Cherokee-D fin measurement needed

[LeeR]

I've printed the Cherokee-D fin pattern from the JimZ Plans TIF, but scaling it to "fit",or "full page" produces a fin a little too big to fit on a 4" wide piece of balsa, with the grain running along leading edge. The JimZ file shows the piece of balsa, and printed "full size", it is well over 4" wide. I gotta believe Estes used standard width balsa stock. I could scale it down, but I'd like to see if someone can give me the length of the root edge, so I can scale it as close as possible.

Anyone out there with a built rocket they could measure, or an original fin template, or a better method of printing than I deduced? :)

Thanks!

[Bob H]

The fin pattern is a TIF file on Jim Z's site so I just saved it and then opened it up in MS Paint and printed it at 100%. The image was exactly 4 inches wide so you are correct in assuming that it was standard width balsa.

I have an original short body, balsa nose cone Cherokee-D and the fins were 2 piece so maybe they used 3 inch balsa for the first production run.

[CPMcGraw]

I've printed the Cherokee-D fin pattern from the JimZ Plans TIF, but scaling it to "fit",or "full page" produces a fin a little too big to fit on a 4" wide piece of balsa, with the grain running along leading edge. The JimZ file shows the piece of balsa, and printed "full size", it is well over 4" wide. I gotta believe Estes used standard width balsa stock. I could scale it down, but I'd like to see if someone can give me the length of the root edge, so I can scale it as close as possible.

Anyone out there with a built rocket they could measure, or an original fin template, or a better method of printing than I deduced? :)

Thanks!

What software are you using to adjust the image? GIMP? Or Photoshop (Photoshop Elements)? Something else? I use Photoshop Elements 5.

Those images are scanned at 100%, so they should be "on the money". Sometimes, if you're using the Micro$oft "Preview" function, the images get munged dimensionally. You really need to use something with a bit more substance and control to work with images (including the printing job). If Photoshop Elements ($80 to $100) is too high, try The GIMP (Free). Both take a bit of getting used to, but they allow you to work the image much better.

The balsa sheet is 4" wide by 9" long, BTW. If you can adjust the image to fit those constraints, it should print out correctly.

[Bob H]

What software are you using to adjust the image? GIMP? Or Photoshop (Photoshop Elements)? Something else? I use Photoshop Elements 5.

Those images are scanned at 100%, so they should be "on the money". Sometimes, if you're using the Micro$oft "Preview" function, the images get munged dimensionally. You really need to use something with a bit more substance and control to work with images (including the printing job). If Photoshop Elements ($80 to $100) is too high, try The GIMP (Free). Both take a bit of getting used to, but they allow you to work the image much better.

The balsa sheet is 4" wide by 9" long, BTW. If you can adjust the image to fit those constraints, it should print out correctly.I used no software other than MS Paint. I opened the TIF image in Paint, opened Page Setup and made sure the scaling box was set at Adjust to: 100% normal size. It printed on one page.

[CPMcGraw]

I used no software other than MS Paint. I opened the TIF image in Paint, opened Page Setup and made sure the scaling box was set at Adjust to: 100% normal size. It printed on one page.

I just tried Paint (on Vista) to see what it would do. I also printed a copy from Photoshop to see if there was any size difference. It looks like Paint is capable of handling the image without resizing.

What I do notice on both printouts is they are about 1/16" narrow along the width of the board, but they are a correct 9" along the length. Not enough to worry about, and I'm not going to adjust the image to "correct" it. The original board may not have been a true 4" wide.

OK, so I'm not too senile yet to learn sumthin' new. :D

[LeeR]

OK, so I'm not too senile yet to learn sumthin' new. :D

Apparently I am ...
:)

It is worse than I thought. Rather than not learning something new, I couldn't even use something correctly that I've used before...

I did a "save image", and it saved a GIF, which opened in the Windows Doc Viewer, and I just played with it. I didn't notice the file suffix said "GIF", and not "TIF". I should have known at this point I was dealing with a GIF.

To add insult to injury, I have Photoshop, and when I dowloaded the TIF, and opened it, and set to 100%, Photoshop told me the size was 9" X 4".

Sorry! But if I learned anything, it is to not use my small laptop display, and go upstairs and use the nice new 22" widescreen, so I can actually read filenames more clearly!

I appreciate all the helpful hints, and it just made me realize I need to use Photoshop more often, although I was impressed that Paint handled this fine, too.

[Mark II]

Be aware of the resolution as well. JimZ's scans are all at 300 dpi, but occasionally they open at some other setting. If you take a 300 dpi scan and open it at 72 dpi, the size will be WAY off!

I just downloaded and printed out the pattern from JimZ's archive, and the fins are indeed laid out on a 9" x 4" sheet. The root edge is 3.5" long, and the leading edge is 2.3125" (2-5/16") long.

I converted the pattern to a PDF and have attached it to this post. Print it at "Actual Size" or no reduction.

Mark \\.

[GIJoe]

I went the easy route, Laser Cut fins from Semroc for $2.35. I had bought some other fins during this shopping spree couldn't pass them up, when I came across an original Estes Balsa Nose Cone.

Joe

[LeeR]

I went the easy route, Laser Cut fins from Semroc for $2.35. I had bought some other fins during this shopping spree couldn't pass them up, when I came across an original Estes Balsa Nose Cone.

Joe

Good thing I already laid out the fins for cutting. If I had known this, I would have placed that $40 order (1 set of Cherokee-D fins, and a bunch of other things that wandered into the shopping cart ...)
:)

[Davidtmp]

I just downloaded and printed out the pattern from JimZ's archive, and the fins are indeed laid out on a 9" x 4" sheet. The root edge is 3.5" long, and the leading edge is 2.3125" (2-5/16") long.
Mark \\.

they Mark, I think the root edge is actually 3.75" long. I'm gonna build one of these at some point, now that I know the fins downloaded are the correct size. Let me know if I am wrong, but the leading edge measurement is about what I am seeing. I'm hoping you just misread.

[Davidtmp]

I have a question about the different Cherokee-D kits.....Kit K-47 has a balsa nose cone and a body tube length of 16.35". Kit 1247 has a plastic nose cone and a body tube length of 18". I have an extra Bull Pup NC to do the Cherokee with. Seems to me that the plastic nc would be longer than the balsa, so the 1247 kit would be maybe 2" longer from tip to bottom. Are the fins the same size in both kits? I can't find kit 1247 plans anywhere, the one on Jim Z's site take you to the K-47 plans.

[GIJoe]

I have a question about the different Cherokee-D kits.....Kit K-47 has a balsa nose cone and a body tube length of 16.35". Kit 1247 has a plastic nose cone and a body tube length of 18". I have an extra Bull Pup NC to do the Cherokee with. Seems to me that the plastic nc would be longer than the balsa, so the 1247 kit would be maybe 2" longer from tip to bottom. Are the fins the same size in both kits? I can't find kit 1247 plans anywhere, the one on Jim Z's site take you to the K-47 plans.

Both sets of plans are on Jimz, the 1247 plans are at the bottom of the page.

Joe

[Mark II]

Dave,

The leading edge is the one that is parallel to the grain. The root edge is the one whose corners are NOT rounded. I'm pretty sure that I measured correctly, but you may want to double-check. The PDF pattern that I attached to my post IS the correct size. Print it out and measure the entire area that shows grain. If it is 9" x 4", then you are on the money.

According to Craig McGraw's notes (http://www.rocketshoppe.com/info/estes_expanded_kit_list.htm#_msocom_19) in the Expanded Estes Kit List (http://www.rocketshoppe.com/info/estes_expanded_kit_list.htm) (an excellent resource, by the way, worth adding to your bookmarks list), the original K-47 Cherokee-D used a shorter body tube (BT-55V) that was 16.35" long, and the model was barely stable at that length. It also had a balsa nose cone (BNC-55AC). Estes later updated the design by lengthening the body tube to 18" (a regular BT-55 length) and redesignated it as kit #1247 (this was in the Damon era). They also gave it a plastic nose cone (PNC-55AC). This later model was noted to have a much more stable flight.

The confusing thing is that the Estes catalogs from the era all list both versions of the Cherokee-D as being 21.6" long. :confused: I consulted Semroc's page of reproduction classic nose cones, and they list the BNC-55AC as being 5.375" long. Add that number to a body tube length of 16.35" and you get a total length of 21.725". Assuming that the plastic PNC-55AC was the same length as the balsa version, if you add 5.375" to 18", you get a total length of 23.375". It's odd that Estes never reported this updated length in any of the catalogs that featured the #1247 Cherokee-D. :rolleyes:

By the way, some more excellent resources for cloning Estes kits are John Brohm's Estes Body Tube/Kit Reference v.3.1 (http://www.rocketshoppe.com/info/Estes_Body_Tube_List_3.1.pdf), his Estes Nose Cone Reference List v10.1 (http://www.rocketshoppe.com/info/Estes_Nose_Cone_Reference_10.1.pdf), and his Estes Fin Can Reference v2.0 (http://www.rocketshoppe.com/info/Estes_Fin_Can_Reference_V2.0.pdf), along with the compiled Estes Nose Cone Pictures (http://www.rocketshoppe.com/info/Nose_Cones.pdf) contributed by Arley Davis. The Building Tips (http://www.rocketshoppe.com/tips.htm) page at Ye Olde Rocket Shoppe (http://www.rocketshoppe.com/) contains a wealth of other information as well that is indispensable to us clone freaks. These PDFs are well worth downloading (I check them all the time) and YORS and the pages it links to all belong in every classic kit fan's or cloner's bookmarks list. They are on mine, and they are some my most used bookmarks. :cool:

Excellent resources for cloning information for Centuri kits are the Expanded Centuri Kit List (http://www.rocketshoppe.com/info/centuri_expanded_kit_list.htm) at YORS, the Master Cross Reference List (http://www.semroc.com/Store/scripts/xref.asp) at Semroc's site, the Cloned Rockets Central (http://www.wilhelm-aerospace.org/Hobbies/flying-rockets/clone/cloned-rockets.html) site (I don't know who maintains it) and Doug Holverson's Centuri Memories (http://members.cox.net/retrojayrocket/home.html) page, to name just a few. (Jay Goemmer, don't you also have a page somewhere on Centuri stuff too? :D )

Hope this helps, and Happy Cloning from one repro freak to another!

Mark \\.

[Davidtmp]

Thanks GI, don't know why I didn't see that myself!

[Davidtmp]

Dave,

The leading edge is the one that is parallel to the grain. The root edge is the one whose corners are NOT rounded. I'm pretty sure that I measured correctly, but you may want to double-check. The PDF pattern that I attached to my post IS the correct size. Print it out and measure the entire area that shows grain. If it is 9" x 4", then you are on the money.
Mark \\.
Oh shoot, I typed the wrong one. It was supposed to be root. And yeah, I do get 3.75. No biggie. My fingers and brain don't always get along.

Thanks for the other info, I did save the Nose Cone and Body Tube sheets for reference a little while ago. I am still finding info on this site that helps a great deal!

[GIJoe]

Be aware of the resolution as well. JimZ's scans are all at 300 dpi, but occasionally they open at some other setting. If you take a 300 dpi scan and open it at 72 dpi, the size will be WAY off!

I just downloaded and printed out the pattern from JimZ's archive, and the fins are indeed laid out on a 9" x 4" sheet. The root edge is 3.5" long, and the leading edge is 2.3125" (2-5/16") long.

I converted the pattern to a PDF and have attached it to this post. Print it at "Actual Size" or no reduction.

Mark \\.

I measured the Fin Blanks from my Semroc fins and come out with these figures:

3 3/4" for the Root Edge
2 1/2" for the Leading Edge
2 7/32" for the Fin Tip
2 5/32" for the Trailing Edge

These measurements are taken as if the Fin Tip wasn't rounded off into the Leading Edge and the Trailing Edge.

Joe

[CPMcGraw]

According to Craig McGraw's notes (http://www.rocketshoppe.com/info/estes_expanded_kit_list.htm#_msocom_19) in the Expanded Estes Kit List (http://www.rocketshoppe.com/info/estes_expanded_kit_list.htm) (an excellent resource, by the way, worth adding to your bookmarks list), the original K-47 Cherokee-D used a shorter body tube (BT-55V) that was 16.35" long, and the model was barely stable at that length. It also had a balsa nose cone (BNC-55AC). Estes later updated the design by lengthening the body tube to 18" (a regular BT-55 length) and redesignated it as kit #1247 (this was in the Damon era). They also gave it a plastic nose cone (PNC-55AC). This later model was noted to have a much more stable flight.

Here's a heads-up: The latest revision of the XEKL is due in a few days. I'm finishing up some last-minute updates, and will be sending it to Scott shortly.

I have a clone of a short-body CD, but with the PNC-55AC. It has flown once on a C6-5 without showing any stability trouble. I have not tried it on a D12-5. I think RockSim indicated it was below margin at ignition, but may have been above margin by the time it cleared the rod (due to BP burn-off).

The confusing thing is that the Estes catalogs from the era all list both versions of the Cherokee-D as being 21.6" long. :confused: I consulted Semroc's page of reproduction classic nose cones, and they list the BNC-55AC as being 5.375" long. Add that number to a body tube length of 16.35" and you get a total length of 21.725". Assuming that the plastic PNC-55AC was the same length as the balsa version, if you add 5.375" to 18", you get a total length of 23.375". It's odd that Estes never reported this updated length in any of the catalogs that featured the #1247 Cherokee-D. :rolleyes:

This wasn't the first time a kit length was found to be wrong. Centuri was worse. Most every catalog entry was rounded off. Estes did try to get reasonably close, but Centuri rounded up and down.

[Bob H]

The confusing thing is that the Estes catalogs from the era all list both versions of the Cherokee-D as being 21.6" long. :confused: I consulted Semroc's page of reproduction classic nose cones, and they list the BNC-55AC as being 5.375" long. Add that number to a body tube length of 16.35" and you get a total length of 21.725". Assuming that the plastic PNC-55AC was the same length as the balsa version, if you add 5.375" to 18", you get a total length of 23.375". It's odd that Estes never reported this updated length in any of the catalogs that featured the #1247 Cherokee-D. :rolleyes:If you look up the Cherokee-D in the old catalogs on the Ninfinger site you will see that they used the same picture every year. The Estes logo is the old one with a capsule orbiting the Estes name.

http://ninfinger.org/rockets/rockets.html

The decals on Jim Z's site are the newer logo.

[Mark II]

[...]
This wasn't the first time a kit length was found to be wrong. Centuri was worse. Most every catalog entry was rounded off. Estes did try to get reasonably close, but Centuri rounded up and down.
Yeah, sloppiness in documentation (http://www.ninfinger.org/rockets/catalogs/fsi70/fsiflyercov.jpg) like (http://www.ninfinger.org/rockets/catalogs/fsi71/71fsicov.jpg) that (http://www.ninfinger.org/rockets/catalogs/fsi79/79fsif.jpg) is simply (http://www.ninfinger.org/rockets/catalogs/fsi90/90fsif.jpg) inexcusable (http://www.ninfinger.org/rockets/catalogs/fsi93/93fsif.jpg)... :rolleyes: :D

(In case anyone is wondering, I'm a big FSI fan. :D )

Mark \\.

[LeeR]

[...] Assuming that the plastic PNC-55AC was the same length as the balsa version,

It is the same length, I checked my PNC-55AC earlier. Lots of good info in all the replies here. I didn't think to check that the Bullpup uses the same PNC-55AC as the later CD. I scrounged one out of the parts box, and sure enough, I've got one. I was trying to decide if I would cut down an 18" tube, and then saw this info on the later version using the 18" tube.

Oddly enough, when you load the #1247 plan, it has the K-47 plan pages shown, with the #1247 plans appended at the end.

I've had the decals for a couple years, so this has moved to the "build now" list. I never built one when they were in production. I'm testing out the production runs of my Fin Wizard to make absolutely sure all the body tube sizes are OK -- the prototype table was only a BT-50 model, so I've got a couple sizes yet to test.

I did make the fins out of basswood, and then decided to taper the fins. These are a pain, since you've got to sand everything but the root edge. No knife edge aggressive tapers on these, they are only gently rounded.

[Mark II]

I have a Cherokee-D parts pack that I bought from Thrustline, back when it was still up and running, and I have decals from Excelsior. I'm reluctant to open up the kit now. I may do a clone of it myself instead. (Not logical, I know.)

Mark \\.

[CPMcGraw]

It is the same length, I checked my PNC-55AC earlier. Lots of good info in all the replies here. I didn't think to check that the Bullpup uses the same PNC-55AC as the later CD. I scrounged one out of the parts box, and sure enough, I've got one. I was trying to decide if I would cut down an 18" tube, and then saw this info on the later version using the 18" tube.

Oddly enough, when you load the #1247 plan, it has the K-47 plan pages shown, with the #1247 plans appended at the end.

I've had the decals for a couple years, so this has moved to the "build now" list. I never built one when they were in production. I'm testing out the production runs of my Fin Wizard to make absolutely sure all the body tube sizes are OK -- the prototype table was only a BT-50 model, so I've got a couple sizes yet to test.

I did make the fins out of basswood, and then decided to taper the fins. These are a pain, since you've got to sand everything but the root edge. No knife edge aggressive tapers on these, they are only gently rounded.

The best starting point for a Cherokee-D these days, if you're going to build a PNC version, is the C-C Express. I have not seen an official 2009 kit list from Estes, but it was still shown in the 2008 catalog. CCX has the PNC-55AC, a full BT-55, and most of the parts for the "D" mount.

[GIJoe]

It is the same length, I checked my PNC-55AC earlier. Lots of good info in all the replies here. I didn't think to check that the Bullpup uses the same PNC-55AC as the later CD. I scrounged one out of the parts box, and sure enough, I've got one. I was trying to decide if I would cut down an 18" tube, and then saw this info on the later version using the 18" tube.


I measured my Bull Pup PNC-55AC against an Estes BNC-55AC. I got a .25" difference. I only have the one balsa NC so I am not sure if the variation is there. I also have a set of Original Decals to use on my clone. As soon as the weather warms up, I will finish it off. Had I known the original was marginal, I would have lengthen the BT, guess I am stuck now with adding a little nose weight.

Joe

[tbzep]

IMHO, the shorter body tube Cherokee-D looks better than the 18" BT version. I've had no stability issues with short version Cherokees from the original up to 4" diameter on "J" EX motors. If you are a little worried about stable flight, just check the CP/CG and add a little nose weight if needed. I've never had to.

[rocketguy101]

I measured the Fin Blanks from my Semroc fins and come out with these figures:

3 3/4" for the Root Edge
2 1/2" for the Leading Edge
2 7/32" for the Fin Tip
2 5/32" for the Trailing Edge

These measurements are taken as if the Fin Tip wasn't rounded off into the Leading Edge and the Trailing Edge.

Joe
I still have the fin pattern from my original Cherokee from the 70s. Measuring "to the sharps" I get the following:

3.75" (95 mm) for the Root Edge
2.5" (64 mm) for the Leading Edge
2.20" (55.5 mm) for the Fin Tip
2 .18" (55 mm) for the Trailing Edge

The pattern must have been made for 3" balsa, as it is a two-piece fin. I scanned it 100% into a PDF (the 1" grids in the background did not show up so well in the BW scan, so I made a grey scale scan too).

My original "short tube" flew fine, and I cloned that version.

EDIT: here is RS sim image

[LeeR]

I measured my Bull Pup PNC-55AC against an Estes BNC-55AC. I got a .25" difference. I only have the one balsa NC so I am not sure if the variation is there. I also have a set of Original Decals to use on my clone. As soon as the weather warms up, I will finish it off. Had I known the original was marginal, I would have lengthen the BT, guess I am stuck now with adding a little nose weight.

Joe

I measured the plastic version, and it was exactly the length given in the BMS catalog for their balsa clone. I have had variations in really old Estes cones, so that might explain your difference. With this one being so pointy, that could be the reason -- easy to lose a 1/4" of a long pointed cone.

I visited Estes in 1966, and remember seeing their nose cone machine. I recall taking pictures, but I've only found a few, and none of that machine. I seem to recall the lathe feeding in really long blocks of balsa. I also seem to recall they had a rack of grinding stones, but do not recall the "turning" method. The grinding stone may have given the profile, and maybe a cutter completed the shoulder. I do remember them getting cut off, dropping into a box, and the next cone getting started, all pretty automated.

I'd love to know if anyone has pictures of some of those old Estes machines. I also remember seeing Mabel make engines, and the contraptions for making igniters, and wadding from TP (not sure if it was Charmin, or Northern, or maybe Scott? ...)
:)

[GIJoe]

I remeasured both my nose cones, being a bit more accurate this time. I am about 1/16" of an inch short on my Balsa cone and 1/16" long on my plastic Nose Cone. The 1974 Catalog reports the length at 5 3/8" so I would have to agree with that assessment.

Joe

[Davidtmp]

I'm looking to clone about 6 or 7 rockets, some don't have the thickness of the balsa sheets on some. I may have missed it somewhere too, trying to get a list together back and forth from home and work.

What are the average thickness of fins on Estes kits? 3/32, 1/8, 3/16? I'm gonna say normal A,B,C, small D's. The larger rockets like the D-Region I think is 3/16, been forever since I replaced the fin. Or am I 1/16 large on that? This will give me a ballpark figure of what I am looking at.

Thanks guys

[CPMcGraw]

I'm looking to clone about 6 or 7 rockets, some don't have the thickness of the balsa sheets on some. I may have missed it somewhere too, trying to get a list together back and forth from home and work.

What are the average thickness of fins on Estes kits? 3/32, 1/8, 3/16? I'm gonna say normal A,B,C, small D's. The larger rockets like the D-Region I think is 3/16, been forever since I replaced the fin. Or am I 1/16 large on that? This will give me a ballpark figure of what I am looking at.

Thanks guys

BFS-10 = 1/32"
BFS-20 = 1/16"
BFS-30 = 3/32"
BFS-40 = 1/8"
BFS-50 = 5/32"
BFS-60 = 3/16"
BFS-70 = 7/32"
BFS-80 = 1/4"

The Cherokee-D used BFS-40.

[Davidtmp]

Craig,
OK, looking at Willie Logans page on discontinued parts, I see that the balsa sheets on the Orbital transport are BFS-20L which looks to be a long piece of Balsa. On the A-20 Demon the balsa sheet lists BF-58. So does this mean it is actually a 5/32" balsa sheet, with the last number representing the length of the sheet Estes used(maybe 8")? So really we look at the first number and see what range that is in to determine the thickness.
Am I on the right page?? :)
Nice work you guys have done on the cloning sheets, helps a great deal.

[CPMcGraw]

Craig,
OK, looking at Willie Logans page on discontinued parts, I see that the balsa sheets on the Orbital transport are BFS-20L which looks to be a long piece of Balsa. On the A-20 Demon the balsa sheet lists BF-58. So does this mean it is actually a 5/32" balsa sheet, with the last number representing the length of the sheet Estes used(maybe 8")? So really we look at the first number and see what range that is in to determine the thickness.
Am I on the right page?? :)
Nice work you guys have done on the cloning sheets, helps a great deal.

Watch out on some of the kit fin sheets, as the part number is occasionally the same as the kit's catalog number. The Demon was K-58, so the fin sheet was BFS-58. The Demon used BFS-40 sheet stock, like the Cherokee-D.

Do you have a copy of the 1974 Parts Catalog (http://www.ninfinger.org/rockets/custom_estes/custom_estes.html) ? Page 4 shows some of these die-crunched sheets advertised as separate items. The Demon fin sheet is listed as being 1/8" x 3" x 12".

[LeeR]

BFS-10 = 1/32"
BFS-20 = 1/16"
BFS-30 = 3/32"
BFS-40 = 1/8"
BFS-50 = 5/32"
BFS-60 = 3/16"
BFS-70 = 7/32"
BFS-80 = 1/4"

The Cherokee-D used BFS-40.

An easy way to remember these as you browse instruction sheets looking for fin thickness -- take off the zero, and the number tells you how many 1/32 of an inch in thickness the fin material is.

[Davidtmp]

ok, well now I am confused. That sheet shows the Cherokee fins as being 3/32" and the Demon's are 1/8". Could Estes have used 1/8 on kit #1247? Just trying to get it straight.
This clone stuff sure isn't easy! Thanks for the sheet Craig, another link I'll be sure to refer to often.

[CPMcGraw]

ok, well now I am confused. That sheet shows the Cherokee fins as being 3/32" and the Demon's are 1/8". Could Estes have used 1/8 on kit #1247? Just trying to get it straight.
This clone stuff sure isn't easy! Thanks for the sheet Craig, another link I'll be sure to refer to often.

You made me go look at it again... :o

The scan of the K-47 fin sheet says 1/8" on it, but as you noted, the parts catalog says 3/32". When I built my K-47 clone (short body version) I used 1/8" sheet. The scan of the #1247 sheet looks to be the same scan, and is marked as 1/8".

I am inclined to take the 1/8" measurement as being accurate, although in practice the 3/32" fins might give better performance due to the reduction in drag. As a general (but not hard-n-fast) rule, in the early years Estes tended to use 1/8" sheets for BT-60 and 24mm BT-55 birds. They used 3/32" sheets for BT-50 and 18mm BT-55 birds, and 1/16" sheets for BT-20 and BT-5 birds. As with everything, there are exceptions to this rule, and some of the later designs used 3/32" on BT-55s with 24mm mounts (case in point: #1955 Ranger, which used the exact same fin set as the #1278 Vigilante and the #1368 Comet).

[Mark II]

These is often a sheet of notes appended to the kit plans available at YORP and at JimZ's, and in a few cases, someone has written in or digitally added annotations with the dimensions for some of the parts to the exploded drawing of the kit on the first page of the plans. It is always worthwhile to take a few seconds to look over that drawing, just in case in might have such notations. Also, when in doubt about anything related to a classic kit, don't hesitate to post the question here at YORF. I have yet to see the forum be completely stumped by a question about a classic kit from the past 50 years, no matter how obscure it was! (And there have been some real doozies, too, like the kitted DOM design that someone spotted on ebay a couple of months ago...)

Mark \\.

[Davidtmp]

I am inclined to take the 1/8" measurement as being accurate, although in practice the 3/32" fins might give better performance due to the reduction in drag. As a general (but not hard-n-fast) rule, in the early years Estes tended to use 1/8" sheets for BT-60 and 24mm BT-55 birds. They used 3/32" sheets for BT-50 and 18mm BT-55 birds, and 1/16" sheets for BT-20 and BT-5 birds. As with everything, there are exceptions to this rule, and some of the later designs used 3/32" on BT-55s with 24mm mounts (case in point: #1955 Ranger, which used the exact same fin set as the #1278 Vigilante and the #1368 Comet).
That is a great ball park figure I was looking for too. It helps. I have the Ranger and the Comet at home, I may look at them and look at a 1/8" sheet and go from there. I know I am splitting hairs at this point.
I may just make 2 Cherokee's, one short body with balsa NC and a longer with PNC, and may just go with 1/8" fins since I probably already have that stock in my stash at home.
Thanks guys!

[sandman]

The Cherokee D fins are indeed 1/8" NOT 3/32"!

I just checked an original kit to verify.

[Davidtmp]

The Cherokee D fins are indeed 1/8" NOT 3/32"!

I just checked an original kit to verify.
Then 1/8" it is then! Thanks for that confirmation Sandman.

[CPMcGraw]

The Cherokee D fins are indeed 1/8" NOT 3/32"!

I just checked an original kit to verify.

Thanks, Sandman! I was hoping someone with an original would shout about it, as I vaguely remember us having this discussion several years ago... Either here or on OldRockets...

[CPMcGraw]

That is a great ball park figure I was looking for too. It helps. I have the Ranger and the Comet at home, I may look at them and look at a 1/8" sheet and go from there. I know I am splitting hairs at this point.
I may just make 2 Cherokee's, one short body with balsa NC and a longer with PNC, and may just go with 1/8" fins since I probably already have that stock in my stash at home.
Thanks guys!

Since you sound like a Cherokee addict, check out this thread... (http://forums.rocketshoppe.com/showthread.php?t=157&highlight=Cherokee+Double). The thread is about four years old, but still buildable.

[Mark II]

Anyone who isn't a Cherokee-D lover hasn't seen one yet! :chuckle:

Mark \\.

[LeeR]

Anyone who isn't a Cherokee-D lover hasn't seen one yet! :chuckle:

Mark \\.

I've got to admit, I liked the decals, so ordered them on a whim from Excelsior a few years ago. But I always thought the fins were just odd. In testing my Fin-Wizard, I needed BT-55 test build, and made a Cherokee-D. I think I'm hooked. Besides finishing and getting it decaled, I'm interesting in the staged versions I've seen in other threads.

Maybe it is more of being a lover of them once you see them up close and personal!

http://i265.photobucket.com/albums/ii220/hobbes_pics/Cherokee-D/th_fin-wizprod27.jpg (http://s265.photobucket.com/albums/ii220/hobbes_pics/Cherokee-D/?action=view&current=fin-wizprod27.jpg)
http://i265.photobucket.com/albums/ii220/hobbes_pics/Cherokee-D/th_fin-wizprod30.jpg (http://s265.photobucket.com/albums/ii220/hobbes_pics/Cherokee-D/?action=view&current=fin-wizprod30.jpg)