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🌞 New Stock Frame Design 🌞


#783

Here is another solution using a unistrut construction:
A unistrut P2484 angle support is used to keep the short piece of unistrut rigid. The short piece is oriented with the channel up to allow adjustment for chain alignment in & out.

The top beam is attached using a carriage bolt, modified square washer and adjustable handle - in this case a Kipp 06601-5A51 but many will work. The washer had to be trimmed to fit inside the unistrut channel and the hole squared to hold the carriage bolt from turning. This assembly makes chain spacing relatively painless.

I plan to use a 12’ unistrut top beam with the vertical unistrut supports 12" in from the ends to reduce any flex. This fits with the rest of my frame design that I will share later as it progresses.

Any feedback? Suggestions?
Here are photos:


#784

All bolts are 1/2-13".


#785

@bar, that is the angle that you saw in the work over the weekend, they are available for <$6 each in multiples of 20

the current design has the legs 16" from the end. If flex ends up being any problem, take a piece of plywood (4" tall x up to 82" long) and glue/screw it to the back center of the top beam.

I don’t like the flex, but I also don’t think it’s enough to be a significant problem to us, and the simplification of not having to drill through the long side of the beam are significant.


#786

flip that unistrut over so it’s attached to the top beam via a short nut and bolt, then use standard captured nuts in the (near) horizontal unistrut to hold it against the angle bracket. no need to modify anything.

one problem with your approach is that when you aren’t all the way out at the end of the horizontal arms, they are in the way of the chains. If the beam is fixed to the end of the arms, and the arms move for adjustment, you don’t have that problem.


#787

I’m figuring that we will have variations between builds in any case, most people just aren’t that precise. I allow for it in the design and it will work even with significant errors between parts that are supposed to be the same size, let alone between parts on one machine and parts on another machine. I tend to try to maximize what I can get from the lumber, and since the metric sticks are going to be a bit longer, it makes sense to go ahead and use the wood.


#788

could you test using rope and weights instead of stretchy string to provide the take-up for the slack (you would need a short piece of something to direct the rope/weight behind the cutting area


#789

I see your point. However my experience with captured nuts is that they do not slide easily. Once tightened the teeth cut into the beam, and by design they lock into place when installed. The idea is to allow smooth movement of the top beam on the horizontal rail sections. That is why I’ve used the carriage bolt & washer arrangement.

The 2 short bolts holding the horizontal rails make them absolutely rigid tied to the upright support unistruts. The intention is to remove even the slightest flex in the position of the top beam as the stresses of the sled pull it at multiple angles. The rest of the frame structure will stabilize the upright support unistruts as well.

Chain interference with the horizontal rails will not be an issue considering the 12’ top beam will be 2’ out and 2’ up from the 4’x 8’ work area.

Another issue: Using wood for the structure is relatively inexpensive but by its nature swells and shrinks with changes in humidity. This may not be a problem for many users however for me maintaining accuracy is extremely important. I intend to use wood for media support but in ways that allow for its instability.


#790

remember, the chain angle at the top is only 10 degrees from horizontal. this is a drop of just over 2 inches per foot, so at 2 feet, and the need to drop 2 x 1 5/8 + distance from top beam to the top of the chain, you are actually going to be getting pretty close (and if you used a 10’ beam so that you only had 1’ or so to the leg, you would be in trouble)

remember, you aren’t expected to adjust the beam position very frequently, only when you are changing your workpiece+wasteboard thickness significantly. you have a 1" or so variation in thickness that you can use in any one setting.


#791

Thanks for your input. Yes, you are right that for most people the chain spacing will not be much of an issue and I admit for most my design is probably overkill. Personally I need a great deal of flexibility for working with non-standard media - that’s what I’m planning for anyway. I’ll post photos and info for ideas and suggestions as the frame comes together. Thanks again - I appreciate your help.


#792

I’m going to name my design “the $80 build”

Less than 90 minutes with Documenting - I will say it will be under 60 minutes. Screw count 9 - This is a minimum build but I believe it will work. It’s designed to mount the work to the frame and have it flush with the outer edges for full access to the entire sheet.

2- 12 ft boards

1 - 10 ft board

1 - 8 ft board

1 sheet of wood . 3/4 inch thick

Note there are 2 side pieces and 12 screws not in place.

The top mount is deviated from the drawing slightly. The total build height 6 foot 8 inches. The full depth for stroage when folded 12 inches deep.

IMG_4312

Thank you


#793

ok, new diagrams
fig 1.pdf (47.1 KB)
fig 4.pdf (48.9 KB)
fig 5.pdf (52.4 KB)
fig 3.pdf (57.5 KB)
fig 8 minimal.pdf (50.0 KB)
fig 8.pdf (51.4 KB)
fig 2.pdf (58.5 KB)
fig 7.pdf (61.5 KB)
fig 9.pdf (63.7 KB)
fig 9 minimal.pdf (61.7 KB)
fig 6 minimal.pdf (63.8 KB)
fig 6.pdf (64.6 KB)
fig 13.pdf (66.1 KB)
fig 12.pdf (66.2 KB)
fig 11.pdf (69.3 KB)
fig 10.pdf (74.1 KB)
fig 14.pdf (95.3 KB)
cut list.pdf (799.1 KB)


BTW - Not sure if we should limit the number of posts
#794

revised build instructions

Assembly instructions for the Maslow frame. This process deliberately avoids specifying measurements. Instead everything is positions by using other boards that have been cut as spacers. This produces more consistent results

The only measurement that’s needed is when you are squaring the frame, and that can be done with a piece of string (just use something that doesn’t stretch)

To keep everything square, you want to have a factory end on the 72" front legs, one of the 60" back legs, the 10" top beam supports, and two of the 24" pieces for the rear kickers (I’ll post a revised cut-list to show this grouping,probably graphically)

When fastening with glue and screws, the main purpose of the screws is to hold everything together while the glue dries, but they also provide a backup if the glue fails. “real woodworkers” can flatten/sand the surfaces and glue and clamp instead of screwing and end up with a good, strong joint. Normal people should leave screws in place 

This is ordered to keep things as small as possible as long as possible so that most of the work can be done on a bench/table

Options
There are a few common variations on this frame

  1. additional wasteboard support
    Some people live in areas where the temperature/humidity can change rapidly, this can warp the plywood. Other people are experimenting with using sheets of foam for the wasteboard. By adding a couple extra boards to the Maslow, the main plywood board is not needed and the wasteboard can be mounted directly to the frame
  2. Support for cutting extra thick/thin material
    By default, the Maslow can cut material up to about 1" thick, this variation allows for more thickness
  3. unistrut top beam
    Unistrut is a metal beam commonly used to support pipes and conduit in industrial buildings. (in the US, Home Depot and Lowes carry it, but not always in stock). It is a 1 5/8 (41mm) channel that is designed to hang things from easily. It is available with holes already in it and will be a little stiffer than stick lumber and will not distort with humidity changes.

Assembly Instructions

  1. attach kickers to front legs

    1. use spacer blocks under the combined legs to lift them 1.5" off the ground
    2. take a 60" rear leg and clamp it to the side of a front leg with factory ends together and flush.
    3. put a spacer block narrow side against the bottom of the 60" piece
    4. position the kicker against the ground and the spacer block (on what will be the outside of the front leg, so one on the left and the other on the right).
    5. Check that it is square
    6. Fasten to front leg (screw and glue)

    IMPORTANT: This is one of two places in the build where the angles and distancesare critical. Make sure that the kickers are as square to the front legs as you can make them. Use the same pieces of wood as spacers for attaching the kicker to each of the front legs.

  2. attach the leg spacer to the rear kickers

    1. place a block along the inside of the rear kickers (on the same side as the leg), flush with the back of the kicker
    2. glue and screw the block to the front leg.
  3. position the top cross-member block not used on minimal version

    1. take the two 16" diagonals and set them against the lower block
    2. position a block flat against the leg, with the grain forward
    3. glue and screw the block to the front leg.

    IMPORTANT: make sure the block does not slip and extend forward of the front leg, with the kicker sticking forward of the leg it will not sit flat on the ground

  4. attach the rear legs to the front legs

    1. lay the rear legs next to the front legs with the bottoms flush
    2. drill through the back leg and use a lag bolt to attach it to the front leg
  5. angle the rear legs

    1. pivot the rear legs so that the edge of the leg and the top corner of the rear kicker line up
    2. glue and screw in place)
  6. connect the front legs with cross-members

    1. attach one 82" cross-member across the top of the each of the set of blocks attached to the front legs, glue and glue and screw into the block
      The bottom of the cross-member will be even with the top of the kicker

    *IMPORTANT: make sure the cross-members doe not slip and extend forward of the front leg, with the kicker sticking forward of the leg the front leg is up off the ground

  7. Optional, not compatible with minimal frame connect the verticals to the cross-members

    1. use the 28" diagonal brace pieces as spacers to position the verticals in from the blocks (exact position is not critical)
    2. glue and screw
      NOTE: this is fastening into the end grain of the verticals, which is very weak, but these do not have much force against them (they just support the workpiece/waste-board) so we can get away with this.
      Optionally cut 4 more blocks and use them in the corners.

  8. square the frame
    OPTION cut the corners off of the crossmembers so that they do not stick out beyond the boards they attach to

    If you are using both crossmembers:

    1. use a string or tape measure (requires an assistant), check that the diagonal distances between the corners of the cross-members are the same. If they are not, rack the frame until they match (push on the corners with the longest distance to distort the shape)
    2. glue/screw the 16" diagonal braces across the back of the frame, attaching the legs to the lower crossmember
    3. glue/screw the 28" diagonal braces across the back of the frame, attaching the legs to the upper crossmember


      If you only have one crossmember
    4. use a square to align the legs square to the crossmember
    5. glue/screw the 16" diagonals across the back of the frame, attaching the legs to the crossmember

  9. Optional connect the rear leg crossmember

    1. connect the 88" rear crossmember to the rear legs so that the ends of the crossmember are flush to the outside of the legs and the crossmember is resting against the kickers
  10. prepare the top beam

    • if using the unistrut mounting (depth adjustment option)

      1. place the 6" unistrut pieces on top of the front legs, flush with the top of the leg
      2. place the top beam centered across the unistrut pieces, flush with the top of the leg
      3. mark the sides of the unistrut on the bottom of the top beam
      4. flip the top beam and attach the unistrut to the top beam at the marks, with the end of the unistrut flush with the front of the beam.
      5. place the spring nuts inside the unistrut
      6. attach the metal angles to the unistrut
    • if using wood supports for the top beam

      1. clamp the 10" top beam supports with the non-factory end flush to the top of the legs on the outside of the front legs
      2. center the top beam over the end of the top beam supports
      3. drill through the top beam for bolts to the supports
      4. drill pilot holes in the supports if you are using lag bolts
      5. remove the top beam and unclamp the top beam supports
  11. stand up the frame

  12. attach the top beam

    • if using unistrut
      1. position the top beam and unistrut assembly on the top of the legs
      2. drive lag screws through the angle into the legs to anchor the beam in place
    • if using wood supports
      1. square up the 10" top beam arms against the top of the legs.
      2. glue and screw in place
      3. attach the top beam flush with the front of the top beam arms.

    IMPORTANT: This is the second place in the build where the angles and distances are critical. Make sure that the arms are as square to the front legs as you can make them, and that the edges (top AND back) are flush.


New * Basic * frame design
#795

@bar, please install the top blocks, but then build the minimal frame up through standing everything up (without gluing the diagonal braces)

then go back and remove the diagonal braces and go back to step 6 and add the upper crossmember (don’t bother with the verticalsor the rear crossmember), and proceed adding all the cross members, again though standing everything up.

I think the added rigidity is worth the extra piece of lumber, but if you really think it’s not, and it’s a lot of extra work, we can make it the ‘extra stiff’ option. even with the two diagonals, I think it’s going to be wobbly when trying to set up the top beam


#796

a good place to get bolts (US and metric) is https://www.boltdepot.com they ship things out the next day and use US priority mail (typically 3 day delivery) which allows up to 70 pounds/package, so shipping is pretty cheap.

the bracket used for the adjustable ones are $4-6 each in quantity (search for p2484 on google to find a bunch of links). This is the same one shown in the unistrut build yesterday, the unistrut is $3/6" piece from home depot, so I’m sure you can find it cheaper elsewhere (at home depot it’s under plumbing accessories, pipe hangers)


#797

Is Figure 14 the correct drawing? It appears to show unistrut arms with a vertical wooden top beam and not wooden arms with a horizontal top beam.

Also, if having the top beam horizontal is not a good idea and the only reason we are doing so is to avoid the solution of drilling all the way through the edge of a 2x4, aren’t there other solutions that would work well enough? There’s not a lot of forces acting on this joint… basically, it takes a small share of the weight of the beam, sled, motors, chain, etc. because the arm is tilted at 15-degrees. The only thing it really needs to do is to keep the top beam from sliding off the arm. Why not just put in another block of wood like we do with the other members.

Edit: if you do the change to the cutlist detailed in next post, you have enough room on 2x4x10 #7 to create two 5.5-inch blocks. All it takes is one additional cut since you will be left with an 11-inch piece of wood. Those two blocks and some screws and Bob’s your uncle.

Pardon the crude drawing…


#798

Step 6:

Which one is optional? The top? Need to indicate which one in the instructions. Also, if one of the crossmembers is optional, then a set of the blocks should also be optional, correct? If so, should move a set from 2x4x10 #7 on the cut list up to #3 on the cutlist (if you follow).

Step 7:

These are now 28-inches.


#799

The concern with using a block is how to make sure the top beam doesn’t get angled.


#800

If the block is at a right angle, then the top beam is at a right angle. Is the concern that you can’t get the block at a right angle?


#801

I’m going to hold off on this until @bar builds the frame and see if we really need to have the version without the top crossmember. I’m hoping that the result is just floppy enough to be worth using the extra board and not have to list it as an option :slight_smile:

fixed, thanks for reviewing things


#802

For me, it’s more that if it’s only anchored at the back, there may end up being a gap at the front. in your first drawing a few posts ago, there’s nothing pulling the top beam down against the support, it’s all strictly being pulled against the block in the back, and a gap can open in the front. If you were to make this joint with gorilla glue, the expansion of the glue would tend to tilt the top beam.

pulling down against the support doesn’t have this problem, the clamping force of the fasteners pulls the two factory surfaces against each other.