Another 'Presto'

[Spankbucket]

Hi all

I have just commenced my model of the 'Presto', this one in 1:76 scale.

I wanted a boat about 3 feet long so this scale fitted perfectly.

I intend to make the paddles from scratch in styrene etc. but probably won't attempt to do the feathering feature as I am not engineer enough to tackle the complexity. With my experience on the 'Queen of the Esk/Josie Olsen' I am confident I can get a workable result if I stick to the basics.

I'll keep you all posted.

My inspiration has been Don's superb model excellently displayed and described on this site. I have purchased a copy of the plan from the same US EBay seller and scaled it appropriately.

Any recommendations/suggestions from you all would be appreciated.

Cheers...Bernie

[marinemole]

Very organised and methodical start. Look forward to another build of the Presto

Andy

[Talisman]

Any recommendations/suggestions from you all would be appreciated.

Cheers...Bernie

Just one from me .... keep us posted! Lovely looking boat! Made, maybe slightly, more difficult at a smaller size?

Look forward to hearing more!
Regards,
Kim

[Spankbucket]

Thanks for your positive comments Andy and Kim

Yes I guess it is slightly more complicated in a smaller scale as the paddles have to be built from scratch. But the materials I will use are easier to work and correct any mistakes.

The keel is obeche and the frames/ribs are balsa. The planking will be balsa and the hull will be skinned in fibreglass coated in polyester...in other words...just like my previous effort on the 'Josie Olsen' which was really good experience.

I certainly intend to post as regularly as I can as long as I am making progress...I generally part-complete projects, put them aside and then get back to them later.

I was thinking of independant drives to each paddle and incorporating an Action Electronics controller. Now that I can see the narrow beam of the hull I may have to rethink this.

Cheers...Bernie

[Spankbucket]

Hi all

Progress is steady and here are some photo's:

Pic 1 shows the frames cut from 3mm balsa on my small bandsaw. The patterns were cut on my PC/CraftRobo. It's a pity I cant afford a laser cutter as the result is still only as good as one's accuracy/skill level and mine is pretty average!

Pic 2 shows the frames cut to shape including slots for a 'Sheer Clamp'.

Pic 3 shows a few frames glued to the keel using a small square to get them true. I also have a smaller engineer's square which proved invaluable as the frames are rather close together.

Pic 3 shows the finished assembly. I decided to attempt a curved deck and you can see the simple card template I used to mark this into the frame patterns. I also incorporated the bulwarks into the frames although not to scale.

Hope I'm not posting too much detail.

Cheers...Bernie

[marinemole]

Hope I'm not posting too much detail.

Cheers...Bernie

Never too much detail. Keep it coming. Nice start.

Andy

[Spankbucket]

Hi all

I decided to plank the hull in 1/32" (0.8mm) sheet balsa. Mainly because I didnt narrow the frames to accept anything thick so the hull should come out near to scale (hopefully)?

Although thin, the close spacing of the frames and the final fibreglassing will give me a resilient hull....I hope!

When I restudied the plans I realised that the bulwarks I had incorporated were redundant between the central frames so they were eliminated.

Here  a couple of pictures:

Cheers......Bernie

[Talisman]

Hi All,
Bernie, looking good, the extra thickness / beam on the hull may throw her ever so slightly out of scale but the benefits are as I’m sure you know already extra beam and draught which usually equals more stability... Is there anybody alive to pull you up on the modeller’s licence?

Looking great so far!

I'm interested to know more about the '' Shear Clamp slots''

Regarding the ownership of a Laser Cutter... Your right it isn’t cheap but I do offer the service ... however, you and your own tools seem to be getting along just fine. ... Me, on the other hand, well I’m just plain overworked lol.
What is the problem with cnc machines working 24/7 my neighbours seem to have other ideas.. Like sleep and other luxurious ... lol

Keep going I am enjoying this.
Regards
Kim

[Spankbucket]

Hi Kim

Thanks for your positive comments.

I had never heard the term 'Shear Clamp' until I read the 'Josie Olsen' instructions....you're never too old to learn

Going back to my model plane days I then knew it as a stringer...but in the case of a boat one that defines the shear line. The slots were to position it in.   However I did have some bother as inaccuracies crept in which I had to botch round!

As an ex computer career person I have always fancied a CNC machine of my own so that I could, like you, go from CAD to cut...maybe one day!

Today I have been hand sanding the hull and I also made the rudder from brass rod and styrene sheet.

Cheers..Bernie

[Spankbucket]

Hi All

Slow progress today and will be this week as my wife is going into hospital to have her gall bladder removed. Assuming the op goes ahead as planned on Wed I'll be nursing a lot of the time....now where did I put that 'nursie' uniform?!

Sanded the hull today ... it is extremely thin and the ribs show through like a porcelain cup. I gave it a couple of coats of clear dope to stiffen it up before a bit more sanding. I'll probably fibreglass it this week.

Here are more photos:

1. Rudder made from salvaged styrene from a Ferrero Roche box... it's a wonderful 'free' material as are broken CD cases.

2. I am seriously considering two cheapo motors and paddles that I salvage from one of my kids toys many years ago thinking they would come in useful. That day may have come! (They were the fans out of blowers from a sailboat game). Although nothing like the prototype paddles they have a diameter suitable for  a starting point and have plastic bushes to fit on the motor shafts so I shall seriously again consider twin independently controllable motors. Has anyone got experience of this that I could benefit from?

Cheers......Bernie

[Taifoon78]

...

Pic 3 shows the finished assembly. I decided to attempt a curved deck and you can see the simple card template I used to mark this into the frame patterns. I also incorporated the bulwarks into the frames although not to scale.
...

Presto have a very sharp hull lines. Like a destroyers some time later. Good job.
 

[Spankbucket]

Yes...built for speed just as a destroyer. She apparently did 20+ knots on her sea trials.

Please have a look at Don's posts on this ship.....he has done considerable research which he has posted here.

His 'Presto' was my inspiration!

Cheers.......Bernie

[Spankbucket]

Hi all

After studying the various posts on the subject of paddles and drive methods I looked up double/motor gearbox combinations for model cars.

I found this:
http://www.eBay.co.uk/itm/Tamiya-Twin-Motor-Gear-Box-model-car-tank-robot-89915-/140590131133?pt=UK_ToysGames_RadioControlled_JN&hash=item20bbd327bd

"Brand New TAMYIA Japan series no. 89915, Twin Motor Gear Box  , Tamiya’s twin-motor gearbox consists of two independent motors and gearboxes in one compact housing, making it perfect for small robots and tank chassis . You can assemble the gearboxes to have a 58:1 or a 204:1 gear ratio., motors included. The equivalent tamiya model but in grey color housing box is series no. 70097 . Brand New, good quality Japan manufactured. Highly accurate static Display Model. "

Has anyone had experience of these and is it likely to be a valid choice for what is a very light boat?

Many Thanks

Bernie

[Dave R.]

Check this out from Pololu Robotic & Electronics;
Low-Voltage Dual Serial Motor Controller + Tamiya Double Gearbox Combo, $39.95.
I'm not sure it's exactly what you need... could be?
I didn't find any dimensions but I bet you could call.
The dual geared motors alone are on sale for $9.25.

Dave

[Spankbucket]

Hi Dave

Thanks for that...I had been looking at their site this am and they look very comprehensive and professional.

But..I had missed the Dual Motor Controller....I had been thinking of using an Action Electronics mixer and 2 x ESC's. This item might be an alternative ... I'll go check.

Cheers Bernie