I ordered a drill jig from TroyBuilt for my DZD 40. I was too lazy and didn't take the spinner washer off the airplane to check and the jig had imprinted on it DZD 40-160 6 hole. YES, I used a drill press.
As you can see, all the holes are half a hole off on this $50 prop.
At first I though of filling the holes with epoxy and useing the engine prop six hole washer and drill new holes between. Geese!
OR, take my Drimel Tool and "hog" out half a hole to make fit.
I have the feeling what you guys are going to tell me.
Engine RPM is 7400 with 20-8 prop.
Jim

I'd fill the holes by epoxying a dowel in them, and drill the new holes in between the wrong holes.

At 7400 RPM's I'd say you've got a $50.00 paint and epoxy mixer. What are the chances of a structural failure to a modified swinging dagger? For $50.00 I would'nt bet your life on it. If we were talking servo mounting holes, that would be one thing, but a propeller?

Plug the holes with a tight fitting dowel, ca in place from both sides, and redrill.

I would ditch the prop and get a new one.

next time drill the prop using the correct guide holes.

Don't feel too bad. I did this too, Shi& Muth$# Fu^&* wrong guide holes.

My vote is with TOM. You are only a half a hole off. The hubs on those big props are thick enough to leave a lot of wood after the holes are drilled. A tight dowel with CA is probably stronger than the wood. That is why we put CA in the screw threads in wood.

First, I would return that drill jig to TroyBuilt, asking for a refund plus a compensation for the damaged propeller.
If they stated that the drill jig was good for your engine and it was not, THEY have a problem.

If there is no success that way, then, I would plug the holes with wood dowels and carpenter glow, which is soffer to redrill.
Then I would use the engine prop six hole washer as a drill jig, using a proper diameter central shaft or bolt for perfect centering.
I would drill the first hole (only one), on the same spot, starting with very small diameter bits, since the drilling will tend to deviate away from the new dowel.

Once that first hole is complete and correct respect to the center shaft or bolt, insert a bolt or dowel (tight fit) into it.
That would eliminate any accidental angular rotation for redrilling the rest of the holes.

Repeat the drilling for the rest of the five holes.
For better results, drill each hole half way in and then flip the prop hub and do the same from the other face.

I believe the propeller will not be weaker if you do not redrill in the space between the existing holes.

Best luck!

How close is the smaller set of holes? It looks like they might be used for alignment after the gluing.

There was a good point in the last post. Since you have a drill press you already had a drill jig. The prop retainer would have done fine as the drill jig.

Your prop has a wood core. Meaning that a wood dowel will be easily compatible with the core material. The method of plugging drilled holes with a wood dowel is one that has been used for a great many years on many propeller sizes and types with little chance of failure when done correctly. Tight fittng and secured with a good adhesive. I do the same in carbon propellers of larger size and have yet to have one come apart when attached to the plane correctly. One of the up sides, if there are any, of using a hardwood dowel is that a dowel with greater wood density than the core of the prop hub will assist in preventing hub compression when affixing the propeller to the engine. Still best to use a torque wrench and not over torque at all, eliminating any chance of hub compression.

i would use the prop and do as tom suggested....also make sure to balance to prop to be on the safe side

I was wondering why nobody brought this up. So far the thread has been about fixing a prop that looks very much like the vendor's fault. Have them take care of it.

He has the correct drill guide, there are 12 holes in the guide, he chose the wrong 6 to drill. No big deal, I've done it myself, hardwood dowels and epoxy or CA will fix the hub.

%#*%## I'll Be....you are correct. I have the right drill jig....but, use the wrong set of holes.
See what happens when you get in a hurry to get to the flying field with a extra prop!
I think I will use the dowel and white glue method at this time.

But, I want to say....I have been sent the wrong drill jig before.
About three months ago I ordered a drill jig for a DA50 4 bolt. And it wasn't even close.
Sent it back and Troybilt. They gave me credit which was no problem with me.

When I ordered this DZD 40 drill jig, I ALSO ordered another DA 50 drill jig at the same time...and it is correct.
So go figure??
Check before drilling.
Thanks all
Dummy Jim

And I should also thank a couple of other people on here that spotted the "other set" of holes in the jig.
Thanks also guys
Jim

i have a psp jig for a da 50 and it too seems a bit off...i have to end up drilling larger holes after i take the jig off to get the props to fit right

Drill jigs for the DA 100/150 and 3w 100/150 also have different hole patterns. It's up to the user to identify the engine and the associated hole pattern on the jig. Yea, I drilled a hole from the wrong pattern once too, but I stopped at the one. Hard to sell a 28" pre-drilled 2 blade prop to anyone with a 150....

I have noticed that my jig is a little off also. The diameter is a little smaller than the prop hub. Probably manufacturing tolerence or sloppy design. I usually just drill a larger hole or use a chainsaw file if it is close. The center post will locate the prop on the hub. The holes are for clamping. A little oversize likely doesn't matter.

I noticed you said you had a drill press.
In that case, why are you using a jig? The prop washer makes for the absolute best locator if you have tools to drill straight through the prop, aka drill press

It would be in the trash here... I am not going to take a chance hurting someone. If it did fly apart and hurt someone, what is my defense? I saved $50 and doweled a prop that should have been thrown away.

It is a shame, but it is nothing but trash now.

Misdrilled prop? No problem. Perfect excuse to buy another engine (to fit the prop), then a new plane to match the engine, servos, receiver, etc etc........

What I soon found out about using jigs. Make sure the jig is the same bolt hole pattern to the hub plate for your engine. Set them in aliment with each other and take a close look. The holesshould match pretty close. Youcan check that too with tight fitting bolts, drill shanks or pins. I have found out that after you drilled the first hole is to use a tight fitting bolt or round pin to locate it. Then drill another hole on opposite side and pin that one also. Drill & pin as you go....they come out better. Balance also.

Capt,n

757 LOVE IT!!! That is the same reasoning that I use with my wife!!

Did you purposely leave out the trailer or other means of transport for the new plane?

Forgot the larger, better equipped new shop too.

For those that are terrified of plugging a hole and re-drilling a prop. The process has been taking place for 50 years with extreme success. You do the same thing to a firewall if you want to change engines. Don't let your inexperience scare you. You miss out on way too many wonderful things that way. Those that cannot drill a straight hole or wobble the bit may should consider buying another prop.

I do the same as captainjohn. Pin it with bolts as I go. Holds the alignment that way.