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Thread: CNC vs octura?

  1. #1

    Default CNC vs octura?

    What's the difference between the cnc machined props and say an octura??? Are they heavier? What would be the equivalent of an m445 if it was cnc out? Y is everyone using the other brands and not cnc Thanks in advance!

  2. #2

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    Octura are heavier, MUCH heavier, it really took me aback the first time I held a CNC prop, I've not weighed either but I wouldn't be surprised if the CNCs were less than half the weight of an Octura ready to go, and a third of the weight fresh out of the pack.

    An M445 equivalent would probably be a 447 as the blades are thinner than the thick M series, and they have less blade area which comes from having even less tongue and a slight backcut which all contribute to less load, however I would start with the same size and work up keeping an eye on heat as ever.

    In the FE race scene over here there are more CNC alloy props in use than there are carbon, BeCu and stainless combined, both ETTI and Tenshock are way more popular than Octura here and R2 are probably about the same, Tenshock seem to be the best of them and I know several people that have switched from ETTI to Tenshock and noticed a difference, R2 come at a different price point so I haven't seen that crossover for direct comparison yet.

    I use Octura because I have a box full of them, and over the years I have learned to shape and bend them to my and my boat's liking so I don't think it gives me any disadvantage, if I was starting out now, I would buy a bunch of Graupner carbons (right now, while they are still available, as Graupner are teetering on the edge) and when I found the right size I would buy a Tenshock CNC the same size as the blade shapes are very similar. It is a quick and easy way of getting to a prop that performs very well, can be cheaper too as we know Octura's put more load on than Graupner's if you get how much smaller you have to go wrong and buy another than an R2 CNC would have been cheaper and a Tenshock about the same.

    I would guess what puts most people off CNC is the price being around double what an Octura is over here, it makes them a pretty expensive proposition if like me you don't factor your labour into the equation, if you do however they are amazing value, I spend a full day on preparing 2x 15 Octura props normally, if I had spent that day at work doing overtime I would probably had a better time, (I hate doing props and my hands start aching after a couple of hours, and I always cut myself) and would have earned 120 which is enough to pay for 4x Tenshock CNC props at 30 each, but I would have a lot less job satisfaction.

    There are some for whom CNC props will not be good enough, I hear the 7075 alloy they are made of does not take kindly to bending and can crack or snap if tried to bend much, so super tweakers like the Snowman won't like them, they are weaker than stainless or heat treated BeCu too so I doubt they will be any good for those running SAWs.

    We run much higher KV setups here than you do in the states, with correspondingly much smaller props to keep the amp draws reasonable, the idea of 1500kv in a 4s boat seems completely alien to me.
    I haven't seen a prop bigger than 45mm on a raceboat for years, so I cant say how well the larger sizes hold up.
    Paul "tug Killer" Upton-Taylor, Cat lover.
    FastElectricBoats.co.uk

  3. #3

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    Funny you say that, I'm one of the odd balls who is running high rpm with small prop.

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    Wow thank u for the detailed response! Will have to read it a couple times to understand it fully!!!

  5. #5

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    R2 hobbies props a a mild grade aluminum compared to some other like the ones OSE sells. I bought a pair and I'm not thrilled with the quality.

    Never tried Etti or Tenshock props.

    BerCu Octura props and other such as ABC and Propshop props are generally stronger material than poor aluminum or even the better ones OSE sells.

    If you ding an Aluminum prop most times it's done, Octura, ABC, Grimm racer etc.. are re-workable more than aluminum.

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  6. #6

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    Isnt CNC technically just anything made on a lathe by a computer? or somthing? to me sounds like a car manufacturer called... CAR

  7. #7

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    Close, I would guess they are made on a (Computer Numerically Controlled) milling machine not a lathe, but you are right that CNC just describes the manufacture process rather than the company name, hence us discussing CNC props from several different companies, ie ETTI, R2 and Tenshock.
    Last edited by NativePaul; 09-19-2013 at 04:22 AM.
    Paul "tug Killer" Upton-Taylor, Cat lover.
    FastElectricBoats.co.uk

  8. #8

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    Quote Originally Posted by iamandrew View Post
    Isnt CNC technically just anything made on a lathe by a computer? or somthing? to me sounds like a car manufacturer called... CAR
    yes it's just a huge precision machine controlled by a computer

  9. #9

    Post Aluminum Props

    Quote Originally Posted by ray schrauwen View Post
    R2 hobbies props a a mild grade aluminum compared to some other like the ones OSE sells. I bought a pair and I'm not thrilled with the quality.

    Never tried Etti or Tenshock props.

    BerCu Octura props and other such as ABC and Propshop props are generally stronger material than poor aluminum or even the better ones OSE sells.

    If you ding an Aluminum prop most times it's done, Octura, ABC, Grimm racer etc.. are re-workable more than aluminum.
    ...If you ding an Aluminum prop most times it's done...
    VERY true statement, see attached pix. T6061 CNC'ed x442, I got a little too close to the shore last summer, kiss $22 + ship goodbye.

    But, I'll buy replacements in time for summe, I don't have the time nor inclination to spend all day prepping props. I spend a good couple / three hours prepping the CNC props as it is to get the machine marks out + add a satin finish per these instructions... http://www.aquacraftmodels.com/acces...op-tuning.html

    BTW: they are very light weight as Paul stated

  10. #10

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    It's always good to have a wide selection of props Alum. or any material. ...and yes the CNC ones do save alot of time. It's also nice for those that have aging hands and sore knuckles from arthritis.

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  11. #11

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    So I wouldn't have to do anything to a cnc prop to run it? Example-sharpen or balance it or anything, just throw it on and run it!?

  12. #12

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    Quote Originally Posted by Megabiker98 View Post
    So I wouldn't have to do anything to a cnc prop to run it? Example-sharpen or balance it or anything, just throw it on and run it!?
    Yes, that's what they're designed for... http://www.offshoreelectrics.com/pro...+2+Blade+Props

  13. #13

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    I disagree. I haven't bought a cnc'ed prop from OSE but, I've bought them from elsewhere and although you don't have to sharpen them, it makes a world of difference.

    Finishing them doesn't do much but, blade sharpness is important.

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  14. #14

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    Quote Originally Posted by Billy Barnacle View Post
    Yes, that's what they're designed for... http://www.offshoreelectrics.com/pro...+2+Blade+Props
    sweet!!! So I can get two of those props for the price of one pre-balanced octuras!!! Hahaha
    Or would it be wiser to get an m445???
    Last edited by Megabiker98; 02-16-2013 at 09:52 PM.

  15. #15

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    45mm


    40mm

    These are not "M" series they are basically, like Octura x445 and x440 with tongues on.

    To get M series I found these on Ebay


    and this in 40mm

    I've never tried the ebay props. HK also sells M type cnc props.
    Last edited by ray schrauwen; 02-16-2013 at 10:04 PM.

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  16. #16

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    Ahhh dang I've heard the x series props create lift! Darn so the cnc props from offshore won't work! And I just ordered from hobbyking, and don't wanna pay expensive shipping for a while! Hahah looks like ill be rocking the octura m445 for a while then!! :/

  17. #17

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    Quote Originally Posted by ray schrauwen View Post
    I disagree. I haven't bought a cnc'ed prop from OSE but, I've bought them from elsewhere and although you don't have to sharpen them, it makes a world of difference.

    Finishing them doesn't do much but, blade sharpness is important.
    Ray,
    I didn't buy mine from OSE either, got them from Jan, his are made from T6061, or were when I got mine. Steve wasn't selling CNC props last summer, or at least I don't remember seeing any in his store.

    I like the fact that they're balanced, and I'm going to have to respectfully disagree with you on the finishing part. Think about it for a minute, tuners always tell people to scuff up the bottom of their hulls, scotch brite, 400-wet/dry, etc., so why wouldn't you want to do the same to your prop?? Sorry guy, but I'm not understanding your logic

    The Grim Racer prop guide I included a link to in post #9 states...
    "We recommend a satin finish on the prop. A super shiny prop can cavatate more than a brushed satin finish. A satin finish can also help your boat accelerate out of a turn faster. Using a scratch pad, buff the entire prop down until all the shine is off the blades. Be careful as you are now working with a very sharp propeller."

    Kinda figured Mikey has forgotten more about props than I'll ever learn, so I went with his advice.

    Look at the tool / machining marks on the HK prop you included a link to (see attached), that's what I was referring to in post #9, those are what I'm trying to get rid of, I start with 220 wet/dry and work my way down to 400, I also work on taking out any dings on the leading edges, get 'em nice and sharp

    JMHO / .02
    Last edited by Billy Barnacle; 02-16-2013 at 11:43 PM. Reason: Forgot The Pic

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    Nice prop do you have a link?

  19. #19

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    Post 15 last link.^^^^

  20. #20

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    Quote Originally Posted by Megabiker98 View Post
    Post 15 last link.^^^^
    Thank you

  21. #21

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    Quote Originally Posted by Billy Barnacle View Post
    Ray,
    I didn't buy mine from OSE either, got them from Jan, his are made from T6061, or were when I got mine. Steve wasn't selling CNC props last summer, or at least I don't remember seeing any in his store.

    I like the fact that they're balanced, and I'm going to have to respectfully disagree with you on the finishing part. Think about it for a minute, tuners always tell people to scuff up the bottom of their hulls, scotch brite, 400-wet/dry, etc., so why wouldn't you want to do the same to your prop?? Sorry guy, but I'm not understanding your logic

    The Grim Racer prop guide I included a link to in post #9 states...
    "We recommend a satin finish on the prop. A super shiny prop can cavatate more than a brushed satin finish. A satin finish can also help your boat accelerate out of a turn faster. Using a scratch pad, buff the entire prop down until all the shine is off the blades. Be careful as you are now working with a very sharp propeller."

    Kinda figured Mikey has forgotten more about props than I'll ever learn, so I went with his advice.

    Look at the tool / machining marks on the HK prop you included a link to (see attached), that's what I was referring to in post #9, those are what I'm trying to get rid of, I start with 220 wet/dry and work my way down to 400, I also work on taking out any dings on the leading edges, get 'em nice and sharp

    JMHO / .02
    I so call finish them too same as you but, if they had a sharp leading edge I wouldn't touch them. All CNC props I have with the only exception being a CMDI, needed leading edge work for full performance. My CMDI 5018 x3 was sharp as a knife from factory. I would like to see if the VXB from ebay would sharp like CMDI, that would help justify the extra cost compared to what OSE has or HK.

    Are OSE CNC props completely razor sharp from the package or not???

    The Chinese ones I have worked o.k. from factory but, lit up very nicely after sharpening and scuffing. Easy to keep in balance by remembering how many swipes on 220 paper you do to get a fine edge. I still re-balance but, it's easy with aluminum.

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  22. #22

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    Watch the bore sizes. They have some real oddballs like 5mm, 6mm, 3mm 4mm and threaded 4mm.


    Quote Originally Posted by Billy Barnacle View Post
    Thank you

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  23. #23

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    I'm having good results with my CNC props from OSE
    Jesus is King ..... Magnum Lipo ...Caterpillar UL-1, P-Spec OM29, P-Mono DF33, P-Spec JAE, Aussie 33" Hydro-PSport, FE30-LSH, Sprintcat CC2028 on 8s, PT SS45 CC1717 Q Hydro, PS295 UL-1 power, OSE Brothers Outlaw TP5682 on 8s , Rio 51z CC2028 on 8s

  24. #24

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    What are they like? Do they have a razor sharp leading edge like a CMDI or are they sorta blunt like a raw Octura or Prather??
    I'd like to know please, thanks!

    Quote Originally Posted by Brushless55 View Post
    I'm having good results with my CNC props from OSE

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  25. #25

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    Quote Originally Posted by ray schrauwen View Post
    What are they like? Do they have a razor sharp leading edge like a CMDI or are they sorta blunt like a raw Octura or Prather??
    I'd like to know please, thanks!
    Ray,
    The ones I got from Jan have a sharp edge, but there is the occasional very minor ding here or there. I'm a perfectionist, figure if I'm going to invest the time to remove the machine / tooling marks, than I should also make sure the leading edges are as sharp as I can possibly make them.

    Jan's are now precision machined from strong 7075 aluminum / magnesium hybrid (like Steve's) here's link in case your interested... http://kintecracing.com/CNC_Machined_Props.html

    Regarding the odd ball bore sizes... I found instructions at Steves site (I attached them) for making spacers from brass tubing to fit 3/16" props to one of the odd sizes you listed, 4mm. What I do different.. make the spacer the full length of the prop hub and cut slots for the drive dog - see attached example.

    Hope That Helps Out...

  26. #26

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    Quote Originally Posted by Brushless55 View Post
    I'm having good results with my CNC props from OSE
    Are these the ones your getting??... http://www.offshoreelectrics.com/pro...Props&sortby=3

    Unfortunately, he's out of 42mm - so far that seems to be the size my boat like's most, but I do want to try a 43mm this summer, see what happens.

  27. #27

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    Thank you. I didn't completely read your post the first time like I should have about the sharpness.

    Quote Originally Posted by Billy Barnacle View Post
    Ray,
    The ones I got from Jan have a sharp edge, but there is the occasional very minor ding here or there. I'm a perfectionist, figure if I'm going to invest the time to remove the machine / tooling marks, than I should also make sure the leading edges are as sharp as I can possibly make them.

    Jan's are now precision machined from strong 7075 aluminum / magnesium hybrid (like Steve's) here's link in case your interested... http://kintecracing.com/CNC_Machined_Props.html

    Regarding the odd ball bore sizes... I found instructions at Steves site (I attached them) for making spacers from brass tubing to fit 3/16" props to one of the odd sizes you listed, 4mm. What I do different.. make the spacer the full length of the prop hub and cut slots for the drive dog - see attached example.

    Hope That Helps Out...

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  28. #28

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    Quote Originally Posted by ray schrauwen View Post
    Thank you. I didn't completely read your post the first time like I should have about the sharpness.
    Your welcome, glad I was able to hellp out

  29. #29

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    Has anyone tried these props? I looking for a good set of CNC'd L&R props for my twin 1515's

    http://www.ebay.com/itm/VXP-VX4218-3...item27cbc8f593

  30. #30

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    nope never tried them! MYGOD! $129 😱 I most likely won't be trying them! Hahahah

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