Homelite 26cc gas engine conversion

[Team_Monkey]

OK, that's a long shaft, you will need a regular long shaft style prop adapter for that. If you tried to swing a prop that far away from the engine it would vibrate itself apart, don't do it. The prop adapter we came up with is only for low power, short shaft engines.

You may want to contact JAG about if they have a long shaft adapter for that engine, contact av8tor about if he has an adapter or kill the deal and find a short shaft engine. Depends on where you want to spend money.

As for plans, that's too easy. You could take the regular Corocub plans and scale them up from 76" span to 85" span. Or build it the stock size except reinforce the nose and paint the windows instead of cutting them.

You inspred me so I made a deal to pickup another 25cc homie on Monday.

 

[sierra_bravo]

I thought that the shaft length would be a problem. I cant cancel the order since he already shipped it but I do have a machining shop near me that can cut it and re thread it. If not I know Jag sells a prop adapter for long shaft engines.

I found the plans for the corocub plans about 10minutes before reading you message and I'll just be using those plans but scaled up to an 85 inch wing span and a 55 inch fuse length.

I have a pretty good idea on what to do for the two part wing. What I am planing to do is something very similar to what peter did on his giant cargo ship. Basically I want to run one 1/2" aluminum rod through the top fuselage an into the wing halves and then have two bolts that go through the wing halves and the rod and then have a nut on top of the rod where the bolt is going to go through that will hold everything in place. I would run the rod 3/4 of the wing halves and it will be attached by two nylon bolts on each wing halve. I would just have a one piece wing but I can't fit it into my car.

Here are some photos of what I am talking about.




All photos are from Flite test.


but for now I am going to wait for the engine to arrive. Which should be tomorrow

-Sam

 

[Team_Monkey]

That works but it will be heavy. Those AL tubes are built for strength and are a thick wall, low grade AL, not 6061 or even 3032 aircraft grade. I use them as a fuse for a SPA3DT but that's a different story.

Find a 20" section (roughly 25% of span) of 3/4" (+/-) diameter thinwall AL tubing, like a section of an expandable pool skimmer handle or an expandable paint handle. Wrap a single layer of wax paper around it and tape closed. Now wrap a few layers of brown packing paper around that just to get the size of paper you need.

Now lay down a layer of wax paper on your building table and lay the paper flat on that wax paper. Wet out the paper with 15 minute epoxy thinned with a little (a little mind you) rubbing alcohol. "Wet it out" means just saturate the paper with as little epoxy as possible, squeegee off excess glue. Too much glue is just wasted weight. Now wrap the sticky, wet paper around the wax paper covered tube. Keep rolling it to work the paper tight to the tube form and work out a little more epoxy. Rubber band the mess together and let it sit for a few days.

Once it is dry you can run a blade around the center and you are left with two wing tube halves to be glued (epoxy) to the spar and bottom coro of your wing. Rough up the surface of the tubes with sandpaper before gluing. Remove the wax paper from your AL tube and it will slide on easy. You will want a little piece of something to close off the ends of the paper tubes so the AL tube doesn't work loose towards one side or the other. You can use velcro or just the regular wing hold down bolts as shown on plans to hold the wing together.

Here are a couple pics of a wing tube I made for a 1/4 scale cub. Yes it is a balsa bird but the tube process is the same.




I know that's a wordy post but you will have a much lighter wing tube than one made from the square structural tube AL.

Good Luck!

 

[sierra_bravo]

Is the 25cc homey you said you were getting for the 1/4 cub?
For the spar is the wing tube a two part solution. Also instead of using cheap home depot aluminum what if I buy some thin wall 6061 square tube I would think that would save a some weight. For the prop adapter I pretty sure im going to buy the JAG long shaft adapter since I don't want to cut and re thread the crank shaft but because it is made the ryobi 31cc engine im not sure if it will work on the homelite 30cc. I could do some work on the engine. I took apart the muffler and striped everything out of it. I couldn't drill the two holes for outlet tubes but that doesn't take a lot of time or effort

-sam

 

[Team_Monkey]

That cub already has a DLE 30 on the nose. The new 25cc is for me to make a matched set for a big twin. I already bought new piston rings and matchING carbs off eBay last year. If you take time to wait and.watch sometimes you find deals.

You can run one outlet on he muffler. Mine has a single 1/2" downpipe. Maybe you should email JAG just to.be sure about the adapter.

 

[Team_Monkey]

Oh and my friend lives 2 hours north of you. The shop he purchased coro from went out of.business. Sorry.

 

[sierra_bravo]

I called JAG to ask about the prop adapter and he said that it would work for the homelite 30cc. I went ahead and ordered it with the prop washer and prop bolt. I also called my local machine shop to ask if they could cut and re thread the crankshaft and they said they could but they would have to see it to give me a price. As for the I'll just make two 1/2" holes since I like the two tube design more. For the tubes I am going to use this .

-Sam

 

[sierra_bravo]

So I never received my prop adapter from JAG but I did get a refund. So I am looking for a prop hub again and so far I found this which I would drill the part that goes on to the crankshaft so it would fit. But it looks very weak. I also found this and this . I'm thinking the one for the 30cc DLE may work and I could use tap to thread it on the inside. Tower hobbies also sell the prop nut and washer.

-Sam

 

[Team_Monkey]

Hmmm, I'm leary of the electric adapter solution. A home shop person might drill dead center on a mass but it is darn hard and if you're off a tiny bit it will shake your plane apart. As you said, it would be very weak.

Maybe a part like this adapter from HobbyKing would be easier to manage? http://www.hobbyking.com/hobbyking/store/__6933__XYZ_Engine_Part_Number_11_26cc_.html
This type "should" slide over your drive shaft and be held in place with the nut on the end. The thing to do is download the engine manual for the DLE-30 or the HobbyKing engine and see if there is an exploded view to see how they go together.

On a side note I finally have all the parts to convert (2) 25cc Homies for a 1/4 scale twin. I'll have a separate thread for mine to not muddle your waters here.

Good Luck!

 

[sierra_bravo]

yeah the electric adapter was a bad idea. I found the exploded DLE 30cc view and judging on how the prop hub goes on the DLE it looks like i could thread it with a tap and screw it on the home lite crank shaft. But there is a problem. If im not wrong then the DLE 30cc crank shaft is 5/16" and I know that the homelite 30cc is 3/8". So its the dle hub is 1/16" to small. I could take the dle hub to a machine shop and have them drill it out and then i'll thread it. It looks like it will work i mean it pretty much the same as the JAG adapter and works the same way (screw adapter on - put on prop - attach bolts to hold on prop). I kinda want to see one of the DLE hubs in person to get a better judgement but I don't think my local hobby shop would have one on hand. If I cant get one by the end of august then Av8tor said he could make one for me.

-Sam

 

[Team_Monkey]

Your best bet is to get the correct adapter for the engine. Either find one or get it from Av8tor. Second best would be to have a local shop cut and run a die on the shaft to make it short enough to use the home made adapter. It's unfortunate you're having so much trouble as the whole idea is for a conversion to be easy. LOL

I'm not sure the DLE-30 adapter will work for a long shaft engine, it looks too short. The long gold "nut" mounts the adapter to the crank and acts to align the prop and as a mount for a nose cone. The prop is held in place by the four prop bolts and the washer. Here's a pic from mine downstairs.

 

[sierra_bravo]

To bad I cant get a detailed drawing of the hub I need. My local machine shop can make me the part but they need some type of drawing with the dimensions of the hub.
thinking about it I could make one(a drawing). Looking at the motor the hub would have to be 3/4" tall and could be at the maximum 3/4" wide. If it's not to much of a problem monkey do you think you could get the measurements of the 30cc DLE hub I would just need to know how wide and long it is.

I just reread you previous post. I'm going to get the shaft cut a rethread thats why im looking at the dle hub.

to bad attaching a prop ain't this easy




Thanks
-sam

 

[sierra_bravo]

Ok so I made a quick and simple 3d model in sketch up.

Here is a top view


and here is a side view


I'll get an email with these sent to my local machine shop and ask for a quote.

-Sam

 

[sierra_bravo]

I went to home depot this morning and bought a 3'x6' sheet of 4mm coroplast to start making the fuselage. I got some work done and so far im liking the results. I was pretty easy to make(or at least cut out) and I now have a general idea of the size of the plane. I took a photos of the fuselage with the rudder and elevator held in place with a rubber band



I still have to cut the fuselage tube and then i'll glue it in and i might be able to glue the rudder elevator. I got the servos today from Value hobbies and hopefully i'll get them this friday.
-Sam

 

[Team_Monkey]

I'll send you an engineering drawing for an adapter that I found years ago on the web. With one minor modification it will work for you.
Check for a PM so we can email.

 

[sierra_bravo]

So FINALLY after so much searching on the internet I found a shop that could make the part and I now have the finished prop hub. I went to the machine shop this morning and the guy who works there said that he could easily make one. So I showed him the 3D model I maid and he sketched a quick drawing and then went to work. He actually let me watch him make it and talked me through what he was doing since it's the first time I went to a machine shop. So I was standing there for about 1 1/2 hours and I got to see him using the manual lathe and I have to say it's pretty cool getting to see the guy get a solid piece of 2025 aluminum that he got from a scrap metal bin and turn it into the hub. So I can now get some more work done on the motor like taking the muffler to a welding shop so someone could weld in the outlet tubes.

I took a photo of the finished hub.





-Sam

 

[sierra_bravo]

So i haven't really been posting updates on this forum alot because I've been posting them all on the RCU forum thread . But I do have a question. I'm build the spad ultra stick and the plans call for a wing with dihedral that are made out of 2&4 mil coro but I wanted to know if the wing could be made out of only 2mil coro without losing alot of strength also if instead of giving the wing dihedral if I could made a straight wing so the plane would have better roll performance and would be slightly easier to transport.

-Sam

 

[sierra_bravo]

So i haven't really been posting updates on this forum alot because I've been posting them all on the RCU forum thread . But I do have a question. I'm build the spad ultra stick and the plans call for a wing with dihedral that are made out of 2&4 mil coro but I wanted to know if the wing could be made out of only 2mil coro without losing alot of strength also if instead of giving the wing dihedral if I could made a straight wing so the plane would have better roll performance and would be slightly easier to transport.

-Sam

 

[Team_Monkey]

You can do anything you want when you build your own plane. I would suggest an all 2mm wing, single 4mm layer control surfaces and you might look for more weight savings in the fuse. The original was built like a tank and flew like it with a 31cc Ryobi on the nose.

I loved my 26cc homelite based plane with an all 2mm 72" span wing and 4mm tube fuse. Came in about 12.5# If you build a pretty plane like the SPADStick it will be heavier so watch it. I had good flight performance but had to manage my up lines. Here's video a friend shot of it. Runs from 12 seconds to about 2:20. That has a 9mm carb, stock 10yr old ring and stock exhaust worked over.

https://youtu.be/Wgi598S4eWQ?t=12s

 

[sierra_bravo]

Ok i'll be making the wing from 2mil coro. I already built the fuselage about 2 weeks ago and I got the prop mounted but I still have to set-up a bell crank system for throttle control. As for the straight wing i'll do some more research on it to and a dihedral wing. I want the straight wing just so it a bit easier to transport. Also I found a local shop that sell 2mil coro in 4'x8' sheets for $11 a sheet so I know where to get the rest of the coroplast from.

Also when you say "The original was built like a tank and flew like it " does that mean the plane will fly like this. I thought a plane as heavy as the spad ultra stick would be slow and lumbering when flying.

-Sam

I dont really have a good photo of the full fuse but I do have some photos of the tail feathers with the servos installed.