Well after having built & flown one of these Graupner Hawks and Simon bending it [sm=cry_smile.gif],it was decided to build another. Simon asked if I would do a build thread on this one, probrably so he can keep an eye on the progress of it and give me the hurry up!

This is another pre-production kit so the production kit may differ. Also this model has come with no manual or accessories so I'll be making that bit up as I go along

The kit, retracts, turbine, radio equipment & all of the accessories were through Dave @ Motors & Rotors.

I decided to start on the fin so that I can put it safley to one side.

The servo is fitted into the fin with the output arm facing upwards with an internal linkage. Its not possible to get to the output arm once the servo is installed even to connect the clevis, so I had to screw the pushrod into the clevis which was already fitted to the servo after the servo had been fitted. I hope that the pictures will explain! The control horn was aeropoxy'd into the rudder and uses a Graupner aluminium ball link to connect it to the pushrod.

Another couple of pictures of the fin assembly.

Steve

Finished yet ?

Dave

Urrr, no!

How about you, Grippen done yet????

Steve

Steve,

Nice to see progress on the plane - get it ready in time for Classic Jets?

Now, stop taking pics and get back to work!

Finally, did you not hear me the last 50 times, with a flame out and lock out all in one instant what else was I meant to do with the plane?

Simon

Simon

I've told you before stop talking about your a*se and brain...

Dave

Urrrrr, not crash it

Steve

Any remote chance we can get some build details on this "build thread" at some time in the future?

Mike

Mike, let me know what you would like to know & I'll try and help.

Got some more done now. I have started on the wings and the first job is to open up the wheel well opening. This is supplied as a 'lolly pop' style opening presumably so that the model can be built as a sports jet without gear doors fitted.

I left the gear doors in one peice until I was happy with fit in the wing. The wing does have moulded in guide lines for the doors but this is a little over size. I then razor sawed the gear door into 3 peices.

A door shut has to now be fabricated as a stop for the door when shut. The gear doors are double skinned so a packer has to be installed first to pack the shut away from the wing skin. I used some epoxy board for this job which was glued in flush with the opening. The gear door does vary in thickness so thinner glass board had to be glued in as well in places to shim the door shut. Thin glass board was used for the door shut which was left to protude into the wheel well by a few mm's.

Your'll also be able to see the flap servo mount in the photo.

More Pics

Chill out Mike,

Remember we are all having fun here and choosing to share a bit of information, not writing online instruction manuals. A bit of banter never hurt anyone in between somebody completing what is an involved and complex build.

Stevie, as you can see Simon is still in denial and cant wait to crash your latest creation! Simon, Im definitely bringing the video camera when this one flies...

Colin,

I am not in Denial - a bad workman always blames his tools!

Simon

Hopefully with 3mm retract tube there will be no need for Simon to prove he "doesn't" fly inverted...anyway me and Stevie will probably fly it for a few weeks first

Dw

I think I will just keep this one, Simon can 'own' it but I will fly it

Steve,

That is an offer I just can not refuse.

I have taken such a confidence bashing with the 1st one that your wish may just come true!

Simon

You big tart!

Anyway we are going off-topic again so will post some pics later of the main gear door hinging once the glue has dried and air ram install if I get that far.

Steve

Dave

Just had a thought (painful!). Do Festo make a nipple that will fit the retract unit with a 3mm nipple on as standard? I think that it is similar to the one that JetCat supply with there turbines for use with the gas quick connect? M5 thread?

Just to keep everyone in the loop the supplied retract units have a 4mm nipple so I fitted 4mm tubing on the original Hawk. We used a UP3 valve so had to reduce the tube sizing to 3mm at some point in the line. On the ground the gear worked fine but in the airflow the gear clearly unlocked and started to move but would not retract all the way. Both Dave & myself flew a circuit and rolled inverted to put the gear and doors away but this is where Simon came unstuck.

Dave has seen this on some of the Comp-ARF Hawks where builders had also used 4mm-3mm tubing. Dave managed to force 3mm tubing onto his units after a lot of swearing by the sounds of it!


Steve

The 3mm Festo tube fitted without any problems-I'd do that...if your rubber grip won't do it bring the units here and I'll put a 1m on each

Dave

Thanks Dave

Ok gear doors are now hinged. The kit only contains one half of the hinge which is cut from epoxy glass. These are glued to the gear door after cutting a slot into the second skin of the door. A hinge now had to be made.
I used a piece of 5mm dia carbon rod with a 3mm pushrod up the middle. A slight flat was sanded onto this until a good fit was achieved (height wise) in the gear door area. This was aeropoxied to the wing skin and left to set.

I have also no fitted the air rams. The work horizontally and the supplied door hinge is designed to work with this setup. A Ultra Precision 1.5 inch ram was used.

I machined up a standoff from nylon bar which I glued into the leading edge of the wing and then screwed the air ram to this. A JR ball link was fitted to the ram door hinge and adjusted so that a minimum ram stroke the door was opened to the correct angle. The ram will not fully open but the pressure from this will hopefully keep the door shut in operation.

Steve

Another couple showing the air ram installation.

Steve

Looking good steve, this build is more than I know how to so Iam glad to see you are finding it a breeze.

Good info.

When its finished can I have a go?

Robbie

Well seeing that Simon has no say in these matters its a YES from me

Steve

Stevie - can you get it done before the start of January so I can have a go too, before I head back to the US

If crasher Robbies having a go, blimey its gotta be a free for all.

Dear All,

Since the recession has hit me HARD I have decided that once this model is finished it will be a fully functional static display model.

You are all welcome to come around to my garage and have a touch and feel!

Simon