"Jim Wilk> "Jim Wilk>
>> ...
>
>
>> ...
>>
>> The samples in your tester are similar to my centrally spliced gantry
>> hoist track problem. I'm trying to determine where to best locate
>> splice plate bolts so their holes minimally weaken the four 4" x 5.4
>> channels that comprise the track. Maybe along the web's neutral axis,
>> if the web has sufficient bearing strength or I weld on
>> reinforcements?
>>
>> Another possibility is welding loose-pin hinge leaves under the lower
>> flanges to take the tension.
>>
>
> I'd like to help you with this, if I can.
> Sorry - been preoccupied getting the "testing" thing going
>
> I'll see if can find past articles where you describe the issue.
> Do you have a webpage you post pictures and articles to - like I do?
> So I can see what you mean?
>
> Regards,
> Rich Smith
> --------------------------------
>
> So far what I have is four 8' sections of 4" x 5.4 lbs/ft channel
> iron, which are former pallet rack shelf supports, and a Harbor
> Freight gantry hoist trolley to run on them when bolted back-to-back > like an I beam.
>
>
> I built a lighter version from four 8' sections of 3" channel, with
> two hung back-to-back from the front and rear roof beams of a storage
> shed and two more making a temporary track extension out over the path
> past the shed, where I set up the sawmill and load logs and beams
> to/from a narrow trailer. The moving overhead hoist is very useful to
> move logs onto the sawmill bed and adjust the partly sawn cants, by
> suspending them in a loop of nylon rope hung on a pulley so I can
> easily turn and level them. The rolling bandsaw mill head needs nearly
> 8' of clearance between the shed and the track's outer end support > post
>
> That part works quite well for 8' oak logs and 6" square beams for
> shed columns. I have to set up the overhead extension track by my self
> and one channel's weight is near the max that I can maneuver with one
> hand while inserting bolts with the other. Safe handling and a
> shortage of covered storage space are why I don't use a single 16'
> beam (~240 lbs) for the track.
>
> The problem is 12' logs for roof beams, which could overload the 3"
> channel and won't fit the 10' deep shed. I have another shed 19' long
> by 4' wide that can hold 12' beams if I hang a crosswise travelling
> hoist from its roof to move them in. It contains some already, which I
> moved by an unsatisfactory temporary arrangement of the 3" extension
> channels. I'd like to run the 4" channels out 8' over the sawmill to a
> braced post beyond it and in through the shed plus 4' out the far side
> to another post, for lifting logs off the trailer. In that case the
> track will be centrally supported from above at the joint between its
> 8' sections, no problem.
>
> The extreme case is joining the four sections to make one 16' gantry
> track hung from tripods at the ends, perhaps to load a bulky appliance
> onto a truck. I may never need it but I'd like to find a center splice
> joint design that doesn't exclude or conflict with the central
> mounting from the shed roof beam. Hopefully one design will work for
> both centrally and end supported cases. That knuckle joint under the
> tension flanges looks good because I could raise the ground-assembled
> track by it and then lift and level the two outer ends separately, and
> it won't transfer sag on one side into lift on the other, and shift a
> shed column off its footing. I don't quite know how to design one to
> weld onto the channel flanges, for instance how much to taper the
> leaves to distribute the elongation and weld shear stress.
>
> Specifically I'd like to know if bolts in tapped holes in the upper
> flange can be considered part of the compression area and the accepted
> way to reinforce the holes for splicing plate bolts through the
> channel web. Does the reinforcement need to be diamond shaped to avoid
> vertical welds?
>
> Since I'm not on the clock I can customize bolts on the lathe and
> hand-fit them with minimal clearance. They are all Grade 8, fine > thread, 150KSI.
Hi Jim >
>
>> ...
>>
>> The samples in your tester are similar to my centrally spliced gantry
>> hoist track problem. I'm trying to determine where to best locate
>> splice plate bolts so their holes minimally weaken the four 4" x 5.4
>> channels that comprise the track. Maybe along the web's neutral axis,
>> if the web has sufficient bearing strength or I weld on
>> reinforcements?
>>
>> Another possibility is welding loose-pin hinge leaves under the lower
>> flanges to take the tension.
>>
formatting link
(mechanical)>
> I'd like to help you with this, if I can.
> Sorry - been preoccupied getting the "testing" thing going
>
> I'll see if can find past articles where you describe the issue.
> Do you have a webpage you post pictures and articles to - like I do?
> So I can see what you mean?
>
> Regards,
> Rich Smith
> --------------------------------
>
> So far what I have is four 8' sections of 4" x 5.4 lbs/ft channel
> iron, which are former pallet rack shelf supports, and a Harbor
> Freight gantry hoist trolley to run on them when bolted back-to-back > like an I beam.
>
formatting link
>
> I built a lighter version from four 8' sections of 3" channel, with
> two hung back-to-back from the front and rear roof beams of a storage
> shed and two more making a temporary track extension out over the path
> past the shed, where I set up the sawmill and load logs and beams
> to/from a narrow trailer. The moving overhead hoist is very useful to
> move logs onto the sawmill bed and adjust the partly sawn cants, by
> suspending them in a loop of nylon rope hung on a pulley so I can
> easily turn and level them. The rolling bandsaw mill head needs nearly
> 8' of clearance between the shed and the track's outer end support > post
>
> That part works quite well for 8' oak logs and 6" square beams for
> shed columns. I have to set up the overhead extension track by my self
> and one channel's weight is near the max that I can maneuver with one
> hand while inserting bolts with the other. Safe handling and a
> shortage of covered storage space are why I don't use a single 16'
> beam (~240 lbs) for the track.
>
> The problem is 12' logs for roof beams, which could overload the 3"
> channel and won't fit the 10' deep shed. I have another shed 19' long
> by 4' wide that can hold 12' beams if I hang a crosswise travelling
> hoist from its roof to move them in. It contains some already, which I
> moved by an unsatisfactory temporary arrangement of the 3" extension
> channels. I'd like to run the 4" channels out 8' over the sawmill to a
> braced post beyond it and in through the shed plus 4' out the far side
> to another post, for lifting logs off the trailer. In that case the
> track will be centrally supported from above at the joint between its
> 8' sections, no problem.
>
> The extreme case is joining the four sections to make one 16' gantry
> track hung from tripods at the ends, perhaps to load a bulky appliance
> onto a truck. I may never need it but I'd like to find a center splice
> joint design that doesn't exclude or conflict with the central
> mounting from the shed roof beam. Hopefully one design will work for
> both centrally and end supported cases. That knuckle joint under the
> tension flanges looks good because I could raise the ground-assembled
> track by it and then lift and level the two outer ends separately, and
> it won't transfer sag on one side into lift on the other, and shift a
> shed column off its footing. I don't quite know how to design one to
> weld onto the channel flanges, for instance how much to taper the
> leaves to distribute the elongation and weld shear stress.
>
> Specifically I'd like to know if bolts in tapped holes in the upper
> flange can be considered part of the compression area and the accepted
> way to reinforce the holes for splicing plate bolts through the
> channel web. Does the reinforcement need to be diamond shaped to avoid
> vertical welds?
>
> Since I'm not on the clock I can customize bolts on the lathe and
> hand-fit them with minimal clearance. They are all Grade 8, fine > thread, 150KSI.
Can you sketch?
That is always helpful. I do that even when it seems we all agree, as
it can be amazing how a sketch reveals that the impressions are not
the same.
I'm thinking - maybe weld some brackets on top of the channel with the
bolted flange faces facing.
I'd normally wish there could also be a flange underneath - but the
close-fitting "standard" carriage would collide with it, so not
possible.
That said: if I understand correctly (big "if") - the loading may be
"cantilever beam" - tension on top, compression underneath.
Extending out of the shed?
Suspended - near the door?
In which case flange on top, nothing needed underneath as compresses
together would be bril.
Load analysis of the section - as channels tend to twist under load,
and is singular, I wouldn't dare use Euler-Bernoulli beam calculation
as works for symmetrical beams.
Sorry verbal description is hard to "see".
Rich S