jackabel

I am starting to build a Don Smith Cessna T-50 and have been unable to find information on recommended engines. Can anyone help?

Thanks,

Jack

STUKA BARRY

I've seen many Bamboo Bombers and they fly great with Quadra-52's or Zenoah G-45's. The D&B 3.7 Twin would be a good comination too if your into twins.

jackabel

Barry:

Thanks for the help.

JeffH

My Feedback: (43)

Be very careful with over powering the T-50. The tail is not held on with much. Also, fuel space is very very limited in the nacelles if built per the plans. I am running G-23s on mine, and it should be fine. An aquaintence had G-38s on his and it was wayyyy too fast. His tail also came off, built per the plans. The robart gear takes up a lot of room. I am running 10oz tanks and that is all you can get in there with foam packing. The plans leave alot to be desired, with some stuff just 'magically working out'. I hope to finish mine this winter.

Murphey

My Feedback: (11)

Jack: I'm currently building a Don Smith Cessna T-50, and am using Zenoah G-26's...with electronic ignition, not magnito's. Should be ample power. I built a similar sized twin recently using 2 G-20EI's. This 2nd twin was a bit lighter than the T-50 but was more than adaquately powered...so I think I'm OK power wise.

Are you building it after a specific plane? I have quite a number of photos I'd be happy to share, as well as sources for other accessories...just letme know.
I'm finishing mine as the "Songbird" from the 50-60's TV show SKY KING...

Murphey

jackabel

Thanks for all of the input, everybody. Here is a chart of the engines all of you have mentioned. Quite a range! I am kind of a radial nut and was considering the Saitos below. It looks like the D&B and Saito twins may be to much engine. Any additional comments?

And Murphey, no, I haven't gotten that far yet. And, yes, I would certainly appreciate any photos you would care to share.


Engine CCs Cu In.s Weight (Oz) HP HP/Cu In.
Zenoah G-20 20.00 1.22 33.00 1.70 1.39
Zenoah G-26 26.00 1.59 53.60 2.06 1.30
Zenoah G-23 23.00 1.40 51.00 2.00 1.42
Zenoah G-38 38.00 2.32 67.00 2.50 1.08
Zenoah G-45 45.00 2.75 69.00 3.30 1.20
Quadra-52 52.00 3.20 4.50 1.41
D&B 3.7 Twin 61.00 3.72 80.00 4.84 1.30
-
Saito FA 200R3 32.98 2.01 50.80 2.00 0.99
Saito 325 5 cyl 53.00 3.23 84.00 3.80 1.17
Saito 300 Twin 50.00 3.05 63.50 4.70 1.54

Thanks, Guys

JeffH

My Feedback: (43)

I am not sure of the fuel burn on the 200 3cyl, but the other two Saito's use WAY too much fuel to get a decent sized tank in the nacelle. The OS 160 Gemini fits, and would have the power. It would probably fly 7-8 minutes on a 10-12 ounce tank and still have a small reserve.

rhsmrt50

Jack, if you are interested in radials?.........there are several out there that are the 1/5 scale of the Don Smith Bobcat............they are quite expensive tho...............I have considered them for my own project.................but, I have also found that the Sato 150 is a good choice.........with ample power and a nice sound......especially two of them running.............I also have 32 oz tanks per engine installed above the Robart gear......it fits just fine right behind the firewall mounted with 1/4" foam tape.........should give at least 20 min of time per engine easy.........even though the 150 is a guzzler............anyway, I have a lot to share with you if you love this airplane as I do..............Rich.

Murphey

My Feedback: (11)

Great looking build Rich! Any chance you could share a few pics of the tanks in the Nacelle? Also, what is the source for the radials shown in your post.
Thanks!
Murphey

rhsmrt50

Hello Murphy.......in regard to your first question about the 32 oz tank location......I have no photos as of yet, but will send as soon I do.......and ......in refference two the various radials out there that are 1/5 scale.....or........other radials that will fit within a nine inch cowl......the very first choice would be the "Robart R780 Radial Engine"........a 7 cylinder radial engine .......by, Power Research Division of Robart Mfg......you can go to their site and get all of the specs.......robart.com/R780/r780constuct.aspx..........the price is also impressive.........the other radial I had in mind was not as scale, but could be modified by adding the typical Jacobs details.........it is made by "Technopower".........they make a five, seven and a nine cylinder that will fit the cowl........Sato also has a three cylinder.......add a few dummy cylinders around it and it will look real and sound great!.............thanks, Rich.

rhsmrt50

Jack........here are a few pic's of the Sato 180.

Rich.

Murphey

My Feedback: (11)

Rich: Thanks for the radial info but I was referring to the photo of the dummy radial in your post...but you are correct, the price is "impressive for sure. I also noted in one of your photo's that you had to modify the tail cone as did I! And one more request...where did you get the scale tail wheel and yoke? And by the way, great job on the door! Very impressive!!
Thanks
Murphey

rhsmrt50

.....5.5in Robart tires on custom made T-50 style rims and tail wheel.

rhsmrt50

.....oh.......okay.........well, since I could not find a 1/5 scale of the Jacobs L-4MB, then that meant I had to look for the best resemblance........it turns out to be the Williams Bros. 1/5 Pratt & Whitney cylinder kit........slightly modified it will pass very nicly........problem is, it is out of production.........so.........off to "Ebay" for a search!!.......lo and behold, I found a couple......but, I needed 14........I figured that would take forever, so I decided to make a mold and cast the rest........while I was at it, I also designed the crankcase and gearcase on AutoCad.......made wood blanks of both and from that the selastic RTV molds.... and from that came nicely detailed Resin copies.........sounds like a lot of work????........not really, just alot of fun.........will send pic's of the process............Rich.

rhsmrt50

Jack and Murphy........a few pic's of the casting process.......hope they all come thru .......Rich.

rhsmrt50

.....I seem to be having trouble send pic's.............ok............let's try again.

rhsmrt50

......okay.......the tail wheel is a two inch Du-Bro baldy........the center hud has spokes.......you dont what that, the original had asolid hub.......go to Ace Hardware......or any other good hardware and pick up a couple of 7/8" brass washers.......the inside hole should be 5/8" ......but is not that critical.......make sure it's 7/8's ID to snap onto the rim of the tailwheel......reallydoes not have to be Brass.......can be fiber or steel washer......Diameter is the most critical.........The Yoke is of 1/4 solidalum rod.......hand formed around a 1/2 steel rod chucked in a vice.........nothing magical.........just mark acenter point on the alum rod.........make sureyou have plenty of leverage.........and with your own mussels.......pull it into the proper yoke........you may have to tweek itback and forth to get theright clearance for the tire.........then trim of access......now........to make it look like stamped steel tube at the point where axel is inserted....(see pic) ......requires a little time on a 1 incn belt sander.........this workd great, just nont go too fast.................now, to drill for the axel to passthru only required a woodblock between the forks of the yoke stabilize it.....drill straight thru.........or one side at a time by flipping over if you wish........simple on a drill press.........the hard part was to drill a 3/16 hole at 45 degrees fro the steering shaft.............but, as it turned out, a simple wood jig held the part in fixture for a perfect pass the first time..........Rich.

rhsmrt50

Thank Murphy.......here is a couple of the door and latch with window molding..........if I can get it to come thru.........having trouble with downloading pic's it seems..............just be patient.........Rich.

rhsmrt50

.........Yes, I found that the tailcone was too tall and I had to take a section out to make it correct with the top plane of the stabilizer and the bottom of the rudder..........you are the first person that I know of, other than me to bring forth this problem...........thereare other design problemswith the plan accuracy...........the stabilizer and elevator are not symmertrical........so check before you you lay it up........if its off......do a flip of the left side and build from that...........another problem I encountered was that the rib patternfor the wings did not match the plan view, this could be caused by poor reproduction of the original Velums.........what itinvolved was a lot of time re-drawing all the ribs in the left wing.......and then making aflopfor the right wing...........thank goodness for that...............okay you guys.........I'am tire of talking.........time to hit-thu-sac.......as we say down here in Texas......

Rich.

JeffH

My Feedback: (43)

I had to section my tailcone as well.
It looks as if you are using a functional tail wheel lock? It will turn with the rudder when locked, and caster when unlocked?

JeffH

My Feedback: (43)

How did you do the window molding??? That is one of the reasons I stopped working on mine. I could not come up with an acceptable way to do make those.

rhsmrt50

Hi Jeff.........as you know, the real T-50 had a non steering tailwheel and was full swiveling for taxing, but was locked straight ahead for takeoff by a lever in the center of the cocpit just above the pilots heads..........in real life, the pilot taxied using individual brakes..... by pressing the rudder peddles forward with a toe action......and, at the same time introduce r & l rudder action with engine differential.......so, with that in mind how close to scale would you like to be..........I gave this idea a lot of thought.........talked to some of my other scale friends etc..........if I really wanted to employ these features to my project..........they are available.........the brakes, there are several out there to choose from..........theengine differential is another matter...........there is a great article covering this very subject in the August 2007 issue of Model Aviation........starting on pg-33.........the title is,Twin Tuning by Eric Henderson..........it's a great article on how to do it...........if you do not have this issue, or you are not a member of AMA yet...........Iwill be glad to send a copy at your request..........only need an address.............now, back to the subject...........as youread the article for settingup your twin you will find this to bea very simple procedure......and theonly cost will be for a pair of tac's ......if you dont already have them........or just borrow a few from the guys.............Now, the method that I will be using to syncronize my engines will be a system available called the "TWINSYNC"..........it is asystem thatkeeps your engines in perfect sync at all times while in flight.......and has a built in and progamable engine out in flight feature............it can also becoupled with rudder and tailwheel for engine differential while taxing..........Check it out on Google........in the meantime, I will find you anaddress...................Jeff, sorry I got off the main subject,which was........does my tailwheelhave a locking system?............no, what you see is a steeringand a drag brake system designed to help with ground handling and a hold....... using full up elevator to keep the ship from creapingwhile idling........much like a car in gear withfoot on the brake.............thanks for your interest..............Rich.

JeffH

My Feedback: (43)

thanks for the reply. I see now what you will be using it for.

About that window molding...how did you make that?

rhsmrt50

......Dont let that stop you Jeff.............they are a nice scale feature if you are doing a partial or complete interior..........but if you would like to install them on all of the windows just to help give depth and create an illusion of an interior...... that would be just great!!!.......and in the meantime, give you some experience with working with paper........a very easy material to work with..........the molding shown with the door is made of bond paper..........simply put......the weight of bond paper (as I call it) is between printer paper and index card stock.........it is just perfect for model details........such as the window moldings that we are about to discuss.........but also......simple fillet work.......like where the vertical meets the horizontal stab...........I will include a few pic's ofthis very subject on my own project........Jeff, once you have the finished shape of the windows installed on the framework........the next step is to take a sheet of tracing paper and cut a 1/2 in strip and then form it inside the opening......then where it overlaps, apply aslice of clear tape to hold the shape...........once in place applyatouch of white glue to opposite corners just to keep from moving while you trace the inside andoutsideshape of the window with a sharp pencil............after arriving with the correct outline and before removing from the window opening, make an index mark that corosponds on the framewith thewindow opening...........removethe tape that holds the section together...........then you will have thelenear shape to trace on to the bond paper...........the best method for the transfer is makea copy of the original ona copy machine if you have one..........if not, youcan take the original to a copy center and have several copies made, especially if it is the door window or the elicptical rear window or the cocpit side windows.......they are duplicates of each other..........once you have a copy..... the next step is to transfer it to the bond paper that you have selectedfor the finished part............there are several ways to do this..........my best method is to use "One Coat Rubber Cement"........you can purchase it from any art supply house........it'snot real expensive and I use it to transfer all of my patterns to finish material, wood, metal, plastic, etc..........be sure to ask for 'Best Test" one coat..........do notlet them sell you the twocoat ..........it will not come off of your part.........that is the nice thing about the one coat...........the pattern can simply be pulled loose from thepart after it has be cut out........it can also be left in place for final finishing........such as sanding right up to the line.....and then remove it.............this product also comes in the 8 oz can which includes the applicator brush.........also, while you are there, be sure to purchase a pint of "Bestine"......this is a rubber cement solvent.......once opened, rubber cement begins to thicken due to vaporation........so, adding a littleBestine to thin it to the proper consistency for application is a must to prolong the life of the product...........Bestine is also great for removing any film left over after the pattern has been removed........now, since you are appyling the pattern to paper, you need to use a very thin coat of the cement.......oh, I forgot.......you can also double the bond paper if you need a duplicate........now, once the pattern isin place, simply cut it out with a hobby knife.........apply a thin coat .e sure to punow, once you have applied the pattern to the bond paper, then is a simple matter of cutting it out with asharphobby knife........now that the parts cut and ready........join the ends withmagic mending tape.....orsome other thin, clear tape.........it now in theshape of a goofy looking circle.......thats ok........now ,install it in the window opening using the index marks discussed earlier.........it shouldfit tight and conform very well .........once pressed intoshape, apply.....with a small tube applicator fitted to a bottle of CA............now, carfully apply a very thin coat tosurface of the bond paper making sure it doesnot go around the edges of the frame and bond to the window opening.........we dont want that now..........there is more to come..............I am tired of writing at this point...........but we will pick this subject up later................please excuse any type-o's.............Iam not a typist.............I hope that word was spelledcorrectly............

Rich.

drdoom

My Feedback: (9)

How Nice. Incredible work. Thanks for sharing.