RBean

I'm looking for information on the ESM F6F Hellcat. I totalled my H9 Hellcat being stupid and flying it into a high wire. I've decided I have to have another Hellcat. I'm limited in size to about 72" wing span as that is about the largest that will easily fit in my vehicle. The H9 was a little heavy with a DLE 20 and CJ retract and flaps which added two more servos but flew good. The CMP Hellcat does not look real scale and only has the out board flaps. So I am considering an ESM Hellcat. Can't find much info about it. What I have found is they fly ok and a DLE 30 is plenty off power, but have to add nose weight. Maybe I'll go with an OS 33, not sure. Then there is the landing gear/retracts. I want to go electric. ESM has their Gen. 5 electric retracts. Are they any good? Then there are WingSpan rotating retracts, but I've read they have a lot of slop, but don't know, personally. The Lados seem to be hard to get and expensive. Sierras are ok but I want electrics. Also I learned with the H9 that the retracts need to be 95-100 degree. 90 degree is not enough to be scale forward rake, to say nothing about ground handling on a grass strip.

Also I want to use a three blade prop. A Hellcat just doesn't look right with a two blade. Does a DLE 30 have enough power in this plane to give up some efficiency with a three blade, or do I need to go larger say a 33 or 35cc since it needs nose weight anyway?

Anyone with experence with this plane, let me know what you think.

BubbasanJohn

I am almost done building mine and I was looking for information on how much weight people have used to balance and I saw your post.  I have a DLE 35RA up front.  Not sure how this will balance out.  I used Sierra landing gear and they are very nice.  I was going to use the electric gear from ESM but they were out of the hellcat gear and think they still are.  I am going to use a 18x6 for break in and 16x8 carbon fibre 3 blades after. 

BubbasanJohn

Ok, the plans have CG at 117mm. I just tested mine and I'm coming in at 140mm. Looks like Im gonna have to add 3 pounds of lead up front. WOW

RBean

Thanks for the reply. That tells me I don't need to spend money on a light weight engine like the DLE 30 or 35RA. My CMP Zero thas a 25cc conversion, with electronic ign. 52oz. I built platforms and mounted both ignition and receiver batteries under the cowl as far forward as possible, still had to add a heavy hub and a chuck of lead to the engine mount. Weights 16 lbs but flys good. How much space between the firewall and front end of cowlings on the Hellcat? Let us know how the build goes.

BubbasanJohn

I would use the heaviest engine possible. The Plane already is set up for pull/pull on rudder and elevator. Put batteries and all else as far forward as possible. The DLE36RA I chose is light. Wish it was heavier. So to balance at 115mm I have 3.63 pounds of with attached to the stand offs. You could add weight to the cowl for sure. ESM has the cowl attached by some small screws, so you would have to re-engineer the mounting if you were going to add weight to the cowl.

So I was going to try to maiden today. DLE35RA would not start. Had to pull the carb off and unstick a litte valve that was stuck closed. While I did work out the nose weight issue, I missed my maiden as trouble shooting took some time as I tought it was the ignition but turns out it was the carb.

I honestly think that regardless of engine you will need to add nose weight. Dont think my receiver batteries are anywhere close to 3.63 pounds.I am curious to how your turns out.

panhndl

My Feedback: (10)

Why not put the Evolution 40 GX in the front of the plane? It is pricey but much heavier than the DLE or OS. It also is a little bigger cc wise and will be able to swing a more scale 3 blade.

raptureboy

Not alot of info but may help http://www.rcuniverse.com/forum/m_94...tm.htm#9446983I have a CMP that I am bashing, I cut the wings down to be more scale and added scale flaps, You can check out this thread http://www.rcuniverse.com/forum/m_25...tm.htm#2530290 also if you want to kit build Chad designed a real nice one http://www.rcuniverse.com/forum/m_11...m.htm#11202842

BubbasanJohn

Yeah, but its not going to make the nose weight disappear si at this point, the added $$$ to get another engine is just not making much sense.

BubbasanJohn

Thanks for the links, going to read thru them now.

panhndl

My Feedback: (10)

I was really posting for RBean's use. I wouldn't suggest you buy another engine, but if you haven't purchased an engine at all and was looking at this plane, the Evo 40GX does look good. Another possibility would be the Roto 35 or possibly the Roto 50 twin. I bet the twin will have both heads poking out, though. The Evo 40, DLE 35 and Roto 35 have similar dimensions but the Evo weighs almost a pound more than the DLE. It appears the Roto weighs about in between the DLE and the Evo, but it's hard to say for sure since it doesn't specify if that is engine only, with muffler, with ignition, etc. The downside is that the Evo will cost $550-$600 while the DLE costs $350 and the Roto costs $450.

RBean

I have a G-38 setting on the shelf. It needs a muffler but other than that ok, I think. I thought it would be too big and heavy for this plane but maybe not. What do you think. Is there enough room in the cowl for this big old ugly engine? It should be able to turn an 18-8 three blade prop.

BubbasanJohn

panhndl, sorry I jumped in there. I think what you are saying is real sound for this type of plane with a short nose moment.

Yes it should fit. and as panhndl points out that the heavier the better engine wise on this bird.

BubbasanJohn

Ok, So I was not happy with 3.6 pounds of weight added to the nose. That is alot. I got a pm form a member that said that all he needed was to put a battery pack mounted to the engine mounts to balance this plane with his OS twin 160.

I checked the weights of the os twin and my DLE 35ra and there is not a lot of difference. I went back to the intall of my gear and moved the receiver up as far as possible, as well the 6v regulator and made space for the 2 Lithium Ion packs directly against the firewall on the inside of the plane. the batteries were only moved about 4 inches forward but this should help as they are now forward of the CG as are the iother components. The only component that is rearward of the CG is the servo that controls the air valve. I' am sure this is adding to my issue here but cant imagine tht its is a majority of the 3.6 pounds.


I was looking to mount the nose weight to the engine standoffs. While this seemed like a good plan initially, it made installing the cowl impossible. There was also concern about the weight vibrating with the engine. If it ever came loose it would have been real trouble. What I am planning to do now is remeasure the weight needed for balance and put the nose weight as far foward as possible by using lead shot and epoxy directly inside the cowl lip closest to the front part of the cow (saw this done on the scale builder forums)l. I think that by doing this I will require less weight than the amount needed at the engine mounts. I did mount the air system for the retracts in the belly pan.

I will have to strengthen the cowl mounting ring and screws to hold the added weight. I am concerned about ever removing some weight. Last thing I would want to happen is to have the weight shift or come loose.

Anyone have anythoughts on this? Would be grateful for any ideas.

Chad Veich

My Feedback: (60)

John,

I've put weight in the front lip of the cowl on nearly every one of my radial engine warbirds. Never had any problems but, as you noted, a good solid cowl mounting system is required. Even if you can't (or don't want to) put all of the required weight in the front lip just putting a portion of it in there will help as you can't get it much further forward! Good luck with the Hellcat.

RBean

John,

The Zero is also short nosed radial. I built plantforms as far forward as would fit under the cowling. Mounted the 6V and 4.8V batteries there. This helped a lot. Still had to add heavy hub and a little weight. After over a year add maybe a hundered flights it's still ok.

BubbasanJohn

Thanks Chad.  Glad to hear from a modler like you that this is a sound plan.

RBean, I did build a platform initially but this too made the cowl impossible to fit.  Most likely because I was trying to cram 3.6 pounds into the platform it grew to large. 

Really trying to get this sorted for a maiden sunday. 

Thanks for the feedback guys.

BubbasanJohn

Troy built told me that people are having good success with the cg at 112mm.  I'm all balanced now. Just trying to repaint in a different color scheme before my maiden Sunday. Going to repaint as a British hell cat flown off the HMS Essex in 1944.

RBean

I'm planning on getting the Hellcat, from either Troy Built or VQ Warbirds. Got my G38 down and checked it out. It was in a crash two years ago. The prop shaft was slightly bent. I fixed with a plastic hammer and run out gage. Less than .002 run out now. I have ordered new bearings (I figure the crash and hammer adjustments didn't do the bearings and seals any good) and a new insulator block as I found the old one cracked. Also ordered a new muffler. I already have the receiver and servos etc. I still need to settle on retracts. I really want to go electric. Still trying to decided. Can't get much feed back on the WingSpan Rotating gear. Lados are hard to get and have heard less than good thing about the ESM landing gear and retracts.

RBean

Ok, I've ordered some parts for the G38 and will install new bearings and muffler and test run the engine. If it works ok then I'll need to decide what retracts and order the plane. This engine weights over 75 oz with a spring starter which is almost twice the weight of a DLE 30.

BubbasanJohn

Be glad it weighs that much.  Think you can get away with zero nose weight.  Keep us posted!!!

BubbasanJohn

Oh, forgot to add apicture. Ready for maiden, but have been held up on a bad ignition system. Working with troy built to get this settled but I have been waiting 2 weeks with at least 1 more week waiting.......DAMN. So in the mean time, I got sick of looking at all the blue hellcats and decided to change mine up a bit. This scheme is loosly based on a hellcat that flew off the HMS Essex in 1944.

RBean

BubbasanJohn, your Hellcat looks great.

johnny bubba

My Feedback: (1)

Thanks RBean! Just wish it could get flying.

RBean

I got the parts in and got the G38 running. turns a Beila 17-10 three blade 6,450rpm (the DLE 30 turned this same prop 6,000rpm), turned a Master Airscrew 16-8 the blade 8,300. I'll probably try a Xoar 18-8 three blade. The DLE 30 turned it 6,600 rpm so the G38 should get around 7,000 which would be about right. Time to order the Hellcat. Still havn't decided on the landing gear/retracts.

RBean

I got my G38 running and was just about ready to order the plane. Now I have found out the price has increased to $369 at both TBM and VQ Warbirds. Also more the problem, I can't use the WingSpan Rotating Electric Retracts as they are only rated for 10 lbs. I think this plane will weight over 16-17 lbs. The Lados are rated for up to 22 lbs but they are only 90 degrees. At least 100 degrees needed. The only option is Sierra air retracts and I don't really want to buy any more air retracts, although in truth they have not been much problem. There is no ESM electric retract in Version 3 for the Hellcat, at least not that I can find. Maybe I'll put this project on hold for a while and see if Lado, ESM or maybe Robart comes out better gear.