PROFI RAMBLER .049
11-29-2012, 12:50 AM
#52
Senior Member
RE: PROFI RAMBLER .049
ORIGINAL: MJD
I think the ''problem'' with the price, is that it is a 0.8cc /.049 ci engine, and we are conditioned to think that smaller displacement means less money. That might be true for ''mass'' produced Cox or Norvel engines - maybe mainstream engines is a better term - but the fact is that these are top level competition engines, and they require all the same manufacturing and machining steps as any other engine, and probably require more care in terms of fits and tolerances than engines several times their size.
To me, yeah it's a bit pricey, but I am getting a state of the art competition oriented engine that will give me all kinds of sts and giggles. I have engines worth more than this that won't get me anywhere near as excited. The Profi .061 is the most fun I've had with my pants on for a while.
Now if you want to fall out of your chair, get a quote for a state of the art F2A .15... egads.. I thought I wanted one really badly until I found out they were worth about two Moki 2.10's and a fancy dinner out for the wife and I. We're talking $600-$700 per. That's the price of keeping up with the Joneses in F2A though. So I satisfy my high rpm racing engine urges with 1/2A's and 1cc for now. I had a woody to build an RC speed model with a Profi F2A engine, can you imagine? If it can pull a C/L model at 208mph, with lines, it obviously has the ability to pull a clean RC model at higher speeds. Might be a cantankerous b and would take a fair bit of engine savvy to get everything dialed in right, but the F2A guys do it on a regular basis, so why not? Maybe I'll find ''last year's model'' F2A engine sometime for a relative bargain.
I think the ''problem'' with the price, is that it is a 0.8cc /.049 ci engine, and we are conditioned to think that smaller displacement means less money. That might be true for ''mass'' produced Cox or Norvel engines - maybe mainstream engines is a better term - but the fact is that these are top level competition engines, and they require all the same manufacturing and machining steps as any other engine, and probably require more care in terms of fits and tolerances than engines several times their size.
To me, yeah it's a bit pricey, but I am getting a state of the art competition oriented engine that will give me all kinds of sts and giggles. I have engines worth more than this that won't get me anywhere near as excited. The Profi .061 is the most fun I've had with my pants on for a while.
Now if you want to fall out of your chair, get a quote for a state of the art F2A .15... egads.. I thought I wanted one really badly until I found out they were worth about two Moki 2.10's and a fancy dinner out for the wife and I. We're talking $600-$700 per. That's the price of keeping up with the Joneses in F2A though. So I satisfy my high rpm racing engine urges with 1/2A's and 1cc for now. I had a woody to build an RC speed model with a Profi F2A engine, can you imagine? If it can pull a C/L model at 208mph, with lines, it obviously has the ability to pull a clean RC model at higher speeds. Might be a cantankerous b and would take a fair bit of engine savvy to get everything dialed in right, but the F2A guys do it on a regular basis, so why not? Maybe I'll find ''last year's model'' F2A engine sometime for a relative bargain.
It's just a lot of D****d money period! I'd rather have the Parra .09 right now, gow or diesel because the prop choices are much better and you can throttle them. Mid 24-26k on a 5-5 is pretty respectable for a glow .09 let alone a Diesel!
11-29-2012, 01:29 AM
#53
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RE: PROFI RAMBLER .049
Mine was made from second-hand used real estate agent housesigns-the stuff (coreflute) is widely used here for temporary or short term signage that has to be weather proof and last for a week or so......
ChrisM
'ffkiwi
.....the unused unprinted white stuff I use to make model boxes for domestic travel and model storage ....usually over a light stripwood internal frame.
ChrisM
'ffkiwi
.....the unused unprinted white stuff I use to make model boxes for domestic travel and model storage ....usually over a light stripwood internal frame.
11-29-2012, 05:44 AM
#54
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RE: PROFI RAMBLER .049
It's just a lot of D****d money period! I'd rather have the Parra .09 right now, gow or diesel because the prop choices are much better and you can throttle them. Mid 24-26k on a 5-5 is pretty respectable for a glow .09 let alone a Diesel!
11-29-2012, 06:56 AM
#55
RE: PROFI RAMBLER .049
ORIGINAL: MJD
Well, yeah, it is expensive. C'mon, let me make myself feel better about it would ya?
It's just a lot of D****d money period! I'd rather have the Parra .09 right now, gow or diesel because the prop choices are much better and you can throttle them. Mid 24-26k on a 5-5 is pretty respectable for a glow .09 let alone a Diesel!
11-29-2012, 06:58 AM
#56
RE: PROFI RAMBLER .049
$200 is not that much for a basically homebuilt motor. I wouldn't want to make the piston/cyl. for that much money, much less the other parts. It would take all day, and plating is beyond me (I think) So, does that make you feel better?? I can't believe the Magnum's and other motors can even be made for $40. Just everyone is used to these kind of deals now, me included.
11-29-2012, 08:22 AM
#57
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RE: PROFI RAMBLER .049
I was curious how far we'd have to drive to fly 1/2A's together - ouch! You're way out in the SW corner.
Hey I feel great about buying the Profi, no second thoughts.
BTW the estimated cost of the piped full speed version is $350. Hmmm.
Hey I feel great about buying the Profi, no second thoughts.
BTW the estimated cost of the piped full speed version is $350. Hmmm.
11-29-2012, 09:19 AM
#58
Senior Member
RE: PROFI RAMBLER .049
ORIGINAL: aspeed
$200 is not that much for a basically homebuilt motor. I wouldn't want to make the piston/cyl. for that much money, much less the other parts. It would take all day, and plating is beyond me (I think) So, does that make you feel better?? I can't believe the Magnum's and other motors can even be made for $40. Just everyone is used to these kind of deals now, me included.
$200 is not that much for a basically homebuilt motor. I wouldn't want to make the piston/cyl. for that much money, much less the other parts. It would take all day, and plating is beyond me (I think) So, does that make you feel better?? I can't believe the Magnum's and other motors can even be made for $40. Just everyone is used to these kind of deals now, me included.
I usually just don't get around to it!
11-29-2012, 09:22 AM
#59
Senior Member
RE: PROFI RAMBLER .049
ORIGINAL: MJD
I was curious how far we'd have to drive to fly 1/2A's together - ouch! You're way out in the SW corner.
Hey I feel great about buying the Profi, no second thoughts.
BTW the estimated cost of the piped full speed version is $350. Hmmm.
I was curious how far we'd have to drive to fly 1/2A's together - ouch! You're way out in the SW corner.
Hey I feel great about buying the Profi, no second thoughts.
BTW the estimated cost of the piped full speed version is $350. Hmmm.
Wow.. I wonder what kind of prop it will turn and what RPM.... One thing I learned from racing electrics is that prop efficiency falls off a cliff under 5" so 20% more power from a hotter engine doesn't mean anything if you have to spin a 3-3/4" prop to get it.
Might make a killer ducted fan motor though...
11-29-2012, 09:27 AM
#60
Senior Member
RE: PROFI RAMBLER .049
ORIGINAL: MJD
Well, yeah, it is expensive. C'mon, let me make myself feel better about it would ya?
It's just a lot of D****d money period! I'd rather have the Parra .09 right now, gow or diesel because the prop choices are much better and you can throttle them. Mid 24-26k on a 5-5 is pretty respectable for a glow .09 let alone a Diesel!
Actually, I'm trying to make myself feel better about the 3Kw worth of solar panels I am buying this week. [
]Sometimes it sucks having to be an adult, one bad thing about this economy is that suddenly all the toys we always wanted and more than a few ones we didn't know we wanted yet are too easily available to us. I 'need' yet another motorcycle, that classic pony car you couldn't afford 6 years ago is within reach if you just stretched that little bit further etc.
11-29-2012, 10:20 AM
#61
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RE: PROFI RAMBLER .049
A counter-weighted one blade prop approx 4" diameter (or perhaps 2" radius is a better way to put it) in the 43-48k range. Spin them fast enough they work okay. CP has already flown in the 150 range with APC 4.2x4 props on other small engines. Guys are flying insane speeds on electrics with 4.1" props at a bazillion rpm.
You just cannot get the hp of out small engines without the rpm. Displacement x rpm/60 x efficiency = amount of fuel burned per second = power. Since the stroke is so small, piston speed it not outlandish. F2A .15 speed engines turn up in the 43k range all the time, and they hold up fine for many runs at about 1.7 times the stroke of an .049. Even at that rpm I think they have lower piston speeds than Formula 1 engines.
I think my Profi .049 will pay for itself faster than a bank of solar panels.. [8D]
But seriously, what kind of payback period are you looking at with the solar bank?
You just cannot get the hp of out small engines without the rpm. Displacement x rpm/60 x efficiency = amount of fuel burned per second = power. Since the stroke is so small, piston speed it not outlandish. F2A .15 speed engines turn up in the 43k range all the time, and they hold up fine for many runs at about 1.7 times the stroke of an .049. Even at that rpm I think they have lower piston speeds than Formula 1 engines.
I think my Profi .049 will pay for itself faster than a bank of solar panels.. [8D]
But seriously, what kind of payback period are you looking at with the solar bank?
11-29-2012, 02:15 PM
#62
RE: PROFI RAMBLER .049
I found noticeable gains when flying TDs in C/L combat by cutting the 5x3 rubber prop down to about 4 inches.
I'm amazed at how APC is right on top of just about every application that is out there. Where does all their input come from..? Top level competitors I imagine.
I've disagreed with them for dropping the 7.2x8.6......but they know their sales figures don't lie. Too bad for some of us because that was an awesome prop for .40-.50 speed projects.
Their selection of 1/2A props is pretty awesome considering how few 1/2A flyers there are.
DD...I admire your sense of "fiscal restraint"..the solar power system doesn't have to pay dividends right away...it is more of a rainy day investment the way I look at it. A day might come when those systems are worth twice their weight in gold.
I'm amazed at how APC is right on top of just about every application that is out there. Where does all their input come from..? Top level competitors I imagine.
I've disagreed with them for dropping the 7.2x8.6......but they know their sales figures don't lie. Too bad for some of us because that was an awesome prop for .40-.50 speed projects.
Their selection of 1/2A props is pretty awesome considering how few 1/2A flyers there are.
DD...I admire your sense of "fiscal restraint"..the solar power system doesn't have to pay dividends right away...it is more of a rainy day investment the way I look at it. A day might come when those systems are worth twice their weight in gold.
11-29-2012, 02:41 PM
#63
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RE: PROFI RAMBLER .049
There was a program up here where Ontario Hydro would buy surplus solar power into the grid from homeowners at about 5-6 times the going rate, as an incentive to take out a 2nd mortgage to put it in. A bunch of people jumped on that bandwagon, but it may have expired by now. I save hydro by making my wife shave in the dark and take cold baths.
CP - I asked Fred at APC once what numbers he had to produce to justify making a new prop mold - the answer was 5000. Judging by how many APC 4.2x2 and 4.2x4 are hanging in bags untouched at the LHS's around here, undoubtedly they have that and several times more in the pipeline. Some LHS's have the oddest inventory, like a bunch of 7x9 at one spot I was at recently.. no wonder they go broke. Someone must have just decided that if it is on the product list, they should inventory it. I doubt it was due to predictions of a surge in C/L B speed activity.
I guess dropping the 7.2 x 8.6 had to do with the trend towards higher and higher rpm in those events? Dunno.
CP - I asked Fred at APC once what numbers he had to produce to justify making a new prop mold - the answer was 5000. Judging by how many APC 4.2x2 and 4.2x4 are hanging in bags untouched at the LHS's around here, undoubtedly they have that and several times more in the pipeline. Some LHS's have the oddest inventory, like a bunch of 7x9 at one spot I was at recently.. no wonder they go broke. Someone must have just decided that if it is on the product list, they should inventory it. I doubt it was due to predictions of a surge in C/L B speed activity.
I guess dropping the 7.2 x 8.6 had to do with the trend towards higher and higher rpm in those events? Dunno.
11-29-2012, 03:38 PM
#64
RE: PROFI RAMBLER .049
I thought maybe the 7.2x8.6 was a Formula One pylon prop..? It sure ran good on a K&B F1 engine I bought off ebay. I still have one of those props, have a mold box built but haven't cast the mold of the prop...just need to finish up a gigantic project ahead of that one.
I haven't checked to see if
Wilk or Hazel carry the same prop.
Without an infinite selection of props, if all you do is buy off the shelf..then all you will get is "off the shelf" results. This is why having various CF props is a necessary evil so that you can modify and check the progress of those mods to see if you're working in the right direction or not. Kind of like a search party where some luck is involved and possibly some false "leads" to weed out, too..
I haven't checked to see if
Wilk or Hazel carry the same prop.
Without an infinite selection of props, if all you do is buy off the shelf..then all you will get is "off the shelf" results. This is why having various CF props is a necessary evil so that you can modify and check the progress of those mods to see if you're working in the right direction or not. Kind of like a search party where some luck is involved and possibly some false "leads" to weed out, too..
11-29-2012, 04:33 PM
#65
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RE: PROFI RAMBLER .049
ORIGINAL: combatpigg
I haven't checked to see if Wilk or Hazel carry the same prop.
I haven't checked to see if Wilk or Hazel carry the same prop.
P-8 7 3/8 X 8 1/4 This prop is based on Ray Brown F3D Pylon Prop.
Z-1 7 1/2 X 8 1/2 This prop is based on Zoomer B Speed prop 7X8 re-pitched.
L-1 7 X 8 1/2 This prop is Glen Lee's B Speed Prop.
I have Mike Hazel's list somewhere, will take a look this evening.
11-29-2012, 04:47 PM
#66
RE: PROFI RAMBLER .049
A 7-10" used to be the right prop for a B Speed when you could use 80% nitro. Now a 7-8" seems to be the one. I think they are about 24,000 rpm in the air. MJD, I am a long way from Orangeville now.. I used to be in Waterloo. Really there are no fields that are paved near here anyway, maybe River Rouge in Detroit, but a bulletproof vest and a gun are needed. I am likely closer to Devious Dave in Michigan now. I am/was? a machinist and don't get around to making much stuff either. I got most of the stuff in the shop if I feel like doing things though.
11-29-2012, 05:10 PM
#67
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RE: PROFI RAMBLER .049
I was looking on Steve Wilk's prop list just now - for 1/2A speed he has a few single bladers listed, they are all 2-5/8" (5.25" disc diameter) from 4.5 - 5.0" pitch. These sound too big for 40k+ engines, more like hot TD sizes? I need to talk to a 1/2A speed guy.
SC-7 2 5/8 X 5
1/2A Single Blade Prop designed for 1/2A Speed 049 with a tuned pipe.
This Prop is based on Super Cool's 1/2A Speed Prop
SC-6 2 5/8 X 4 1/2
1/2A Single Blade Prop designed for 1/2A Speed 049 with a tuned pipe.
This Prop is based on Super Cool's 1/2A Speed Prop.
H-1
2 5/8 X 4 1/4
1/2A Single Blade Prop designed for 1/2A Speed 049 with a tuned pipe.
This Prop is based on Carl Dodge's 1/2A Speed Prop.
F-6
2 5/8 X 5
1/2A Single Blade Prop designed for 1/2A Speed 049 with a tuned pipe.
This Prop is based on Bob Fogg's 1/2A Speed Prop.
F-5
2 5/8 X 4 3/4
1/2A Single Blade Prop designed for 1/2A Speed 049 with a tuned pipe.
This Prop is based on Bob Fogg's 1/2A Speed Prop.
F-4
2 5/8 X 4 1/2
1/2A Single Blade Prop designed for 1/2A Speed 049 with a tuned pipe.
This Prop is based on Bob Fogg's 1/2A Speed Prop.
F-3
2 5/8 X 4 1/4
1/2A Single Blade Prop designed for 1/2A Speed 049 with a tuned pipe.
This Prop is based on Bob Fogg's 1/2A Speed Prop.
SC-7 2 5/8 X 5
1/2A Single Blade Prop designed for 1/2A Speed 049 with a tuned pipe.
This Prop is based on Super Cool's 1/2A Speed Prop
SC-6 2 5/8 X 4 1/2
1/2A Single Blade Prop designed for 1/2A Speed 049 with a tuned pipe.
This Prop is based on Super Cool's 1/2A Speed Prop.
H-1
2 5/8 X 4 1/4
1/2A Single Blade Prop designed for 1/2A Speed 049 with a tuned pipe.
This Prop is based on Carl Dodge's 1/2A Speed Prop.
F-6
2 5/8 X 5
1/2A Single Blade Prop designed for 1/2A Speed 049 with a tuned pipe.
This Prop is based on Bob Fogg's 1/2A Speed Prop.
F-5
2 5/8 X 4 3/4
1/2A Single Blade Prop designed for 1/2A Speed 049 with a tuned pipe.
This Prop is based on Bob Fogg's 1/2A Speed Prop.
F-4
2 5/8 X 4 1/2
1/2A Single Blade Prop designed for 1/2A Speed 049 with a tuned pipe.
This Prop is based on Bob Fogg's 1/2A Speed Prop.
F-3
2 5/8 X 4 1/4
1/2A Single Blade Prop designed for 1/2A Speed 049 with a tuned pipe.
This Prop is based on Bob Fogg's 1/2A Speed Prop.
11-29-2012, 06:00 PM
#69
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RE: PROFI RAMBLER .049
I got the smaller pitched single blade from Steve. He said to file the hub to get ther pitch I wanted. I guess thats the single blade benefit.
11-29-2012, 06:10 PM
#70
RE: PROFI RAMBLER .049
I never considered that you could tilt the prop. I would feel kind of "weird" trying that for the 1st time to see how well it works.
I might feel kind of weird no matter how many times I "got away" with it beforehand......
You would need to surface both sides of the hub parallel and I would fill the void in the hub with JB Weld.
I might feel kind of weird no matter how many times I "got away" with it beforehand......
You would need to surface both sides of the hub parallel and I would fill the void in the hub with JB Weld.
11-29-2012, 06:29 PM
#71
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RE: PROFI RAMBLER .049
yeah, he said to do it to get the pitch you want and then JB weld on the counter weight. I was wondering how the hole works out after, but I guess you just put it TLAR and then balance it.
11-29-2012, 06:59 PM
#72
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RE: PROFI RAMBLER .049
ORIGINAL: forsakenrider
I got the smaller pitched single blade from Steve. He said to file the hub to get ther pitch I wanted. I guess thats the single blade benefit.
I got the smaller pitched single blade from Steve. He said to file the hub to get ther pitch I wanted. I guess thats the single blade benefit.
11-29-2012, 11:01 PM
#73
RE: PROFI RAMBLER .049
MJD, if you run into a 1/2A Speed Guru ask him how much of a take off roll they need.....!
If I knew better, I'd just have the plane Wilks designed hand launched with no landing gear.
I might even set a sheet of plywood on the bed of a pickup truck and go with a stooge release.?
If I knew better, I'd just have the plane Wilks designed hand launched with no landing gear.
I might even set a sheet of plywood on the bed of a pickup truck and go with a stooge release.?
11-29-2012, 11:48 PM
#74
Senior Member
RE: PROFI RAMBLER .049
ORIGINAL: MJD
A counter-weighted one blade prop approx 4'' diameter (or perhaps 2'' radius is a better way to put it) in the 43-48k range. Spin them fast enough they work okay. CP has already flown in the 150 range with APC 4.2x4 props on other small engines. Guys are flying insane speeds on electrics with 4.1'' props at a bazillion rpm.
You just cannot get the hp of out small engines without the rpm. Displacement x rpm/60 x efficiency = amount of fuel burned per second = power. Since the stroke is so small, piston speed it not outlandish. F2A .15 speed engines turn up in the 43k range all the time, and they hold up fine for many runs at about 1.7 times the stroke of an .049. Even at that rpm I think they have lower piston speeds than Formula 1 engines.
I think my Profi .049 will pay for itself faster than a bank of solar panels.. [8D]
But seriously, what kind of payback period are you looking at with the solar bank?
A counter-weighted one blade prop approx 4'' diameter (or perhaps 2'' radius is a better way to put it) in the 43-48k range. Spin them fast enough they work okay. CP has already flown in the 150 range with APC 4.2x4 props on other small engines. Guys are flying insane speeds on electrics with 4.1'' props at a bazillion rpm.
You just cannot get the hp of out small engines without the rpm. Displacement x rpm/60 x efficiency = amount of fuel burned per second = power. Since the stroke is so small, piston speed it not outlandish. F2A .15 speed engines turn up in the 43k range all the time, and they hold up fine for many runs at about 1.7 times the stroke of an .049. Even at that rpm I think they have lower piston speeds than Formula 1 engines.
I think my Profi .049 will pay for itself faster than a bank of solar panels.. [8D]
But seriously, what kind of payback period are you looking at with the solar bank?
Agreed, you need RPM to get HP, but there comes a point of diminishing returns because as hp increases with rpm, torque and prop diameter necessarily have to go down.
As for the panels, no idea on the pay-off. I can eventually grid-tie and get paid for my excess wattage but this is going to be an off-grid cabin application. I see them as stored wealth and am building a place on some land I bought in '07 because I am worried about our economy. Global economics aside, none of the factors that brought us the last downturn have been addressed or corrected and each time we borrow our way out of crisis it's more and more painful in the future. I just want a fall back option with no responsibilities but taxes and feeding myself.
11-29-2012, 11:52 PM
#75
Senior Member
RE: PROFI RAMBLER .049
ORIGINAL: combatpigg
I found noticeable gains when flying TDs in C/L combat by cutting the 5x3 rubber prop down to about 4 inches.
I'm amazed at how APC is right on top of just about every application that is out there. Where does all their input come from..? Top level competitors I imagine.
I've disagreed with them for dropping the 7.2x8.6......but they know their sales figures don't lie. Too bad for some of us because that was an awesome prop for .40-.50 speed projects.
Their selection of 1/2A props is pretty awesome considering how few 1/2A flyers there are.
DD...I admire your sense of ''fiscal restraint''..the solar power system doesn't have to pay dividends right away...it is more of a rainy day investment the way I look at it. A day might come when those systems are worth twice their weight in gold.
I found noticeable gains when flying TDs in C/L combat by cutting the 5x3 rubber prop down to about 4 inches.
I'm amazed at how APC is right on top of just about every application that is out there. Where does all their input come from..? Top level competitors I imagine.
I've disagreed with them for dropping the 7.2x8.6......but they know their sales figures don't lie. Too bad for some of us because that was an awesome prop for .40-.50 speed projects.
Their selection of 1/2A props is pretty awesome considering how few 1/2A flyers there are.
DD...I admire your sense of ''fiscal restraint''..the solar power system doesn't have to pay dividends right away...it is more of a rainy day investment the way I look at it. A day might come when those systems are worth twice their weight in gold.