Spiro

I would agree that this is not a project to be taken lightly. A thrown blade could easily seriously injure or kill someone, if struck in the wrong spot. The suggested 2500 rpm produces nearly 30% higher centrifugal blade forces over 2200 rpm. I do not know what the factor of safety is on these parts, nor what condition any one persons equipment might be in, but I wouldn't want to be anywhere near a helicopter that far past its never exceed rotor speed. If the rotor shed a blade at some 2500 rpm that thing would be coming at you at nearly 100 feet/sec. How would you like to take that to the throat tip first?

Also, for reference, my Vmax7 hits 2200rpm at the head all day long with 6 degree grips (24860 engine RPM, at 11.3:1 gear ratio). When I first ran the motor and tached the head speed, I called up Paul at LMH to ask if this was ok, since the original documentation stated never exceed of 2000rpm. Paul also told me that 2200 would be all right, but not to go any higher. I usually tach my LMH before I put it up and set the needle to keep the head speed below 2200. It flys with plenty of authority with around 2100rpm head speed.

My recommendation for using an alternative engine would be to set the max throttle position such that max head speed is where you want it, as notasme suggested. This would allow you to set the needle as needed so the engine runs correctly, but still would guarantee you don’t accidentally over speed the head.

For what it is worth, and play safe!

Spiro

darthdrk

Can I chime in?
Just a thought, with a metal feathering plate or CF plate which are available as aftermarket parts Also there is a distributor over in Germany selling Carbon fiber blades. Would these upgrades make that engine set up a little safer at the higher RPM head speed. It will take alot of force to rip through the fibers to sling(throw) a blade. Also i was thinking with the Longer blades and boom it should help in maintaining a lower RPM. Also A little more weight could be added to the chopper. I notice a big difference between the Electric and the gas versions weight and I also notice that the electric has and develops a higher head speed. I have both chassis and My electric version with the same blades and boom as the gas version takes off like a rocket and its a much heavier setup. help me out here.

lyk2fly

My Feedback: (3)

I don't know what the saftey factor is for the LMH but if the manual says 2000 is the safe "never exceed" head speed, and the LMH folks provide an engine upgrade (vmax7) that is going to exceed that speed....and then tell you that it is alright......that suggests to me that they may not know what the safety factor is either. Notasme has done a wonderful thing with his engine modification. He has plowed new ground.....and that does involve risks. Maybe now the LMH folks will learn how desperate their customers are to find a dependable engine. I can't understand how a company that seems to be as popular as they are has not contacted another engine manufacturer to build an engine to their specs. The vmax6 is pathetic and I'm afraid most people feel the same way about the vmax7. I'm also afraid that instead of correcting the nitro problem the LMH folks may shift their efforts to electric. Most upgrades seem to be for the 120. I have nothing against electric....but I prefer nitro. The 110/116/117 helis provide many hours of enjoyment and I have learned much about flying with my 110. But I've also had hours if disappointment.
Mark

spdfrek

My Feedback: (12)

Oh I'm a relatively safe guy....But I wanted to see what everyone elses thoughts were on this safty factor here.I mean...you should never need to exceed 2200 rpm with 6/6 grips on there.Should MORE then fly well enough at that point...especially seeing as the engine has the power to pull those grips.However simply limiting throttle movment cant gaurantee that it'll never over rev...perhaps if it runs lean cause a fuel filter clogs or the like...I suppose one good afix a tach that could be remotely monitored and throttle up slow and steady...See what rpm in blew up at.....but thats not something I really wanna try badly...I agree....No one should attempt this unless they know what they are getting into...I for one am ok with the problems...And I am just looking for a reliable engine over here..I'll be sure to keep everyone posted....BTW is there any harm in flying with snow as long as electronics are taken care of?Just curious....Fixed wing guys do alot so....Thanx again for all the help you guys provide.

Joey

darthdrk

Seemingly there was a time and sometimes still, getting a good V7 upgrade engine was a roll of the dice. I had have 3-4 V6 engines and overall I rate the engine at a D+ One engine Ive burned more gas trying to get it to fly than actually flying. I went through three V7 engines until I finally got a winner, my fourth engine. Its been a real charm. I rate this engine at an A. but the fustrations that came along with weeding through V7 engines was a Pepto Bismol experience. When I had time and wanted to fly, I couldnt. Now I would like to fly but do have no time (working on Heli bodies). I personally do feel as if LiteMachines is turning their back on the nitro guys. Also dont think that the electric guys dont have their share of problems because they do and i think even more so. It really dont take as long as it has to address the sorry engine problems with the nitro helis. Seemingly its the only problem that we who fly these things are having (myself, use to have engine trouble because I got a good V7 engine over two gallons of gas through it in less than a year). looking at the forums, It seems electrics are out selling gas helis. But the cost of operating them is much more expensive. Well, with Lipo batteries comming out 20-30 minute flights are possible from what ive read but realisticly who can find flying that long fun(I understand you can land whenever also). Its good to be able to come in and land every now and then to give the heli a once over. I guess its still going to be a to each his own when it comes to gas or electric. Now does it really take that long for Litemachines to remedy the nitro problem???. Mabey someone will come up with a great resolution and choppahedzs will get wind of it and try to capitalize on it...mabey. We'll see.

lyk2fly

My Feedback: (3)

Joey, I don't think the snow will hurt your heli. The cold will make the plastic more brittle, so it will break much easier should an impact occur.
Mark

spdfrek

My Feedback: (12)

Aim for a big snowbank then....got it This should be a good learning experiance for me at any rate.

Joey

iloweru

i also have installed a better motor then the stock one. i tried v6 and v7 with no luck at learning how to fly helis.then i put a xtm 15ps in my 110 the power it has is unreal. i just started flying heli i am able to fly as hi as i want with the upgrade. if any of you heli fliers are thinking of doing this to your heli DO IT you won't be sorry . except that you didn't do it sooner.

T.W.

Hi iloweru, maybe you'd like to post an article telling (and preferably showing) how you fixed your motor in place, and how you got-over any problems you encountered along the way too. I'm not alone in looking for an easy (non-engineering) way to do what you've done

As Darth said, the stock engine is the only problem that we who fly these things are having to contend with, so any additional information you have would be of great interest to me, and to many others too

Tony

iloweru

it has a xtm 15 motor with a losi flywheel and clutch , 19 tooth losi bell a longer main shaft to move the gear down to hit the bell gear bigger fuel tank and a 6 cell battery pack. i have pix but i dont know how to post them.

iloweru

here are some pix

T.W.

Thanks for posting your pix iloweru

To me it proves the point that "sometimes you just have to try these things." Your LMH must weigh a lot more than was originally intended, but it flies; and the balance point must move dramatically between the take-off and the landing, but it still flies

Well-done! The fact that your set-up works is inspirational. I really must find one of these engines and give it a go myself

Tony

iloweru

it is heaver then stock but the motor makes up for it. it stays level in hover , flys the best it ever has.

T.W.

Just when my V-7's starting to look like it may work (hopefully) I've found an ad for an OS car engine I could fit to my LMH instead. But I can't find any reference to this particular OS engine on the 'net and I'm starting to wonder if the ad's incorrest. The ad says that the engine is an: "os 11 cx" Is there such a thing? Would it have enough power to do the job? What do you think?

Tony

fiat

Tony it's probably an os.10 or .12 and yes I do beleive that this is plenty of power. If this next v-7 dies I am going to take the motor out of my sons rc car it's an os.12.. I try this combo and see.. Alan

T.W.

Thanks Alan. I have some really good info about how this modification can be done - easily and without any engineering! I'll get it all together and PM it to you later

Tony

lawrencelkl

Hi guys,

i am currently trying to put a .12-.15 car engine into my lmh 116, anyone can give mi some updates on their mod? i.e. which cluch bell to use etc, thanks

Lawrence

Cambo

My Feedback: (2)

I looked into the mod a while back and gave up before i started. It was going to involve alot more modification than i thought it would and gave up.

You are going to need that basic clutch setup for that engine and and probably a 14 tooth clutch bell.
If i was you i would contact Matt at http://www.ballistictechnology.com/
He makes a lot of upgrades for the Corona (electric) but if you e-mail him he might very well make a custom crutch and gear for you.
That is probably you best shot.

I would also seriously consider pricing a larger heli

Good Luck

Peter_d

Hi Lawrence, long time....

I just made a post regarding my apache crutch which I was going to mount a .11 car engine on.... I got it going but went electric because the engine was old and I got tired of fiddling with engines instead of flying.
All I do now is charge the Lipo, go outside take the apache for a spin and having a Blast ! and then go inside to charge again.

Ok, if you still want to do it, you need to do the following.
Take your car enigine to a LHS and let them tell you what you need to put a clutchbell from Team Associates on your engine.
Team Associates pitch is 32 (I think) which is the same as LMH uses.
Then, come up with a plan to mount the engine it to your crutch... thats it !

Keep us posted !!

//Peter

rcflyertim

[size=3][font="Arial"]Notasme

How are the mods going? Did you install the collective Pitch head? Have you done anything recently with the engine or heli?

lawrencelkl

HI Peter,

thank you for your help, i am ordering some parts from tower hobby, so i will try to look for a T.associated clutch system from there as well.
i replaced my old alrton mechanical gyro with a gwspg-03 piezo gyro and it was flying really well with the norvel .061 engine but after some flights it just get tired and again i have to fiddle with the engine again.

i noticed that the engine 'sound' changed a lot. so i stripped it down and do a cleaning and tighten back all parts. i will go out there and see if this help with the same engine or else i will just start doing the car engine mod.

also, have u ever tried the vmax .07 engine? do u recommend to do an engine upgrade to vmax 7 instead? many thanks.

Lawrence

notasme

rcflyertim,

I have not flown yet this year. I have not (yet) converted to a collective head. I have been converting to EP (thought I would give it a try). I bought a Astro VE motor and after 15 minutes of hovering it was toast. I am waiting for them to send me a new motor.

I used all of the recommended parts but (cc45, 4000mah Lipo, Astro 803). The total weight (with battery is 43oz).

Cambo

My Feedback: (2)

I hate the v-max 7

It always quite on me in the air and i broke a rod on one of them.

mac91

Can anyone give me some dimensions of the lmh as i am thinking of making a cp version and just wanted to now the length and general dimensions as well as blade size if anyone could help that would be great thanks.

Peter_d

Lawrence,

I would go for the car engine and not the V7 upgrade.
Because I belive they still have the con rod problem with these engines.

Please !!!!!!!!! Somebody correct me if I'm wrong here !!!!!

//Peter