Bates 106" B-26 Marauder build
#376
Thread Starter
My Feedback: (43)
RE: Bates 106
Robart gear.
I got my repaired gear back from Robart.
I talked to Eric at Robarts and he said they made up a couple extra sets of gear while they were fixing up my gear so if you want to build a B-26, I would strongly suggest that you buy them now since it's very difficult to find them.
I got my repaired gear back from Robart.
I talked to Eric at Robarts and he said they made up a couple extra sets of gear while they were fixing up my gear so if you want to build a B-26, I would strongly suggest that you buy them now since it's very difficult to find them.
#377
Thread Starter
My Feedback: (43)
RE: Bates 106
New 4 blade props.
My Beila 4 blade 20X10 props just came in.
I'm hoping the DLE-55's will have no trouble turning them and, according to the plans, I have 2 3/4" clearance to the ground. Also, according to the plans, the props are almost scale size (about 1/4" too small).
Not likely that I'll get the engines and gear back on until late Winter/early Spring.
My Beila 4 blade 20X10 props just came in.
I'm hoping the DLE-55's will have no trouble turning them and, according to the plans, I have 2 3/4" clearance to the ground. Also, according to the plans, the props are almost scale size (about 1/4" too small).
Not likely that I'll get the engines and gear back on until late Winter/early Spring.
#378
RE: Bates 106
How close is the Bates compared to a Bob Parcell? They dug out the one he had above the shop that someone started and he bought a few years ago. Turns out the wing is over built, weighs 15 pounds, and is no where near completed. We looked at the plans and the detail on the gear is not very good, cant figure out how it retracts.
#379
Thread Starter
My Feedback: (43)
RE: Bates 106
acdii,
I'm not familiar with a bob parcell!
With gear and two engines, a 15 lb wing sounds pretty light. Twin wings are usually heavy: they can't be racking when all the weight of the plane lands on the gear plus the torque of two gas engines.
The retracts go almost completely vertical when they retract.
If you're planning on finishing it and don't have the retracts, I strongly suggest that you get them quickly from robart as they just made an extra two sets as they have 'discontinued' on their web site for the this gear set.
I'm not familiar with a bob parcell!
With gear and two engines, a 15 lb wing sounds pretty light. Twin wings are usually heavy: they can't be racking when all the weight of the plane lands on the gear plus the torque of two gas engines.
The retracts go almost completely vertical when they retract.
If you're planning on finishing it and don't have the retracts, I strongly suggest that you get them quickly from robart as they just made an extra two sets as they have 'discontinued' on their web site for the this gear set.
#380
RE: Bates 106
The wing didnt have anything on it, just the spar, ribs, LE TE and part of the nacelles. It was WAY over built. The ribs were made from 1/4 plywood, and not the light stuff either, the same stuff you would make a firewall out of. It would be better built with lighter ribs, maybe 1/8-3/16. The ailerons and flaps were really overbuilt. the skins are 1/16" ply covered with 3/16" balsa, and look like teardrops instead of the nice smooth comtrol surfaces they are supposed to be. When you look at the cross section, you can see the rib, and ply, and the shape is perfect, then there is this thick balsa sheet on top.
I should get some pics to show just how heavily built the wing is. It may fly, but it would not fly well.
#385
My Feedback: (221)
RE: Bates 106
Hey Sam, just in case you didn't know, there is a B-26 being restored at the MAPS museum at the Akron Canton airport. Not too far from you. You can get inside and crawl all over it. I'm a member if you would like to visit some time. At the very least, I can get you specific pictures if you like.
Gary P.
Gary P.
#387
RE: Bates 106
Here is a fully flying one down in Florida. Sorry, all I had was my eyephone. Wishing Ihad my Canon SLR with me, there were so many shot ops that I regret missing.
#388
Thread Starter
My Feedback: (43)
RE: Bates 106
Gear install:
I manage to get a few things done.
The gear was installed and the 20 or so air/wire connections made between the wing and fuse.
I had to completely remove the entire Dbalsa cockpit kit in order to connect the nose servo to the nose gear arm. The new nose canopy was installed.
Props:
Beila 4-blade 20X10's:
TONS OF ROOM!: 2.5" from the ground and 7/8" from the fuse. Can't get any more scale than that!
Engine replacement:
I may have outsmarted myself!
Due to all the weight from 3 full cockpits, moving turret, gear doors, bomb doors and bombs, the Zenoah G-38 (top right in picture) required too long of a runway for takeoffs.
I got some DLE-55 (top left in picture) REAR exhaust but the angled sparkplug and also angled ignition cap forces the wires beyond the firewall. Just now it occurred to me, I'm guessing that maybe I can now drill a hole in the bottom of the nacelle and route the plug wire via the hole (might work). I'll have to remove the plug wire, each time I need to remove the cowl. I tried routing the plug wire to the side but it creates too large of a loop. I noticed that the DLE-55 SIDE exhaust plug wires are at a 90 degree angle: would allow a side routing of the plug wire but that's 80 bucks each for more ignitions.
The DA-50 (bottom left in picture) was my alternative but the side muffler is too large. These are going into the Z 118" B-25. I've also got some wrap around mufflers:I'll worry about this 'down the road'.
My last option was G-62's (bottom right in picture) with nice small bennett mufflers. With no ignition, they make of an easier install. Not sure the G-62's have the same power to handle the 4-blades, though, as does the 55's.
I made all new removable fire walls for the new engines rather than butcher up the old fire walls for the G-38's.
Always something!
I manage to get a few things done.
The gear was installed and the 20 or so air/wire connections made between the wing and fuse.
I had to completely remove the entire Dbalsa cockpit kit in order to connect the nose servo to the nose gear arm. The new nose canopy was installed.
Props:
Beila 4-blade 20X10's:
TONS OF ROOM!: 2.5" from the ground and 7/8" from the fuse. Can't get any more scale than that!
Engine replacement:
I may have outsmarted myself!
Due to all the weight from 3 full cockpits, moving turret, gear doors, bomb doors and bombs, the Zenoah G-38 (top right in picture) required too long of a runway for takeoffs.
I got some DLE-55 (top left in picture) REAR exhaust but the angled sparkplug and also angled ignition cap forces the wires beyond the firewall. Just now it occurred to me, I'm guessing that maybe I can now drill a hole in the bottom of the nacelle and route the plug wire via the hole (might work). I'll have to remove the plug wire, each time I need to remove the cowl. I tried routing the plug wire to the side but it creates too large of a loop. I noticed that the DLE-55 SIDE exhaust plug wires are at a 90 degree angle: would allow a side routing of the plug wire but that's 80 bucks each for more ignitions.
The DA-50 (bottom left in picture) was my alternative but the side muffler is too large. These are going into the Z 118" B-25. I've also got some wrap around mufflers:I'll worry about this 'down the road'.
My last option was G-62's (bottom right in picture) with nice small bennett mufflers. With no ignition, they make of an easier install. Not sure the G-62's have the same power to handle the 4-blades, though, as does the 55's.
I made all new removable fire walls for the new engines rather than butcher up the old fire walls for the G-38's.
Always something!
#389
Thread Starter
My Feedback: (43)
RE: Bates 106
Engine replacement (cont)
Ignition/fuel dot:
I used a 7/8" forstner bit to drill out a hole in the engine box and bottom of the nacelle to route the spark plug wires.
I'm glad I, originally, put hatches in for possible future ignition engines from the original Zenoah G-38's with magneto's. It was pretty easy just to cut some 1/8" ply, cut/screw on an ignition switch and fuel dot, epoxy some 1/4" square bass wood to the two formers and screw on the switch panel.
A 24 oz dubro tank, AA 5 cell, 2700 ma battery packs and the ignition module all fit inside the engine box.
It's going to be tricky connecting the choke/throttle to servos on the outside of the firewall.
No problem with engines overheating with a good 1" of the cylinder head sticking out the bottom of the cowl.
The engines are rear exhaust DLE-55's.
Beila 4-blade props:
I had to see how the new props look.
I drilled out the 4 holes aligning them with the 'meat' of each prop blade.
2 1/2" prop clearance to the ground and 1 1/4" to the fuse; tons of room.
Ignition/fuel dot:
I used a 7/8" forstner bit to drill out a hole in the engine box and bottom of the nacelle to route the spark plug wires.
I'm glad I, originally, put hatches in for possible future ignition engines from the original Zenoah G-38's with magneto's. It was pretty easy just to cut some 1/8" ply, cut/screw on an ignition switch and fuel dot, epoxy some 1/4" square bass wood to the two formers and screw on the switch panel.
A 24 oz dubro tank, AA 5 cell, 2700 ma battery packs and the ignition module all fit inside the engine box.
It's going to be tricky connecting the choke/throttle to servos on the outside of the firewall.
No problem with engines overheating with a good 1" of the cylinder head sticking out the bottom of the cowl.
The engines are rear exhaust DLE-55's.
Beila 4-blade props:
I had to see how the new props look.
I drilled out the 4 holes aligning them with the 'meat' of each prop blade.
2 1/2" prop clearance to the ground and 1 1/4" to the fuse; tons of room.
#391
Thread Starter
My Feedback: (43)
RE: Bates 106
Yeh Cal, they are pretty cool. One nice thing with twins is you can usually get away with scale props as two engines usually will fly more than double the weight that a single engine will handle so efficiency usually isn't a major factor (also, this plane just flies in circles).
#392
Thread Starter
My Feedback: (43)
RE: Bates 106
Engine replacement (cont)
Throttle servo:
I ran out of aluminum L servo mounting brackets so I had to stop by home depot and pick up a 36" piece of 1/8" thick by 1" L stock and cut it up into 1/4" wide brackets (seems like I just made up a bunch of these!). Some 2/56" screws fit through the servo grommets and into the drilled/tapped holes. Some hex head screws hold the aluminum bracket to the fire wall (or in this case, a wood shelf).
I reversed engineered the servo mount by making the double ended socket head throw rod and connecting up the throttle arm to the servo arm, turned on the receiver to get proper location in relation to the fire wall and then epoxied/screwed the 1/4" thick ply shelf to the fire wall. Eventually the epoxy will fail around the fire wall so I also use screws to attach the shelf to the fire wall. To get the proper angle between the servo arm and throttle arm, I had to rotate the arm as there is an offset slot in the throttle arm allowing such.
=======
As Johnny used to say 'I did not know that':
My 6" wheels were rubbing on my SBD so I put 5.5" tires on the rims: wasn't sure this would work but both tires fit the same size rim (at least for this size rim).
Throttle servo:
I ran out of aluminum L servo mounting brackets so I had to stop by home depot and pick up a 36" piece of 1/8" thick by 1" L stock and cut it up into 1/4" wide brackets (seems like I just made up a bunch of these!). Some 2/56" screws fit through the servo grommets and into the drilled/tapped holes. Some hex head screws hold the aluminum bracket to the fire wall (or in this case, a wood shelf).
I reversed engineered the servo mount by making the double ended socket head throw rod and connecting up the throttle arm to the servo arm, turned on the receiver to get proper location in relation to the fire wall and then epoxied/screwed the 1/4" thick ply shelf to the fire wall. Eventually the epoxy will fail around the fire wall so I also use screws to attach the shelf to the fire wall. To get the proper angle between the servo arm and throttle arm, I had to rotate the arm as there is an offset slot in the throttle arm allowing such.
=======
As Johnny used to say 'I did not know that':
My 6" wheels were rubbing on my SBD so I put 5.5" tires on the rims: wasn't sure this would work but both tires fit the same size rim (at least for this size rim).
#395
Thread Starter
My Feedback: (43)
RE: Bates 106
Engine replacement (cont)
I changed my mind and decided to use the original removable fire walls to save me time aligning the cowl mount blocks, etc.
I removed the original wood mounts off the fire wall that held the throttle/choke servos.
A large hole was drilled in the fire wall right behind the carburetor.
The right engine was mounted with no offsets. The left engine was mount with about 3 degrees right thrust.
Dubro ball links were used to connect the throttle/choke linkages. I tapped the throttle/choke linkages to insure no slop and less likely to vibrate loose. After making some aluminum L servo brackets, they were mounted to some 1/4" thick ply and epoxied/screwed to the fire wall. For the choke linkage, I cut about a 1/4" off the ends of the ball links to make them as short as possible as there isn't a whole lot of room around that engine. I lucked out and only had to flip the throttle linkage 180 degrees which rotated the linkage about 30 degrees so it would align with the throttle servo. The choke linkage required no mods.
I used a 1/4" forstner bit on the back of the fire wasll to recess the servo screws used to mechanically (besides epoxy) secure the servo ply base to the fire wall (anything outside the 4" square hole has to be recessed so the removable fire wall is flush with the nacelle former). I also drilled a bunch of small holes where the surfaces met to give the epoxy some tooth.
The props are from TBM, beila 4-blade 20X8's.
The DLE-55 rear exhaust engines started up very easily. Full choke and 1/2 throttle to force the fuel in. After a spurt, I opened the choke and put the throttle back to idle.
Getting 1600/5800 RPM's on the engines. Plenty of power now.
Setting up the engines was easy with the JR 11X as it has multi-engine adjustment for the left and right engine.
Video of engine test:
http://www.youtube.com/watch?v=tqIfc...ature=youtu.be
I changed my mind and decided to use the original removable fire walls to save me time aligning the cowl mount blocks, etc.
I removed the original wood mounts off the fire wall that held the throttle/choke servos.
A large hole was drilled in the fire wall right behind the carburetor.
The right engine was mounted with no offsets. The left engine was mount with about 3 degrees right thrust.
Dubro ball links were used to connect the throttle/choke linkages. I tapped the throttle/choke linkages to insure no slop and less likely to vibrate loose. After making some aluminum L servo brackets, they were mounted to some 1/4" thick ply and epoxied/screwed to the fire wall. For the choke linkage, I cut about a 1/4" off the ends of the ball links to make them as short as possible as there isn't a whole lot of room around that engine. I lucked out and only had to flip the throttle linkage 180 degrees which rotated the linkage about 30 degrees so it would align with the throttle servo. The choke linkage required no mods.
I used a 1/4" forstner bit on the back of the fire wasll to recess the servo screws used to mechanically (besides epoxy) secure the servo ply base to the fire wall (anything outside the 4" square hole has to be recessed so the removable fire wall is flush with the nacelle former). I also drilled a bunch of small holes where the surfaces met to give the epoxy some tooth.
The props are from TBM, beila 4-blade 20X8's.
The DLE-55 rear exhaust engines started up very easily. Full choke and 1/2 throttle to force the fuel in. After a spurt, I opened the choke and put the throttle back to idle.
Getting 1600/5800 RPM's on the engines. Plenty of power now.
Setting up the engines was easy with the JR 11X as it has multi-engine adjustment for the left and right engine.
Video of engine test:
http://www.youtube.com/watch?v=tqIfc...ature=youtu.be
#396
Thread Starter
My Feedback: (43)
RE: Bates 106
Final adjustments.
I put some stronger centering springs on the nose gear (ACE hardware has small springs) to insure the rotation is complete when the gear is lowered (I had trouble with this on the P-61).
On the taxi test, the brakes were not working. I noticed about a 1/16" gap between the hub and axle. I'm figuring that since the robart disk brakes push against the hub, this maybe the problem. I snugged the axle up to the hub and, although there is now some friction, I think that will help as the brakes now grab the wheel much better on the trial test. I figure two dle-55's will overcome a little friction!
CG:
I still had my two half round dowels from the last CG check and taped them to the bottom of the wing and set the plane on the ends of my PVC pipe stand that had some short pieces of wood taped to the top of the PVC pipe.
The dle-55's are lighter than than the G-38's (even with the extra batteries) so the 6-8 ounces of lead in a plastic bag was removed from the tail and she balanced perfectly with gear up and down. With the gear down, the nose moved about an inch down due to the nose gear moving forward but the mains are virtually a straight up/down movement.
Flaps:
I'm figuring this plane will be like the full size so I added more flap to slow her down. (this is where I'm glad that I used a servo on each flap!).
ready to rock-n-roll
I put some stronger centering springs on the nose gear (ACE hardware has small springs) to insure the rotation is complete when the gear is lowered (I had trouble with this on the P-61).
On the taxi test, the brakes were not working. I noticed about a 1/16" gap between the hub and axle. I'm figuring that since the robart disk brakes push against the hub, this maybe the problem. I snugged the axle up to the hub and, although there is now some friction, I think that will help as the brakes now grab the wheel much better on the trial test. I figure two dle-55's will overcome a little friction!
CG:
I still had my two half round dowels from the last CG check and taped them to the bottom of the wing and set the plane on the ends of my PVC pipe stand that had some short pieces of wood taped to the top of the PVC pipe.
The dle-55's are lighter than than the G-38's (even with the extra batteries) so the 6-8 ounces of lead in a plastic bag was removed from the tail and she balanced perfectly with gear up and down. With the gear down, the nose moved about an inch down due to the nose gear moving forward but the mains are virtually a straight up/down movement.
Flaps:
I'm figuring this plane will be like the full size so I added more flap to slow her down. (this is where I'm glad that I used a servo on each flap!).
ready to rock-n-roll
#397
RE: Bates 106
More power and less weight you gotta like that.
The plane really looked good last weekend while you were doing the taxi test, best of luck with the maiden.
Later!!
Anthony
The plane really looked good last weekend while you were doing the taxi test, best of luck with the maiden.
Later!!
Anthony
#400
Don´t worry about your problem with the time. I have same problem. There are many people who has airplane ready for the maiden flight, but there are no time for it. I wish you good luck!