Comp ARF BAE Hawk build thread
#776
Stan
No not done any mods apart from hysoling a carbon outer on push rod and making hole bigger for the push rod. On my plane it certainly did not seem it needed putting the horn at the corrected angle etc you did not have to force to make the connection to servo arm. One thing I am doing though is to change my servo arms to metal from Dubro plastic
I was aware of this 'problem' but I found that it was not a problem on my Hawk also I used clevisis and not ball joints, if your using ball joints I would ensure that they are bolted ones and not 'press' on type
Alan
Edit: as Dave has posted I think there are some planes that need the horns cracking and some that do not, when I was installing the rods I was ready to do what Dave had suggested but just found it was not necessary.
No not done any mods apart from hysoling a carbon outer on push rod and making hole bigger for the push rod. On my plane it certainly did not seem it needed putting the horn at the corrected angle etc you did not have to force to make the connection to servo arm. One thing I am doing though is to change my servo arms to metal from Dubro plastic
I was aware of this 'problem' but I found that it was not a problem on my Hawk also I used clevisis and not ball joints, if your using ball joints I would ensure that they are bolted ones and not 'press' on type
Alan
Edit: as Dave has posted I think there are some planes that need the horns cracking and some that do not, when I was installing the rods I was ready to do what Dave had suggested but just found it was not necessary.
#777
Thread Starter

Stan
I know it sounds extreme, but the "cracking" the horn and re gluing is the best solution. It takes seconds and the lines are then good. I'd stick with a clevis at the servo arm end to keep the action inline, you could trim the cover moulding and fit a ball link inside the horn but you will not get a totally solid flap as easily. (I sleeve my 3mm rod with carbon tube also). I built a Hawk for a friend begining of this year and it was fine, I'll talk with CARF about this as I thought it was sorted. Actually a guy picked up a Hawk kit from me yesterday that has just been ordered, I'll get him to check the alignment
Dw
I know it sounds extreme, but the "cracking" the horn and re gluing is the best solution. It takes seconds and the lines are then good. I'd stick with a clevis at the servo arm end to keep the action inline, you could trim the cover moulding and fit a ball link inside the horn but you will not get a totally solid flap as easily. (I sleeve my 3mm rod with carbon tube also). I built a Hawk for a friend begining of this year and it was fine, I'll talk with CARF about this as I thought it was sorted. Actually a guy picked up a Hawk kit from me yesterday that has just been ordered, I'll get him to check the alignment
Dw
#778
Alan And Dave,
Thanks for your input.
I like the idea of bolted ball joints to help correct the angle. It is not a perfect fix but if it works leave it alone.
A friend here in Tucson Has not started his yet. He says he is going to mount his servo on the inside of the top skin between the gear mount and original servo mount. He says that it is then in line with the horn and he can still get his gear in and out. I will look into that also.
Stan
Thanks for your input.
I like the idea of bolted ball joints to help correct the angle. It is not a perfect fix but if it works leave it alone.
A friend here in Tucson Has not started his yet. He says he is going to mount his servo on the inside of the top skin between the gear mount and original servo mount. He says that it is then in line with the horn and he can still get his gear in and out. I will look into that also.
Stan
#779

My Feedback: (44)
ORIGINAL: afterburner
I would like to give a big thumbs up to Erwin at Airtech in Germany. Last Friday I was working on installing the nose gear on the Hawk and realized I had some blow by in the cylinder. I figured I would send an email to Airtech before calling it a night because I didn't know how to take these cylinders apart and maybe they could give me some info. No more than ten minutes later I get an email on my phone from Erwin and we go back and forth with a few emails and he wants a picture of the cylinder. A few more back and forths on Saturday and he says he'll send me a new cylinder. Monday he emails that it is being sent out. This morning(two days later) Fedex shows up with my cylinder and a few other items for my trouble! I am very impressed and if I can give Airtech any of my business in the future I will. I can't even get someone to answer the phone or an email at Robart and this company is sending me a replacement air cylinder from Germany via two day FedEx.
Marty
I would like to give a big thumbs up to Erwin at Airtech in Germany. Last Friday I was working on installing the nose gear on the Hawk and realized I had some blow by in the cylinder. I figured I would send an email to Airtech before calling it a night because I didn't know how to take these cylinders apart and maybe they could give me some info. No more than ten minutes later I get an email on my phone from Erwin and we go back and forth with a few emails and he wants a picture of the cylinder. A few more back and forths on Saturday and he says he'll send me a new cylinder. Monday he emails that it is being sent out. This morning(two days later) Fedex shows up with my cylinder and a few other items for my trouble! I am very impressed and if I can give Airtech any of my business in the future I will. I can't even get someone to answer the phone or an email at Robart and this company is sending me a replacement air cylinder from Germany via two day FedEx.
Marty
I need to add my gratitude also for Erwin at Airtech-Germany, the Broken Hawk that I purchased (see post 732) was missing some key components for the nose wheel assembly, after a few e-mails back and forth, Erwin identified the replacement parts that I needed and is shipping them to me at a reasonable price for what was required.
Thanks Erwin!
#780

My Feedback: (44)
I have made a little progress on my rebuild project, I have the broken section of the fuselage glassed internally, I used 6 oz cloth and then I will lay in a strip of CF down each side of the fuselage.
I will use 2 oz cloth for the exterior repair, the reason for the 6 oz cloth is I wanted to create a buffer zone for when I sand the v groves in the exterior skin where the cracks were so I don't break into the CF layer that will be applied.
I will use 2 oz cloth for the exterior repair, the reason for the 6 oz cloth is I wanted to create a buffer zone for when I sand the v groves in the exterior skin where the cracks were so I don't break into the CF layer that will be applied.
#783
I know this problem has been addressed lightly before.
I have a problem getting my inner gear doors to close without hitting the tires.
I have not been able to get any toe in, this is with the tires set straight ahead.
Someone mentioned using shims to change the angle of the gear so there would be more clearance.
what part of the gear mount did you place the shim and what was the thickness you used.
I could keep experimenting till I get the right combination but could use some help here.
Thanks for your help,
Stan
I have a problem getting my inner gear doors to close without hitting the tires.
I have not been able to get any toe in, this is with the tires set straight ahead.
Someone mentioned using shims to change the angle of the gear so there would be more clearance.
what part of the gear mount did you place the shim and what was the thickness you used.
I could keep experimenting till I get the right combination but could use some help here.
Thanks for your help,
Stan
#784
Well it looks like I found the right combination to offset the gear so the doors will close.
I added 1/32 shims to the two outboard gear mount tabs. This has brought the tires low enough to clear the inner doors when retracted.
The problem of toe in still exists. The best I have been able to get is the wheels pointed straight ahead. No toe in. I will settle for this.
Turned out to be a simple fix.
Stan
I added 1/32 shims to the two outboard gear mount tabs. This has brought the tires low enough to clear the inner doors when retracted.
The problem of toe in still exists. The best I have been able to get is the wheels pointed straight ahead. No toe in. I will settle for this.
Turned out to be a simple fix.
Stan
#786

My Feedback: (18)
Joined: Jun 2002
Posts: 3,021
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From: New City, NY
ORIGINAL: tucson
Alan And Dave,
Thanks for your input.
I like the idea of bolted ball joints to help correct the angle. It is not a perfect fix but if it works leave it alone.
A friend here in Tucson Has not started his yet. He says he is going to mount his servo on the inside of the top skin between the gear mount and original servo mount. He says that it is then in line with the horn and he can still get his gear in and out. I will look into that also.
Stan
Alan And Dave,
Thanks for your input.
I like the idea of bolted ball joints to help correct the angle. It is not a perfect fix but if it works leave it alone.
A friend here in Tucson Has not started his yet. He says he is going to mount his servo on the inside of the top skin between the gear mount and original servo mount. He says that it is then in line with the horn and he can still get his gear in and out. I will look into that also.
Stan
What did you end up doing with the flap setup? Mine are way off. I tried the "cracking the horn" technique. Big mistake. I should have thought it through more. Now I've got hours of cutting, dremeling and fitting a new horn in there at the right angle.[:@]
Marty
#787
ORIGINAL: afterburner
Tucson,
What did you end up doing with the flap setup? Mine are way off. I tried the ''cracking the horn'' technique. Big mistake. I should have thought it through more. Now I've got hours of cutting, dremeling and fitting a new horn in there at the right angle.[:@]
Marty
ORIGINAL: tucson
Alan And Dave,
Thanks for your input.
I like the idea of bolted ball joints to help correct the angle. It is not a perfect fix but if it works leave it alone.
A friend here in Tucson Has not started his yet. He says he is going to mount his servo on the inside of the top skin between the gear mount and original servo mount. He says that it is then in line with the horn and he can still get his gear in and out. I will look into that also.
Stan
Alan And Dave,
Thanks for your input.
I like the idea of bolted ball joints to help correct the angle. It is not a perfect fix but if it works leave it alone.
A friend here in Tucson Has not started his yet. He says he is going to mount his servo on the inside of the top skin between the gear mount and original servo mount. He says that it is then in line with the horn and he can still get his gear in and out. I will look into that also.
Stan
What did you end up doing with the flap setup? Mine are way off. I tried the ''cracking the horn'' technique. Big mistake. I should have thought it through more. Now I've got hours of cutting, dremeling and fitting a new horn in there at the right angle.[:@]
Marty
I made carbon fiber rods to stiffen the original rods provided in the kit.
I used a ball joint on the servo arm side to correct the angle. I used the connector provided in the kit on the flap horn.
I have to say it works fine that way. Very acceptable.
Stan
#788

My Feedback: (44)
Does anyone know the correct P/N for the (orange touch up paint used on the T-45?
When looking on COMP ARF web site for spare parts they list Red P/N 970008, however they list the same red for the Red Arrow Scheme, so I know that is not correct
To verify my buddy brought over a wing from a Comp ARF Extra 300 which is Red for comparison, it is way off, see photo.
I did a search on the COMP ARF web site and found they have two different oranges, one is P/N 970007 and is listed as Orange and the other is P/N 970014 and is listed as Dark Orange.
So the question which one is it?
When looking on COMP ARF web site for spare parts they list Red P/N 970008, however they list the same red for the Red Arrow Scheme, so I know that is not correct
To verify my buddy brought over a wing from a Comp ARF Extra 300 which is Red for comparison, it is way off, see photo.
I did a search on the COMP ARF web site and found they have two different oranges, one is P/N 970007 and is listed as Orange and the other is P/N 970014 and is listed as Dark Orange.
So the question which one is it?

#792
Finally got round to fixing on the pitot tube assembly (as spraying rest of plane anyway). Turned up a pitot tube same as I made for my 1/7th scale hawk. Stuck a M4 thread on the fixing end of the pitot tube and turned a tube with a internal M4 thread which will be glued with hysol in to the end of the carbon tube that's already inside the molding.
Just got the red to spray, at least this will get rid of the mold line..
Alan
Just got the red to spray, at least this will get rid of the mold line..
Alan
#796
I am having a bit of a problem trying to set the right height for my Jetcat thrust tube. the engine (JetCat) is mounted on the engine rails. I am not using any packing.
The Carbon turbine deflector guard which mounts to the bellmouth and its mounting ears sit between the engine mount and engine rails is keeping the thrust tube sitting to high.
I cannot lower the thrust tube( airplane inverted) because of the turbine deflector guard. I do not want to add packing to raise the engine on the engine rails.
Is the deflector guard really necessary?
What have some of you done to solve this problem?
Thanks,
Stan
The Carbon turbine deflector guard which mounts to the bellmouth and its mounting ears sit between the engine mount and engine rails is keeping the thrust tube sitting to high.
I cannot lower the thrust tube( airplane inverted) because of the turbine deflector guard. I do not want to add packing to raise the engine on the engine rails.
Is the deflector guard really necessary?
What have some of you done to solve this problem?
Thanks,
Stan
#798
Alan,
That would be great.
I can't imagine what is wrong with my setup.
In order for me to get the 25-30mm space between the end of the turbine exhaust cone and the point where the bellmouth meets the ss thrust tube the engine for some reason is further back from where Dave W recomends the front of the turbine to be. This is with the thrust tube extending out the rear of the fuse 3-5mm.
The engine I am using is the 140RX which I believe is the same length as the 120sx.
Because of all this the carbon deflector in order for it's mounting ears to lay under the jetcat mount has to be further towards the rear not allowing the front end of the bellmouth to lay in the grove at the end of the carbon deflector by at least an inch.
I hope I have made myself clear on the issue.
I always end up with some strange issue's in my build[
]
Thanks for your input,
Stan
That would be great.
I can't imagine what is wrong with my setup.
In order for me to get the 25-30mm space between the end of the turbine exhaust cone and the point where the bellmouth meets the ss thrust tube the engine for some reason is further back from where Dave W recomends the front of the turbine to be. This is with the thrust tube extending out the rear of the fuse 3-5mm.
The engine I am using is the 140RX which I believe is the same length as the 120sx.
Because of all this the carbon deflector in order for it's mounting ears to lay under the jetcat mount has to be further towards the rear not allowing the front end of the bellmouth to lay in the grove at the end of the carbon deflector by at least an inch.
I hope I have made myself clear on the issue.
I always end up with some strange issue's in my build[
]Thanks for your input,
Stan
#799
Stan
Here goes with the pics any more dimensions just ask, the plywood spacer I used was 1/8" and I did turn a plug up to get the correct centre with the carbon bell mouth entry etc...
I noticed you state you don't want to use packing but I found on mine if I used the 1/8" everything inline plus the Hawk flies spot on with no pitch change whatsoever with any throttle settings. The way I did it was the ony way with the carbon shield that gave me what I was looking for.
The tube exits the fus by 5-6mm.
If you set up the engine to the settings then using a plug say plywood for diameter of the bell mouth and balsa (both centred and glued together) to fit exhaust of turbine that will allow the centre height of the thrust tube.
Just noticed for a second time the JetCat rubber disc that holds the JC fod guard in place the rubber has perished/rotted again.... won't be buying a third will get some decent rubber sheet and make my own [
]
Alan
Here goes with the pics any more dimensions just ask, the plywood spacer I used was 1/8" and I did turn a plug up to get the correct centre with the carbon bell mouth entry etc...
I noticed you state you don't want to use packing but I found on mine if I used the 1/8" everything inline plus the Hawk flies spot on with no pitch change whatsoever with any throttle settings. The way I did it was the ony way with the carbon shield that gave me what I was looking for.
The tube exits the fus by 5-6mm.
If you set up the engine to the settings then using a plug say plywood for diameter of the bell mouth and balsa (both centred and glued together) to fit exhaust of turbine that will allow the centre height of the thrust tube.
Just noticed for a second time the JetCat rubber disc that holds the JC fod guard in place the rubber has perished/rotted again.... won't be buying a third will get some decent rubber sheet and make my own [
]Alan
#800
Alan,
Thank you for the detailed pictures they are perfect and help a lot.
I can see where the packing would help center the engine on the bellmouth. Earlier in this thread people were saying to eliminate the packing to get the Hawk to have no pitch change with power changes, that's why I elected to eliminate the packing.
One person went as far as to mount the engine on the bottom (reverse side) of the engine mount.
It is nice to know that with your setup you have no pitch changes with power changes.
One more question, The bellmouth has a curved lip at the end. The deflector has a recessed grove at it's end to accommodate the lip. As you can see the two do not mate and are off in my case by at least 1/2 -1".
Did you grind off the lip where it contacts and rest on the deflector? That would lower the pipe slightly. In your pictures it looks like you might have done that.
I wish the manual had the detailed pictures you have sent me.
Again, thank you
Stan
Thank you for the detailed pictures they are perfect and help a lot.
I can see where the packing would help center the engine on the bellmouth. Earlier in this thread people were saying to eliminate the packing to get the Hawk to have no pitch change with power changes, that's why I elected to eliminate the packing.
One person went as far as to mount the engine on the bottom (reverse side) of the engine mount.
It is nice to know that with your setup you have no pitch changes with power changes.
One more question, The bellmouth has a curved lip at the end. The deflector has a recessed grove at it's end to accommodate the lip. As you can see the two do not mate and are off in my case by at least 1/2 -1".
Did you grind off the lip where it contacts and rest on the deflector? That would lower the pipe slightly. In your pictures it looks like you might have done that.
I wish the manual had the detailed pictures you have sent me.
Again, thank you
Stan


