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Fourfingers
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« on: June 25, 2019, 08:46:17 AM » |
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Wonder if anyone has (reliable) power output figures for this little gem?
Looking at revs on different props I'm guessing about 0.06 bhp.
Any data most welcome
Thanks
john
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cvasecuk
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« Reply #1 on: June 25, 2019, 10:24:17 AM » |
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The review figures in Feb 98 Aeromodeller and the revs being quoted here lead to a figure of 0.03 to about 0.035 bhp.
That is more than adequate for a Tomboy!
Ron
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Fourfingers
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« Reply #2 on: June 25, 2019, 11:53:20 AM » |
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Thanks Ron
Sounds a bit underwhelming to me, but it makes up for it in its behaviour! So a Mills, or even my Mini ETA 0.35 would have more clout?
Its not all about bhp, john....
Have an 061 BB on order. Talk about from the sublime to the ridiculous!
john
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ffkiwi
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« Reply #3 on: June 25, 2019, 07:44:16 PM » |
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They are directly comparable to a Mills 75 power wise-and just a nice-if not better-handling...plus the annoying little foibles of the Mills ...tank tabs, prop driver, fang marks on the conrod if the liner rotates-are all absent....the only very minor criticism I have is the two point lug mounting.....and the ED Baby was the same-and a lot of those were sold and used....
BHP is a bit of a red herring-unless you include the context of the rpm where it occurs....and translate that into appropriate prop sizes....
ChrisM
'ffkiwi'
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Fourfingers
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« Reply #4 on: June 26, 2019, 04:16:03 AM » |
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Hi Chris, never did have a Mills, although remember lusting after one. At £2 16s 3d plus tax never quite got there.
I dont mind two hole lugs on wee engines- makes for easier mounting with my farm-yard tools.
You are right about power though, will an engine give the revs on a given prop to make your latest creation head to the skies? Does make trial&error expensive onprops and building ever-smaller planes, though!
Ah well, nights drawing in now!
john
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ffkiwi
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« Reply #5 on: June 26, 2019, 09:48:23 PM » |
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Run the MP Jet Classic on 7x4, 8x3 and 8x4 props to get the best out of it-mine (and I have 6!) rarely see anything different to a nylon 8x4....and on that are utterly reliable and hassle free....whether in FF sport or small radio vintage models.
ChrisM
'ffkiwi'
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Fourfingers
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« Reply #6 on: June 27, 2019, 06:48:19 AM » |
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Yep, got all those, Chris.....plus a few others! 8x3 seems to give most oomph (bench test only now ... windy as hell here just at present, like tha Mistral).
Also a 7x3 three-blader as recommended by Olli. Will report later.
john
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Olli-Matti
Copper Member
Kudos: 1
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 Finland
Posts: 8
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« Reply #7 on: July 19, 2019, 02:12:20 PM » |
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I did manage to get a genuine English Mills from a UK gentleman named Norman through ebay for a decent price. I did get it started today with a MA 7x4x3 for comparison. Mills did run 10500 with this prop, I were surprised a little. It really did get a groove going on
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Fourfingers
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« Reply #8 on: July 19, 2019, 04:13:32 PM » |
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Ollie
I did obtain a MA 7x4 3-blader. Not cheap! Put it on the MPJet /Tomboy. Good revs, nice thrust. Launched into gentle breeze, climbed, stalled and nose-dived into ground. Three-blader became two.
Maybe the Baltic next time?
Soft landings
john
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Squirrelnet
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« Reply #9 on: July 19, 2019, 04:33:17 PM » |
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Launched into gentle breeze, climbed, stalled and nose-dived into ground. Hi John Sounds powerful enough for your Tomboy, maybe a couple of degrees of downthrust and you'll have it flying nicely .... If you already have a couple of degrees of downthrust you maybe have the CG too far back ? Balance on the mainspar ? Happy Flying Chris |
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Fourfingers
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« Reply #10 on: July 19, 2019, 04:40:45 PM » |
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Hi Chris
Yes, thats the problem ... I do have adequate downthrust. Lovely flat glide. But the CG is well back. Dont like adding weight, but maybe I should?
john
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ffkiwi
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« Reply #11 on: July 19, 2019, 08:06:07 PM » |
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Well you have a choice...you can keep crashing and breaking props....or you can take the well founded advice offered and get the CG right!-which on your own admission will require noseweight to remedy. Regardless of model type-the CG location has only a relative small range-in terms of actual physical distance and % chord-over which it works....for FF power duration (ie a pylon model) it can be as little as 1/4" or so range.....for something like a Tomboy, that probably expands to a range of about 5/8"-from too far forward to too far back.....with the optimum being ON the spar....and as hundreds of thousands of aeromodellers can tell you-from having learned the hard way-a nose heavy CG position is more easily dealt with than a tail heavy one....
ChrisM
'ffkiwi'
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Squirrelnet
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« Reply #12 on: July 20, 2019, 03:26:16 AM » |
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Dont like adding weight, but maybe I should? Hi John I would definitely rebalance on the mainspar and re-trim the glide. In reality the model shouldn't really 'feel' the extra weight as it will be flying in trim and an MP 040 should be more than enough to come with any very small increase in wing loading There is an old adage - A nose heavy model flies badly and tail heavy model flies once  Chris |
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Fourfingers
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« Reply #13 on: July 20, 2019, 05:49:53 AM » |
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OK guys, youve persuaded me! Extra nose weight it shall be ...
I think my TB can afford it. Some data was posted a while back by a club in NZ. Apart from a skinny electric one (pah!), mine weighs less than the rest of the bunch.
More props on order.
Changing tack, slightly: got a new MP 06 BB recently. Something of a screamer! Oddly, for a diesel it likes a good drink before flicking. So much so that I cant get her to fire with the muffler on - no exhaust prime possible.
Thrown it away anyway (the muffler) never did have a motor that ran well with them. Engine baking oven, as I think one wag called them.
Neighbours are all deaf anyway thank God!
jc
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ffkiwi
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« Reply #14 on: July 20, 2019, 05:43:11 PM » |
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OK guys, youve persuaded me! Extra nose weight it shall be ...
I think my TB can afford it. Some data was posted a while back by a club in NZ. Apart from a skinny electric one (pah!), mine weighs less than the rest of the bunch.
More props on order.
Changing tack, slightly: got a new MP 06 BB recently. Something of a screamer! Oddly, for a diesel it likes a good drink before flicking. So much so that I cant get her to fire with the muffler on - no exhaust prime possible.
Thrown it away anyway (the muffler) never did have a motor that ran well with them. Engine baking oven, as I think one wag called them.
Neighbours are all deaf anyway thank God!
jc
for their size These are nice engines-but an entirely different kettle of fish to the classic 040 of course...at the other end of the performance spectrum.....I have all the variations made-which amounts to about 7 of them-including the fairly scarce PB diesel and the low production F1J Special variants. As for starting with the muffler on...can't you just prime through the intake? ....and certainly some of my 061s have a priming hole located between the muffler screws...directly opposite the exhaust opening...though you'd only use a hypodermic for priming, as it is a small hole...[it is quite possible that yours doesn't have such a hole...I've noticed small minor detail differences in my various 061s over the years...there being about a 20 year range in age over my examples..and they're manufactured in batches rather than continuously... ChrisM 'ffkiwi' |
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