Author: Mark Lancaster <mlancast2004@...> Time: Mon Feb 16, 2004 6:43 pm PST Link
Group,
When removing material to fabricate the taper detail of the HS710 and HS714 I chose to grind the excess off with my bench grinder (grinding wheel) and deburr with my scotchbrite wheel. In doing so I would generate a fair amount of heat; I would stop and let the metal cool when it became hot to the touch(a relative thing); then resume grinding off a little more until the metal became hot again. It worked great. When bending the 6-degree angles, it did so with ease by placing the parts in a vise, clamping a couple of 2x4s to each side of the part, and pushing the bend into the part, very little effort needed (certainly not to the degree of beating it with a mallet per the plans, which sounds like alot of force must be required). Then I became concerned that perhaps the heat could have affected temper in the part. I dont even know if AL has a temper. I have no comparison given I treated all the tapers in this manner. Could this affect the integrity of the aluminium HS 710 and HS 714
outboard ends?
---------------------------------
Do you Yahoo!?
Yahoo! Finance: Get your refund fast by filing online
[Non-text portions of this message have been removed]
Author: "vbpiper" <vbpiper@...> Time: Tue Feb 17, 2004 3:25 am PST Link
Mark,
I would certainly not recommend the bench grinder for use on the
aircraft parts. I would strongly recommend a band saw. I finally
bit the bullet and bought one at Harbor Freight for about $125. It is
variable speed and works fine. When my tech counselor (thanks, Randy
Lervold) came to check the empennage, he saw the bench grinder over
on my workbench and asked if I had used it on the aluminum. Luckily,
I had used the old hacksaw to cut the tapers. Trust me, a band saw
will be nearly a necessity when you get to the fuselage (more
fabrication).
As for the force required for the bends, mine didn't seem to require
a lot of pounding with the mallet, but I guess it's relative.
Now, on to the pure conjecture: I seems that if you only got the
parts warm to the touch, it shouldn't affect the temper of the metal,
but realize that the temperature in the immediate area of the grinder
was probably much higher. The band saw generates some (minimal) heat
also, so maybe a call to Van's is in order, but without some specific
information as to temperatures generated, I would personaly remake
the part and not risk it. They are not that expensive, and it surely
won't be the last part you remake.
Have fun!
Ward
fuselage RV-7A
P.S. If you do talk to Van's, please post their response. I would
be interested to see what they say.
--- In RV7and7A@yahoogroups.com, Mark Lancaster <mlancast2004@y...>
wrote:
> Group,
>
> When removing material to fabricate the taper detail of the HS710
and HS714 I chose to grind the excess off with my bench grinder
(grinding wheel) and deburr with my scotchbrite wheel. In doing so I
would generate a fair amount of heat; I would stop and let the metal
cool when it became hot to the touch(a relative thing); then resume
grinding off a little more until the metal became hot again. It
worked great. When bending the 6-degree angles, it did so with ease
by placing the parts in a vise, clamping a couple of 2x4s to each
side of the part, and pushing the bend into the part, very little
effort needed (certainly not to the degree of beating it with a
mallet per the plans, which sounds like alot of force must be
required). Then I became concerned that perhaps the heat could have
affected temper in the part. I dont even know if AL has a temper. I
have no comparison given I treated all the tapers in this manner.
Could this affect the integrity of the aluminium HS 710 and HS 714
> outboard ends?
> ---------------------------------
> Do you Yahoo!?
> Yahoo! Finance: Get your refund fast by filing online
>
> [Non-text portions of this message have been removed]
Author: "Bruce" <wingtime@...> Time: Tue Feb 17, 2004 9:19 am PST Link
Using a bench grinder is usually not recommended for aluminum since
it will load up with aluminum. In addition, the type of material
that the wheel is constructed out of might be a concern. I have no
idea what they make them out of but I have heard that you should
avoid anything made of aluminum oxide.
The there is a temper to aluminum but I doubt you got it hot enough
to be a concern. My understanding is that if you heat aluminum up
to 600 degrees you anneal it making it soft. However, over time it
will harden again on it's own. (this depends on the alloy of course)
I cut my HS710/714 using a table saw with a carbide blade. It cut
like butter and left a nice clean edge, however the shavings were
deadly. Then I finished them on my belt/disc sander. Even the belt
sander will get the part hot. I just keep a pan of water handy that
I dip the part in to keep it cool.
As mentioned before a small tabletop band saw will come in handy.
Author: "Bob Collins" <bcollins@...> Time: Tue Feb 17, 2004 2:31 pm PST Link
I just used a hacksaw, a file, and a Scotchbrite wheel.
However, it's been awhile since I built this part, but i do NOT
remember anything about beating anything with a mallet. Quite simply,
the angle can be EASILY obtained as you discussed, just putting it in
the vise and leaning on it (I believe this is made clear in the
Orndorff video). You don't need to heat up parts or anything.
If you've taken off the material as directed, it is an EXTREMELY easy
bend to make (hint: use the law of physics. Insert the end with the
material removed into the vice and use the remaining part for
leverage, not the other way around).
If you're leaning on the angled end itself to make the
bend...well....why?
Bob
St. Paul
--- In RV7and7A@yahoogroups.com, "vbpiper" <vbpiper@c...> wrote:
> Mark,
> I would certainly not recommend the bench grinder for use on the
> aircraft parts. I would strongly recommend a band saw. I finally
> bit the bullet and bought one at Harbor Freight for about $125. It
is
> variable speed and works fine. When my tech counselor (thanks,
Randy
> Lervold) came to check the empennage, he saw the bench grinder over
> on my workbench and asked if I had used it on the aluminum.
Luckily,
> I had used the old hacksaw to cut the tapers. Trust me, a band saw
> will be nearly a necessity when you get to the fuselage (more
> fabrication).
> As for the force required for the bends, mine didn't seem to
require
> a lot of pounding with the mallet, but I guess it's relative.
> Now, on to the pure conjecture: I seems that if you only got the
> parts warm to the touch, it shouldn't affect the temper of the
metal,
> but realize that the temperature in the immediate area of the
grinder
> was probably much higher. The band saw generates some (minimal)
heat
> also, so maybe a call to Van's is in order, but without some
specific
> information as to temperatures generated, I would personaly remake
> the part and not risk it. They are not that expensive, and it
surely
> won't be the last part you remake.
> Have fun!
> Ward
> fuselage RV-7A
> P.S. If you do talk to Van's, please post their response. I would
> be interested to see what they say.
>
> --- In RV7and7A@yahoogroups.com, Mark Lancaster <mlancast2004@y...>
> wrote:
> > Group,
> >
> > When removing material to fabricate the taper detail of the HS710
> and HS714 I chose to grind the excess off with my bench grinder
> (grinding wheel) and deburr with my scotchbrite wheel. In doing so
I
> would generate a fair amount of heat; I would stop and let the
metal
> cool when it became hot to the touch(a relative thing); then resume
> grinding off a little more until the metal became hot again. It
> worked great. When bending the 6-degree angles, it did so with
ease
> by placing the parts in a vise, clamping a couple of 2x4s to each
> side of the part, and pushing the bend into the part, very little
> effort needed (certainly not to the degree of beating it with a
> mallet per the plans, which sounds like alot of force must be
> required). Then I became concerned that perhaps the heat could have
> affected temper in the part. I dont even know if AL has a temper.
I
> have no comparison given I treated all the tapers in this manner.
> Could this affect the integrity of the aluminium HS 710 and HS 714
> > outboard ends?
> > ---------------------------------
> > Do you Yahoo!?
> > Yahoo! Finance: Get your refund fast by filing online
> >
> > [Non-text portions of this message have been removed]
Author: "Bob Ward" <wendoure@...> Time: Tue Feb 17, 2004 5:47 pm PST Link
And the loading up with Aluminium is itself a safety issue. Grinding wheels
have ben known to explode due to impacted aluminium impregnation forcing the
wheel apart. To grind Al use only a belt sander, and keep it cool with
water, as you say.
Bob Ward
RV7A Australia
----- Original Message -----
From: "Bruce" <wingtime@y...>
To: <RV7and7A@yahoogroups.com>
Sent: Wednesday, February 18, 2004 2:47 AM
Subject: [RV7Yahoo] Re: HS710 HS714 Taper Detail
> Using a bench grinder is usually not recommended for aluminum since
> it will load up with aluminum. In addition, the type of material
> that the wheel is constructed out of might be a concern. I have no
> idea what they make them out of but I have heard that you should
> avoid anything made of aluminum oxide.
>
> The there is a temper to aluminum but I doubt you got it hot enough
> to be a concern. My understanding is that if you heat aluminum up
> to 600 degrees you anneal it making it soft. However, over time it
> will harden again on it's own. (this depends on the alloy of course)
>
> I cut my HS710/714 using a table saw with a carbide blade. It cut
> like butter and left a nice clean edge, however the shavings were
> deadly. Then I finished them on my belt/disc sander. Even the belt
> sander will get the part hot. I just keep a pan of water handy that
> I dip the part in to keep it cool.
>
> As mentioned before a small tabletop band saw will come in handy.
> Van's Air Force - World Wide Wing
> www.vansaircraft.net
> Yahoo! Groups Links
Author: "Bill Cloughley" <flybill7@...> Time: Wed Feb 18, 2004 10:10 am PST Link
I tapered my HS710/714 two weeks ago using the vixen file
and vise. It took a lot of elbow grease but came out nice.
A band saw would have been much, much faster, and I realize
I will probably have to get one eventually, but I was at the
saturation point as far as spending money on tools.
As others have said, the bends were easily done with the vise
and a little manual push.
... Bill
RV7 Emp
Severna Park, Maryland