|
Matronics Email Lists Web Forum Interface to the Matronics Email Lists
|
View previous topic :: View next topic |
Author |
Message |
naumuk(at)alltel.net Guest
|
Posted: Fri May 04, 2007 5:57 pm Post subject: Locating engine mount holes |
|
|
All-
I know that this question was posted only a couple of weeks ago, but everything but the answer wound up in the archives.
I just fabricated a firewall from scratch. What's the easiest and most accurate way of locating the engine mount holes?
Let's make sure the answer gets in the archives this time!
Bill Naumuk
HDS Fuse/Corvair
Townville, Pa
[quote][b]
| - The Matronics Zenith-List Email Forum - | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Zenith-List |
|
|
|
Back to top |
|
|
ter_turn(at)yahoo.com Guest
|
Posted: Fri May 04, 2007 7:26 pm Post subject: Locating engine mount holes |
|
|
Hi Bill,
I am looking at the same dilemma myself and have decided to just wait until my engine mount attach
fittings are bolted on and then mark and drill the firewall. That way a couple of mm one way or the other won't hurt. Good luck.
Terry Turnquist
601XL-Plans
St. Peters, MO
Bill Naumuk <naumuk(at)alltel.net> wrote:
[quote] All-
I know that this question was posted only a couple of weeks ago, but everything but the answer wound up in the archives.
I just fabricated a firewall from scratch. Ahhh...imagining that irresistible "new car" smell?
Check out [url=http://us.rd.yahoo.com/evt=48245/*http://autos.yahoo.com/new_cars.html;_ylc=X3oDMTE1YW1jcXJ2BF9TAzk3MTA3MDc2BHNlYwNtYWlsdGFncwRzbGsDbmV3LWNhcnM-]new cars at Yahoo! Autos.[/url] [quote][b]
| - The Matronics Zenith-List Email Forum - | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Zenith-List |
|
|
|
Back to top |
|
|
p.mulwitz(at)worldnet.att Guest
|
Posted: Fri May 04, 2007 8:39 pm Post subject: Locating engine mount holes |
|
|
Perhaps I am getting this wrong, but I think the notion of where to put the engine mount on the firewall has nothing to do with the engine. After all, I am just a kit builder and put the holes for the engine mount on the firewall according to the plans.
It seems to me the location of the firewall mounting bolts is dictated by the longerons attached to the fittings on the other side of the firewall from the engine. It is the longerons that dictate the location of these holes.
Once the mounting position of the engine mount is fixed by the fuselage design, it is the problem of the engine mount designer to build a mount that fits these bolts to the engine itself.
Just my ideas on this subject . . . .
Paul
XL fuselage
At 08:20 PM 5/4/2007, you wrote:
[quote]Hi Bill,
I am looking at the same dilemma myself and have decided to just wait until my engine mount attach
fittings are bolted on and then mark and drill the firewall. That way a couple of mm one way or the other won't hurt. Good luck.
Terry Turnquist
601XL-Plans
St. Peters, MO
Bill Naumuk <naumuk(at)alltel.net> wrote:
All-
I know that this question was posted only a couple of weeks ago, but everything but the answer wound up in the archives.
I just fabricated a firewall from scratch.
[b]
| - The Matronics Zenith-List Email Forum - | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Zenith-List |
|
|
|
Back to top |
|
|
planecrazydld(at)yahoo.co Guest
|
Posted: Sat May 05, 2007 1:25 am Post subject: Locating engine mount holes |
|
|
The fuse side mount fittings are the primary transfer points for the loads from the powerplant into the fuse. As such, as Paul points out, they control everything. When the mount is fabricated or installed, it needs to fit those locations - not those locations fit it. Keep in mind that the mount needs to fit without straining, because that is a recipe for a cracked mount somewhere down the road.
Paul Mulwitz <p.mulwitz(at)worldnet.att.net> wrote: Quote: | Perhaps I am getting this wrong, but I think the notion of where to put the engine mount on the firewall has nothing to do with the engine. After all, I am just a kit builder and put the holes for the engine mount on the firewall according to the plans.
It seems to me the location of the firewall mounting bolts is dictated by the longerons attached to the fittings on the other side of the firewall from the engine. It is the longerons that dictate the location of these holes.
Once the mounting position of the engine mount is fixed by the fuselage design, it is the problem of the engine mount designer to build a mount that fits these bolts to the engine itself..... |
Dave Downey
Harleysville (SE) PA
Zodiac 601XL/Corvair?
Don't pick lemons.
See all the new 2007 cars at Yahoo! Autos. [quote][b]
| - The Matronics Zenith-List Email Forum - | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Zenith-List |
|
|
|
Back to top |
|
|
naumuk(at)alltel.net Guest
|
Posted: Sat May 05, 2007 5:04 am Post subject: Locating engine mount holes |
|
|
All-
From the responses, I can see I didn't get my point across. I found out that the print locations will work for at least Corvair, Jab, and Rotax installations, so that's not an issue. I know where the holes are supposed to go, getting them there is the problem. Every firewall (Scratchbuilt, at least) is going to deviate a couple of mm's from print. Getting the Y axis locations isn't a problem because you can use the flat bottom as an origin. Finding the X axis center is more iffy.
A couple of weeks ago someone posted a method for accurately locating the holes on a firewall and unfortunately it didn't make it into the archives. That's what I'm looking for.
Since I "Slept on the problem" a possible solution is coming to me, but it would be nice if I didn't have to reinvent the wheel.
Thanks.
Bill Naumuk
HDS Fuse/Corvair
Townville, Pa
[quote] ---
| - The Matronics Zenith-List Email Forum - | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Zenith-List |
|
|
|
Back to top |
|
|
p.mulwitz(at)worldnet.att Guest
|
Posted: Sat May 05, 2007 6:01 am Post subject: Locating engine mount holes |
|
|
Hi Bill,
Sorry if I misunderstood your problem. Perhaps you are trying to make the engine mount bolt holes before it is time to do so.
It has been many months since I did this operation, so I don't really remember how it was done. I do remember it involved fitting the steel fittings at the ends of each longeron to both the firewall and longeron at the same time. Meanwhile, the skin has to fit both the longeron and the firewall flange. When all this is accomplished, the steel fittings will dictate where the engine mount bolt holes go on the firewall.
If my memory serves correctly (something that will get you in trouble if you depend on it) one of the critical items was the forward bend in the cabin bottom skin. This had to fit around the corner on the firewall and the whole thing had to be held in place by the engine mount bolts to make it work. All in all it is a nasty Chinese puzzle to solve.
My advice to you is to wait until you have all the parts in hand and are ready to make it all happen before worrying about the engine mount bolt hole locations.
Best regards,
Paul
XL fuselage
At 05:59 AM 5/5/2007, you wrote:
[quote]All-
From the responses, I can see I didn't get my point across. I found out that the print locations will work for at least Corvair, Jab, and Rotax installations, so that's not an issue. I know where the holes are supposed to go, getting them there is the problem. Every firewall (Scratchbuilt, at least) is going to deviate a couple of mm's from print. Getting the Y axis locations isn't a problem because you can use the flat bottom as an origin. Finding the X axis center is more iffy.
A couple of weeks ago someone posted a method for accurately locating the holes on a firewall and unfortunately it didn't make it into the archives. That's what I'm looking for.
Since I "Slept on the problem" a possible solution is coming to me, but it would be nice if I didn't have to reinvent the wheel.
Thanks.
Bill Naumuk
HDS Fuse/Corvair
Townville, Pa
[b]
| - The Matronics Zenith-List Email Forum - | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Zenith-List |
|
|
|
Back to top |
|
|
wjones(at)brazoriainet.co Guest
|
Posted: Sat May 05, 2007 6:33 am Post subject: Locating engine mount holes |
|
|
Hey Bill ,I went with what the plans called for.856mm across the top of the firewall. Bottom holes 15mm from bottom of firewall and 610mm between centers. This will leave you with 460mm between the top and bottom holes. Of course all this is started from the center of the firewall .All lined up to the longeron locations for a good fit
Wade Jones South Texas
601XL plans building
Cont. 0200
[quote] ---
| - The Matronics Zenith-List Email Forum - | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Zenith-List |
|
|
|
Back to top |
|
|
Jaybannist(at)cs.com Guest
|
Posted: Sat May 05, 2007 6:44 am Post subject: Locating engine mount holes |
|
|
Bill,
As I have previously posted, the recommended way to locate the holes is to drill pilot holes in the center of the forward vertical plate of the engine mount brackets. When the brackets have been properly located on the fuselage longerons, drill the firewall through the pilot holes. Then drill out the pilot holes for the bolts (which WW refers to as "studs"). William Wynne has said "It is acceptable to slightly flex the motor mount in order to get it to line up with the studs. After we weld them, the motor mounts are stress relieved so they will generally slide right on the studs. There will be a slight variation on plans built aircraft for the location of the holes, and the motor mount can accommodate this up to about 3/32"."
Jay in Dallas
"Bill Naumuk" <naumuk(at)alltel.net> wrote:
Quote: | All-
From the responses, I can see I didn't get my point across. I found out that the print locations will work for at least Corvair, Jab, and Rotax installations, so that's not an issue. I know where the holes are supposed to go, getting them there is the problem. Every firewall (Scratchbuilt, at least) is going to deviate a couple of mm's from print. Getting the Y axis locations isn't a problem because you can use the flat bottom as an origin. Finding the X axis center is more iffy.
A couple of weeks ago someone posted a method for accurately locating the holes on a firewall and unfortunately it didn't make it into the archives. That's what I'm looking for.
Since I "Slept on the problem" a possible solution is coming to me, but it would be nice if I didn't have to reinvent the wheel.
Thanks.
Bill Naumuk
HDS Fuse/Corvair
Townville, Pa
|
| - The Matronics Zenith-List Email Forum - | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Zenith-List |
|
|
|
Back to top |
|
|
naumuk(at)alltel.net Guest
|
Posted: Sat May 05, 2007 6:48 am Post subject: Locating engine mount holes |
|
|
Paul-
On the HDS you don't have a choice- all the components that are riveted to the firewall use the mount holes as origins.
Bill Naumuk
HDS Fuse/Corvair
Townville, Pa
[quote] ---
| - The Matronics Zenith-List Email Forum - | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Zenith-List |
|
|
|
Back to top |
|
|
naumuk(at)alltel.net Guest
|
Posted: Sat May 05, 2007 7:13 am Post subject: Locating engine mount holes |
|
|
Jay-
Since this is previously posted,
do not archive
Bill Naumuk
HDS Fuse/Corvair
Townville, Pa
---
| - The Matronics Zenith-List Email Forum - | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Zenith-List |
|
|
|
Back to top |
|
|
naumuk(at)alltel.net Guest
|
Posted: Sat May 05, 2007 7:13 am Post subject: Locating engine mount holes |
|
|
Wade-
Agreed, the plans locations work for different engine installations.
do not archive
Bill Naumuk
HDS Fuse/Corvair
Townville, Pa
[quote] ---
| - The Matronics Zenith-List Email Forum - | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Zenith-List |
|
|
|
Back to top |
|
|
naumuk(at)alltel.net Guest
|
Posted: Sat May 05, 2007 7:14 am Post subject: Locating engine mount holes |
|
|
Paul-
Since I already responded to this re: HDS,
do not archive
Bill Naumuk
HDS Fuse/Corvair
Townville, Pa
[quote] ---
| - The Matronics Zenith-List Email Forum - | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Zenith-List |
|
|
|
Back to top |
|
|
kensmith(at)springnet1.co Guest
|
Posted: Sat May 05, 2007 7:19 am Post subject: Locating engine mount holes |
|
|
You are absolutely correct in regards to the exact location of the mount attach points. Any change in the location no matter how small should always be approved from the designing engineers at Zenith. Change in location will proably require some structural change for attachment.
Ken
Paul Mulwitz wrote: [quote]Perhaps I am getting this wrong, but I think the notion of where to put the engine mount on the firewall has nothing to do with the engine. After all, I am just a kit builder and put the holes for the engine mount on the firewall according to the plans.
It seems to me the location of the firewall mounting bolts is dictated by the longerons attached to the fittings on the other side of the firewall from the engine. It is the longerons that dictate the location of these holes.
Once the mounting position of the engine mount is fixed by the fuselage design, it is the problem of the engine mount designer to build a mount that fits these bolts to the engine itself.
Just my ideas on this subject . . . .
Paul
XL fuselage
[b]
| - The Matronics Zenith-List Email Forum - | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Zenith-List |
|
|
|
Back to top |
|
|
dredmoody(at)cox.net Guest
|
Posted: Sat May 05, 2007 7:38 am Post subject: Locating engine mount holes |
|
|
The longerons do indeed dictate the position of the engine mount brackets but the engine mount and its design and dimensins dictate the location of the holes. I drilled the pilot holes according to the directions (drawings and photo assembly guide) then enlarged them to the correct bolt size. Many moons later, when my FWF package arrived form Jabiru USA the mount matched up to the bolts pretty well, so I'd have to say the instructions and fabrication of the mount are in agreement.
It is important to (A) locate the pilot holes accurately (of course), then (B) back drill the pilot holes to the engine mount brackets, then (C) enlarge them to size, preferably firewall and bracket at the same time. If you err, make sure the error places the bolt hole slightly farther from the base of the bracket rather than closer to it. If the hole is too close to the bottom of the bracket it clashes with the AN3 bolts which attach the bracket to the longeron.
Dred
[quote] ---
| - The Matronics Zenith-List Email Forum - | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Zenith-List |
|
|
|
Back to top |
|
|
planecrazydld(at)yahoo.co Guest
|
Posted: Sat May 05, 2007 8:31 am Post subject: Locating engine mount holes |
|
|
on April 11 I posted this - maybe it is what you were remembering? While not the easiest way it is a very accurate way to determine the "average" centerline of an irregular shaped piece with supposed symmetry:
one way to achieve a near "average" centerline:
- Cut out a cardboard pattern that will fit precisely inside the flanges of the firewall blank from bend radius tangent to bend radius tangent. Perhaps some odd shaped holes in the cardboard near the edges that can be traced with a sharpie for matching positioning later?
- Mark or cut the existing "tooling holes" holes in the cardboard from the firewall
- Then turn over the cardboard and re-trim to fit as well as possible. Trace the odd shaped hole in the cardboard on the firewall with a sharpie again to allow repositioning later.
- Re-mark or cut the hole locations in the cardboard.
- Find the center between each set of holes in the cardboard and drill a 1/16" pilot hole in the cardboard there.
- Replace the cardboard in the firewall and position with that set of alignment marks. Make a sharpie mark through the 1/16" holes in the cardboard.
- Flip the cardboard and repeat.
- Remove the cardboard.
- Find the center between each pair of pilot hole markings: there is the centerline.
Note that you can do this even if there are no pilot holes to transfer from the part. The greater the distance between the 1/16" pilot holes in the cardboard, the greater the precision of this technique to find the center of a non symmetrical part.
Bill Naumuk <naumuk(at)alltel.net> wrote: Quote: | All-
From the responses, I can see I didn't get my point across. I found out that the print locations will work for at least Corvair, Jab, and Rotax installations, so that's not an issue. I know where the holes are supposed to go, getting them there is the problem. Every firewall (Scratchbuilt, at least) is going to deviate a couple of mm's from print. Getting the Y axis locations isn't a problem because you can use the flat bottom as an origin. Finding the X axis center is more iffy.
A couple of weeks ago someone posted a method for accurately locating the holes on a firewall and unfortunately it didn't make it into the archives. That's what I'm looking for.
|
Dave Downey
Harleysville (SE) PA
Zodiac 601XL/Corvair?
Looking for earth-friendly autos?
Browse Top Cars by "Green Rating" at Yahoo! Autos' Green Center. [quote][b]
| - The Matronics Zenith-List Email Forum - | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Zenith-List |
|
|
|
Back to top |
|
|
naumuk(at)alltel.net Guest
|
Posted: Sat May 05, 2007 9:21 am Post subject: Locating engine mount holes |
|
|
See final
do not archive
Bill Naumuk
HDS Fuse/Corvair
Townville, Pa
[quote] ---
| - The Matronics Zenith-List Email Forum - | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Zenith-List |
|
|
|
Back to top |
|
|
naumuk(at)alltel.net Guest
|
Posted: Sat May 05, 2007 9:22 am Post subject: Locating engine mount holes |
|
|
See final
do not archive
Bill Naumuk
HDS Fuse/Corvair
Townville, Pa
[quote] ---
| - The Matronics Zenith-List Email Forum - | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Zenith-List |
|
|
|
Back to top |
|
|
naumuk(at)alltel.net Guest
|
Posted: Sat May 05, 2007 9:22 am Post subject: Locating engine mount holes |
|
|
Recently archived.
do not archive
Bill Naumuk
HDS Fuse/Corvair
Townville, Pa
[quote] ---
| - The Matronics Zenith-List Email Forum - | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Zenith-List |
|
|
|
Back to top |
|
|
|
|
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum You cannot attach files in this forum You can download files in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|