Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Messages - Paul Rule

Pages: 1 [2] 3 4 ... 6
Modifications / Re: camshaft/timing celeron gear
« on: May 08, 2012, 04:30:12 AM »
The bad gear was all celeron (or phenolic) including the teeth... which was what didn't last.  The 'new' gear has an aluminum rim & teeth on a 'celeron' hub.   Franklin Service Bulletin # 17  Feb. 13, 1942  addressed this and said replace them at overhaul (500hrs.)

The rate of wear (failure?) apparently was higher then they thought and with S.B. #21 of Dec. 7, 1942 (1 yr. after Pearl Harbor) they said pull any accessory and replace immediately if not previously done. 

If you have a 4AC-199 S/N 200533 or higher they came with the new gear.  If you have a 4AC-176 S/N 125270 or higher - same thing.

Old gear P/N not given - new gear  P/N 10725   (cost at that time was $6.00 !! )

Culver General Discussion / Re: 4AC-199 Franklin Engine Barn find
« on: March 19, 2012, 10:39:16 PM »
From my 4AC199 manual & Parts book:  Reference the marks on the prop flange to the centerline of the case... there should be a top center and a 28 deg BTC mark.  The magneto points should open (fire) at the 28 BTC mark.  Be sure the impulse coupling(s) have 'clicked' then back up just enough to get to the 28 BTC mark.   Best to use a vibrator timing light but a 0.001" shim (or cigrette paper) as a feeler gage will work if you are carefull.

If you hear 2 destinct 'clicks' when you pull through then you have an impulse coupling on each mag.  If you hear only one, you may have 2 perfectly timed mags, or you may have 2 impulse couplings and one is stuck or has a broken spring. You may also have have only one impulse but I doubt that... 2 are standard. If you have a broken spring (and you have mounted 2 separate kill switches) try running on one mag at a time...the bad mag will have a much higher RPM drop.

90 HP  at 2500 RPM max.  7:1 comp ratio.  4.25 " bore.  3.5" stroke.  Oil press.- 35-45 psi.   240 deg. MAX oil temp.

Maintenance and Repair / Re: Leveling the Cadet
« on: February 28, 2012, 05:34:30 PM »
Brett & Bill,

Post corrected 4/2012... after more thimking!

As a check to your posts above; (and brushing off my trig functions calculator) I looked at Bill's LCA engine mount drawing to see that the firewall is dimensioned to have a 20 degree slant.   Also, the vertical distance between the firewall mount bolts is 15.00".  That would be from center of upper longeron  to center of lower , since the steel brackets inside are the same (2 LH and 2 RH).  The 15.00" vertical and the 15.963" hypotenuse give a base of 5.460" or 5 15/32".

The difference between 11/16" (Bret's post above) and 15/32" is 0.119" or about 1" vertical error at the elevator. 

A 1 inch change at the elevator is about 0.38 degrees..... basicly very good !!

Attached is a drawing that should provide a clear picture.

Culver General Discussion / Re: Sun n Fun
« on: February 25, 2012, 02:05:54 AM »
Yes and yes! 
If anyone is flying past the Atlanta area on their way down I'm having a BBQ at my hangar on the 26th. I'll probably head down to Lakeland on Thursday

Where is your hangar in the ATL area, Joe? I won't get to S&F but might find you on one of my many visits to ATL.  Lived and worked there for years.  PR

Culver General Discussion / Re: New wings for the Culver Cadet
« on: February 25, 2012, 02:00:18 AM »
Good post Brett,  I agree with what you have said.  I believe I recall that the CAR 4a required a loading of 4.2 G but will have to find it again to be sure.  The inboard lower aluminum bushing of the landing gear attachment cuts into the lower spar cap and creates "THE" high stress point.  If the gear attach fitting is not removed this area can not be inspected.  Because of the work to remove the fitting it is difficult to inspect. 

It is reasuring to remember that the fatigue life of wood is so high that it has never been precicely established!  These wings should last longer then all of us if they only had to stand up to normal fiying!  Its moisture and over stressing that gets them.

In two years when I move to NM full time (where my hanger is)  I plan to build some spars.  I have several as patterns and I have a jig (for routing out) that I think was used by one of the factories for forming the top & bottom faces.  I plan to try a "D" shaped aluminum bushing (withe flat of the "D" down) to reduce or eliminate the cutting into the lower cap as much as possible.  A "D" shape will carry the same vertical load but the side loading (into the end grain) will need to be investigated.   

It is interesting to note that in ANC-18 (Design of Wood Aircraft Structures, 1944) on page 235 &236 the Cadet spar was the subject of at least 5 test loadings to failure with modifications between each.  The production spar, it appears, was loaded to failure at a moment of 174138 in. lbs. on the fuselage (outboard) attach bolt.  I calculate that the 1/2 spanwise center of lift is very close to the inboard aileron hinge.  Using that (48" out from the attach bolt) and estimating the weight of one wing to be 100 lbs...(sombody put one on a scale and report back...!)  gives a design load of 4.37 Gs and an ultimate (fail) load of 6.56 Gs which is VERY close to the current utility catigory.

The indication from these same tests is that without the stress point at the gear attach bushing the design load would increase to 5.7 Gs.

Maintenance and Repair / Re: Factory plans/drawings?
« on: February 25, 2012, 12:45:55 AM »

Culver Aircraft seased to exist so olng ago that the Cadet drawings have been scattered over the years and have been copied / reproduced / re-drawn by many different people.  If a good set of (original) drawings could be pulled together and digitized for internet transmission that would be a great thing.  I am not sure that this is possible.  Several people are working to help this along but it is work... and slow.  Some drawings are slowly being put in the drawings section of this site.

Remember that drawings that are not original (Culver Aircraft) drawings carry little weight (as approved data) with the FAA.  That is not to say they are a great help in your restoration work...

Burk Bell (N41730) reproduced (from factory original) a very good drawing of the fuselage a number of years ago (1993).  He was asking $30 at that time.  I am not sure if he is still selling them but here he is:

Burke Bell
3030 S. Piper Drive
Erie, CO 80516

Culver General Discussion / Re: GEAR FAILURES AND HOW TO AVOID THEM
« on: February 22, 2012, 12:22:31 PM »

The mechanical advantage is not a problem but what you describe causes me concern.

I recomend strongly that you find and fix what ever is causing the lever to drag or not move freely.  A correctly rigged and un-dammaged gear lever SHOULD MOVE AS "SMOOTH AS SILK".  If it is hard to move this indicates either mis-rigged or damaged!!!

The one exception is that you should relieve the "UP" pressure on the ratchet (by pulling on the wheel) in order to move the lever fron RAISE to LOWER.  This is a two handed operation (therefore- trim it up and/or hold the stick with your knees).  Then keep your right hand sliding/gripping the wheel to slow the "fall" of the gear as it extends.

Sometimes (in the air) a little down pressure on the wheel is needed to hold the gears aginst the stop in order to slide the pins in freely.  This seems to vary with individual airplanes.  Gear fairings (or 500 x 5 wheels) may cause an air load that stops the gear before it reaches the down stop.

If it is difficult or drags moving into the lock position that is most critical and indicates that the down stop is not rigged correctly or that the two gear are not in 'sync' and do not arrive at the exact down position together. 

 Put it up on jacks and see if it is as hard to move on the ground as it is in the air.  If  all the above does not help and it is it is hard to move on the jacks ... fix it before flying again!  Far too many Culvers have been on ther bellys!  Review my rigging post.

Culver General Discussion / Re: LCA / LFA
« on: February 11, 2012, 02:45:53 PM »
My info agrees with Bill's. 

That Continental 75 was not the more common C-75-12 of today, that can have starter and gen. mounted.  It was an A-75 which is little more then an A-65 that is turned faster... without provision for electrics.  That would be most similar to the C-75-8.  It is worth noting that the Type Data sheet for the LCA does not list the "C" series engines but I think there is a Continental memo somewhere that equates the "A" & "C" ... maybe someone can add that.

Continental was not yet making any "C" engines, only "A".  As I understand it Continental, at that time, was reluctant to make the modifications Culver requested for mounting electric accessories.  "Air Cooled Motors" (aka - Franklin) on the other hand offered electrics.

The LFA was the 'special' and was probably a product of the Culver dealer's sales pressure.  Radios and night flying lights were still rare in this size airplane.  Some radios were very heavy... making a well equiped LFA effectivly a single place airplane.

The electrical alternative for the LCA owner was a wind driven generator (2 are listed in the TC).  I have not seen an installation but know that at least one location used was the RH leading edge in the sheetmetal just outboard of the wheel well.  The same location as the landing light in the LH wing. 

With WW-II looming on the horizon and the name "CADET" clearly a hope of military trainer contracts, radios and electric systems would be essential.  When the PQ-8 program began and radio control was being installed they saw that a generator failure would result in the loss of an airplane.   Franklin was willing to modify the 90hp for dual generators and the military designation for that engine was YO-200-1  (ie:  AC4-199 w/2 gens.).  It is interesting that Culver also made a plate between the oil pan and the carb that tapped engine vacuum as a back-up to the engine driven vacuum pump (which failure would also cost an airplane). 

Culver General Discussion / Re: slots in wings
« on: February 09, 2012, 04:59:27 PM »
One comment on my experiences with the slots...

If you are doing repairs on your slots, work hard to get then the same LH and RH.  I flew an airplane that came out of rebuild that had a measurable difference in the slot size.  If you were not looking for it you would miss it but because of it's handling in flight I got out a tape and started comparing LH & RH.  The slots were 1/4" to 1/2" more open on one side (variable spanwise).  Result?  Real wing heavy on that side!  Didn't fly it enough to install an aileron tab but I am not sure a normal sized tab would have been enough to correct it. 

So, what did I learn from that regarding performance and / or drag??  Learned this -  it does make a difference.  More slot = less lift = higher AOA required = more drag.   Is it measurable in day to day flying or when comparing airplane "A" to airplane "B"?  Probably not unless we take REAL carefull measurments and get kinda scientific about it!!

Culver General Discussion / Re: Cadet Brakes
« on: February 08, 2012, 10:57:11 PM »
My "Culvers Going Places" (Issue #5) says the original master cylinders are from a 1939 Plymoth.

Culver General Discussion / Re: GEAR FAILURES AND HOW TO AVOID THEM
« on: February 08, 2012, 10:38:11 PM »
Neal,  To the best of my knowledge Culver never produced any detailed maintenance instructions other then the 5-6 pages in the back of the parts book and the Service Memos. Neither gives information on rigging the gear retract system. 

Here is my procedure for what it's worth... (this assumes that everything is assembled and not too far from correct function).  Maybe others will add their ideas below:

1) Take time to get a good secure method of lifting and supporting the airplane even when you are climbing in and out of it.  Also take time to read and understand Service Memorandum #1 - Care and Operation of Retracting L.G.
2) Make completely sure that there is NO EXISTING DAMAGE to the system.  No bent push rods, no bent or partly sheared bolts and everything secured correctly.  It is not possible to get the rigging right if any of the pushrods have been bent in service.  NOTE: Both main gear push tubes were made with slight bends to clear other things in the wings.
3)  With the gears 1/2 way up and the lever in the "RAISE" position insure that the locking pins are just clear of (but very close to) the 'half moon' plates that move with the gear.  See my gear pin drawing to understand why.
4)Disconnect the LH gear (both push rod and locking pin rod) and block it in the down position for now.  Rig the RH gear in the up position such that with the ratchet's last click, it is within 1" of as far as it can go up.  Adjust the outer link in 1/2 turns to do this.
5) Lower the gear and adjust the 'down stop' screw (lower LH end of the rack & gear box) so the lock pin locks the RH gear. The pin movement into the gear should be 'smooth as silk'.
6) With the RH gear locked down rig the LH outer link in 1/2 turns until that lock pin also slides in 'smooth as silk'.
7) Re-connect everything and retract the gear.  If it is possible to retract the RH gear back to the same 'ratchet's last click' and the LH gear is not hanging out of the well... be happy, that is about as good as you can do.
8) If the LH gear is ahead of the RH and prevents getting back to that 'ratchet's last click' you will have to start over and rig the RH gear a little lower, say 2 inches from hitting. 

One gear seems to always lead the other into the wheel well.  This is in part because one gear 'rack' is above and one is below the center gear so the gears are 'pushed' from different points.  It is real hard to get them fully retracted, together. 

From a safety standpoint it is most important that the lock pins move into the lock position as smoothly as possible and as completely as possible AND do it only when aginst the down stop screw.  This is the "standard" by which you must judge the 'health' of your system as time goes on so get a feel for it now and remember what it's suposed to work like.  If some day it does not work as well that is your "red flag" to fix before further flight or fly gear down only... until you can.

Documentation / Re: O-200 Continental?
« on: February 08, 2012, 11:25:22 AM »
Tom's post reminded me...   Everyone who is thinking of changing engines from Frank. to Cont. remember that the cowling is shorter by about 1-2 inches for the Franklin.  Also, the Cont. O-200 has different rubber mounts and different size mount bolts... thus requires a new mount.  If you plan to go that route you might make the new mount just the right amount shorter so as to reduce the work on the cowling.   Some Continental engine mounts had a cross tube blocking the space for the starter.  If you plan to mount an engine with starter check for that.  Many mounts have been modified by now but maybe not all.

Modifications / Re: Stinger tailcone
« on: February 08, 2012, 10:48:34 AM »
I have a drawing for a home-made stinger tail cone in an older Cadet news letter.  Will try to scan and post it. 

Documentation / Re: Culver Factory Service Memorandums
« on: January 31, 2012, 09:45:01 PM »

I am learning that things were done differently under the CAA.  Remember that back then there were no IAs.  The CAA Inspector had to sign off your 'Pierodic' (read Annual) inspection on an all purpose form (___) that predated the 337.

  I will research this more later but ...a quick look at some of my old documents indicates that Airworthiness Directives included multiple issues and were not limited to one maintenance issue.  These AD letters had to be carried onboard the airplane until superseded by a later letter. 

I have, for example, AD-730-1 (for LCA & LFA) dated Jan. 21- 1946  which includes Mandatory Notes #1 thru #7 and Service Notes #1 thru #7 (just coincidence that both are 7).  Mandatory Notes had to be done at each 'periodic' and Service notes were optional.   The header says this AD supersedes AD-330 / AMB (Airworthiness Maintenance Bullitin) #39, 68, & 77.

It says - for example:
Manditory Note #1 (Superseded Special Note 2 dated 6-24-42 of AD-330) (Applies only to sn 101 to 459) Inspect and alter front stabilizerattachment in accordance with Culver Service Memorandum # 12.

So you have:  Airworthiness Directives / Airworthiness Maintenance Bullitins /  Manditory Notes / Service Notes from the CAA and (at least) Service Memorandums from the factory that may or may not have been a part of a past AD...

If you are not too confused, I hope this was helpful.. :(

Maintenance and Repair / Re: Leveling the Cadet
« on: January 31, 2012, 01:42:26 PM »
I have looked a lot but have not seen "THE MARK"!

A few of us have come up with alternate methods of leveling (usually easier).  Next person that has a reason to level your airplane try all 3 and report back!

1)  The door sill should be 2 degrees nose down when the airplane is level.  2 Degrees is equal to a 5/8" block at the end of an 18" straight edge.  Masking-tape a small block of wood 5/8" thick 18" from the end of your level.  Set the level on the door sill (block FWD) and that should read level.

2)  Place a block of wood on the top of the spar inside the cabin to raise the level above the steel tubing and that should be level too.

3) (Added 2/2)   On a review of the LAR-90 TC sheet, it states that the LAR-90 is basicly the same as the PQ-8 which we know to be basicly the same as the LCA / LFA except for the gear.  The Leveling means for the LAR-90 is to remove the wing-fuselage fairing and place a level (vertically) aginst the front face of the spar.  This is effectively the same as #2 above.

Pages: 1 [2] 3 4 ... 6