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knussear
12-24-2005, 05:25 PM
Hi All,

Just inherited a skimmer 400 with plans and parts, but no instructions.

Does anyone have a copy that they could scan and email me?

Thanks for the help!

Ken

knussear
01-02-2006, 04:05 AM
No response, but please disregard.

I called hobby-lobby and they sent me a set for a nominal fee.

Turns out you don't really need them. You can pretty much figure everything out from the plans.

Ken

TeslaWinger
01-09-2006, 03:36 AM
Never built one, but I like the looks of it- and the price. I saw one fly and it turns nicely. Glad you got hooked up. HL rocks. Let us know how you like the kit and the flying.
Enjoy,
TW

cassat
01-24-2006, 11:07 AM
I am building one here also. Wing is complete. Just the fuse to finish. Was going to use a geared 370.

knussear
01-24-2006, 02:08 PM
Just got mine done,

I'll post some picts tomorrow, WX permitting I'll have the maiden flight.

cassat
01-24-2006, 02:11 PM
Great,

Can't wait to see the pics. What size of battery will you be using?

TeslaWinger
01-28-2006, 05:45 PM
A 7.2v Speed 400 can use a 3 cell lipo. A 6V S400 can use a 2 cell lipo. Use at least a 1500 ma pack. With a geardrive you can get a good climb from a S400 rigged like this. Give it all the cooling air you can. I swear the S400 geared is the best value in the hobby- possibly only exceeded by the Skimmer kits!

I got to fly that guy's Skimmer finally! It handles as nice as it looks and I will definitely be building one soon. He must have seen me lovin it and offered to trade it for my Queen Bee that I had let him fly (No way could I witness him trash the handlaunch so I gladly did the duty- it is a handful!) so I could try this lil sailplane. Nice try, buddy! HORSETHIEF!!

He's got 8 NIMH 1100 ma pack in there now and it performs well. I got him up to speed on lipos and now his lipo esc and a 1500 ma 3 cell Kokam lipo pack are on order to trim some weight and stretch the flights- and ensure me a bit more flight time on it for... testing purposes... :D

TW

cassat
01-28-2006, 06:00 PM
Yes,

I did get some new Lipos also as well as the 8 NiMH. Which ESC speed control works good with the Lipo's?

Cassat

knussear
01-28-2006, 10:06 PM
Well I flew it today and not sure what is going wrong. The plane was unstable as hell and didn't seem to have the power to climb out of the field. Any more than the slightest amount of rudder and it wanted to fall out of the sky. I used a 7 cell 1000mah NIMH. Not sure if I'm too heavy or ??? I'm running a 6X3 foldable prop that came with the plane, and a Zagi 400 motor.

Any ideas?

Ken

ragbag
01-29-2006, 11:51 PM
Well I flew it today and not sure what is going wrong. The plane was unstable as hell and didn't seem to have the power to climb out of the field. Any more than the slightest amount of rudder and it wanted to fall out of the sky. I used a 7 cell 1000mah NIMH. Not sure if I'm too heavy or ??? I'm running a 6X3 foldable prop that came with the plane, and a Zagi 400 motor.

Any ideas?

Ken

Stranger than fiction!!!!

If you are not getting the airspeed you need it would be cantankerous. I am assuming the trims are right and it is square.

The doc that I speak of in the Skimmer 600 thread had problems with his. It flew but was fast and uncontrollable because of some warps.

I have the Skimmer 400, Graupner speed 400 6 volt, direct drive, Jeti 012 ESC, Graupner 6X3 folder, 8 cell 1100 NMH.

It flies right out of my hand.
What radio are you useing, I use a Futaba Skysport 4.

If I set the trim lever all the way up I get about another 300 rpm.

Some poopood me until I showed them it was so. This could be a little of your problem, not getting full power.

I don't explain it I just use it. :rolleyes: It is not the same with my other radios, 6xa, 9C and Spektrem.

By George:)

TeslaWinger
01-30-2006, 01:28 AM
Cass, I use the FMA stuff. The Super 20 esc for single S400 setups and the Super 30 esc for my twin S400 Porter. I like their Kokam lipos since they have never failed me- unless I killed them myself- and the M5 receiver is a small wonder that I happily own 3 of.

My Castle and Jeti escs work fine for brushless motors, both in and outrunners with lots of hours on both. The Jeti Advance esc is a breeze to quickly program the esc for brake, lipo or NIxx cutoff, inrunner or outrunner settings with its programming card.

I just replaced the esc on my Bird of Time e glider today (had 'borrowed it' for my Queen Bee) and had it programmed in about one minute. The EBoT awaits spoilers for my quaking smallfield landing knees!

KNU- Bummer, buddy! The S400 direct works best with a clean light plane like a foam delta. Add a gearbox of some type and enjoy the difference it makes.

The Zagi motor is timed for pusher operation so it is not maxing out in a tractor role-but would be perfect for a redrive since it reverses the motor with a standard geardrive. A 6V S400 would be a hotter choice for 7 cells than a 7.2v motor. A 1500 ma 3 cell lipo would lighten the load and supply more power (to a 7.2V S400)- both critical for climb. Anything is better than direct drive with a small prop. A reduction drive totally changed my flying experience with this class sailplane with a climb rate triple what I had direct. But it shouldn't make it handle like that...

Deploying rudder causes drag. Might you be flying a bit too slow already when the additional drag pushes it into a mush? Heres a few WAGs:

CG balance first. Sounds 'aftish'- move the battery forward 1/4" at a time and fly each change. When I set up a new plane, I tape a straightedge to each elevator/stab and fin/rudder and center the trims. Knowing the controls are centered lets you make CG changes without adding mystery!

Too much incidence- wing taking 'too big a bite' would account for mushy behavior. I have used a piece of 1/32 balsa under the trailing edge of a musher and the leading edge of a diver and perfected a glider that was too mushy or too 'divey' that was otherwise balanced right. Usually that's the last resort and I think they got it right on this one, so think elsewhere.

All the usual suspects are worth scoping out too- Washout- the imbalance or lack of it across the wing trailing edge. Stab warps, all that...

I converted an Aspire 2 meter poly glider to e power using just a Speed 400 and a 4:1 metal reduction drive and a light 3 cell 1500ma lipo. The climb is not very good, as expected, but it is so light- and the sink rate so very low- that it flies at half the speed my heavier more apropriately powered and wingloaded 2 meter e gliders do and seems mushier in handling with its very light wingloading and amazing slow flight turning ability. Somewhere between the wimpy feather motor and the raging lead powerhouse is the right setup. Gasbag or lead sled. Pick yer poison!

All it needs is two things- to be shaped right and balanced right. Sounds easy, huh? :D

Blue Skies,
TW

knussear
01-30-2006, 03:04 AM
OK,

Thanks for the input.

Seems like airspeed and power were the trick. I picked up a Lipo 3s 1650 for $35 yesterday. Rebalanced and checked all/fixed minor damage from yesterday. Ran with the same prop. That thing climbed straight up like a rocket. Big difference. Seems like once she got moving the stability got alot better. It needs a lot less rudder throw than my other planes for it to move, so I was probably over correcting and without enough airspeed and there was the issue.

Winds picked up during the flight today, handled really well though. Had to motor up a couple of times to get it back near me, landed great.

Ken

ragbag
01-30-2006, 11:43 AM
Have heard nothing but good about the little Skimmer 400 and as I have said once do got his trimmed out he loves it. A couple of other fellows have now picked up the Skimmer 600 as some have started to call it.

Hobby Lobby only lists it as the Skimmer.

http://www.hobby-lobby.com/skimmer.htm


By George:)

TeslaWinger
02-06-2006, 03:09 PM
Alright, KEN! A 3 cell S400 (7.2V motor if ya wanna make it last a bit) absolutely kicks tailfeathers! Congrats! This is what its all about- climbing up at a ridiculous angle and STAYING up with that light pack. You have arrived, my friend! Now try a redrive and watch the climb improve again!
Enjoy,
TW

knussear
02-06-2006, 03:41 PM
Please elaborate on "redrive" I'm not familiar with the term. Will it give more RPM or allow turning a larger prop?

Ken

Alright, KEN! A 3 cell S400 (7.2V motor if ya wanna make it last a bit) absolutely kicks tailfeathers! Congrats! This is what its all about- climbing up at a ridiculous angle and STAYING up with that light pack. You have arrived, my friend! Now try a redrive and watch the climb improve again!
Enjoy,
TW

TeslaWinger
02-07-2006, 02:29 AM
Oooops! There I go slingin the lingo! Sorry, K! :D

A "redrive" is a REDUCTION GEAR DRIVE- or BELT DRIVE (found on some larger units), also known simply as a gearbox.

A simple arrangement of a small gear (a pinion gear) is pressed and glued to the motor shaft and meshes with a gear that is 3 times larger (in the case of a 3:1 reduction, for example) that is attached to the driven prop shaft.

The motor's rotation must be reversed to drive the prop in the right direction due to this- which would put your Zagi motor back in the rotation direction that is timed to be its most powerful, since the Zagi guys time them for max pusher operation. One look at these geardrives will make this clear why it reverses. What is NOT obvious is how much improvement in climb you can get using one!

With a planetary gearbox type (the driven gears 'orbit' around the gear on the motor's output shaft) it's a bit more mechanically complex arrangement within a gearbox housing but it does not require a reversal of the motor direction due to this arrangement. The simple 'single stage' gearboxes are lighter and cheaper, planetary is heavier and more expensive due to more machining and number of parts.

Take a look at the Hobby-Lobby website (among many others) and check out their selection of reduction drives and see the props that a Speed 400 would use when fitted with various gear reductions. Their "recommended setups" is very valuable for seeing what would work in your plane.

Find a similar size and type plane and see what they recomend in gear ratios and corresponding props! Make sure the power setup is similar (same voltage, same motor - for instance a 6 volt or 7.2 volt Speed 400 driven by the same number and type of batteries to get this right.

Until you get to the point where you are playing 'what if' with your own designs and power systems using E Calc or Moto Calc computer programs, this is a great way to get a feel for what a 'redrive' can do for your plane.

A useful ratio, for example, is 3:1 (reduces the prop speed by three times and triples the torque from the same motor. A Speed 400 can be made, with such a gear or belt reduction to drive a larger prop- say a 9" diameter prop with a 6" pitch (a 9x6) instead of the generic 6"x3" prop a Speed 400 uses when it is driven direct.

Direct is fine for a clean fast lil dart like a Zagi type delta, but when it is called upon to climb a larger glider at slower speeds it needs a bit more torque and diameter (larger props are much more efficient.) A slower prop will not drive the plane as fast- but the increase in thrust will certainly make a big difference in climb for a glider since climb occurs at a slower speed than a delta's cruise!

Hope that helps- and thanks for calling me on the "techspeak!"

Regards,
TW

PS: Having said all that, understand that the lightest setup- direct- I actually preferred on my Ascent, a small glider, since I was going for the lightest setup I could get since I wanted to optimize soaring potential in light conditions. This used 2 1500 ma Kokam lipos and a 6V Speed 400 and a 6x3 folding CAM prop (Hobby Lobby). All depends what you are trying to optimize. A MAX CLIMBER would be heavier and more powerful- an advantage in windy conditions, but I love light wind thermal soaring and tend to be a fan of the 'floaters.'

A Speed 400's climb can improve using a gearbox- but a Speed 600 will totally SHINE with one since it is a very heavy motor! I was disgusted with my old 2 meter Windstar S600 direct 'climb' till I used a geardrive (HobbyLobby, again) and I was blown away by the huge improvement and really started having fun then!

I could now reach altitude so quickly that I then used smaller lighter batteries (another big improvement, being lighter) since I didnt need to grind away for the entire charge to get up just once! Changed everything for the better- and the most valuable lesson I learned that year! All of a sudden I could stay up all afternoon if I chose when the conditions were good since the lighter glider didnt just sink out of lift like the 'lead sled' did!

Enjoy

knussear
02-07-2006, 03:13 AM
Thanks,

Looks like some of those might take some room to fit. Seems like the planetary versions are more likely to fit in the fairly tight front end that the spinner has? Sounds like a project coming up.

Ken

ragbag
02-07-2006, 02:37 PM
Quote:
With a planetary gearbox type (the driven gears 'orbit' around the gear on the motor's output shaft) it's a bit more mechanically complex arrangement within a gearbox housing but it does not require a reversal of the motor direction due to this arrangement. The simple 'single stage' gearboxes are lighter and cheaper, planetary is heavier and more expensive due to more machining and number of parts.
End Quote.


The purpose of the planetary gear box is to make it in-line drive instead of offset. It doesn't require as large a frontal area.

You can realy get into the bearing load also, another can of worms.

I find that the Himax that I fly is not heavier.

Also if you reverse a motor that is direct drive it will not be as efficient unless you retime it for the new rotation.


By George:)

knussear
02-07-2006, 03:20 PM
That clears it up.

I'm running a Zagi 400 that is already reversed, so the gear box should also get it back in tune.

Ken

sawadee
02-09-2006, 12:40 AM
I see rarbag mentioned some of his group using the "600". I just ordered one from HL and it is on back order. Anyone know anything about the "600"

knussear
02-09-2006, 02:15 AM
I saw a 600 thread started up not long ago.

ragbag
02-09-2006, 10:25 PM
Have heard nothing but good about the little Skimmer 400 and as I have said once do got his trimmed out he loves it. A couple of other fellows have now picked up the Skimmer 600 as some have started to call it.

Hobby Lobby only lists it as the Skimmer.

http://www.hobby-lobby.com/skimmer.htm


By George:)
Here is the Skimmer that Hobby Lobby lists, as I said some are calling it the Skimmer 600, I guess because it has a 600 brush motor in it.

Here is the Wattsflyer thread on the Skimmer:

http://www.wattflyer.com/forums/showthread.php?t=3911

By George:)

ragbag
06-11-2006, 12:00 PM
I finaly got to spend more time with the Skimmer 400 that I had purchased at a fly-in. Started haveing trouble with power cutoff. After close examination I decided it was heat, there was no ventilation in the fuselage.

I took two spoons from Grandy's the just happened to be the right color and cut the tips off of them. Some grinding and fitting.

Made some holes in the fuselage and mounted them with Goop. After a run on the bench I had minimum heat in the motor, as expected, nothing like it was before the modifications.
I did open a vent hole in the bottom of the fuselage also, didn't take any shots of it though.
Looks like it should do it for me.


12734 12735


.

ragbag
06-16-2006, 11:12 PM
Flew the Skimmer today, it did everything I wanted to do. No heat at all and today is one of the hottest so far this year.

The spoons did the trick.:)