Search found 24 matches

by Colin Helliwell
26 Oct 2017, 19:25
Forum: General IOM
Topic: Battery musings
Replies: 2
Views: 1315

Battery musings

A few questions on battery power for receiver+servo/winch - inputs would be received with interest: What battery capacity (and voltage) do people use? NiMH, or LiPo? What peak current is needed? LiPo has a better energy density than NiMH - are there 'power packs' available which will fit in a typica...
by Colin Helliwell
24 Mar 2015, 19:18
Forum: General IOM
Topic: Spar form/size
Replies: 2
Views: 2403

Re: Spar form/size

Thanks Dave. I've done some more trawling around, and am reading about 'jacklines'/'luff-lines' on round/sleeved masts. For others looking into the topic like me: http://www.onemetre.net/Build/Jackline/Jackline.htm http://modelyacht.blogspot.co.uk/2014/01/iom-new-rig.html [I think this guy refers to...
by Colin Helliwell
23 Mar 2015, 16:37
Forum: General IOM
Topic: Spar form/size
Replies: 2
Views: 2403

Spar form/size

I'm wondering about the choices on spar sections (round/groovy) and diameters. Can anyone give me pros and cons of the various options? Thanks. Edit: I do realise that a larger diameter is likely to be (subject to wall thickness) stiffer than smaller and that, in any case, the sail cut should be app...
by Colin Helliwell
27 Oct 2014, 17:46
Forum: General IOM
Topic: MX 14 Fin
Replies: 3
Views: 3301

Re: MX 14 Fin

I need some help please. Yes A 6mm rake, and after some filing, surely can't be right - that is a lot . Have you checked with them though? It'd surely be weird if this was their normal quality level, so maybe it was just a duff batch? [a Friday afternoon run...?]. It's all small businesses in this ...
by Colin Helliwell
10 Oct 2014, 16:52
Forum: General IOM
Topic: Drum winch at lowish price
Replies: 22
Views: 11677

Re: Drum winch at lowish price

David L Alston wrote:Fellas /

....
Thanks David. That was the type of reply I was wanting/expecting! :)

(Annoying that some of it should be down to over-loading FETs - jeez there's so many to choose from, can it be that difficult to pick one up to the job?!)
by Colin Helliwell
07 Oct 2014, 09:30
Forum: General IOM
Topic: Drum winch at lowish price
Replies: 22
Views: 11677

Re: Drum winch at lowish price

What response did you want or expect ? … Wow you have got a bargain there my old china plate. We are all going to rush out and fit one of those for sure. Why did we not think it before !! Well, something a bit more technical, I guess - something about its spec which identifies a reason for possible...
by Colin Helliwell
05 Oct 2014, 12:12
Forum: General IOM
Topic: Drum winch at lowish price
Replies: 22
Views: 11677

Re: Drum winch at lowish price

David L Alston wrote:The only drawback being, apart from the postage cost.. is that it will last about 5 minutes in an IOM at the top of A rig conditions.
Oh... what makes you say that?
by Colin Helliwell
03 Oct 2014, 17:43
Forum: General IOM
Topic: Drum winch at lowish price
Replies: 22
Views: 11677

Re: Drum winch at lowish price

I've haven't had the time on this project lately, so I can't give 'real' info, but I've purchased a http://www.mxcomponents.com/en/winches-drums/12-servo-winch-11-ay.html . (Annoyingly the postage was nearly as much as the servo itself, but hey-ho!). Fits into the existing tray (in fact, is a bit un...
by Colin Helliwell
03 Oct 2014, 17:32
Forum: General IOM
Topic: Rudder servo strength
Replies: 12
Views: 6884

Re: Rudder servo strength

Just an update I have purchased a Hitec HS-5495BH and tried it in my elderly TS2. Whilst it appeared to work fine, there was a small amount of interference with the RMG winch as a result of which I have gone back to my trusty HB325 for the time being. RMG recommend only a standard non digital servo...
by Colin Helliwell
28 Aug 2014, 18:18
Forum: General IOM
Topic: Rudder servo strength
Replies: 12
Views: 6884

Re: Rudder servo strength

Have come over all impulsive and ordered a Hitec HS5495BH - digital, 7.5kg-cm@7.4V, 0.15sec, standard size. Seems a reasonable spec, and as David rightly points out, it's the Herbert on the tiller that will be a key factor.
by Colin Helliwell
28 Aug 2014, 16:56
Forum: General IOM
Topic: Rudder servo strength
Replies: 12
Views: 6884

Re: Rudder servo strength

Yep, I'd been looking at the digital for the position repeatability. And I've got a winch and Rx that will run at 7.2v so it would make sense for the rudder servo to also, otherwise it means dropping to NiMH's or using a regulator - weight & space either way. Came across a low-cost Hitec digital - H...
by Colin Helliwell
22 Aug 2014, 20:53
Forum: General IOM
Topic: Sheeting angle
Replies: 1
Views: 3002

Sheeting angle

The plans for my [ageing] Nimbus show the sheeting coming through at deck-level and through a fairlead to the boom. Other pics I've seen of (probably more recent) IOM designs often feature a ~2cm pillar fairlead through which the sheet exits. I was drawn to that at first - it keeps the pull purely i...
by Colin Helliwell
22 Aug 2014, 20:18
Forum: General IOM
Topic: Rudder servo strength
Replies: 12
Views: 6884

Re: Rudder servo strength

Colin in the Shiraz I have ordered they fit an HB325 which has 3kg.cm of torque - I can only assume the builders have experience to suggest that this servo is sufficient: http://www.servoshop.co.uk/index.php?pid=HITHS325HB&area=Servo .... There are a lot of experienced IOM sailors on here, guys wha...
by Colin Helliwell
22 Aug 2014, 20:06
Forum: General IOM
Topic: Rudder servo strength
Replies: 12
Views: 6884

Re: Rudder servo strength

What I've got in there at the moment (i.e. it came with the boat) is a Futaba S148 - specs I've found online say this is 3kg-cm @6V).
[That reminds me - if it's a 6V max then I maybe need to consider voltage as well as torque, if I stick a7.4V LiPo in there!]
by Colin Helliwell
22 Aug 2014, 19:00
Forum: General IOM
Topic: New Nylet Spirit is here! Progress at last!
Replies: 76
Views: 43580

Re: New Nylet Spirit is here! Progress at last!

and let's look at the ever helpful Mr Alston's last post: We are all painfully aware of who built the boat, how you acquired it on E-bay. We have all endured the painful commentary and slow progress together with the saga of weight , servo mounting and all battery purchase. For the life of me I can...
by Colin Helliwell
22 Aug 2014, 18:47
Forum: General IOM
Topic: Rudder servo strength
Replies: 12
Views: 6884

Rudder servo strength

Is there any perceived/generally-accepted wisdom on the amount of torque an IOM's rudder servo should be able to impart?
(In case it's relevant: CSA of my present rudder is ~130cm2; 7cm leading-to-trailing edge ['chord length'?], with shaft @1.5cm from leading edge).
Ta.
by Colin Helliwell
26 Jul 2014, 16:14
Forum: General IOM
Topic: Radio pot, antenna routing
Replies: 7
Views: 4589

Re: Radio pot, antenna routing

Thanks
by Colin Helliwell
25 Jul 2014, 18:03
Forum: General IOM
Topic: Radio pot, antenna routing
Replies: 7
Views: 4589

Re: Radio pot, antenna routing

Thanks. I'm a digital/software engineer, but working in the field of RF products - it is indeed a black art! Yep, 2.4gig is readily absorbed by water - that's why we use it to cook with ;) The questions re. antenna placement was for the polarisation: 90 degree antennae both lying flat would be ok-is...
by Colin Helliwell
21 Jul 2014, 17:28
Forum: General IOM
Topic: Radio pot, antenna routing
Replies: 7
Views: 4589

Radio pot, antenna routing

Just wondering what's the accepted practice for putting holes in a plastic radio pot for the servo wires (best to bring them through high in the pot, or towards the base?), and for sealing the apertures after? Also, for a 2.4GHz radio, is it the norm to route the antenna up through the deck to get g...
by Colin Helliwell
09 Jul 2014, 21:36
Forum: General IOM
Topic: Drum winch at lowish price
Replies: 22
Views: 11677

Re: Drum winch at lowish price

Thanks for the info Levend. The plastic (?) gears seem a bit of a concern, but as you say - it is at a much lower price than RMG. I think my next step is to decide whether I dare slice out a big section of aft deck to give me access for this style of winch - currently, I only have space for a Hitec-...
by Colin Helliwell
22 Jun 2014, 15:02
Forum: General IOM
Topic: Drum winch at lowish price
Replies: 22
Views: 11677

Re: Drum winch at lowish price

Thanks David. Yes, I'll be racing. I never enjoy pottering/day-sailing in a dinghy and don't expect model yachting to be different - racing is what gives the enjoyment and challenge, for me. I am cautious about the time I'll be able to find however, hence the wish to be conservative with the initial...
by Colin Helliwell
19 Jun 2014, 19:32
Forum: General IOM
Topic: Drum winch at lowish price
Replies: 22
Views: 11677

Re: Drum winch at lowish price

Lol thanks. Space for an arm is a problem though - it's a Nimbus with very limited servo room: less than 4"x3"
by Colin Helliwell
19 Jun 2014, 18:59
Forum: General IOM
Topic: Drum winch at lowish price
Replies: 22
Views: 11677

Re: Drum winch at lowish price

Thanks John, I'll have a look for the modifying route (or if you can point me to a link or search term...?) - re-engineering summat isn't a problem, so that could certainly be a way forward. I'd imagine smooth mark rounding is wise anyway, rather than slamming the helm down and sheeting in like a ma...
by Colin Helliwell
19 Jun 2014, 14:19
Forum: General IOM
Topic: Drum winch at lowish price
Replies: 22
Views: 11677

Drum winch at lowish price

I'm trying to choose a drum winch servo for a hull I'm refitting. It's an old boat and design, and my first, so at this stage I don't want to go to the expense of an RMG. The Hitec HS-785HB is obviously very low cost, but how much of a problem is the slow speed - for a beginner, club sailor (albeit ...