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What do you think of FORMOST 150 ?

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What do you think of FORMOST 150 ?

Old 06-23-2008, 02:18 PM
  #576  
RCISFUN
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Default RE: What do you think of FORMOST 150 ?

You got it!
Send me your e-mail and I can send you either CAD files or the PDF drawings
Old 06-23-2008, 07:06 PM
  #577  
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Default RE: What do you think of FORMOST 150 ?

you need to build another one. I can cut parts next week on cnc router to your plans. mine is not yet finished but I have most parts installed .
Old 06-23-2008, 07:53 PM
  #578  
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Default RE: What do you think of FORMOST 150 ?

Did you get a copy of my CAD files?
Old 06-23-2008, 08:52 PM
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Default RE: What do you think of FORMOST 150 ?

yes I have your cad files and have cut all parts . I modified some to fit my formost. diferent shear webs relocated opening in 1/4" lg rib. I'm on vacation next week so I may have some time to cut some parts.If you have any ideas to change anything let me know and I will modify my drawings
Old 06-23-2008, 09:45 PM
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Default RE: What do you think of FORMOST 150 ?

Sounds good!
Old 06-26-2008, 03:28 PM
  #581  
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Default RE: What do you think of FORMOST 150 ?

Ok, I shimmed up the stab by putting 1/16" worth of washers on top of the fin at the aft bolts. Also shimmed the right boom which was flopping around on the spar and that resulted in evening up the booms back by the stab taking out some droop that was here.

Results were effectively not much of an improvement. The airplane will fly straighter thru an immelman on take off, but the pitch trim was only improved some. If anything, the roll trim variation with speed got worse. However, when accelerating to full speed it now climbs and rolls left rather than dives and rolls left. So, the next step will be trying to figure out whats wrong with the wing alignment.

Today it was nearly dead calm. One of the few times I've flown it with no wind. Really shows the need for a speed brake with the residual thrust from the P-80. Really hard to kill off the speed in the pattern.
Old 06-26-2008, 03:45 PM
  #582  
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Default RE: What do you think of FORMOST 150 ?

Before the demise of mine I was thinking of adding a center speed brake section to mine, just hinge a piece of plywood 1/8" T x 1.5" W x whatever length fits across the center section, should have been easy
Old 06-26-2008, 05:06 PM
  #583  
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Default RE: What do you think of FORMOST 150 ?

Except that the bottom of the airplane isn't particularly flat. The perfect place for the speedbrake is under the fuel tank but actuation becomes a problem. I didn't rebuild the interior like everybody else and the only place for a servo is under the front of the engine. Actually, all the fuselage glass is wrinkled and not smooth like it once was, so I can't even use that to mold over.

It's starting to look like fixing all the faults is a bigger job than expected. Just need to get up the energy to do it.
Old 07-05-2008, 02:19 PM
  #584  
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Default RE: What do you think of FORMOST 150 ?

A little fun with my Dad's Formost at Rabbit dry lake - he's in green/black.
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Old 07-18-2008, 02:49 AM
  #585  
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Default RE: What do you think of FORMOST 150 ?

I have just about finished all of the mods on my Foremost 150. There sure are a lot of mods to do. I need to know about the engine thrust line. Somebody here mentioned 3 degrees down thrust. Can anyone comment on this?
Thank You
Randy Krul
Old 07-18-2008, 06:29 AM
  #586  
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Default RE: What do you think of FORMOST 150 ?

Randy,
I used a couple of small (4-40 Size) flat washers under the front mount of my Turbine, seemed to work fine.

Rich
Old 07-18-2008, 10:16 AM
  #587  
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Default RE: What do you think of FORMOST 150 ?

Hi Rich,

I have just finished my Formost 150 and should be test flying next weekend. I'm using a P-80, only because I have it lying around. I had to raise the entire turbine 3/16th" plus raise the front 1/8" just to clear the formers under the turbine. Did you get your trailing link struts from Digitech, and if so, what number struts did you order? Did you use Robart 630 retracts? Did you have to modify them at all? Did you have to modify the wheel wells in the center wing section? I have my ailerons cut to make inboard section flaps. Should there be anything I need to look for, such as high angle of rotation or any roll to left or right?

Thanks,
Larry
Old 07-18-2008, 11:14 AM
  #588  
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Default RE: What do you think of FORMOST 150 ?


Larry I will try to answer your questions


Did you get your trailing link struts from Digitech, and if so, what number struts did you order? (Yes) don't know the number I just wrote to Sandor and he sent me the correct ones, once I paid for them of course
Did you use Robart 630 retracts? They started our as the 700 series, they sucked, gear would not lock in the down position..sent back to Robart and they converted to air up / down for free.
Did you have to modify them at all? Robart converted, no mods required to fit struts.
Did you have to modify the wheel wells in the center wing section? Yes
I have my ailerons cut to make inboard section flaps. Should there be anything I need to look for, such as high angle of rotation or any roll to left or right? None


Old 07-18-2008, 12:32 PM
  #589  
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Default RE: What do you think of FORMOST 150 ?

Rich,

Were the struts made for the 700 series retracts? The 630's have a 1/2" opening for the struts. How much were the struts from Digitech? Right now I have 6061 aluminum struts with coil spring in them. I haven't made any mods to the main retract rails. Most of my flights will be off grass and I think I'll need the trailing link struts. The maiden flights will take place on a paved runway. Again thanks for the information....

Larry
Old 07-18-2008, 12:42 PM
  #590  
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Default RE: What do you think of FORMOST 150 ?

Flying a P-80 in mine as well. There's enough residual thrust from the engine to make the airplane a real floater. The flaps will help some, but you will need a lot of throw to get enough drag to make a real difference. I used full span flaperons for awhile which helped, but still could have used more drag. Right now I've scabbed on split flaps under the wing stubs and they provide more drag but still not enough for my taste. They also cause a lot of ballooning which needs a chunk of elevator offset. The flaperons caused a pitch down effect. Really, it needs a speed brake with this engine.

If you haven't done it yet, it would be worth your time to put an incidence meter on the wing and stab. I had nearly 2 degrees of right wing LE up incidence which has caused no end of roll problems. I've gotten a lot of it out, and it's better, but it's still not right. I ended up shimming the stab up with a couple washers under the aft hold down bolts. I think the booms are also cocked a little sideways.

I did not shim my P-80 for up or down thrust. The accel/decel checks I've done seem to show no need for thrust adjustments. Of couse, all the other stuff not being straight could be masking anything. 167 flights so far.

BTW, Nitro has them back in stock along with a smaller one.
Old 07-18-2008, 12:55 PM
  #591  
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Default RE: What do you think of FORMOST 150 ?

Larry,
The Digitec retracts come with adapters to fit the 1/2" strut opening of the 600 series, basically they are steel bushings with rods that fit the drilled strut, I believe they are $150 USD

The other option is to by the "Small" set of trailing link struts from Dreamworks that are made to fit a 1/2 retract direct, I have both and they are equal in quality however I do prefer the direct method.

If you look back through this thread you will see that I cut open the gear mounting area and made 1/4" plywood ribs and rails to mount the retracts, the off the shelf kits have crap wood glued directly to the fiberglass, you may get away with this if you can land like it like a feather; however the way I put them down the stock set up would not last past the first landing
Old 07-18-2008, 02:26 PM
  #592  
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Default RE: What do you think of FORMOST 150 ?

Rich,

I did download the cad drawing you provided here, I just didn't do the mods to the main gear rails yet. I still have a week and I might do them yet. Thanks for the information about the small links from Dreamworks. I'll look into them. Anyone ever think about clamshells for stoping, just like full scale jets use?

Larry
Old 07-18-2008, 02:37 PM
  #593  
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Default RE: What do you think of FORMOST 150 ?

For as cheap as this airplane is, invent away!!

If I do this again, the first thing I would do is get a speed brake installed under the fuel tank area. The airplane doesn't really need flaps to land slowly, it does need drag.

I used Robart 550 retract units bolted to the existing rails. Only problem has been the screws like to loosen up every so often.
Old 07-18-2008, 03:47 PM
  #594  
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Default RE: What do you think of FORMOST 150 ?

Thud Driver - you didn't reinforce where the retracts mount to? Loosening screws can be fixed with CyA, I'd think.
Old 07-18-2008, 04:18 PM
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Default RE: What do you think of FORMOST 150 ?

No, too much more work than I wanted to do. Thought I'd wait until I ripped the gear out before I'd cut it open to reinforce. Yes, I glued the screws in (sort of). And, yes, I've beat it off the ground a couple times and the gear and mounts are still there. I'm also still waiting for the wings to break off. [8D]
Old 07-19-2008, 10:40 AM
  #596  
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Default RE: What do you think of FORMOST 150 ?

Best way to slow down a heavy jet is using crow. Aileron up-flaps down. BVM has a program on their website to set it up. They use this system on Kincats & Bobcats with great success.
Old 07-19-2008, 12:21 PM
  #597  
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Default RE: What do you think of FORMOST 150 ?

This jet isn't particulary heavy and has a relatively light wing loading. Yep, love to do crow if I had enough channels on the radio and/or the matchboxes.
Old 07-26-2008, 11:04 PM
  #598  
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Default RE: What do you think of FORMOST 150 ?

Hi Thud Driver,

Well I flew my Formost today. You were right. After take off and some altitude, I let go of the up elevator and right aileron I was holding and it pitched down and left. After about 3/4 right trim and 1/2 up trim I had it flying real nice. Went about 50 feet on asphalt before rotating. When I landed I noticed the right flap had some down and the left flap had some up. Explains the left roll. Adjusted the flaps and took off again. Still needs right trim, but not as much. My CG is at 6.5" from leading edge of wing at fuse. About 10ยบ nose down. Before I mess with the CG, I might take out some down thrust. Flew in a 25 MPH wind. Flaps caused it to float, but it did slow down. Remember I'm using a P-80. Don't know how it will land in no wind. I was looking at the speed brakes of the Composite Flash. Looks like they might be what is needed on thei plane to make it slow down...

Larry
Old 07-27-2008, 09:52 PM
  #599  
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Default RE: What do you think of FORMOST 150 ?

Flew my Formost this last week flew well but had some problem with elevator trim, come to find out one of my elevator servos was unpluged. Flew the intire flight with one elevator servo. Thank god for redundacy. Using DS-821s on the elevator. It has a JJ-1400 and I did all the mods, except glassing the wings, as described in this forum. Also modded with split flaps inside each boom to fuselage. Has an external centerline tank, I made out of Estes parts, for the smoke fluid but have not hooked up the pump yet. Wing loading seems to be fine and JJ-1400 seems to have enouph power but surley not overpowered. Cut a hatch in the bottom forward of nose gear for the 3 2000 MiAmp Lipos. Balanced about 1" forward of spar.
Old 07-28-2008, 04:53 PM
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Default RE: What do you think of FORMOST 150 ?

Well I found out what makes the Formost go into a left roll. The left wing has 1ยบ washout and the right wing has 1.5ยบ washin. Left wing at root, 2ยบ positive, at tip 1ยบ positive. Right wing at root, 2ยบ positive, at tip, 2.5ยบ positive. This gives the right 1.5ยบ washin. Leading edge up at tip 1.5ยบ for right wing. Thus a left turn.....

Larry

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