Can I convert this Ryobi?
 

Hi guys,

I'd like to have a go at a gas conversion and have read a lot on this excellent forum (;)). Unfortunately we have a much smaller choice of donor engines over here in England and model names (of strimmers, blowers etc) are different.

Anyway, I'd be real grateful if someone could have a 'look' at this Ryobi 31cc I found and let me know if it's a go'er and can I get the additional parts I'll need from WhackerEngines or elsewhere.

http://i21.ebayimg.com/03/i/01/a1/37/84_1.JPG

Thanks very much! I have two days to go on the bidding... :D

P.P.

RE: Can I convert this Ryobi?
 

Its exactly what I used. Flys great on a 82" ws bandito grande. Most coversion companies have parts for the ryobi.
Edwin

RE: Can I convert this Ryobi?
 

Company posting shows 25:1 fuel ratio. All I have seen are 32:1 ratio. Wonder if seller is in error or maybe Ryobi has some internal changes for Europe market???

RE: Can I convert this Ryobi?
 

Heck, thats just what ya need. Pete at wackerengines can fix you up with all the parts to put it on a plane for cheap. I'm just about ready to fly my Hanger 9 Super Cub with the 31cc ryobi and his 2" mount and muffler was just the ticket to get that long motor under the Cubs cowl and keep from cutting it up. And yes, I mounted the motor WITHOUT the need to push back the firewall too:D Piper

RE: Can I convert this Ryobi?
 

Hi Guys,

Hey, sorry for not getting back to you... for some reason I never got any notifications of replies [sm=confused.gif] Anyway...

Thanks for the confirmations, later this afternoon that Ryobi might be mine :D I did send WhackerEngines an email a few days ago but haven't heard anything back yet. Has anyone done a blow-by-blow conversion on this forum? Hmm, s'pose I should do a search here first huh? ;)

Edwin, thanks for the Bandito Grande tip. I had a look at the plan on RCM's site and it looks like it would be a good large scale trainer. I was originally thinking of a 74" UK design with a 21cc McCulloch engine in it (the Mc's are far more popular over here than Ryobi or Homelite) but it all depends on what motor I end up with, then i'll build a plane for it. Am I doing this the correct way round? LOL.

Thanks again,
Steve

RE: Can I convert this Ryobi?
 

keep in mind that the ryobi's end up a couple inches longer than most conversions, the plane you choose should have an easily modifiable nose. it also comes out very narrow due to the rear exhaust and carb, very nice if you cowl it in.

only problem point in the conversion is to be careful cutting the plastic backplate. also one of the backplate mounting holes needs a small washer added because for some odd reason the plastic is thinner on one corner.

the hub and mount are very easy to make yourself if you want to save a buck....


dave

RE: Can I convert this Ryobi?
 

Hi Dave,
Thanks for your post.

Well, I won the auction :D and I'm happy with the price - £37 or about $70 delivered. I've also sent another email to Pete @ WackerEngines asking for their conversion instructions and an idea of shipping costs for a mount and a hub. Unfortunately I don't have any machining facilities and I'd rather have something that's proven if I'm dealing with an 18" prop @ 7000rpm - eek! ;)

I'm not sure if the UK model design I'm thinking of using will be o.k. to mod for the Ryobi so I need to e-mail the designer just to make sure. I think it may be lacking in wing area from what I've read during my searches here but I can always run it past you guys huh? I've attached the advert for the plan of the SportStar and am open to comments & advice.

No doubt I'll be back soon with some dumb questions - no matter how hard I search lol.

Cheers,
Steve

RE: Can I convert this Ryobi?
 

Hey purple pilot:
Do not worry, may order over seas could be time consuming and expensive. if you have one morning or afternoon free, could go to a local machinery shop and explain what you want. it takes no more than an hour to mill the prop hub and the prop washer. I Just copy a US engines ones, and even that I desing them a little thinner in diameter saving some weight. and around 5 cms. long. the prop washer is the same, they work great.

Rodolfo.

RE: Can I convert this Ryobi?
 

Purple,
I modified the bandito grande a lot to handle a gas engine. Sheeted the aft control surfaces with 1/16" balsa and mounted the servos in the back. The bandito builds very light and is a frame structure behind the wing trailing edge. I sheeted the inside of the frame with 1/8" balsa on the inside of the frame work so there wouldnt be any outside contour problems. I moved the firewall back 3 1/4" and made it out of 3/8" ply. I balanced with no led at all. Also moved the canopy back one fuse former and lowered the profile for a more streamlined look. I made a fiberglass cowl sorta P-51 style. The flaps and ailerons were increased in size to 2 1/2" wide. With all those mods, its ready to fly dry weight is 13 lbs 14.5 ozs. Attached is my stock built Bandito Grande and my modfied version. It flys great.
Edwin

RE: Can I convert this Ryobi?
 

Hi Rodolfo,
Thanks for the thought but unfortunately it's not so easy - or rather whenever I've gone looking for a company to do me one-offs before it's never been easy [:o] Any 'professionals' I approach will be looking at a £25 'tooling fee' and £25 per hour labour (min one hour) thereafter -> £50 = $90 approx. Time wise, again, a small company will fit it in as & when they can around their larger orders so that could be weeks - USPS is amazingly fast I've found ;)

Add to that that I haven't got the foggiest idea of what I want them to machine as I have nothing to copy yet [sm=confused.gif] and I think a trans-Atlantic purchase will be easier. But... I've just found another Ryobi 31 wacker :D So maybe the parts for this second one could be copied.

I actually engaged my brain-cell earlier and did a Google search resulting in finding web-sites for JAG Eng. and Paragon Aero. Both have the conversion instructions on-line [sm=thumbup.gif] but both are quite a bit more expensive than Pete @ Wacker.

Would still love some on-line conversion images tho...

Hi Edwin,
Thanks for the Bandito info! I really like the look of your mod'ed plane, very 30's racer-esque. Nice [sm=thumbup.gif]

Hmm, the Ryobi's weigh 4lbs huh? That's over twice the 1.20 OS used in the SportStar (above). I can see why you had to move the firewall back by 3&1/4 inches aswell as it being longer! As I mentioned, I'll have to see if the designer will enter into some correspondance with me about modifications for the gas motor. But I need to get the engine running first - that should be fun! Eek, again!

Thanks again guys, keep the info coming as it's much appreciated.

Steve

RE: Can I convert this Ryobi?
 

just checked out the wacker site and the ryobi parts are a good deal...but then some of us still like doing it the hard way:eek:

if your engine is the long shaft version then the hub is simply a spacer...a stack of washers would do just fine. mikenlapaz even made a hub from plastic[8D]

the mount is just a piece of rectangular aluminium tubing...all you really need is a drill, a hacksaw and file[8D] you can also just use long backplate bolts with drilled dowels or metal tubes as stand-offs

either way you will have fun

dave

RE: Can I convert this Ryobi?
 

ZAGNUT is right, I made my last mounts out of scrap square aluminum tubing I borrowed from a shop of aluminum doors and windows. Just drill the bolt pattern fror the cranckase cover and a hole for the carb. I mounted the mount to the engine and then the opposite side was bolted to the firewall with 8-32 bolts and blindnuts...very cheap and easy.
I guess I´m lucky too, because 15 minutes from home there is a little machinery shop where i bring the dural ( U$5) and they milled a prop hub, the prop washer and reduce the flying wheel for just U$ 12.00 So I do not spend more than U$20.00 in the conversion.

Oh, the balance of the flying wheel is on me!!! but I have run 2 ryobi with the wheel only reduced and with no balance at all and they run great with almost no vibes.

Sooner I hope to have a lot of pics of my conversions and mounts.

Tato Lazo.

RE: Can I convert this Ryobi?
 

Hi Dave,
If I could do it myself then I would, trust me ;) I have plenty of time and very little money (hey, I work for Wal-Mart, well, ASDA in England which is owned by WM). The screwiest thing is that my ol' dad used to build live-steam locomotives (3&1/2" gauge - the ones that can pull 1/2 dozen kids around on little carriages) and he used to have a lathe & small mill but that all got sold-off when he passed away nearly twenty years ago - I wasn't into R/C then [sm=frown.gif]

I see what you mean about the engine mount tho... I could probably make that myself. Any idea of the wall-thickness of the aluminium rectangualr tubing, a couple of millimeters (1/16" )? I'm pretty sure that once I get the motor and start to work on it things will become much clearer.

BTW (off topic) how is it in Tel-Aviv nowadays? I was there twice in 1999 - working unfortunately. I've never had so much trouble trying to get out of an airport as BenGurion lol ;)

Hi Rodolfo,
Hmm, that skimming & balancing of the fly-wheel was also a concern of mine (maybe I worry too much lol :D) so thanks for letting me know that yours work fine - very reassuring! If you happen to have any photos/images of your conversion then it'd be great to see them.

Thanks a lot guys! This info is priceless to me!

Oops, one last question... what planes are you flying these 4lbs/1.8kg Ryobis in???

Steve

RE: Can I convert this Ryobi?
 

More searching and I found what I was looking for... a photo-by-photo R-31 conversion :D

So for anyone else in my position go here:- [link=http://www.geocities.com/CapeCanaveral/Hangar/1071/ryobi2.htm]Ryobi 31 conversion piccies[/link]

Going back one step from the above page gives lots of other links... [link]http://www.geocities.com/CapeCanaveral/Hangar/1071/[/link] ...scroll down a bit and look under the Radio Controlled Models heading.

Thanks to Marty Hammersmith (if you happen to read this) for that invaluable info.

RE: Can I convert this Ryobi?
 

Hi Purple Pilot:

Here's a couple pictures of a really simple Ryobi motor mount. It's just a flat piece of 1/8" (3mm) aluminum plate cut out to suit. You could mount it on stand-offs, but I chose to bolt it to a plywood fire-wall for rigidity. In the photos, the whole mess is being held on by clamps for a trial fitting.
You may be able to put your hands on a piece of plate easier than the square tube. A bit easier to work with too. I've just used the 4 scews that hold the plastic intake block to the motor, but it may be wise to use slightly longer ones to make uo for the plate thickness.

RE: Can I convert this Ryobi?
 

hehe

RE: Can I convert this Ryobi?
 

Purple Pilot

I just finished building a Balsa USA Stringray 120 and used a converted Ryobi with whackerengines part. Peter was a great help and his parts worked out great. I am posting a few pictures on the building process. I hope they help. I had to move the firewall back 2".

Thanks

RE: Can I convert this Ryobi?
 

Purple Pilot

Here are some more pic's that my help. I also mounted the servo's for the elevator and rudder as fare to the rear on the fuselage as possible. I also mounted the battery and receiver in the rear of the plane.

The Balsa USA stingray 120 has an 83" wing span with 1276 sq. in. wing area. The total flying weight on the plane with the Ryobi 31cc conversion engine came out to 14 lbs. I am getting 7200rpm with a MAS 18x8 prop. She flies real well.:D

RE: Can I convert this Ryobi?
 

Hi Sportflier,
Thanks for the images and your motor mounting method. My engines on its way.. WooHoo! (Homer stylee ;)) and the plans for 'Ryans Rebel' have been ordered from RCM. I decided to go for the stick-type model as I just thought it'd be easier & faster to get in the air and also easier to modify and generally mess around with.

Hi Jim,
I saw your build while I've been surfing around these past few days - your Ryobi looks superb! Did you have to do a full strip down for the red finish, is it a powder coat or paint? Nice [sm=thumbup.gif]

Hey, more pictures while I was typing :D

I did look at the BUSA Stingray 120 (aswell as the Sig 4*120 & Lanier Stinger 120) but they aren't even available over here in England. And if they were they'd be big bucks! Eg the BUSA EAA Bipe costs $225 (£125) here! Hence the plan build...

BTW maybe I'm being very impatient (who, me? :D) but I haven't heard from Peter @ Wacker yet... are they on holiday or something?

Steve

RE: Can I convert this Ryobi?
 

Steve
I painted the engine with a good engine paint I got at the auto parts store. When I had the engine broken down I just cleaned it up real good with a engine cleaner Than I covered the exhaust port, engine shaft, and the rear of the engine where the reed value and carb attach to. I than painted the engine with two coats of paint. After it dried I installed the Flywheel, Magneto, prop shaft, reed value with carb. The paint has held up real good and adds a little to the total project.

I do not know if Sheldon hobbies ships over seas, but they do have the Balsa USA Stingray 120 for $109.00 US. I don't think it would cost $100. to ship it. It only cost $9.00 to ship it to Memphis, TN from California. You might just want to send them an e-mail if you are interested in this Plane. I am very happy with mine.

www.sheldonshobbies.com

Good luck on your project.

RE: Can I convert this Ryobi?
 

Jim,
Thanks again! I dunno if I'll bother with the cosmetics of my Ryobi - probably not to begin with until I fully understand them. Knowing me I'll only break soemthing ;)

Ooo, the Stingray from Sheldons is really cheap [X(] Hmm, I suspect the kit is quite heavy, boxed up... but it's the import duty, our Sales Tax & the 'handling charge' that's slapped on top that really increases the cost. Rough rule of thumb is to add 30% onto the cost on the landed goods in Pounds Sterling. Ends up about the same as from the UK distributor [:o]

Jim I have a quick question if that's o.k.? In a thread from back in January of this year you posted the weight of your modded 31cc as being 48oz but according to the Paragon Aero website the weight is 64oz with mount & muffler, any idea where the difference comes from?

Steve

RE: Can I convert this Ryobi?
 

Steve

Sorry for that post I did last January. The total weight of the engine is 4lbs with all of the conversion stuff you need from wackerengines. I don't know what I was thinking. I think I multiplied 4x12 and is should have been 4x16 for total weight in oz.

I will send Peter a e-mail for you to see if he has your request. I talk to him about twice a month. I am converting a Homelite 25cc at the moment with Peter's help.:D

RE: Can I convert this Ryobi?
 

Thanks Jim, you are a super star! [sm=thumbup.gif] No worries about the weight thing ;) I hope Peter is o.k.

Well, my Ryobi arrived this morning - Yippee! can you tell I'm excited with this project - and from what I can see, with it all still being 'dressed up', it looks o.k. although it seems to have been stored for a while with a little rust on the steel parts. Turns over o.k. with the pull-start tho.

But... aswell as being impatient (;)) I can also get a little insecure... On a couple of web-sites (Paragon Aero) I've seen model numbers given , e.g. 705R, 720R, 725R... well, on the label mine says "MDL: Ryobi 410RB. SN: 903131801. PPN: 500936" Am I worrying for nothing or do I have the wrong motor? Also, on the back of the fuel tank it says 20:1 gas/oil mix, I've read 32:1 and/or 40:1?

Can someone please reassure me :( Thanks as always!

RE: Can I convert this Ryobi?
 

Steve

I'll give Peter a call today and see if he has your e-mail. I will also give him your e-mail address just in case.

I use a 2 cycle oil called Opti-2 in my Ryobi and it is good for any mixture. I have noticed a vast increase in RPM using this oil over standard 2 cycle oils, about 150 more rpms. Here is the web page so you can look at it and see what you think. http://www.opti2-4.com/opti-2.htm My local small engine shop swears but the stuff. He even told me if I burn up an engine using it he will replace the engine. I have run over three gallons of fuel thru the engine without a problem.:D

Thanks

RE: Can I convert this Ryobi?
 

Hi Jim,
Yet again I am indebted to you for your help and it is very much appreciated. I only know of one person on my 'local' UK forum who has done a conversion and that was a McCulloch 21cc so I'm in a bit of a desert over here.

I was going to ring Peter myself but a transatlantic call is prety exspensive from England to the US. It would appear everything is pretty damned expensive in this country! No, no politics... :eek:

O.k. things are getting worse here... I've just removed the carb cover and I don't have a Walbro on there [:o] I have a Chinese thing called a Zama :(

Why me? I must have read hundreds of posts in hours and hours of searching over the past few days and no-one has ever mentioned a Zama carb. Hey, maybe it's a special :D Yeah, knowing my luck, a special piece of c**p!

Depressed of England.