gade600sdi

I drilled a prop at 12:00 and I needed to do it at the 2:00 position, for my 50cc engine. Did I just ruin my $35 prop, or can I re-drill and live with the extra holes (or fill them with epoxy for strenght). Is this dangerous if there is only a little prop wood for meat in between? I would think it could be so I am hesitant to now put 8 bolt holes in my prop instead of the 4.

Tired Old Man

My Feedback: (1)

Of course you did.

Not really. Just obtain an appropriately sized round wood dowel that tightly fits the hole. Glue a piece of the dowel in the hole the full depth of the prop. Then be more careful next time

BTW, what's an "h" prop?

Antique

My Feedback: (4)

Another good reason for a single bolt prop hub...4 bolts are NOT nrcessary on a 50...Or a 62..or an 80..or anything else...A 3/8 24 grade 8 willl hold ANY twin used on ANY giant scale airplane...Our 40+ HP ZDZ custom made racing engines have a single bolt and 2 smaller 10-32s througth the prop...NO slip ever..The spinner backplate is bolted to the hub with 1/4-20 flatheads....
You could pull a truck with a single 3/8-24 grade 8....
Been harping on this for 24 years..And will continue to do so...
In case you don't believe the 40+ hp part, see what it takes to turn a 24x31 carbon prop 10000 rpm in the air..Our ZDZs do... With open stacks, no pipes...I can only image what pipes would do, our rules prohibit pipes outside the fuse...
usrainfo.org

Pelle Gris

+1

KenLambert

My Feedback: (107)

I think you should buy a new prop and send that one to me!

Tired Old Man

My Feedback: (1)

Ralph,

You know I agree with you but what do you think the odds are of manufacturers reverting to a single bolt hub? Zero or less than zero? The whole multi bolt thing was started by a couple of engine makers looking for a sales gimmick.

Your arguement is just as effective as me telling people not to use Amsoil. Both are dead on correct but both are like piing into the wind. A strong wind.

HunkaJunk

Not to mention the fact that Amsoil has a good many customers who have used their products for 20+ years. Believe it or not, years ago when I wanted to switch my dirtbikes to full synthetic, the most readily available to me was Amsoil. It's difficult to convince someone that they are destroying their engine with a product that has performed well for them for a couple decades.

aussiesteve

Plenty of dirt bikes use all sorts of products but I wonder how often dirt bike engines get stripped down? (I do know the answer - and it is significantly more regularly than any of our RC engines should need to be stripped).

Single bolt hubs are certainly the way to go but could you imagine most of the lower cost manufacturers trying to make them? - I wouldn't want to be near one. First they would make the hubs smaller to save money, then they would exacerbate the hub runout most of them build into their engines then they would use a "black colored" bolt into poor thread forms and the end result would be death and destruction for sure

Zenoah, BME, ZDZ and the specialised Engine builders such as Ralph is used to dealing with all understand the use of quality to begin with.

Now back to the original Post

Epoxy in some dowels and redrill. Keep an eye on the hub for any signs of fretting and if they appear - ditch the prop.

mbinkley

Some guys like to have there props drilled at the 12:00 position. Vally View offers that when they drill props for you.
Give it a try

MetallicaJunkie

i have a Mezjlik prop i drilled wrong, all i did was line up the drill jig to drill 4 more holes all evenly spaced and it worked fine.... i now have a prop with 8 perfectly spaced holes and has held up for over 6 gallons strong

if it was a wood prop i might not consider doing that but who knows

TheRickster

My Feedback: (12)

My 3W-55Xi has a 6 bolt hub, can't see 2 more bolt hole being a disaster.... Drill you 4 more inbetween the 4 you have and fly it...

Rick

Tired Old Man

My Feedback: (1)

I certainly hope your engine never experiences a back fire. If it does you better be real fast. I would never recommend someone drill an extra set of 4 or 6 holes in a prop. You obviously have never seen one initiate catastropic failure at the hub. Thousands of tiny knife blades going everywhere at 350 mph.

TheRickster

My Feedback: (12)

First off I was not saying that I drill twelve holes in my props, I was merely making the point that if you have a 4 bolt hub and miss drill and have to drill 4 more you are only 2 bolts more than the 3W and the ZDZ engines.

If I was in a situation where I had to use a prop that was miss drilled I would rather risk the extra holes than risk the issues that arise from trying to tighten the prop hub with differing lengths of dowel rod in it causing uneven crush . Unless the rods are cut to exact lengths and glued in the hub at the exact same depth so as to allow an even compression of the drive washer when tightened. Also it seems to me that with the dowel rod the drive washer is primarily pressing on the dowels rather than the hub because of the difference in hardness of the dowel versus the prop makeup..

I have done the dowel rod before and it worked fine with no issues. If all the steps are followed it works. IF for some reason tho the rods are differing lengths or depths then I feel a greater danger is imposed than just running 4 open holes..

This is my take on it anyways..

Rick

Revy

My Feedback: (1)

I'm with TOM, you'll have a new stir stick or worse if you drill more. I like my props drilled at just after 12 o'clock. Try it out before you choose any other option, including replacement.

Tired Old Man

My Feedback: (1)

The difference with the 3w and ZDZ hubs is they have a screw passing through the hole adding a compression load at exactly the location of the hole. Re-drilling holes is not an issue. Leaving open ones unsupported in a prop hub is not a good thing to do. Plugging the open holes might save you or others your health, or more.

rc bugman

My Feedback: (30)

Hi,

Which is cheaper? The prop or a trip to the hospital?

Take the prop to the band saw and make it unusable.

You know the saying "penny wise and pound foolish.

When in doubt, I always error on the safe side and I have never has a prop come apart and I run WOT all the time with my research planes.

Ditch the prop and reduce the risk

Elson

Bass1

I've been mounting my 50cc props at the 12 o'clock position (or just ever so slightly after) for awhile now and it seems to be easier on my tired old back! Try it before you start dowling, gluing and redrilling you may like it where it is.

Whistling Death

I drill all mine at 12 o'clock.

KenLambert

My Feedback: (107)

why do you guys wait till 12: oclock to drill your props? I am usally at the feild by then.[sm=teeth_smile.gif][sm=teeth_smile.gif]

aussiesteve

Ken, that's just silly and you obviously haven't completely understood it. They say they drill them at their 12 o'clock position. In your case, you would be drilling them at the field as you would already be there at 12 o'clock

For the OP, You may mount the prop "horizontally" and be happy with that also (I am not going anywhere near "o'clock" positions now )

nonstoprc

My Feedback: (90)

I do not like the idea of re-drilling a prop. If flip at 12 o'clock is hard, try to raise the left wheel by an inch or so with a wood block.

Tired Old Man

My Feedback: (1)

Leave the Kama Sutra out of this. Next thing ya know someone will be quoting Dr. Joyce Brothers.

nonstoprc

My Feedback: (90)

Then re-drill is living a virtue life?

Tired Old Man

My Feedback: (1)

If you've been practicing the Kama Sutra it's not possible to have much in the way of virtue remaining. I think that's one of the first things that goes.....

nonstoprc

My Feedback: (90)

Then u need to read the work again.