Topic: OceanWorks Jet drives for 1:12 scale Shannon Lifeboats (Read 40021 times)

RST · « **Reply #25 on:** September 04, 2019, 07:08:25 pm »

Only now you said! I used to have a big ice cream tub of stuff like that. Before eBay took-off you could buy random bags of stuff like that for a few quid that would last a decade or more. I had to ditch mine de-cluttering when I almost lost my house when the oil industry crashed. Don't see those suppliers anymore. Old school and China on eBay and whatever else took over since unless you want to make yourself.

Taranis · « **Reply #26 on:** September 04, 2019, 07:21:57 pm »

Cool I'm glad someone does

thanks Rich

I had some K&S brass tube, think its 1/8th internal. Then I found some styrene tube that fitted inside it (convenient) and tight

So I abraded the styrene and applied slow CA before pushing it in quick! Making the parts only a little over length to begin with! squared off on bench sander after.
Then I tapped 2mm from both ends.
The longer ones pictured are the better product

TIP I used silicon grease on the tap and backed it out frequent to clear the swarf

Taranis · « **Reply #27 on:** September 04, 2019, 08:13:25 pm »

Instead of Lions 2 Christians nil

Servo rods 2 resistance nil

https://photos.smugmug.com/photos/i-dhgRvtB/0/b16a6d26/1920/i-dhgRvtB-1920.mp4

https://photos.smugmug.com/photos/i-hjTpVcj/0/e9220d0a/1920/i-hjTpVcj-1920.mp4

RST · « **Reply #28 on:** September 04, 2019, 08:24:38 pm »

Andy,

Which bit are you pushing -left, right or bucket up/down? Will it be the same powered, and how do you convert your "muckle" hand of god bolted to a human been to a servo pushing with a little 1" lever on a 5v micro motor? You're all pushing such high power motors these days also. I can push/poke things as much by hand, but there's not much comparison apart from saying it's no friction "dry" -which is always good to start with.

Rich

Taranis · « **Reply #29 on:** September 04, 2019, 08:28:32 pm »

I'm applying very much less pressure than the metal gear servos can deliver. Trust me I've done this before

Whichever the servo rods don't bend

regardless of my muckle

RST · « **Reply #30 on:** September 04, 2019, 08:30:30 pm »

Quote

I had some K&S brass tube, think its 1/8th internal. Then I found some styrene tube that fitted inside it (convenient) and tight

So I abraded the styrene and applied slow CA before pushing it in quick! Making the parts only a little over length to begin with! squared off on bench sander after.
Then I tapped 2mm from both ends.
The longer ones pictured are the better product

...I've kind of done the same before. At 2mm / M2 I've used the "hod it and bodge it" approach. Filed a point on a bolt and used that to cut the thread into the plastic tube (takes allot longer than using a tap, but sometimes I didn't have one). Bit of spit on the threads (surprised how well spit works for allot of things!). Rough as a badgers ar**, LoL. Wouldn't consider that for anything at work obviously.

derekwarner · « **Reply #31 on:** September 05, 2019, 02:28:08 am »

Andy....following along as always

.....I do have direct experience with hydraulic servo control systems in Naval Missile Launchers and Gun Mounts, however have no real understanding of control systems for water jet drives small marine craft

1. what type of movement controllers do the full sized water jet drives utilise for linear movement?
2. when we see in your models video, from full port to full stdb movement of each jet nozzle is achievable literally in fractions of a second
3. I can understand this speed of movement is relative to the radial displacement of the servo shaft & arm length x buy any mechanical ratio by linkage arms etc
4. do the speeds of movement represent scale movement?
5. are you concerned with twitchyness in the function of the craft?

I am sure all of the aeroplane and helicopter model pilots cope with these question

however I have zero knowledge or experience in either

Derek

tizdaz · « **Reply #32 on:** September 05, 2019, 07:17:36 am »

Quote from: derekwarner on September 05, 2019, 02:28:08 am

1. what type of movement controllers do the full sized water jet drives utilise for linear movement?
2. when we see in your models video, from full port to full stdb movement of each jet nozzle is achievable literally in fractions of a second
3. I can understand this speed of movement is relative to the radial displacement of the servo shaft & arm length x buy any mechanical ratio by linkage arms etc
4. do the speeds of movement represent scale movement?
5. are you concerned with twitchyness in the function of the craft?

Derek

Im guessing the speed of nozzle movement is determined by how quick you are moving the lever on the TX? also with most newer types of TX's there is an option that lets you adjust the servo speed direct from the TX on-the-fly, so your servo motor will travel full rotation at a set speed no matter how fast you flip the lever :)

Taranis · « **Reply #33 on:** September 05, 2019, 07:29:09 am »

Yes the speed is proportional to how fast or slow you operate the stick

Thank you both

Taranis · « **Reply #34 on:** September 05, 2019, 08:12:36 am »

Burning the midnight oil last night.
Holiday time! first stop Tan Hill the highest pub in England

When I'm back the new trim tabs will be fitted

Taranis · « **Reply #35 on:** September 05, 2019, 02:32:36 pm »

Videos without the servo tray fixed down
https://photos.smugmug.com/photos/i-nJWp6PF/0/9fef0539/1280/i-nJWp6PF-1280.mp4

https://photos.smugmug.com/photos/i-vs5LKp4/0/5d7bfebc/1280/i-vs5LKp4-1280.mp4

https://photos.smugmug.com/photos/i-TJRLjJG/0/1c55c1b0/1280/i-TJRLjJG-1280.mp4

Taranis · « **Reply #36 on:** September 10, 2019, 05:56:45 pm »

I just want to kill a flat spot in my holiday by making a statement regarding OceanWorks and these drives in particular. I know people are buying them and I want you to know that you may not get exactly what you see pictured in this R&D thread.
The reason for this is that OceanWorks don’t sit on their hands and if I or they see room for improvement they make it happen quite quickly

Can’t wait to be back and get mine running

Charlie · « **Reply #37 on:** September 17, 2019, 05:18:05 pm »

Hi Andy,

What motors are you fitting to the OceanWorks Jets?

Charlie

Taranis · « **Reply #38 on:** September 17, 2019, 05:29:16 pm »

I have Turnigy SK3 35:42 1250kv in stock so will use these
My other Shannon uses the 1185kv version
Best with 4s LiPo

dpbarry · « **Reply #39 on:** September 18, 2019, 10:46:54 am »

Have you any preference between the two?

Declan

Quote from: Taranis on September 17, 2019, 05:29:16 pm

I have Turnigy SK3 35:42 1250kv in stock so will use these
My other Shannon uses the 1185kv version
Best with 4s LiPo

Taranis · « **Reply #40 on:** September 18, 2019, 10:48:08 am »

1185 is already sufficient

dpbarry · « **Reply #41 on:** September 18, 2019, 12:38:13 pm »

Cheers.

That's great. Just looking at them on HobbyKing. Not much of a difference in terms of price - ~£2

Declan

Quote from: Taranis on September 18, 2019, 10:48:08 am

1185 is already sufficient

Charlie · « **Reply #42 on:** September 19, 2019, 05:08:11 pm »

Thanks for the info. I have ordered a pair of 1185kv.

Charlie

Quote from: Taranis on September 18, 2019, 10:48:08 am

1185 is already sufficient

Taranis · « **Reply #43 on:** September 19, 2019, 05:17:56 pm »

The videos of mine on the water are with 1185 and easily over scale speed with 4s LiPo
Whether the OceanWorks impellers being only two blade will make any difference I do not know yet but the prop shop brass ones will fit.
I bought them already for the Kehrer jets that I have not used in favour of the IMHO more complete package from OW

Kehrer having no look alike buckets no trim tabs and no intake grills

Taranis · « **Reply #44 on:** September 21, 2019, 04:58:47 pm »

Wife just gave the thumbs up to end our touring so I’ll be home tomorrow keen to continue

Taranis · « **Reply #45 on:** September 23, 2019, 11:36:34 am »

First day back and my tail is wagging

Already today some big changes.
I've rotated the equipment tray 180 degrees so there is now space for the ESC's nearer the motors.
I've replaced the DIY 2mm couplers as I found a FANTASTIC supplier for little wonga.
I've replaced the servo rod keepers for a better easier to fit and remove type same as my other shannon.
The tray will be made removable with minimal effort.

Now the OpenTX operating system for Taranis has all escaped my grey cells so I will be doing it again from scratch for this new model.
To allow full future expansion and channel mixing we need more than 8 channels so as before I'm using 2 8 channel RX
Straight away 8 channels are used by 6 servos and 2 ESC before any other considerations.
I'll be setting them up as port and starboard 1to4 9to13 initially. Lighting and radar are extra but I'm not fitting pumps this time not even for cooling as I don't think they get hot enough

dpbarry · « **Reply #46 on:** September 23, 2019, 11:52:13 am »

Hi Andy.

What about fitting temperature sensors (temporarily) to the ESC's and feeding it back using telemetry using the OpenTX setup?

Just a thought - to gauge what temperature are actually being reached.

Declan

Taranis · « **Reply #47 on:** September 23, 2019, 11:55:34 am »

Already did all that on the other hence I know its not necessary

Taranis · « **Reply #48 on:** September 23, 2019, 01:56:51 pm »

The most recent version of the drives now have 4 motor mounting screws and the mount is now connected to the intake at the bottom to prevent twist.

My upgrade to negate torque twist is this addition of a cross brace and my top motor mounts are now fixed to this

dpbarry · « **Reply #49 on:** September 23, 2019, 02:15:34 pm »

I had a feeling I was about to teach you how to suck eggs!

Declan

Quote from: Taranis on September 23, 2019, 11:55:34 am

Already did all that on the other hence I know its not necessary

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Author Topic: OceanWorks Jet drives for 1:12 scale Shannon Lifeboats (Read 40021 times)

RST

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