August 10 Speed Trials & Build Session

Discussion in 'North Atlantic Treaty Combat Fleet' started by Bob Pottle, Aug 10, 2008.

  1. Bob Pottle

    Bob Pottle Well-Known Member

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    Ralph, Tom, his friend Kip and I got together at Sullivan's Pond today and ran speed tests on the AC HMS Black Prince with three sets of props. When running as an IRCWCC model it used Mabuchi 380RH motors, Rivabo 3 blade, 30mm props and required large drag discs ahead of the props to keep it at 26 sec/100'.

    To our great surprise it ran at 30sec/100' with the small surplus 'Toy' motors and Rivabo 4 blade, 30mm props. It had been expected to be slower than the allowed 37 sec/100'. We switched to the original 3 blade props thinking it would slow down with less blade area, but the props turned faster and the higher rpm pushed it up to 25 sec/100'! Next we tried a pair of plastic Graupner 3 blade, 30mm props with much smaller blade area and speed dropped to 27 sec/100'. Still 10 sec too fast.

    The model ran and turned well, but was bow heavy, which hsd contributed to sinks in NABS battles because the pump is aft and sometimes primed too late. The previous owner's equipment layout will be revised to correct the trim. Ralph took a turn at the helm of his new command (on loan until he builds a new ship) and Kip had his first experience operating an R/C warship. He's now interested in the hobby.

    Scott couldn't attend but continued to work on the HMS Abdiel at home and will run speed trials later.

    Black Prince's speed trials will be run again when the two smaller prop sets arrive from Lowell Briggs (expected mid-week). Whatever works for the Black Prince should be OK for the Minotaur, which is slightly heavier and has almost the same hull (stretched by 1").

    After trials Tom and I worked on the WWI Class 2 monitor HMS Erebus, transferred to his command from mine last month. We'll continue to work on it this week and next, and hope to complete it in time for the August 14 battle.

    Erebus and sistership Terror are the only warships I'm aware of that had bow and stern rudders. Erebus is expected to turn better than HMS Terror, which didn't have the bow rudder but had the smallest turning circle in the NABS fleet until HMS Gorgon came along. Parts of the scrapped 1995 Terror are being transferred to her sistership.

    Later this week Tom's T2 tanker will be in the drydock to complete the internals. Only a few hours work is required to have the cargo ship operational, wearing period Esso colours.

    Bob
     
  2. crzyhawk

    crzyhawk Well-Known Member

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    Bob, have you thought about taking some of the pitch out of the props? Mine in the Invincible are practically flat at the moment. I plat to get the 550's out of there and run some smaller motors. I'm also looking into ESC technology. At the treaty nats this year while running Phil's USS Newport News it was a pretty big advantage to be able to throttle my speed rather then have the all or nothing of the MAG throttle. It also made getting on speed far far easier, not to mention more efficient electronically.

    I'm going to start experimenting with one in my USS Salem, and if I get it down, the MAG in my Invincible will be kicked to the curb.
     
  3. Bob Pottle

    Bob Pottle Well-Known Member

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    Mark,
    These props aren't like some other types I've seen on combat models, having blades soldered into deep curved slots on their conical hubs. That makes the pitch almost impossbile to change without wrecking the prop (I've destroyed one in the attempt and they aren't cheap!) The curved slot determines the pitch and the blades are relatively thick with an airfoil cross-section, so trying to bend the outer part of the blade to a different pitch distorts or breaks it.

    I'm pretty sure the smaller blade types now in the mail will get the speeds of the armoured cruisers and the small Class 1 ships close to their Treaty speeds. Final tweaking can be done with drag discs on the driven shafts (all of these models have only 2 shafts).

    The pump capacity issue was solved for ships of battlecruiser size and smaller after a couple of weeks of testing. I'm confident we'll solve the speed issue in the near future.

    Bob
     
  4. Bob Pottle

    Bob Pottle Well-Known Member

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    Sunday's build session has become ongoing. Tom decided to finish the Class 2 monitor HMS Eerebus before Nagato, so we'll be working on it over the next two weeks and will also complete his Esso tanker. The T2 needs wiring and ballasting before trials.

    Last night we made the plexiglass hatches for the Erebus' fiberglass deck, started repairing the tower bridge transferred from HMS Terror, installed the flex cables for the bow and stern rudders and figured out where to put the internals.

    Tomorrow we'll install the BB cannon and 12-sided barbette, make the aft superstructure (into which the pump will protrude), and hopefully have time to install the drive motors and pump.

    Work resumed on HMS Vanguard. The very thick hull (1/4" sides) was made in 2005 after a NABS Musashi broke 1/8" ribs in my old Warspite (and in other models) with a powerful set of BC guns. No need to be concerned about that anymore. [:D] It took me a weekend and eight cut-off wheels to cut out the hull 'windows' last year. [xx(]

    The Vanguard's thick hull sides pulled inward at deck level while curing so seven 5/32" thick brass rods are being inserted in drilled sockets as hull spacers. These will keep the hull sides at the correct beam and are load bearing so there will be no lateral stress to deform the fiberglass deck. The deck will go on after the prop shafts and rudder have been installed.

    Finished the gun shields for Scott's HMS Abdiel. They're at my office waiting to be picked up later this week. Looks like Abdiel, Von der Tann, Minotaur, Black Prince and Erebus will be battling on the 24th.

    Bob
     
  5. JasonC

    JasonC Active Member

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    im doing the finishing touches on New Jersey i may have her done in time ill know if i can make it today(i get me hours for that week today).
     
  6. Bob Pottle

    Bob Pottle Well-Known Member

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    That's good news Jason. Is your father going to run the NJ? With Tom running the Erebus instead of the Nagato the Axis are greatly outnumbered! We'll have to divide the fleets to better balance the combat units: 'blue and red fleets' instead of Axis vs Allies.

    Bob
     
  7. JasonC

    JasonC Active Member

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    im gona run the NJ he will be running the vdt i believe, and i agree 100% with RvB
     
  8. Bob Pottle

    Bob Pottle Well-Known Member

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    Guys,
    Let's see how the combat units stack up for the first battle.

    As Mike Deskin suggested we can keep the armoured cruisers' IRCWCC units instead of the lower Treaty units (2.5) under a local rule. Mike and the other treaty founders are going to review the AC's stats, which suggest they could be equivalent to WWII heavy cruisers (Class 3). Most had greater displacement, much heavier armour, and equivalent weight of broadside to the CAs.

    New Jersey 7.0 units
    Abdiel 1.5 units
    Black Prince 3.0 units
    Minotaur 3.5 units
    Erebus 2.0 units
    Von der Tann 4.0 units

    That gives a total of 21 combat units, so 10.5 units per team. Possible Red and Blue fleets are:

    Blue - New Jersey, Erebus, Abdiel (10.5 units)
    Red - Von der Tann, Black Prince, Minotaur (10.5 units)

    What do you think?

    Bob
     
  9. JasonC

    JasonC Active Member

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    ok sounds good now what i need to know is the co2? do we have any cause i cant run alota battles off of the 3.5oz for vdt very long.
     
  10. Bob Pottle

    Bob Pottle Well-Known Member

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    I tried to call Steve last night but he wasn't home. Will try again this evening. I hope to be able to use the small NABS fill station. If we can't access the CO2 tank I'll fill my 3 small CO2 bottles and a 7 oz. bottle. I'm converting Black Prince to CO2 cartridges so I'll only need one small bottle to supply Minotaur for a 2 sortie battle. That'll give us 3 spare bottles, and I may buy and fill a fourth one at Banshee Paintball.

    Erebus, Abdiel and Black Prince use CO2 cartridges so only VdT, NJ, and Minoatur need bottles. What size bottle does NJ have? It should have room for one large enough for 2 sorties.

    I'll let you know if we can get the CO2 from Steve.

    Bob
     
  11. Bob Pottle

    Bob Pottle Well-Known Member

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    Good progress on the Erebus last night. Tom salvaged the plexiglass core structure from sistership HMS Terror's bridge and reskinned it with new 0.5mm styrene panels. He replaced damaged and missing sections of splinter screens on the bridge platforms, repaired the compass platform and missing running light brackets. It will have as much detail as Terror did in 1996.

    I made another plexiglass hatch for the fiberglass forecastle deck and started on the aft superstructure, completing it except for the level 2 roof and a platform on the level 1 roof for a pair of Carley floats. The superstructure should be done tonight.

    I may be away for a couple of days but Tom will install the motors, pump, battery, and sheet the hull. On Monday we'll get together to install the superstructure, BB cannon, barbette and pneumatics. We hope to finish the Erebus Wednesday, then the T2. The T2 needs only a couple of hours work before trials.

    New (smaller) props arrived yesterday for the Black Prince and Minotaur. The ACs will run more trials and should have the speeeds dialed in by the end of the weekend.

    After the first battle Gorgon and Prince Robert will get smaller props and be slowed to Treaty speeds. New radio crystals are being ordered so one of them can be used as a loaner with one of my spare radios.

    Lateral hull braces (5/32" brass rods) were installed in Vanguard's thick deck stringer to keep the beam in a match with the plan along the entire length of the hull. Rudder hardware has been received. Now waiting for 12" long prop shafts and for the rudder to be made and installed before the deck is glassed on.

    The shipyard is busy!

    Bob
     
  12. bb26

    bb26 Well-Known Member

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    So when do you plan to have your first battle?
     
  13. HMCS

    HMCS Active Member

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    First battle is this coming weekend. Looks like New Jersey,VDT,Black Prince,Minotaur,Erebus and Abdiel. Hopefully Rob and his Konig will make it out as well.
     
  14. bb26

    bb26 Well-Known Member

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    Have you settled on a location for the battle?
     
  15. Bob Pottle

    Bob Pottle Well-Known Member

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    Konig will be there. We'll meet at the Grove - time to be decided - and proceed to the alternative site if the Grove is too busy.

    HMS Erebus update: Tom and I put in another 4 hour night installing the barbette and BC cannon, the rebuilt bridge and funnel from HMS Terror, and large aft superstructure. Motors are in along with the bow and stern rudder system, most of the armour and two servos.

    Tomorrow Tom will finish the armour, install the pump and start sheeting the hull. On Wednesday we'll do the wiring, pneumatics and finish the sheeting. Should be finished on Saturday. Whew! This has been a fsat build.

    Bob