servari

Hey Brenner,

It's a very good news. I'm looking forward to having a new gearcase at the foot of the christmas tree.

Vincent ...

underdw

My Feedback: (2)

New design looks great Brenner!
Is the new receptable intended to sacrificially wear so that is a maintenance item? (I'm all in favor of this wearing as opposed to the motor pinion)
My gearcase is shipping tomorrow. I'm happy to pay for the return shipping.

Thanks, Dan

Brenner

Hey Dan,

The bronze that we're using is an aluminum bronze alloy, which is pretty tough stuff. The hope is that it doesn't wear, but if wear happens, it's going to happen on the bronze insert, and not the rotor shaft.

Brenner ...

gmr1948

Brenner,

Is the re-grease recommendation still every eight hours of run time?

Gary

Brenner

Hey Gary,

The recommended regreasing interval is 50 flights. However, it is not necessary to dissassemble your drive to regrease it. All you have to do is inject 3cc of grease through the center of the driveshaft.

This 3cc of grease is enough to supplement the grease that should still be inside the Drive. However, if you dissassemble the drive and clean out the old grease, you will have to put more grease back in. Probably about 4.5cc or so.

Overgreasing the Drive will not damage it, and in fact is actually a good way to pack the bearings with grease. Excess grease will push out of the way during operation, and migrate out after a few flights.

However, if you overgrease the Drive by a large amount, then there is a risk that grease will push up between the driveshaft and the front hub, and once it gets there it will extrude out of the front driveshaft bearing and mess up your spinner.

In a case like this, the rear hub rear bearing needs to be removed, and the excess grease needs to cleaned out in order to stop it from leaking when the Drive runs.

Brenner ...

Brenner

Some guys are asking me to mail them pinion gear update kits so that they can update their Drives themselves without sending their gearcase in for us to do the work.

This is not a big problem, and I'm certainly willing to send update kits out to people who want them, but removing the stock pinion gear isn't quite as straight forward as some are supposing, so I'd like to explain how it can be done without damaging the pinion gear bearings.

The key is to have something that can be used to support the pinion gear bearings inner races so that the pinion gear can be pushed, or tapped out. What I use is a gas fitting that fits over head of the pinion gear and pushes against the flat top surface of the labyrinth seal. This seal pushes directly against the inner race of the top bearing, supporting it so the pinion gear can be tapped out from the opposite side of the gearcase.

The complete process is illustrated in the attached pictures. The step by step process is as follows:

1/.. A small screwdriver is used to remove the retaining ring and washer on the bottom of the pinion gear. (picture #1)
2/.. A suitable fixture (in my case I use a gas fitting ..) is used to support the flat face of the labyrinth seal and the gear is placed on top of this fixture with the underside of the pinion gear facing up. (pictures 2 & 3)
3/.. A hammer or mallet is used to tap the bottom of the pinion gear in order to break it free from the Locktite that was used to originally fix it inside the bearings. (picture 3)
4/.. A drift, or center punch tool is used with the hammer to push the pinion gear through the bearings so that it falls free. (picture 4)
5/.. The labyrinth seal is removed from the pinion gear, and assembled on the pinion gear in the upddate kit. (pictures 5 & 6)
6/.. The bronze insert and the replacement pinion gear are installed from opposite sides of the bearings, and assembled with the supplied screw and removable Locktite.

Brenner ...

underdw

My Feedback: (2)

A follow up on my worn pinion issue:

Brenner has been wonderful and is replacing the drive pinion and bearings. He had to do a bit of work to figure out what would work with my down-level drive, but found a solution and is re-assembling the drive to check it out.
If anyone out there is pausing their purchase decision due to concerns about support or service - don't give it a second thought! Companies and people like Contra/Brenner that focus on customer service don't come along too often in this hobby. Thanks Brenner!!!!

On the Neu side, they too have been great. After a bit of discussion regarding the original mis-assembled condition, we agreed that I would pay $60 for the new rotor, and Neu would perform the work, replace a bad front bearing, and repair the loose fan at no charge. That's a fair deal in my mind.

PatternFlyer

My Feedback: (182)

Ok, I've sold some Neu F3A without gear box.
Just got two more came for couple of guys here in Kansas/Missiouri area.

One came with straight original gear.
The other one came with helical gear (popular for heli).

Based on Neu motors, they are discontinuing the motor with straight gear. So far, they told me that as long as they have the shaft with straight gear available. motor can be ordered that way.
I am going to ask Neu to keep the original shaft for F3A motor in stock for those using the motor for ContraDrive.
I've contacted Mr. Brenner Sharp about it and he is also going to talk to Neu about keeping the straight gear shaft in stock.
Producing a pinion adapter for the helical gear will be a lot harder expecially when it is so small.

Here is the link to the Neu Motors website.

[link=http://www.neumotors.com/Site/Welcome.html]Neu Motors[/link]

hope this helps.

Ihncheol

vbortone

My Feedback: (2)

I finishing installing a contra in a Gadious and I would like to pass some ideas in regard the installation. The built a couple of jigs to make the the installation a little be easier. The first one is a shaft with a sanding disk using 3/8 bolt and installing provitional firewall to keep the system in place while sading the nose to get the proper angle for the contra. Here is the picture that makes it more clear. Probably, this idea was posted before. I didn't see any so decided to post but I could be wrong.

vbortone

My Feedback: (2)

Here is a second jig I built to install the firewall at the precise angle and distance require from the now ring. I think pictures are clear but if you have questions let me know.

vbortone

My Feedback: (2)

Last idea. I use plaster of Paris to cast the nose shape. It was very easy to get the from support template shape after casting was done. Here is a picture that makes it clear. Any questions let me know. I am including a picture with final results.

Brenner

I just received a Neu f3a motor from f3aunlimited. Chris and Mike are stocking Neu motors that have been specifically assembled for Contra Drives. They are without the gearbox, and have the old "straight cut gear" on the motor rotor shaft.

This is a link to the page on f3aunlimited's website where it can be ordered:

http://www.f3aunlimited.com/webstore...roducts_id=237

Neu's designation for this motor is: 1513/2Y/Contra

gmr1948

Brenner,

Any new developments since this post?

Gary

Brenner

Hey Gary,

Yes, lots of stuff. Right now Mike and I are working on parts for our next batch of drives. The Drives from this batch are going to be relatively unchanged from the Drives from our last batch, except with these differences:

1/.. We have fully transitioned to using a bronze pinion gear interface with eight point contact. We introduced this change last fall, and since then we have quite a few pilots with several hundred flights using this change, so are feeling pretty confident.

2/.. We are making some small changes to the o-ring grooves in the main bearing bore of the gearcase housing which we hope will provide more support from the aluminum housing when side loads are present. (prop strikes..) Hopefully this will allow the teflon o-rings to support more load without deforming.

3/.. We are adding material around the tapered hub in the front hub spinner section. This is to prevent the skirt from flexing when the front spinner bolt is tightened. We're hoping that this change will allow more torque to be used when tightening the front spinner bolt.

We are also working on making a set of smaller diameter carbon fiber props for pilots who prefer to fly APC props. This is so they have an option that will help them make weight. These props won't be APC clones, but they will be very similar in size and pitch.

As far as colors are concerned, we have switched to a new supplier for anodizing. This was because our previous supplier proved to be incapable of matching colors, and the general quality of his work was poor.

Our new supplier has a range of standard colors that he can supply, but unfortunately he doesn't have our original yellow as a standard color so we are going to switch to offering unanodized Drives without a charge for color, and charging the same $100 batch charge for any color.

Standard colors that are available will be Gold, Black, Purple, Clear, & Red. We can also ask our supplier to match any color that someone might want, but this will have to quoted on a case by case basis.

As far as planes are concerned, I've put together a Contra version Episode that I plan on flying this year. When I get home, I'll try and post some pictures.

Brenner ...

Angus Balfour

Hi Brenner, sounds like you have been busy. I flew my Valiant with the new Neu and new contra (V2 up to V3) a couple of weekends ago. Superb Unfortunately I broke a 22X18 front prop so I have switched to the APC's for practice. They are good but I think I have more breaking with the larger diameter carbon props.

Angus

vbortone

My Feedback: (2)

How you guys balance the APC props? Looks like I need to make and adaptor but I don't have a lathe.

TonyF

My Feedback: (92)

You can balance the rear prop by disassembling the unit and using the backplate that the rear prop mount on. I've been able to use the High Point shaft through that mount.

kemberlysaver

There are many types of metal detector for sale in the market, so it is really hard to make a decision which one to buy and whee to buy. I searched the internet for a long time and then I bought a gold metal detector, which is really helpful. And when I do metal detecting outside it can really distinguish what kind of the metal that it has detected and give an indication for me. And by using such kind of device I have saved a lot of time and energy. In a word, I love the gold metal detector and have confidence in it.

TonyF

My Feedback: (92)

I just posted some info about my Contra equipped BJ Craft Episode in the Episode thread. It has so far shown itself to be a great model for the Contra!

Brenner

Billl Ahrens has been flying his Contra all through the winter down in Florida (lucky guy ...) and his was one of the first Contra Drives that we upgraded with a bronze pinion gear insert.

So far Bill has 150 flights on his upgraded Drive, and he has kindly sent us some pictures of the bronze insert and the spline on the motor rotor to show how it's wearing.

From my perspective things look good. I don't see any visible wear at all, especially on the motor rotor spline.

Brenner ...

Brenner

I'm finishing up an install on a Wind S Pro. I am actually a terrible builder, and I make no claims for craftsmanship, but I thought that a few pictures would help people visualize more clearly how a typical Contra installation goes.

In this case I modified the nose to provide zero degrees of right thrust, and 0.5 degrees of downthrust using a disk sander, and then I used the resulting datum to fixture the Drive in position while I epoxied the mounting plates into the fuselage.

Brenner ...

Jason Arnold

Hi Brenner,

Does your drive normally expel grease all over the place like in the photos?

Cheers,
Jason.

Brenner

Hi Jason,

It does if it's over greased.

We actually have a pretty good sealing system that keeps grease inside the Drive for many, many flights. There are o-ring seals everywhere except around the pinion gear, and we use a non contact labyrinth seal for the pinion gear because of the high relative speed.

The only real path for grease to migrate out of the Drive is through the bearings, and the only way that grease can migrate to the bearings is to get past the o-rings, and this only happens if there is more grease inside the gearbox than is needed. The grease we use is a "Channeling Grease" for high speed bearings and high speed mechanisms. Channeling greases have thixotropic properties that allow them to keep out of the way of high speed spinning components, which minimizes friction losses from excess grease.

Actually, over greasing the Drive is a pretty good way way to lubricate the bearings. It doesn't harm the Drive, and the excess is usually quickly expelled.

The only harm that might come from over greasing is if it overfills the cone inlet to the back of the rear hub behind the rear hub bearing. Usually this cone flings grease back into the Drive with centrifugal force when the rear prop spins, but it is possible to overwhelm it with too much grease, and then grease starts to leak out of the front rear hub bearing.

It takes a lot of grease to do this though. I've only seen it happen once when I double greased a Drive because I forgot that I had already greased it.

Brenner ...

TonyF

My Feedback: (92)

I have 213 flights on the new pinion system in the Nuance and no signs of wear. Also, I see very little if any grease expelling on both of my units. I have gone 125 flights without adding grease and when I took it apart to look at it there was still plenty of grease in the unit.

I really think all of the work done on the Contra design to increase longevity has really paid off. I have gear sets with 250-300 flights on them with no wear and units that have never had a bearing replaced in 600 flights.

OhD

I put the recommended 4 ml in through the shaft after 50 flights and the grease is still coming out 10 flights later. I conclude 4ml is too much. Any new recommendations?

Jim O