Situ with Groen Brothers. Upgrades / Updates

[automan1223]

I called Sparrowhawk the other day and no one was available to talk with me about this old kit I have. I have let too much time go by since I started it, I am curious what upgrades I should be concerned with. It kind of took a side burner as my time and other related projects took priority over getting my rear in gear and this project rolling.

It is an early kit / build one of the first dozen or so... I remember Stan's great posts about upgrades and his builder log.

I will list some here from memory. SPH wanted me to "inventory" the kit but that in and of itself is a huge undertaking anyway.

I am not adverse to building but their demise has taken me by surprise. I am sure that some investor will take this turn key kit to the next level but in the mean time god knows what kind of support we will be able to get.

Rod end upgrade for controls.

Redrive bearing upgrade is that an upper or lower concern ?

Nosewheel upgrade (something about weak fork) ?

landing gear upgrade. (only if you are planning on kaplunking it in)

Anyone chime in ? Mr Stan ?

Thanks,

Jonathan

[mgoroff]

Johnathan,

I have a SH 1.5 - it's a late model SH1 kit with a some SH2 mods. I don't think much changed between the early and late SH1 kits except that more parts where pre-fabed for quicker assembly.

As far as your list goes:


Rod end upgrade for controls.

I'd definately recommend using the upgraded pitch control rod. The original is claimed to be sufficient, but the upgraded rod and larger end bearings are a comforting upgrade to a highly stressed critical part of the control system.


Redrive bearing upgrade is that an upper or lower concern ?

The change was to the design of the upper redrive bearings. I think this is mostly for convenience of maintenance and is not worth doing IMHO.


Nosewheel upgrade (something about weak fork) ?

I'm not sure about this one as I hadn't heard anything about it.


landing gear upgrade. (only if you are planning on kaplunking it in)

I think the upgraded gear was to improve the alignment of the wheel to remove camber and make it easier to manufacture and assemble. My gear has significant camber unless I lower it too much, in which case there is insufficient tailwheel clearance. The extra camber in the mains doesn't have a significant effect. My gyro handles fine on the ground and has no noticeable tire wear in hundreds of landings.

Other items to upgrade or note:

I have the SH2 pulley system on my rudder cables and would highly recommend that upgrade if you can get the parts. It makes the rudder control system *much* smoother.

The newer SHs switched to a shorter prerotator cable that would be worth retrofitting to your kit. Also, the prerotator belt pulley kit from Imflyn MFG is a great upgrade as it keeps the belt from flapping.

You might want to upgrade to the 80amp alternator. It requires a new mounting plate and pulley.

The torque values on the the PSRU and engine support rods was changed to 160-190in-lbs instead of the 30 ft-lbs speced in the drawings. The insert threads are likely to strip at the original torque specs.

I believe there where significant changes to the anti servo tab setup in later models. If you can't get drawings from GBA, I can email them to you. Also, you may want to upgrade the rudder turnbuckles by one size. The original ones are very small and fragile!

I reattached the engine PVC system and oil consumption is vastly improved and the tail stays much cleaner!

Throw away the garbage aftermarket thermostat GBA supplied and use a Subaru OEM thermostat. It's much more reliable and easier to bleed the air out of the cooling system as it has a bleed hole for air.

Marc

[PW_Plack]

Nosewheel upgrade (something about weak fork) ?
I'm not sure about this one as I hadn't heard anything about it...

Wasn't this an issue the first year the SH showed up at Mentone? I couldn't find the thread, so it may have been at the 2003 PRA nationals before this forum started, but two machines snapped front nosegear landing or taxiing. It was promptly remedied with a mod from the factory, and I think all kit owners at the time got a new one.

Perhaps someone closer to the type will recall the exact details.

[rfi]

That's correct, Paul. GBA put a diagonal brace on the nose wheel strut. I was at Mentone and saw the broken nose gears. The nose wheel strut just wouldn't take the shock loads from taxiing on rough ground.

[StanFoster]

Jonathon: The crankshaft support bearing upgrade is nice. Lots beefier...you can see both sides of the bearing...and its easy to take it off and really inspect it.

The front fork upgrade came about when one collaped at Mentone...they designed an upgrade and overnighted the part to Mentone.

I made a lot of noise over those 1/4 rodends that are on the one control that has the most force applied...the fore/aft cyclic. I upgraded mine to 5/16 which is the largest they could retrofit mine to...5/16 is way lots stronger than 1/4 inch. The new SH 11's are 3/8 inch.

The turnbuckle on the tail was originally a silly little 6/32 thread...and I changed mine out to a 10/32 turnbuckle from Aircraft Spruce.

These parts were supposed to be strong enough...but I like to see some beefiness at such critical areas.

Stan

[route66]

Jonathon,
One of the first upgrades GBA made was a beefier bracket for the tail support bracket at the mast. The first was a real flimsy aluminum channel with the first revision being 1/8” channel to a later revision to a thicker machined bracket with outer plate braces. There was never a notice or directive for the upgrade that I am aware of, but my thought is that if there wasn’t a critical concern they would not have changed it. I have seen 3 of the early braces with slight cracks to 1 that was completely compromised. If your kit is as you say 1 of the first 12 it would be a good idea to get a copy of the plans for the latest bracket and make one. I’ll look to see if I have them for you when I get home next week.

[automan1223]

Guys,

Your help is welcome and I really appreciate ALL the advice. I will go ahead and take photos asap along with specs so that I can see exactly what I need to do to make this a safe gyro.

Thank you again

Jonathan

[automan1223]

I had a phone call in with GBA and after my 3rd call and 2 days later I finally got a call back from Dan Banks. My search for a pair of doors turned up fruitless. Seems the doors were a made to order item and the did not automatically ship with each kit. I was aware that early builds were hatched prior to the advent of doors. I am not terribly broken up about it because after flying an open frame tandem I feel kind of closed in, even on a cold less than stellar day.

Word has it an interested party is in talks with GBA for the SP but nothing concrete yet.

The fun of building... if I have to I am sure I could fabricate a pair of doors but for now I am starting to dust off the corner of my shop where my rolling airframe sits. My next big thing is mounting the cabin which looks like a precision function. I sure wish I had Stans Laser setups and hyper accurate jigging. For now I will just have to slide rule it....

Anyway photos in the works on previous post concerns. I think that the build has several of the updates with the landing gear and nose wheel.

Jonathan

[Steve McGowan]

Hey guy's,,

here's what can and was done in....... "49 hrs".... with the quick build kit....

The first pic took 4 hrs from the box,, of course it's painted already.

this was from Sat afternoon till Tues mornin

Steve

[PW_Plack]

Nice Chevys!

[StanFoster]

Jonathon: You can get an inexpensive laser at Menards..or Lowes....that you just set up in the vertical mode.....out in front of your SparrowHawk....and line the plane of red light so it intersects your frame centerline. Its definately not the only accurate way....but it sure makes it simple and accurate to align things. It will be nice seeing your flying pictures in the future. Are you putting in an XM weather GPS? :D just yankin your chain. :D


Stan

[kc0iv]

Jonathon: You can get an inexpensive laser at Menards..or Lowes....that you just set up in the vertical mode.....out in front of your SparrowHawk....and line the plane of red light so it intersects your frame centerline. Its definately not the only accurate way....but it sure makes it simple and accurate to align things. It will be nice seeing your flying pictures in the future. Are you putting in an XM weather GPS? :D just yankin your chain. :D


Stan

Stan,

Talking about lasers. When you use the laser at say 20 feet how wide is the beam? In other words. If you look at the edges of the beam how wide would the beam be from side to side?

The only numbers I can find are related to the error at say 100 feet. And even these do not say how wide the beam is.

I have used transits and used cards to mark the measurements and could hold them well with acceptable error.

I'm think of a project I have that will need a very tight tolerance. And a laser would be faster if it would work.



Leon
(kc0iv)

[StanFoster]

Leon: My laser beam draws a line about 1/16 inch wide. The dot itself is around 1/8 inch wide. When the laserhead is spinning, only the bright smallest part of this dot shows and thats why the line is narrower. If you however point the dot at a wall say 40 feet away...the dot is actually a bunch of concentric rings which all spread out..but you can easily mark the center of it. It is around 3/8 wide at this distance.

I found the laser very handy for aligning my SparrowHawk cabin...and truing up my Helicycle cabin and tail feather alignment as well. It obviously can be done other ways...but this is an available tool in my shop that is the quickest and very accurate.


I use my laser to layout my stairways in the shop. Its like a 3d chalkline. You can project a 2d floor drawing to the actual 3d stairway. Its one of the best tools I have. I used to use a plumb bob....and snap chalklines...but this is so much better and faster.

[kc0iv]

Leon: My laser beam draws a line about 1/16 inch wide. The dot itself is around 1/8 inch wide. When the laserhead is spinning, only the bright smallest part of this dot shows and thats why the line is narrower. If you however point the dot at a wall say 40 feet away...the dot is actually a bunch of concentric rings which all spread out..but you can easily mark the center of it. It is around 3/8 wide at this distance.

I found the laser very handy for aligning my SparrowHawk cabin...and truing up my Helicycle cabin and tail feather alignment as well. It obviously can be done other ways...but this is an available tool in my shop that is the quickest and very accurate.


I use my laser to layout my stairways in the shop. Its like a 3d chalkline. You can project a 2d floor drawing to the actual 3d stairway. Its one of the best tools I have. I used to use a plumb bob....and snap chalklines...but this is so much better and faster.


Thanks for the information Stan. That is the kind of information I was looking for. I'm afraid it won't work for what I want to do. I guess I'll stick to my transit system.

Leon
(kc0iv)

[CLS447]

Steve, we have found those pics of the SH3 very interesting & helpful! Any chance of you posting lots more ?

I imagine that machine is now complete ?

Some things I noticed.....

1. 1 piece PSRU plate( no upper extension) with rubber mounts built right into it instead of rod ends bolted to the top.

2. 2 idler pulleys on prerotator belt( aftermarket ?)

3. Throttle rod bolted to seat slide angles.

4. New dash & kickplate.

5. new crank bearing support plate.

One picture is worth a thousand words ! Thanks