Bronco Type XXIII by Ken

[Ken_NJ]

Cutting away the box

Positioned the disk template where to begin cutting away the internal support structure.






And began cutting with the Dremel abrasive disc



Used the Dremel drum sander to clean up and get it down to the drawn line. Trial fit the SD in position.



The central support cleaned up.



Got this 8250 for Christmas. Before I used it thought about returning it but didn't. I love using it over the corded ones. Highly recommended to have in the shop.



Box cut away with abrasive wheel.



Trial fit of the SD. I left some of the box as support for the hull to maintain some rigidity.



The edges have been cleaned up with a file and the edges of an Exacto blade.

[He Who Shall Not Be Named]

Yea I have some German in my blood. And I'm particular, a perfectionist, stubborn and many other traits within.

Thanks Manfred. I think I've improved some from those days we connected on RCG with the Marlin.

I'm a bit Scott, a bit German... charming. One of my neighbors is French -- why this urge to bliz through their yard and jig upon their lawn?

[Subculture]

They were mainly farmers though- perhaps you should have taken up growing wheat or something?

[Das Boot]

My great grandmother came from Deutschland. So where is my engineering expertise? I guess it didn’t rub off. Nice work Ken.

[MFR1964]

Ken, we grow by experience, just like you've shown with building the propellorshaft housing, learning from your mistakes makes a better builder of yourself, as for cutting out the box, why don't you glue in some braces to keep the hull in shape, once the cradles of the SD are inside and glued tight you can cut those braces to have full access.

Manfred.

[Ken_NJ]

Nice work Ken, you behave like a German Engineer, i like that, keep on going with your good work.

Manfred.

Yea I have some German in my blood. And I'm particular, a perfectionist, stubborn and many other traits within.

Thanks Manfred. I think I've improved some from those days we connected on RCG with the Marlin.

[Ken_NJ]

Propeller bearing housing

A few pictures from the outside. I only have the two screws you see holding the hull together.






Interior picture






Propellor removed showing the smaller bearing. It was a perfect size to fit this opening.






Next up is cutting out most of that box in the forward hull. Not all of it will be removed. One thing I'm concerned about when the box is removed, that the hull is going to bow out of shape. I saw that with the aft section when the deck was cut, the starboard side bowed out.

[MFR1964]

Nice work Ken, you behave like a German Engineer, i like that, keep on going with your good work.

Manfred.

[Ken_NJ]

Propeller bearing housing, second final attempt

More lathe work. Here I'm drilling out for the shaft.



Final housing. You can see the two radial grooves. Those groves fit over the ribs in the hull. The smaller bearing fits into the left side and is flush with the end. The larger bearing sits on the right side but does not sit into a cup on the end.

The drilled opening for the shaft is 7/32 and the shaft is 3/16. The shaft will only touch the bearings, not the acrylic. With bearings at both ends, water will still get in that space between the shaft and acrylic. With water not being able to get out, it is possible slim may accumulate. My thought is I can do two things, one, fill that space with some grease, or two give some way for air to get in and let the water drain out. So I drill a drain hole and a vent hole. I can always put grease in the space and cover up those holes. Will see how this goes. Am I over thinking this?




Here are all the parts. The shaft still needs to be attended to. The gray piece on the right will be adhered to the hull. The acrylic housing has a key which fits into the gray piece to lock it in position and allows me to remove the housing.



Closeup of the housing with bearing CA'd in place, two radial slots, vent and drain holes, key and bearing. The larger bearing is a friction fit so it can be twisted off with a pair of pliers.



Prop bearing CA'd in place.



For the shaft, I marked where the set screw is.



Then used a brass tube to draw a radial line.



Then used the Dremel to make a flat on the shaft.



The flat is essentially a slot. If the set screw on the prop or coupler backed out a little, as long as it doesn't fail out, the set screw will at least hit the outer end of the shaft and not let either fall off the shaft. The slot is essentially a stop. I've seen enough people at Subfest loose their props.



Closeup of the shaft.



And here is the final assembly in place.








There is one more picture I need to take of both halves on the hull together.

[Ken_NJ]

Propeller bearing housing, first attempt

How do you make a bearing housing for the propeller bearings? Hmm? This is the start of what I came up. A bit of engineering going on here. BUT, this was my first attempt which in the end I was not happy with. So there is a second attempt after this one, and the final attempt.

Here are some of the parts I have to work with and put together into something. Note the exit point of the prop shaft. There is an inner and outer rib. The inner rib seals off the opening. The outer is just a small rib. The inner one was filed down to make it the same diameter as the outer one.



Some of the many bearings I have to choose from. Very nice to have a stock of parts.



The balance point of the empty SD is aft of the center of the SD. This will change once the SD is populated.



Marking the center of the hull. The center point is bow to where the exit point of the prop shaft. The rudder skegs were excluded from this. The center of the SD is also noted. And you can see where the aft end of the SD is located in relation to the exit point of the shaft. So plenty of room for the intermediate shaft connecting the motor shaft to the prop shaft.



Another view of the SD and the prop shaft exit point.



Yeah, I get to use the lathe!!! Turning the housing on the lathe, ATTEMPT #1.



The is the housing I came up with. One small bearing will go in the end against the prop. Another larger bearing will be mounted separately in a rib adhered to the hull.



Another view with the two bearings.



This did not suit me. Lots of times you need to make multiple attempts at making something. The end of the acrylic housing, I think it is acrylic, where the smaller bearing for the 3/16 shaft goes, was too thin and cracked. The whole bearing sits into the housing. And, I changed my mind about the setup. The second attempt has both bearings in the housing. Sit tight, the second attempt is coming up.

[Das Boot]

Always room for improvement. You get better the more you do it.

I watch this guy on occasion. Interesting to see what he brings back to working condition.
https://www.youtube.com/@MrCarlsonsLab

I’m a big fan of Mr. Carlson‘s lab. I don’t think there’s anything that guy can’t work on. Too bad he’s way up in Canada, because I’d love to visit that place. He also got a new place to live, and has a nicer test/repair area.

[Ken_NJ]

Always room for improvement. You get better the more you do it.

I watch this guy on occasion. Interesting to see what he brings back to working condition.

https://www.youtube.com/@MrCarlsonsLab

[Das Boot]

I have it already done Casey. Fashioned my own. Just have a few things to finalize. Will be posting it after the weekend.

I think you’ve outdone yourself on this one. The fact of the matter remains, that you and David always make it look so easy. I’ve been working on a 45-year-old amateur radio trying to get it going again. I’m replacing old style relays with new modern ones. I’ve always been better with electronics than cutting plastic.

[Ken_NJ]

I have it already done Casey. Fashioned my own. Just have a few things to finalize. Will be posting it after the weekend.

[Das Boot]

Ken,
Tom had an article a while back of prop shaft support he made. I put these articles in the back of my head until I one day remember them. I got one from Tom for my XXIII project, but unfortunately, I never got around to building it.