Composite ARF Mig29
08-19-2013, 07:00 PM
#201
Hey guys.
Sorry to drag up an old thread. Just wondering if anyone has the detail package with the lights and sensors offered by Heiko Gartner that they would like to sell or if anyone knows where could find one. I've made some of the parts myself but the smaller stuff looks tricky.
Thanks in advance
Levi
Sorry to drag up an old thread. Just wondering if anyone has the detail package with the lights and sensors offered by Heiko Gartner that they would like to sell or if anyone knows where could find one. I've made some of the parts myself but the smaller stuff looks tricky.
Thanks in advance
Levi
04-04-2014, 05:18 AM
#203
As there must be quite a few Mig 29s around gathering dust because of the difficulties of the hydraulic system (and the considerable expense of the update kit ) so I thought I would copy this post from that dealing with hydraulic landing gear.
My Mig has flown with the Omega system but now has a hybrid Hausl. AND UMS pumps in parallel using locking valves in the gear down line controlled by the Jettronics gear sequencer.
It will be flying again later this summer.
Pleased to report that I have re-plumbed the landing gear circuits on my Mig using the Festo HD tubing. Double checking each cut to ensure its square has resulted in NO leaks and a fully operational system.
The system is now a hybrid using the Hausl pump, (on a 3 cell lipo) with a JetTronics gear sequencer closing the locking valves, works very well, in fact after extensive testing, the gear is now airworthy.
Retraction time is still rather slow at 9 seconds on the Hausl pump, a second or so faster with the UMS pump which leads me to believe that volume output from the pump is as important as pressure.
Timing is slightly shorter using the UMS pump which tends to confirm this and when connecting the UMS pump into the output pressure line in the Hausl, downstream of the NRV, the Hausl pump cut-in frequency was much lower than normal suggesting that the EMS pump output is slightly stronger than the Hausl.
Still, the Mig needs nose ballast so installing a second pump creates real redundancy and replaces some chunks of lead !
I have ditched the UMS controller (for now) and will use John Wright (and Mick Burrel )'s system for pump control.
As usual EVERY component was checked for leaks before installation, one or two leaked air but were completely leak proof when tested on hydraulic fluid.
Looks like the Mig will be airborne again soon !
David.
My Mig has flown with the Omega system but now has a hybrid Hausl. AND UMS pumps in parallel using locking valves in the gear down line controlled by the Jettronics gear sequencer.
It will be flying again later this summer.
Pleased to report that I have re-plumbed the landing gear circuits on my Mig using the Festo HD tubing. Double checking each cut to ensure its square has resulted in NO leaks and a fully operational system.
The system is now a hybrid using the Hausl pump, (on a 3 cell lipo) with a JetTronics gear sequencer closing the locking valves, works very well, in fact after extensive testing, the gear is now airworthy.
Retraction time is still rather slow at 9 seconds on the Hausl pump, a second or so faster with the UMS pump which leads me to believe that volume output from the pump is as important as pressure.
Timing is slightly shorter using the UMS pump which tends to confirm this and when connecting the UMS pump into the output pressure line in the Hausl, downstream of the NRV, the Hausl pump cut-in frequency was much lower than normal suggesting that the EMS pump output is slightly stronger than the Hausl.
Still, the Mig needs nose ballast so installing a second pump creates real redundancy and replaces some chunks of lead !
I have ditched the UMS controller (for now) and will use John Wright (and Mick Burrel )'s system for pump control.
As usual EVERY component was checked for leaks before installation, one or two leaked air but were completely leak proof when tested on hydraulic fluid.
Looks like the Mig will be airborne again soon !
David.
04-04-2014, 12:54 PM
#204
Interesting info David. Great to hear yours is sorted.
i have finally sorted mine as well with some great help and advice from Aussie Bart who is a hydraulics expert, and a hell of a good fella.
Im using the Hausl system with the accumulator. As long as the accumulator is at 100 psi it works great. Good retraction times.
The only problem I had was the nose leg collapsing on some taxi tests. I have festo pilot check valves installed on all legs to create a hydraulic lock in the down position which was great, as mine has no internal lock in the cylinders.
The problem was on the nose leg the hydraulic line between the ram and check valve was not up to the pressure created from this beast hurtling down the runway. Mr Bart ended up replacing the loaded hydraulic line for me with a soldered brass tube connected to the ram at one end straight into the check valve which has eliminated the weak spot.
All testing after this has been a success.
Kind Regards
Levi
i have finally sorted mine as well with some great help and advice from Aussie Bart who is a hydraulics expert, and a hell of a good fella.
Im using the Hausl system with the accumulator. As long as the accumulator is at 100 psi it works great. Good retraction times.
The only problem I had was the nose leg collapsing on some taxi tests. I have festo pilot check valves installed on all legs to create a hydraulic lock in the down position which was great, as mine has no internal lock in the cylinders.
The problem was on the nose leg the hydraulic line between the ram and check valve was not up to the pressure created from this beast hurtling down the runway. Mr Bart ended up replacing the loaded hydraulic line for me with a soldered brass tube connected to the ram at one end straight into the check valve which has eliminated the weak spot.
All testing after this has been a success.
Kind Regards
Levi
04-04-2014, 05:03 PM
#205
Go Levi! Get that beast in the air mate and fly it yourself! Clear going on this weekend. Will let you know how I get on.
David, it sound like you might be using servo operated locking valves rather than festo pilot locking valves, is that right?
David, it sound like you might be using servo operated locking valves rather than festo pilot locking valves, is that right?
04-05-2014, 12:43 PM
#207
David, it sound like you might be using servo operated locking valves rather than festo pilot locking valves, is that right?[/QUOTE]
Hi Craig, Yes I am using the Festo valves on the down lines. These are controlled by the Jet tronics sequencer. with the added advantage that the valves also closed when the gear is up, holding them in place which prevents sagging and cracking the gear doors. I have not yet gone to the Leimbach locking cylinders, which are VERY expensive. Having test flown the model with the Omega system and Festo locking valves I doubt these are needed.
My system seems to be working perfectly and is now a hybrid using the best (as I see it) of several systems:
The hyd. rams are those supplied with the Omega system.
The pump is now the Hausl constant pressure system, light and high quality. (10 bar)
The Hausl pump is parallelled with a UMS pump, creating redundancy and slightly increased transit speeds.
All flexible hoses are Festo heavy duty (35 bar) tubing.
The downlock hoses are armoured with spiral springs to resist pressure surges from landing impacts.
All valves are now Hausl.
The down locks are Festo valves servo controlled by the Jet Tronics sequencer.
So far, after extensive testing, it all works, with zero leakage, and what little air was in the system now seems to have totally cleared.
The transit time is around 9 seconds so I may try and source a bigger pump giving greater volume at 10 bar, until then I will fly it with the present system. Flight testing (the model has already flown with the Omega system) will be done with the speedbrake and intake doors inop. until I have even greater confidence in the integrity of the gear hydraulics.
Power will be two Jetcat 160 Sxs derated to arond 30 pounds of thrust each.
Radio will be Weatronics 12-22 with gyros on rudder and taileron.
Thought has been given to using a one-shot air system to blow the gear down in the event of hydraulic pump failure but with two pumps this is probably not needed.
I send my very best wishes to my Australian friends for Wangaratta Jets, (where my Mig first flew !) we have Classic Jets same Friday.
I will miss the 10 hour drive from Sydney !
David.
Hi Craig, Yes I am using the Festo valves on the down lines. These are controlled by the Jet tronics sequencer. with the added advantage that the valves also closed when the gear is up, holding them in place which prevents sagging and cracking the gear doors. I have not yet gone to the Leimbach locking cylinders, which are VERY expensive. Having test flown the model with the Omega system and Festo locking valves I doubt these are needed.
My system seems to be working perfectly and is now a hybrid using the best (as I see it) of several systems:
The hyd. rams are those supplied with the Omega system.
The pump is now the Hausl constant pressure system, light and high quality. (10 bar)
The Hausl pump is parallelled with a UMS pump, creating redundancy and slightly increased transit speeds.
All flexible hoses are Festo heavy duty (35 bar) tubing.
The downlock hoses are armoured with spiral springs to resist pressure surges from landing impacts.
All valves are now Hausl.
The down locks are Festo valves servo controlled by the Jet Tronics sequencer.
So far, after extensive testing, it all works, with zero leakage, and what little air was in the system now seems to have totally cleared.
The transit time is around 9 seconds so I may try and source a bigger pump giving greater volume at 10 bar, until then I will fly it with the present system. Flight testing (the model has already flown with the Omega system) will be done with the speedbrake and intake doors inop. until I have even greater confidence in the integrity of the gear hydraulics.
Power will be two Jetcat 160 Sxs derated to arond 30 pounds of thrust each.
Radio will be Weatronics 12-22 with gyros on rudder and taileron.
Thought has been given to using a one-shot air system to blow the gear down in the event of hydraulic pump failure but with two pumps this is probably not needed.
I send my very best wishes to my Australian friends for Wangaratta Jets, (where my Mig first flew !) we have Classic Jets same Friday.
I will miss the 10 hour drive from Sydney !
David.
Last edited by David Gladwin; 04-05-2014 at 12:48 PM.
09-24-2015, 03:28 AM
#211
The original stab. servos on the Mig were dual JR 8411s, total torque 20kg.cm, meaning the servos had to be matched precisely, before Weatronic that was difficult.
I flew mine with a single JR 8711 on each stab. and it seemed fine, even with twin JetCat 160s. The single servo greatly simplified installation, too.
Having again revised the hydraulic system on mine (it will be revised yet again when Hausl release their new hydraulic pump with brushless motor and I will then install the Festo locking pilot valves), it is again ready to go with two JetCat 140 RXIs.
The stab. servos are now a single JR 6301 on each stab, more than 50 % more torque than the original spec. The single servo greatly reducing the chance of failure in a dual servo setup.
LE and TE flap servos are JR 8711s, plus wing servos for the outboard LE flap sections, rudder 8411s.
I spoke to Peter Hausl at the JWM about how to speed transit times and his recommendation is not higher pressure but increasing the bore of the hydraulic pipes themselves. I may just live with a 9 second time as all flexible hoses in mine are 35 bar Festo tubing.
David. G.
I flew mine with a single JR 8711 on each stab. and it seemed fine, even with twin JetCat 160s. The single servo greatly simplified installation, too.
Having again revised the hydraulic system on mine (it will be revised yet again when Hausl release their new hydraulic pump with brushless motor and I will then install the Festo locking pilot valves), it is again ready to go with two JetCat 140 RXIs.
The stab. servos are now a single JR 6301 on each stab, more than 50 % more torque than the original spec. The single servo greatly reducing the chance of failure in a dual servo setup.
LE and TE flap servos are JR 8711s, plus wing servos for the outboard LE flap sections, rudder 8411s.
I spoke to Peter Hausl at the JWM about how to speed transit times and his recommendation is not higher pressure but increasing the bore of the hydraulic pipes themselves. I may just live with a 9 second time as all flexible hoses in mine are 35 bar Festo tubing.
David. G.
Last edited by David Gladwin; 09-24-2015 at 03:34 AM.
09-24-2015, 09:03 AM
#212
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Thanks David for the input. What servos on leading edge?
Jess Hogan is building mine I don't have any pictures yet, but when I go to see the progress I will take some and post them Danny.
Mine will be powered with two 140 KingTechs and the 18 second gen. Spectrum , I do not need the power distribution box. ( keep it simple ).
Nick.
Jess Hogan is building mine I don't have any pictures yet, but when I go to see the progress I will take some and post them Danny.
Mine will be powered with two 140 KingTechs and the 18 second gen. Spectrum , I do not need the power distribution box. ( keep it simple ).
Nick.
09-24-2015, 01:49 PM
#213
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My kit was missing the pumps and controllers for the hydraulic system. The only thing I have are the cylinders and all the festos from the upgrade pack. David, can you tell me if I can get what I need from MHT?
09-24-2015, 02:28 PM
#214
Danny, the 2 items you need are pictured on this page....
http://hptech.at/startseite/produkte/hydraulik-system/
The first item is the pump/pressure accumulator/controller and the second unit is the control valve. Go hydraulic on the gear but air on the doors and speed brakes and intakes.....much simpler. Use jet tronics sequencer to drive the system. Email hausl to order. I have found him quite helpful.
Levi and I have both the original scale nose cylinder and the updated one on our nose legs.
just to prove it works.....
http://youtu.be/bShZaXjjYCY
http://hptech.at/startseite/produkte/hydraulik-system/
The first item is the pump/pressure accumulator/controller and the second unit is the control valve. Go hydraulic on the gear but air on the doors and speed brakes and intakes.....much simpler. Use jet tronics sequencer to drive the system. Email hausl to order. I have found him quite helpful.
Levi and I have both the original scale nose cylinder and the updated one on our nose legs.
just to prove it works.....
http://youtu.be/bShZaXjjYCY
09-24-2015, 04:43 PM
#215
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Danny, the 2 items you need are pictured on this page....
http://hptech.at/startseite/produkte/hydraulik-system/
The first item is the pump/pressure accumulator/controller and the second unit is the control valve. Go hydraulic on the gear but air on the doors and speed brakes and intakes.....much simpler. Use jet tronics sequencer to drive the system. Email hausl to order. I have found him quite helpful.
Levi and I have both the original scale nose cylinder and the updated one on our nose legs.
just to prove it works.....
http://youtu.be/bShZaXjjYCY
http://hptech.at/startseite/produkte/hydraulik-system/
The first item is the pump/pressure accumulator/controller and the second unit is the control valve. Go hydraulic on the gear but air on the doors and speed brakes and intakes.....much simpler. Use jet tronics sequencer to drive the system. Email hausl to order. I have found him quite helpful.
Levi and I have both the original scale nose cylinder and the updated one on our nose legs.
just to prove it works.....
http://youtu.be/bShZaXjjYCY
I watched the video and love the smooth action of hydraulic.
02-26-2016, 01:00 AM
#222
Great to see some talk about arguably the best scale model ever produced, even if it is only about parts.
Has anyone finished or flown one recently? I know Craig's is getting close and looks fantastic with paint.
Mine has 8 flights now with the most recent flight being last week. Everything is operating great including speed brake and intakes. I am now experimenting with cg and some fine tuning. As CARF say, this really is a dream machine. Just a nightmare to build.
Levi
Has anyone finished or flown one recently? I know Craig's is getting close and looks fantastic with paint.
Mine has 8 flights now with the most recent flight being last week. Everything is operating great including speed brake and intakes. I am now experimenting with cg and some fine tuning. As CARF say, this really is a dream machine. Just a nightmare to build.
Levi
02-26-2016, 12:45 PM
#224
Cool Nick. There is a photo circulating the Internet with a red line locating the cg. This is too nose heavy. I have flown with the plane both nose heavy and tail heavy trying to find the balance.
Too nose heavy and feels pitchy and is hard to slow down on landing even with slats and flaps. Too tail heavy and the Mig starts to snap under moderate amounts of elevator. I'm very happy with my cg so ill measure it today and post.
The only video I have so far is one take off. I'll try to post that as well.
Cheers
Levi
Too nose heavy and feels pitchy and is hard to slow down on landing even with slats and flaps. Too tail heavy and the Mig starts to snap under moderate amounts of elevator. I'm very happy with my cg so ill measure it today and post.
The only video I have so far is one take off. I'll try to post that as well.
Cheers
Levi
02-26-2016, 12:57 PM
#225
The correct c of g is at a point which is directly below the halfway point down the fin Le extension. IE the forward, angled face of the long extension.
Flies perfectly well with that position, totally docile but with full
manoeuvarabilty.
Flies perfectly well with that position, totally docile but with full
manoeuvarabilty.
Last edited by David Gladwin; 02-26-2016 at 12:59 PM.