Mac-

Does anyone have the now discontinued Ripmax Extreme 3D model?

I am presently building one and need to know what engine weight will balance this model without resorting to lead in the nose or tail. The elevator servo will be fitted on the rear fuz. wall near the tail.


Thanks![8D]

affas

I do have the 2-stroke OS 50SX, Balanses perfect with batterypack in front of the servoes. Bad roll rate, but hovers easy. Some spots of bad balsa quality.

Hercmate

A good friend in my club built one a few months back. It flies really nicely (if a little on the heavy side) He uses an Irvine 53 and it balanced perfectly in the middle of the range. If you gonna put the ele servo at the tail use something at bit heavier like a YS 63!

Sprink

Had a Saito 72 in mine. I cut loads of holes in the balsa to save weight, glad I did it still came out at over 5.5 lb.

Elevator servo out back, all the remaining radio gear under the canopy.

I was rather disappointed and scrapped it after a couple of months. I would not bother with the wing tips to increase the roll rate and KE ability.

Mac-

Affas, Hercmate and Sprink,


Thanks for the tips. As you say the Extreme is heavy which has obviously now been superceded by the lighter Extreme Lite ARTF.

...but it's still worth, imo, building![8D]

Sprink

Yes, worth building.

As I say there is loads of balsa to cut out so you can make your own Lite version. Wing ribs and fuz sides are the easiest bits. Use light covering and radio, you probably could get it under 5lb with luck. (I over did it on the radio)

I have not yet seen an ARTF Lite version that has not got twisted ailerions [:@]

Katana

I had one with a 0s 46. Awesome plane till i crashed it

Mac-

Would that be the OS .46 FX?

A clubmate flies the Lite version on this engine and it performs well. I guess that the OS .46 LA would be a tad under-powered![8D]

Mike Bogh

My Feedback: (14)

Whats all them wood parts scattered about...I thought all planes came covered and ready to assemble...

Mac-

...almost a lost art[8D]

Mac-

This will be my first 3D ship in around 20 years of flying/building....just hope it will be worth it!
(....the tips are a tad short!).[8D]

Sprink

Cut them off and throw away. The plane will be better without them.

Can see any sign of weight saving either[]

Mac-

I must admit that the original Extreme is a heavy model but conversely, it's successor, the Extreme Lite ARTF has lightening holes in its liteply reinforced fuz. either side of the leading/trailing edges which can result in failure with heavy landings. A clubmate has the 'Lite' and reinforced these areas with no problems too date.
Perhaps until my 3D skills are well honed it may be prudent to accept a heavier model to practice with?[8D]

Sprink

Light planes fly and 3D better than heavy. "Build to fly, not to crash".

I cut holes everywhere, didnt break it. The extreem has a thick wing, you can land at 0 mph in anything above a light breeze. (first and only plane I have done a vertical landing with)

Too late for cutting out the ribs, but could still do the fuz. I also should have mentioned, but I forgot, to put aerodynamic balances on the elevator and rudder, again like the Lite.[&:]

Mac-

....no problem! I shall be filling the model with Helium gas....outstanding![8D]

Mac-

My Extreme is now almost complete!

At around 5 1/2lbs she's a tad heavy so what engine to use? Ripmax suggest an MDS .58 instead of a .46 no doubt to boost its 3D performance.

Would this model be over-powered with an SC .61 2-stroke fitted?[8D]

Sprink

No, but 61s are a bit heavy for this, especially as you are already at 5.5lb (does this include the engine or not) I used a Saito 72 with 14x4w, went very well. Best two stroke would be the West 50 T1 - designed for funflys like this.

Mac-

I should have stated that I estimate the all up weight at around 5 1/2 lbs. Thanks for the advice.[8D]

Mac-

Well she's almost complete! The weight comes out at 4lbs 5ozs with only an engine to fit. The flight pack may need to be moved to the rear of the servo bay for c of g balancing and the elevator servo is fitted at the tail end.
I painted inside the clear cockpit with Humbrol enamel paint over a primer base of Prymol. The ABS cowl has also been painted and layered on the inside with fibregalss.

She's a tad heavy so I'll need a little extra power?[]

Sprink

Looking cool

Mac-

I've now fitted a new Irvine .53 2-stroke with an APC 13 x 4W prop. Will this combination be sufficient to prop hang my Extreme?
This is my first 3D model and comes out at 5lb 7 ozs all up weight.

Your opinion appreciated.

Thanks![8D]

Ian.W

No, that is to big a prop, luke 3D uses a 13x4 but id recomend the 12.25*3.75 for best results

Mac-

Drat!...when I ordered the Irvine earlier this week the model shop supplier assured me that the 13 x 4W (£8-75) would be ideal on the .53. I must admit that I felt that the 12.25 x 3.75 would probably be the best prop to start off with.

I guess that it's back to the drawing board - prop wise![]

Ian.W

I find the 13*4w is even too much on my west engine, and there far more powerfull than an irvine

Sprink

The normal 13x4 works quite well on the I 53, but ed is right, best results with the 12.25x3.75. The 13x4w is just a bit too much.[]