BubbasanJohn

Howdy all, going to move to 3 or 4 bladed props on my DLE35ra. I only have a few tanks thru it. Currently alternating between 18x6 and a 18X10. When can I move to the 3 or 4 bladed prop? Would 16X10 be ok for the 3 or 4 bladers?

Thanks in advance.

All Day Dan

My Feedback: (5)

These guys should know. Send them an email with your requirements. Dan.

http://www.zingerpropeller.com/

BubbasanJohn

Thanks Dan.  Anyone Else?

3136

I have a 3 blade 16x 10 Master airscrew on a dle 30, that has more than enough power to spin it. Not sure on rpm but it revs out ok.
Sorry I don't have a 35, can't help you there.

BubbasanJohn

Thank you 3136

Granpooba

My Feedback: (5)

I have switched to 3 blade props on my Saito 4 strokes. I can be corrected, but I believe that you only need to go one inch smaller in diameter when going from two blades to three.
Thus a proper size would be 17/6 or 17/8.
If you want to whole scoop on this subject, just visit the Master Air Screw site as they have a conversion chart.

airraptor

My Feedback: (66)

I plan to really load mine DLE 35 down with a Beila 18x10 prop. it is = to a 20x10 load. If going to run a MA prop then a 18x10 would be pretty darn good if they make one. MA props have less pitch than other brands. it would be close to a 18x7-18x8 in APC

MTK

Mezjlik makes a very nice 18x10 in carbon. Pricy but might be worth it IF the 35RA will turn that prop.

I have one of them. I used it for break in of the OS GT33 on pipe. There is enough room on the hub for the4 screw holes

irocbsa

My Feedback: (12)

The biggest MAS three blade prop is 16". The DLE 30/35RA really likes the 16 X 10 MAS three blade, at least from my experience. I have four birds on that combo and it as long as you're not running a huge spinner that shrouds the prop (ex: Bf-109F or G), it's a great setup.

TBM has a three blade 17" Biela prop, but 17" in three blade configuration seems to be the tipping point that overwhelms the engine, at least from the manufacturers that I know of. The Bielas really seem to load the engine down compared to other props of similar diameter. If the MAS profile came in a 17" diameter, it would be practically perfect.

I've struggled with this for quite a while as the 120 sized warbirds would look great with an 18" three blade prop, but that diameter is just too much for the 30/35cc DLEs. That's why I started moving my "30cc" birds up to 50cc engines. A 20" three blade looks really cool on them, and they need the nose weight anyway.

BubbasanJohn

Thanks for the information guys. I forgot that I had ordered a foible biela's when ordering the airframe and engine from TBM. Just found them while cleaning my shop. They are the 3 bladed 16x10s.  So they should be about perfect it sounds.

airraptor

My Feedback: (66)

That 16x10 would be good. I think the MA 16x10 are not enough load. maybe the 30 but not the 35.

I am putting mine on a F-7F tigercat from ESM, sierra gear with hydraulic set up, brakes and all. I will run a custom muffler header set in these. the pistons and chamber will be ceramic coated to help the cylinders to not soak up the heat. I am hoping these props will turn around 5,500-5,800 with this set up. I can clean the props up some also. I went with these for a scale set up or close as i can. I think a scale 3 blade would be a 19"

BubbasanJohn

Thanks for the reply. Where are you getting your engine ceramic coated?  What is cost and what kind of temp drop can be expected?  Sounds very interesting.

MTK

Just a word of caution with Biela props...I've heard a couple woodies running on 50cc class models in 22" -23" diameters and 2 blades. These specificprops were great at converting engine power to noise; very loud noise. Dunno maybe the user was using very small pitch.

Let me recommend that the leading edges of the tips on the 3 blade props be rounded, if not factory done already. Not the whole tip just the LE. Seems to really soften the noise output. Take a quarter and trace around the edge, and sand away

airraptor

My Feedback: (66)

I will be generating a bunch of heat with the bigger engine. Ceramic coating the top of piston and the combustion chamber will reflect the heat back into the power stroke of the engine. This will make a tiny bit more power and keep some of the heat out of the cylinder. You can also Polish the top of the piston and the chamber to get close to the same results but it need to be a mirror finish at at minimum. You can have a heat absorbant coating on the bottom of the piston. You can also have that coating on the outside of the cylinder. It looks like the black crinkle coating on some engines. there are a ton of engine coatings out there to improve our engines. The thing is though you can spend a bunch of money on engine coatings or just by the next bigger engine.

BubbasanJohn

Mkt, thank you.

airraptor

My Feedback: (66)

some you can apply your self but you will need to bead blast the part then have the equipment to spray the coating and then bake it on. no home over will work. easier to just send to someone specialized in it.
Just look in your phone book for ceramic engine coating.


I dont have the time to list everything. search yourself with these words

Ceramic engine coating http://www.performancecoatings.com/index2.html
cryo-treatment of engine parts http://www.300below.com
diamond-like engine coating http://diamondcoating.net

These three different searches will give at least 8 hours of reading.


This you can do to improve your engine.

Ceramic coat top of piston, combustion chamber, exhaust port, header, cannister, muffler and tuned pipe with heat reflective coating.
Coat outside of cylinder and inside bottom of piston to help shed heat.
Use DLC on piston pins, skirts of pistons (if clearence is enough), crank pins, bearing races and carb bores

Do not coat the intake ports as it helps cool the cylinder and preheats the fuel a tiny bit.

The websites above are who I use.

BubbasanJohn

thanks Airraptor

RBean

BubbasanJohn, is the three blade going on your Hellcat? I don't have a DLE 35 but I do have a DLE 30 in a BH FW 190. 70" wingspan. I've tested several three blade props and here is what I got:

Beila 17-10 three blade - 6,000 rpm, the plane took off an flew ok level but lost a lot in verticle. Too much load for the engine.
RCGF 17-10 three blade - 6,000 rpm, did not fly the plane
Xoar 18-8 three blade - 6,600 rpm, flew ok
Xoar 17-8 three blade - 7,150 rpm, flew good

Since the 35 has more power than the 30 I think the Xoar 18-8 would work for you. Valley View RC has them but they are expensive. It would look great on the Hellcat.

BubbasanJohn

yes sir, for the hellcat. I have 2 biela 16x10 3 blades and a Biela 18x10 3-Blade Carbon Fiber Semi Scale Propeller. How long should i wait before testing them out. I have about 3-4 tanks thru the engine.

airraptor

My Feedback: (66)

stock ring or Bowman ring?

airraptor

My Feedback: (66)

The XOAR 3 blades are as much as the carbon Beila ones lol. The XOAR's tach up more which is good. I will now swith to the XOAR 19x8 3 blades and square off the tip to match most of the stock props on the F-7F

Thanks for the info.

BubbasanJohn

Stock Ring

irocbsa

My Feedback: (12)

Where did you get the RCGF three blade? I didn't know they made them?

I really want to use one of the "semi-scale" props from Biela, but the sizes are a bit odd. The 18 X 10 is way too much for a 30 but not enough for a 50. I'm guessing the only way to make it work would be to use a 40cc engine which aren't as common as the 30s and 50s. Maybe an RCGF 45 would be a good choice for that prop?

MTK

I used the 18x10 carbon 3 blader from Mezjlik on the OS GT33. The piped 33 has plenty of power to turn this size at 7400-7500 rpm. On muffler alone it may still work adequately but one should expect 300-500 rpm lower. If you don't already have the engine, don't overlook the OS; it is some kind of powerplant......

The caveat is that the Mezjlik doesn't look like a scale prop, on the ground.

irocbsa

My Feedback: (12)

Yeah, that's the issue I suppose. The "Semi-Scale" props from Biela really load the engine down a lot compared to other brands.