Retracts??
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RE: Retracts??
Both are USUALLY fine- but when I saw "grass", Spring-Air retracts are the only way to go... They are stronger than the mech. and if you ever get low or have an air-leak they come down automaticaly- (Robarts and Rhom-Airs are great also...)
With mechanicals if you bend your gear on a landing (without noticing-) and the next flight they "stall" or get "hung-up" while cycling, your RX batt. will die a FAST death and same for your Pat.
I have a Patriot with mech. and had one with the "Pneumatics." both were incident free, but the airs had less slop, were stronger, and I worried less
With mechanicals if you bend your gear on a landing (without noticing-) and the next flight they "stall" or get "hung-up" while cycling, your RX batt. will die a FAST death and same for your Pat.
I have a Patriot with mech. and had one with the "Pneumatics." both were incident free, but the airs had less slop, were stronger, and I worried less
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RE: Retracts??
Many use Springairs. As razor commented, mechanicals can drain your battery if they hang up, so air may be your best bet. I am installing springairs in a plane I am presently building. Quality seems good. I believe 305's work for the Patriot 40, but, as I recall, some slight mods to the kit are required to fit the nose gear and get it fully retracted into the fuse. They cost over $100 however. Perhaps someone with experience building the Patriot 40 will chime in. Good luck.
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RE: Retracts??
The nice thing about the air retracts is they tend to be a bit easier to rig. Flex tubing is easier to deal with than pushrods.
Ive used both types - and a variety of brands. They all worked fine on both paved and grass. The struts are the key (some cheap gear come with soft wire struts that bend way too easily).
Of note, I have heard the things about mechanicals draining your battery. Ive never had it happen, and Ive never seen it happen.... (with the rare exception of an older pattern ship equipped with Kraft electric retracts - different animals). In my installations, I always review the gear operation before flight to ensure there is no hang-up... and if something got 'that stuck" some part of the control linkage tended to be the weak link. Most retract servos are geared down so far that they simply do not stall - either a linkage or the servo arm is going to break before you stall it.
I prefer the Spring-Air gear for most applications these days. B&D gear are excellent (although slightly different in mounting size than most retracts - just takes a bit of planning). I used the B&D on a number of pattern aircraft. Robarts metal frame gear are good too. I've not seen the EuroKit gear, but they intrigue me a bit.... in particular their gear struts!
The air are not all that much more expensive when you add it all up. Keep in mind you only require a single 'cheap, small' servo to operate the valve. No additional linkages to buy. No retract servo (or two, depending on the installation) Spring-air sells a complete set - includes everything except the air pump.
If you are going to rig up any sort of air-operated gear doors, you want air-up/air-down type gear. Nothing like running out of air, having your doors locked shut and you gear busting down (or worse, partically deploying) through the doors.
For mechanicals, Dave Brown (southern r/c classic), B&D, MK are awesome. Robarts are pretty good.
I even used the $16 cheapo "green gear" in my P-51 (hobbico, MPI, lots of people sell these) - grass field, cheap Cirrus retract servo. Very straight-forward 2 gear installation. Granted, these are not going to hold up long to a Patriot on grass. As its looks now, the gear are going to outlast this airframe - plastic parts are all starting to crack (VQ P-51D) after 3 years of flying.
Ive used both types - and a variety of brands. They all worked fine on both paved and grass. The struts are the key (some cheap gear come with soft wire struts that bend way too easily).
Of note, I have heard the things about mechanicals draining your battery. Ive never had it happen, and Ive never seen it happen.... (with the rare exception of an older pattern ship equipped with Kraft electric retracts - different animals). In my installations, I always review the gear operation before flight to ensure there is no hang-up... and if something got 'that stuck" some part of the control linkage tended to be the weak link. Most retract servos are geared down so far that they simply do not stall - either a linkage or the servo arm is going to break before you stall it.
I prefer the Spring-Air gear for most applications these days. B&D gear are excellent (although slightly different in mounting size than most retracts - just takes a bit of planning). I used the B&D on a number of pattern aircraft. Robarts metal frame gear are good too. I've not seen the EuroKit gear, but they intrigue me a bit.... in particular their gear struts!
The air are not all that much more expensive when you add it all up. Keep in mind you only require a single 'cheap, small' servo to operate the valve. No additional linkages to buy. No retract servo (or two, depending on the installation) Spring-air sells a complete set - includes everything except the air pump.
If you are going to rig up any sort of air-operated gear doors, you want air-up/air-down type gear. Nothing like running out of air, having your doors locked shut and you gear busting down (or worse, partically deploying) through the doors.
For mechanicals, Dave Brown (southern r/c classic), B&D, MK are awesome. Robarts are pretty good.
I even used the $16 cheapo "green gear" in my P-51 (hobbico, MPI, lots of people sell these) - grass field, cheap Cirrus retract servo. Very straight-forward 2 gear installation. Granted, these are not going to hold up long to a Patriot on grass. As its looks now, the gear are going to outlast this airframe - plastic parts are all starting to crack (VQ P-51D) after 3 years of flying.
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RE: Retracts??
Well, I used Eurokit on my Patriot! Please take a look: http://www.rcuniverse.com/forum/m_11...tm.htm#1194725 post#6
those struts really helped on hard landings on grass!
Br Henrik
those struts really helped on hard landings on grass!
Br Henrik