Picture below is from the October 1957 issue of Mechanix Illustrated article about Rock-A-Chute rockets. Photo shows the nosecone with what appears to be a wood plug.

Someone should 3D-scan one of those sharpeners so it can be fabbed.

John (or Rick): How many of the longer ridges are there around the circumference of the nose cone/sharpener - four or five?

John: thin strips of fiberboard or wood or what? I'm rebuilding a crashed Semroc Mark II (tipped off in the wind on a Quest A6-4) and would like to better replicate the sharpener/cone whilst I am at it.

Thanks!!

Hi Bernard;

There are five long ridges around the nose. In my reworked Semroc nose I used 0.047" square styrene strips, each cut to length and then glued to the nose with CA. After the CA had cured, I used a medium grit sanding block to taper each strip. I found that sanding each strip after it had been installed resulted in a much more consistent taper.

About a couple of months after doing my build I came across an original Leeds Sweete sharpener and discovered that the depth of the ridges at the aft end of the sharpener are barely 1/32"; they're much more subtle than what I had imagined, and using 0.030" square styrene strip to replicate the ridges would result in a much more accurate representation.

I found this to be a relatively straightforward (and cheap!) modification to make to the Semroc nose and I'm quite happy with the result. Even with my Fred Flintstone-sized ridges the overall effect, once blended and painted, is quite distinctive and I'm often asked if that's an orignal sharpener when folks see the model. If one were to use a strip size closer to the actual ridge thickness it would be very hard to tell the difference once finished and painted. I plan to build another (I quite like this model, and Carl has done his usual great job with it) and will do exactly that.

As a final note I'll mention that I had prepared an article for our club newsletter outlining my method for this rework, and I've attached a copy below.

Bernard,

Yep, 5 long and 5 short strakes. The cone is 2" long and the long strakes are 1.5" with the short ones being 1.25". They stick out at the base like John said and taper into the cone at the top. I tried to get a good photo but, it's not great.

Just went and checked out John's article and it is very nice. Good work!

Thanks, both of you! I've looked at G. Harry's model in the Museum of Flight more than once and have some pictures I've taken of it....but couldn't tease out the right number from that or from the pics you posted, though I'd just about convinced myself it was five of each.

And thanks for the how-to, John. Very nice. Now all I need to do is stop by the hobby shop for the styrene sheet. I have a little Fourmost cutter - not as nice as the NWS Chopper, but it'll do the job.

added: It occurs to me that if 0.030 sheet would work, so would 1/32 bass wood. I probably have some of that to hand.....:)

And 1/32 bass does in fact work.....I'll have to post a picture. I was not quite as methodical about the spacing as John in adding the strips, but I have to say, even unpainted, it is VERY convincing.

Thanks again!

Well we'll want to see some pictures indeed! Have you decided on your color scheme for finishing the model?

I'll try to take a quick snap this evening and post it.

On color schemes: the crashed rocket that is being reworked was orange except for a yellow nose cone. But I'm tempted to paint the "rhinoplasty" version white and swap it onto my currently flyable Mark II which is painted to look like the one built by GHS that's on display in the Museum of Flight in Seattle. That one is has a fluorescent red body/fins except that one fin is black. That particular model also has a conventional 1/8 inch launch lug on it rather than the one that works on a 1/4 dowel. It also has the fins glued on, not attached with the staples and such. One picture showing both of these points attached. So is a better view of the model overall.

I'd love to be able to have color documentation of other Mark IIs from the early days so as to more readily be able to enter one in a Classic Model competition (NAR event P57). The way the rules are written one needs a color picture for documentation. If you have a place I can look, I'd love to know.

I was showing the reworked nose cone to my wife last night and discussing this problem and she had the brilliant suggestion that I should just paint the model in shades of grey! :D

Bernard,

I've included a photo of my re-makes of Mark II's in the case I carry them in. All of these color patterns I got from photos I've seen. One is modeled from the Museum that you posted a picture of. (The crayon sharpener nose was painted white, the sharpener never came in white. Bill Stine told me it was painted.)

The other photo I've included shows a photo that is from a thread here on the forum of a news reporter that visited Orville's wife and daughter and took a photo.

All the other patterns I got from the Quest Museum web page. The front page says "collection of B&W pictures" but, they are in early color.

http://www.questaerospace.com/q_museumgallery.asp

You have to look carefully at all the photos to find the different variations. The short movie that you can download has a Mark II taking off from a launch pad as well. (at 2:35 into the clip) Though, I couldn't get the link to work tonight but, I have it saved in my Ipod movies.

http://www.questaerospace.com/Image.../MMI_Launch.m4v

I have been biten by the early Mark II bug and I can't get enough. I wish I could find some more early photos as well. I keep hoping that Bill Stine will add more to the Quest Museum. He surely has some more historical stuff. I will try and post some "not really important but, cool" stuff about the crayon sharpeners when I get some other photos taken.

Hope this helps.