drewbags

I have a spinner on mine, long threaded M5 bolt fits into the hub.

Bob Pastorello

My Feedback: (198)

The DL 50 carb is a WT-664A or WT - 624
I have engines with each.
None that I have had the 201b.

Bob Pastorello

My Feedback: (198)

We should never need to make a comparative statement between brands. Others who want to experiment will do so to learn for themselves. "Believers" in one brand over another will discredit contrary information, anyway. Even to the point of posting replies TO someone calling them a liar when they post THEIR results with a certain engine. Of course, it doesn't make a whipstitch difference that the critics do not have any first hand experience, either. Add to that the "standard" forum-doubt on stated rpm readings and comparing becomes an exercise in futility.

It is just ridiculous to see the brand debates rage when they are so pointless.

Your 3W rpm figures sound right based on the DL 50's I have. Canister systems can help things a lot, also.

The DL uses a different carb than other 50cc engines; maybe there are some differences to attribute to that.

paul5992

This forum is for help and talking untill someone comes in and starts calling the dl a clone or a cheap copy. I've heared about the cast block a 100 times the motor runs and fly my plane perfect. So please leave the da talk for some were else.

Bob Pastorello

My Feedback: (198)

paul5992 - regard JXF props.... I have had some, and they work well, but there are variations in firmness and rigidity from prop to prop. Try the "untwist" test. Grab a NX or 3W or Menz....try to untwist the blade and watch. Then do the same with the Xoar or JXF. In my experience the JXF untwists more easily than others. The very WORST out there for this un-twisting are the Master Airscrews, Zingers, and absolute BOTTOM of the bucket, the Top Flites.

Please know that I am not "bashing" products as I only share my personal experience and observations on these threads. If I do not "know" how something acts, I'll not comment.

In the case of props, I have done a lot of experimenting.... my DL's really are "happy" (so I'm happy) with the NX and Xoar 22 and 23 x 8's.

If you are concerned about hub compression, and still want to run a soft prop, simply drill four 1/8" holes through the hub like mounting holes. Get 1/8" hardwood dowel. You will have to tap the 1/8" dowel into the snug fit holes drilled, then simply put a drop of CA glue on front and back. The dowels will absolutely stop compression.

This is the same fix (only done with 3/32" dowels, or hardwood toothpicks) to firm up the cheap-ARF firewall engine mounting holes so they don't compress under standoff tightening. Works like a charm.

SlabBro

Hey all. I'm purchasing the Gene Saucy extra 3oo from GP in Feb w/2.4 radio system. Is this engine to much for this plane?Read the Thor 45 thread and that motor sounds a little scary. I really want to go gas this next year but i'm a flyer who has to watch EVERY penny and so far this sounds to be the motor for entry but wanted to make sure it will fit the plane. later thanks guys

Bob Pastorello

My Feedback: (198)

WAY too much engine. Local guy has one of those with a gas FORTY cc, and it is ridiculously-overpowered.

Sorta like my Obsession with a DL 50.

rcairmike

My Feedback: (19)

aero bob,from what i am reading there is a couple versions of the dl 50.can you tell me what version you have .im just trying to find out if there is a carb diffrence between productions of this engine.thanx much

Bob Pastorello

My Feedback: (198)

Me, too. I've written Bob Kramer at DL USA about this. I have had three of these, now own two, and they work very well; no carburetor issues at all. The "newest" version, that I'm aware of, is the standoffs and thicker mounting lugs version, with some minor hub improvements. Performance is identical to earlier ones that I had.

The newest engine (one week old) has the WT - 664A carb on it.

Ed Vollmer

My Feedback: (14)

What's up with all these different carb numbers? I have installed 6 of these engines on customers planes and the latest carb number is WT 734 (arrived last week). I did not note the numbers on all the other carbs but all appeared to be the same carb for installation purposes. Early on I made a template for drilling the holes and all seemed to work fine.

BTW, everyone is very happy with the engines.

coronabob

My Feedback: (10)

Aerobob,

So glad to have you back in the thread. You mentioned drilling holes to put in hard dowels, are these in addition to the mounting holes? Great idea! I had a Xoar prop on a YS110 that got compressed so badly. Your trick will work there too.

Bob Pastorello

My Feedback: (198)

Yep. Works just fine, done it several times on softer hubs. "Trick" is to be very careful and NOT overdrill the holes for the dowels, so they have to be "driven" in and are snug. That makes sure the CA will wick on the whole circumference of the dowel, and probably actually adds some strength.

arobatx

I've done the same thing with small diameter carbon rod. I didn't do this on purpose as opposed to wood dowels or toothpicks, it was just all I had around at the time. Works like a charm!

Chad

XJet

But surely the prob hub will still compress until almost all the load is taken by the dowels or carbon -- effectively meaning that you're no longer spreading the load over a wide area but concentrating it on a small one.

I'd be concerned that this might then cause premature structural failure of the prop due to splitting, as the torque is now being transmitted through those dowels and not by the hub and washer themselves.

How hard can it be to simply re-torque the prop bolts at regular intervals anyway?

denney47

My Feedback: (359)

I use 3.5" Aluminum Spinner in my DL using a 10/32 socket head bolt.

TLT

Coke

I have to agree with XJet here the hub thus treated will be transmitting the load on the "4" hard points. I would suggest that either the props are being over torqued or are not fit for purpose if they are crushing to this extent under engine munufacturers reccomended torque settings

Bob Pastorello

My Feedback: (198)

Coke, Xjet - have you DONE the modification I'm suggesting to any props and run them?

I have done this a few times, when pressed by needs to use less-than-optimal propellers, and although there may be some stress/load redistribution in the hub, the ones I did sure didn't fail, either.

Not picking a fight, just trying to offer help to someone who was trying to prevent worse problems through hub compression while in use. (As a former ZDZ owner, I can tell you that that phenomenon DOES occur, and can be REALLY BAD when it happens in flight).

I'd be interested in some sort of a means to test the compression load distribution across the whole hub face before and after such a mod?

BTW - with softer hubs, torquing the screws to an appropriately "correct" value doesn't cut it....they will loosen nearly immediately when run, then they must be re-tightened, and that is where the circle starts.

Personally, the NX, Xoar, and PT Models hubs seem to be quite hard. The JXF that I have vary from prop to prop quite a bit.

eugene

Wavy,
No matter the Mfg., 50cc is still 50cc. You have to fill that displacement with fuel to make the power....You cant cook bacon in a cold skillet, it takes fuel for the fire....

chuck l

My Feedback: (17)

In Bob's manual for the DL-50 he says "A general rule of thumb is to richen from the maximum on the ground rpm by 200rpm". How many of you guys do this and can tell a performance difference between richening the high speed needle for the 200rpm drop vs setting the high speed needle for max rpm on the ground?

arobatx

The idea is that the engine/prop combo will unload in the air... adjusting on the rich side of max rpm by 200-300 on the ground is a safety measure to ensure you will not be running too lean when unloading in the air. Personally, I don't consider my engine fine-tuned after adjusting on the ground. I adjust reactively to its performance in the air. too many variables differ between static on-ground tuning and what the engine is experiencing in flight.

Chad

Al Lewis

Bob, You could always set up two dial test indicators on the front plate after tightening the bolts. One on the washer just outside of the dowel and one just outside of the bolt head. Set them both to zero and come back a couple of hours later and see how much they have moved in relation to each other. The one outside of the bolt should move more. I know I kept re-tightening the bolts on my TBM prop and after about the fourth time the hub cracked. The Vess don't seem to have that problem. Also keep in mind that these props are side loaded against the four bolts so over-tightening is not necessary. I just snug them up in a set sequence and then run back through the same sequence until they all remain snug. If your spinner back plate has particularly deep serations it will usually take a little longer to get a new prop set into them as they cut deeper.

Coke

Bob I have to say I have have not done the modification nor would I consider so doing, as I said in my post there's something amiss with the propellers and they should be consigned to the rubbish bin. Not only this if I read your post correctly you then go on to advocate overtightening of the propfixing(s) to alleviate the said problem. From all my time in engineering one should never cure one problem by creating reasons for another possible one with possibly a worse outcome. I too am not looking to pick a fight whatsoever but if I come across such a prop it goes in the bin or is used to light the fire or stir paint

Richard D Bahmann aka/Wrongway

My Feedback: (42)

Go Vess props. Never a dent in the hub material, also NX and Skorpa props in my experience when it comes to wood.

outssider

My Feedback: (23)

i think you guys are getting carried away with the amount of torque you are applying on those prop bolts....take it easy ! just keep them snug...

arobatx

Here you go guys! Pat's comment is of particular interest here....

[link=http://www.rcuniverse.com/forum/m_6243817/anchors_6243817/mpage_1/key_/anchor/tm.htm#6243817]Prop Bolt Torque[/link]


Chad