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Member postings for Martin Harris

Here is a list of all the postings Martin Harris has made in our forums. Click on a thread name to jump to the thread.

Thread: Irvine 53 Mounting Footprint
25/09/2017 23:06:47

Comparing a 46 AX (rear needle) with a British Irvine 53 visually, the mounting hole pattern seems identical but the OS is 1/16 of an inch or so longer to the prop driver. The Irvine is maybe 3/16 of an inch higher but the exhaust flanges line up - and have the same hole spacing so could use each other's silencers if required. My only 55 is in a model so I can't check but the data from OS should be available on line...although I have noted that there are later versions of the 46/55 now...

Edited By Martin Harris on 25/09/2017 23:13:30

Thread: electric power remote cut off?
25/09/2017 21:23:43

Retract or other high power servo operated arming plug?

Thread: The art of Customer service is (not yet) dead
25/09/2017 12:32:17

Reminds me of an old tale...

A young man got a new job running the till at an old fashioned general store. The grizzled old store owner said he would teach him how to up-sell.

"Watch how I do it," he said to the new lad.

As a customer put a bag of grass seed on the counter, the old-timer said to him, "How are you going to distribute the seeds evenly - do you want a rotary seeder, we have them on special offer at the moment" and the customer agreed to have one. "of course," the owner continued, "when you plant those seeds, you'll need some fertiliser"...a large box of which was soon added to the collection on the counter... "and how about some edging"..."and some keep off the new grass notices"..."a hose and sprinkler will certainly help"...

Finally the old boy administered the coup de grace - "of course once your lovely new grass starts growing, you're going to need a new lawnmower to cut it."

Once the large transaction on the customer's credit card had gone through and the young man had helped load all the purchases into the customer's pick up truck as they watched him drive off, the new kid said, "I think I see what you mean. Let me handle this next one."

A customer soon stepped up to the counter and set down a box of tampons. The young salesman said, "You know, you should get you a new lawnmower to go with that."

The man asked the young salesman, "What are you talking about?"

"It looks like your weekend's shot so you might as well cut the grass."

Thread: Understanding Watt Meters
24/09/2017 22:05:02

I don't know about the leaflet but my interpretation of the figures on the HK site is that the 910W corresponds very closely with the maximum cell count (5S or nominal 18.5V) at 50 Amps.

Edited By Martin Harris on 24/09/2017 22:11:09

24/09/2017 21:50:49

About 3 years old? Could be 4 years maybe - plus a year or so on a model shop shelf? LiPo batteries start ageing the day they are made so I'd suggest that from the information you've supplied that the battery is no longer capable of supplying current at a sufficient rate.

Amps WILL drop off as voltage declines so it's quite normal to see the highest current (Watts are directly related) during the first application of power unless the cells are cold enough that a bit of use warms them up enough to increase their internal efficiency...something you might notice on a winter's day.

Thread: The art of Customer service is (not yet) dead
24/09/2017 21:33:58

I hope NVQs have changed a lot in the 20 years or so since I was involved as a candidate and assessor in Customer Service - which seemed to be a pointless exercise of collecting "evidence" that could be loosely justified as meeting the required standards with rather a lot of creative thinking and box filling...

My company embraced them as the most wonderful and career enhancing solution since TQM - a couple of years later all trace of the much vaunted internal NVQ organisation had disappeared.

Thread: Discussion of politics: Discuss.
24/09/2017 21:16:30
I am tempted to unleach a few pithy rejoinders, even though I know they will fail, because the intellect they are aimed against would be insufficient to notice the barb.

I'm afraid that whatever the validity of a viewpoint, veiled attacks on others' intelligence or integrity will result in robust replies and threads will soon descend into anarchy and acrimony. Such attacks are almost inevitable when discussing emotive opinions and for this reason, I agree that discussion of politics (and religion etc.) are best kept outside of this forum.

Thread: Prop to Fuselage clearance
24/09/2017 16:56:32

Take a look at a full size DC3 - clearance isn't exactly massive (ISTR mention of the propeller tips being a foot from the pilot's heads) and various full size references quote a minimum distance from a prop tip to airframe as 1 inch radially and a foot longitudinally so interaction shouldn't be a major consideration. Ducted fans certainly manage with minimal clearances!

23/09/2017 23:35:32

I'm afraid it's whatever the market wants to pay...

If you were selling it at a typical club auction, maybe £20 - £30? However, these go back a long way (I had one in the mid 70s) and it looks to be in excellent condition so you might tap into the nostalgia market. My advice would be to put it on Ebay at a low start price to encourage bidders and hope that 2 or more people really want one!

P.S. I'm a bit intrigued that one wing looks longer than the other - is this a camera angle thing?

Edited By Martin Harris on 23/09/2017 23:38:45

Thread: Transmitters for DSMX indoor receiver/servo modules
23/09/2017 22:08:09
Posted by John Emms 1 on 23/09/2017 20:47:24:

FAQ copied from the DX6e page on

Is DSM2™ and DSMX equipment compatible?

Yes. DSM2 transmitters are forward compatible with DSMX receivers and DSMX transmitters are backward compatible with DSM2 receivers. And because DSM2 and DSMX share the same wideband DSSS foundation, all Spektrum users will enjoy superior range, speed and precision whether they're using DSM2 equipment, DSMX equipment or a combination of both.

To me, that appears to say that any Spektrum Tx (DSM2 or DSMX) can be used with any Spektrum Rx (DSM2 or DSMX).

Curiouser and curiouser....

I'm no expert on Spektrum but might that only apply to non-EU equipment? That appears to be from the US site...

Thread: Hobby King Global Warehouse.
22/09/2017 18:50:44
Posted by Denis Watkins on 22/09/2017 18:06:02:

As it is classed as Dangerous Goods

I'd have thought the main danger comes from a public admission that you want one!

Thread: low voltage lipo battery
21/09/2017 13:02:44

The question to ask is do you trust this battery to power your transmitter reliably at the risk of hurting someone or losing your favourite model?

Thread: EME120 tuning question
20/09/2017 19:58:17

Any help?


Thread: Caption competition!
20/09/2017 18:17:20

When looking for a lost model, start a methodical search from the last point you remember seeing it...

Thread: EME120 tuning question
20/09/2017 17:58:17
Posted by cymaz on 20/09/2017 07:03:39:

Looked at the 1/3 scale cub undercarriage. I have had dealings with Noggin End Metals so will look at getting the steel tubing from there. Pat has said he would mill up the brackets and also mill some radii into the tube ends. That just leaves me to learn brazing !

More to post when I return from holiday smile d

I found the Robart drawing for the Hangar 9 Cub very useful when building an U/C for my quarter scale J3 - and managed to find suitable sized steel tube in B&Q!

Edited By Martin Harris on 20/09/2017 18:00:21

Thread: Wing rib dihedral angle
20/09/2017 17:41:22

It's not ideal but there's little harm in doing it. The dihedral brace or wing joining system sets the dihedral in reality - the wing root ribs contribute little or nothing to the strength of the structure and serve mainly to support the skin or covering material.

Edited By Martin Harris on 20/09/2017 17:42:39

Thread: Caption competition!
20/09/2017 01:18:04

The search for the sharpest tool in the box continues...

19/09/2017 21:08:53

That's not quite what I meant when I said your transmitter might need a re-boot...

Thread: Now I didn't know that
18/09/2017 10:38:15

That seems a bit odd as not all transmitters deliver the same pulse width at 100%. For example, Spektrum's range is 1.1 - 1.9 milliseconds whereas Jeti outputs 1.0 - 2.0 milliseconds. I was under the impression that the throttle calibration procedure was to teach an ESC to regard the transmitter's range as 0 - 100%...

Thread: Should I cut my fuz?
17/09/2017 20:02:22

Difficult to give an opinion without knowing the construction - is the glass structural or just giving shape and what size/location you need the access hatch? As a general principle, avoid any sharp corners - make the hatch circular or oval if possible.

Edited By Martin Harris on 17/09/2017 20:02:56

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