and bolts down so they would not get in the way of the race track. The picture with the white bag is my supply of oar retainers they will be split and cut in half.

[bensid54]

These two pictures show what the final look of the oar racks will be.

[bensid54]

The drive chain and the start of the drive sprockets and reinforcing sleeves.

[bensid54]

What's under these will soon be six ply homemade hardwood plywood.

[Omega1234]

Hi Ben

 

Looks like she's coming together beautifully, particularly with work now commencing on the oar mechanism.

 

 

Great progress, so far.

 

Cheers

 

Patrick

[bensid54]

Thanks Patrick The oar mechanism will be made to function out of the hull and I plan on making it removable for repairs or replacing parts that don't hold up. Hopefully I will have a video of it working in the next couple of months.

[bensid54]

Change of plans for the drive system, originally I was going to make my own chain and sprockets but my lathe is too crude for what I need to do. I ordered sprocket and chain from Servo City which arrived today, the chain came as 196 separate links that had to be clipped together and now I can begin to make the oar drive mechanics. The is the part of the build I have been most anxious to start on and the part that is central to all my work.

[bensid54]

Building the sprockets, the deep ones will be motor driven the shallow ones chain driven. The black sprocket spokes will be mounted in slots I will cut in the disc faces. The opposite side of all discs will be slotted to drive the oar rack with a spring pocket to force the rack away from centre. The deep discs will have a reinforcing band with a set screw to fasten it to the motor and the shallow ones will be mounted on a bearing. 

[qwerty2008]

That chain looks almost identical to Knex chain, I know from experience how much of a pain in the fingers it can be to assemble I have close to twenty feet of the smaller size Knex offers.

 

 

lextin.

[bensid54]

I checked out the Knex chain and see that the links are open on the bottom and could be easily pulled apart where as the ones I have are closed at the bottom which makes them much stronger. The motors are 75 to 1 ratio so there likely will be a need for strong non rusting chain.

[qwerty2008]

After reading your post I looked at the servo city chain and see the difference, the links are backwards.

 

 

 

 

Lextin.

[bensid54]

Slotting the discs and fitting the gears in place, still more to be done but I'm starting to see the light at the end of the tunnel.

[bensid54]

These sprockets are not positive enough so I have ordered better ones. 

[bensid54]

My homemade African Sepili hardwood plywood of which I have started cutting my oar mechanism "race track".

Edited February 16, 2015 by bensid54

[bensid54]

Racetracks glued into position on motor board and motor board temporarily placed in hull.

[bensid54]

The oar racks in place and the one picture shows the guide bearing as it sits in the racetrack when it's done that bearing will follow the inside contours of the racetrack.

[bensid54]

My proper sprockets arrived the other day and are now mounted on the drive discs. The discs with the raised centres will be mounted on the motors output shaft the other two will be chain driven, all the discs will act as thrust surfaces and guides for the oar racks . Still some fine tuning to do to the drive discs and I need to alter the motor board to make the best of my oars range of travel.

[bensid54]

Motor board after cutting out channels for the chains and sprockets, the chains will be running level with the bottom of the motor board and about a 1/4" above the hull bottom. The hull section and upper deck after some sanding and altering to allow free space for the oars to travel in. The oar ports once again will be redesigned to improve alignment, leverage and travel, still a lot of woodwork to be done but I hope to have it in the water by the end of the summer. 

[Omega1234]

Hi Ben

 

I must admit to being really intrigued about how this is all going to come together, so I'm really looking forward to the next installments.

 

All the best!

 

Cheers

 

Patrick

[bensid54]

Slotted the faces of all four drive discs then fastened the sprockets to them with four wood screws for each sprocket, next will be to drill the slot and mount springs to force the oar rack rollers to follow the race track. In two of the pictures they are sitting side by side, notice the sprocket teeth compared to the slot in the disc face are the same place location wise, the reason for this is so that I can time them in pairs to make their movement equal. In two pictures there is a brass sleeve on one of the discs pictured those sleeves will be drilled and threaded for a secure attachment to the motors, the ones without the sleeve will be machined to fit a sealed bearing backed by a thrust bearing. After drilling and machining I will be making mounts for both the motors and driven discs and then assembly of the oar drive mechanism will come together.