UniStrut Frame designs

@wrightwells Yes this is a very fun part of the process! I wish I would have submitted my design/thoughts before building as I’m now taking apart my frame to shore up some weak points. Keep up the good work!

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@wrightwells Would you be able to share your SketchUp model? I’m about to build my frame as well and torn between wood and unistrut. Much better equipped today to do it in wood but if there is no welding required in unistrut it is very intriguing…

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@JWoody18 yes Jeff no problem, how do you want it?

A Dropbox or Google drive link works. Any chance you can save it in 2016 format? Thanks

Jeff

if you wanted to mount motors to cheap galvanized conduit tube, you can just take a short 2x4 or 4x4 and hole saw drill and stick the tube in the wood and secure with some drywall screws to prevent rotation. see photo sample of one end.

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here is the spreadsheet, it lets you see the angle and force differences with different setups

you may also want to look at these motor mounts I designed New motor mount suggestion

for mounting the top beam and having it be adjustable, look at this post using a unistrut angle and short piece of unistrut to allow the top beam to be moved in and out easily

(lots of useful info in that thousand post thread)

the delrin roller was included?
we’ve finally gotten back to the maslow
and are getting quite a bit of slipping and i remember seeing your chain guide.

where would i get a delrin roller if i can’t find the one that cane with the maslow.

1x “full height” 10’ Superstrut??

what is the size? 2x4 when its full height?

full height is just slightly higher than it is wide, there is a low profile
version that is about half the height.

David Lang

ok so my daughter is new to this and i am helping her out… she lives in the Caribbean and all the home depot wood she bought is warped… she want to exchange the top 2x4x10 beam for a Unistrut…
1 what is the 10 foot Unistrut she has to buy
2 what are the necessary hardware to hold the motors etc.
3 how do she hold the Unistrut to the frame because she has the 2x4 wood clamps only…
thanks in advance

the standard unistrut that she finds will probably be the right stuff (the low
profile version is usually special order), it it looks close to square it will
be good.

to mount the motors will take a little creativity, I designed some motor mounts
that make this easy, but there is not a lot of interest in them, so I only made
a few sets. consider drilling pilot holes in the flat bottom of the unistrut and
then using self tapping screws to hold the motor mounts to the unistrut. If you
have the ability to cut/bend sheet metal, you can get the cad at
https://cad.onshape.com/documents/1ed74f3f9193e91b4068dd8f/w/602c198313a06fd8af6075cd/e/ee2e4ad9df4a927c4b5f43b3

you can mount the unistrut on the top of the 2x4 wood bars that would hold the
normal top beam. before you cut those to size, you want to figure out the right
distance for your sled. build your sled and mount the router and ring to it,
then set the ring so that if you hang the sled by the top center of the ring it
hangs vertically with the router at about the height it would be hen cutting (or
close to it). then you will want to add the thickness of any wasteboards that
you use, the frame, and the material you will typiclly be cutting and cut the
top beams to put the motor sprockets out at that distance (so that the chains,
going from the sprockets to the ring, are parallel to the workpiece)

roller chain and sprockets are designed to work with up to a 3 degree
misalignment, which is a little over .6 in per foot, so you can be an inch or so
off without a big problem, but the closer you are the more reliable it will be.

David Lang

wow … thanks for all the help. this sounds a little complicated for my daughter and me but with your help i think we can get through this …

1 is there any simple instructions for all this? jus thought it was replacing the top beam with the Unistrut and mount the motors? mounting the Unistrut on top of the wood bars would it not make it higher?

need a little more help with this " before you cut those to size, you want to figure out the right
distance for your sled. build your sled and mount the router and ring to it,
then set the ring so that if you hang the sled by the top center of the ring it
hangs vertically with the router at about the height it would be hen cutting (or
close to it). then you will want to add the thickness of any waste boards that
you use, the frame, and the material you will typically be cutting and cut the
top beams to put the motor sprockets out at that distance (so that the chains,
going from the sprockets to the ring, are parallel to the workpiece)"

a step by step? because we are new to this and do not understand. Should we build it normal and then just change the top 2x4x10 for the 10’ Unistrut to get a better understanding of the build?

thanks in advance

1 is there any simple instructions for all this? jus thought it was replacing the top beam with the Unistrut and mount the motors? mounting the Unistrut on top of the wood bars would it not make it higher?

yes, but a couple inches higher is usually not a problem (check if it will fit
through doors if you plan to move it). the maslow is very forgiving on
dimensional changes.

The published fram instructions/dimensions were made before we had the ring kits
out in the field, and it turns out the arms holding the top beam are a bit
longer than they really should be. The exact weights and router that you use
also affect the balance of the sled, so giving the exact dimensions is hard to
do.

go ahead and build it using a unistrut top beam instead of a twisted 2x4 and you
will probably be ‘close enough’ to have a working machine.

make it so that the chains are close to parallel to the workpiece to avoid the
chain skipping of popping off.

If the sled is not balanced (in the Z direction, the axis of the router), then
you will limit how close to the edges you can cut, and may have the sled tilt
up/down at some points in the cutting, but it will work in the center area. you
can ignore everything below until you have a working machine if you want.

need a little more help with this " before you cut those to size, you want to figure out the right
distance for your sled. build your sled and mount the router and ring to it,
then set the ring so that if you hang the sled by the top center of the ring it
hangs vertically with the router at about the height it would be hen cutting (or
close to it). then you will want to add the thickness of any waste boards that
you use, the frame, and the material you will typically be cutting and cut the
top beams to put the motor sprockets out at that distance (so that the chains,
going from the sprockets to the ring, are parallel to the workpiece)"

a step by step? because we are new to this and do not understand.

ask around and see if you can order a unistrut longer than 10’ (they are
available in 20’ lengths, but commonly special order), going to a 12’ top beam
(and 13 ft chains instead of the stock 11 ft chains) will help accuracy.

build the machine aas directed, just with the unistrut on top of the arms
instead of the 2x4 on the front of them.

when you have a sled built, the ring can be set to different heights above the
sled. the process that I describe is the way to figure out what the right height
is for the weights and router you are using (producing the most stable sled,
which will let you get closer to the edge without it tipping)

once you have the sled balanced, you will want to see how far out of parallel
the chains are when you look at the machine from the side. If they are off by a
lot, you may suffer from chain skip near the top (especially top corners) of the
workspace, the ideal thing is to move the top beam in or out to make the chains
parallel.

does this clarify things a bit more?

David Lang

hello first of all, thanks for your help. so we bought the unistrut to mount on the top of the 2x4 wood bars. On top of the wood bar the unistrut is too thick can we use the other side?

I don’t know what those blue parts are that you are showing, but as long as the pull of the chain will not collapse the unistrut, it’s just as strong in one direction as the other.

these are the bar beams that you said to mount the Unistrut on top … i can mount on front also on both beams and move the base forward so it will be parallels?

How did you attach the chains?

just an example of my unistrut frame:

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