🌞 New Stock Frame Design 🌞

I am not sure if @bar has some more updates to go, but reading through the latest wiki page https://github.com/MaslowCNC/Mechanics/wiki/The-Default-Frame-Assembly-Guide , I had some comments/questions.

Firstly it says that it requires 2 sheets of 3/4" plywood, but I only see one being used, and the other one it says that it is not structural and just a waste board, so maybe neither should be listed as required.

Also I wonder if step 9 shouldn’t be moved up so that it is easier to line that up to 90 degrees before it is attached the the angled legs.

Just getting ready to build my frame as my kit is shipping soon.

Thanks.

2 Likes

you are attaching the beams on one side and the real legs on the other side, so
one is in the way of the other no matter what.

My original instructions had the machine standing up before doing these top beam
supports.

If you do them before you do the rear legs, you either have them in the way
when you do the crossmembers (as opposed to having everything one 2x4 off the
ground laying flat), or you have to delay attaching the rear legs until the rest
of the frame is together (which doesn’t seem like an unreasonable choice, but it
does mean you are doing the rear legs with the rest of the machine assembed
instead of when it’s just the legs)

Are the most current models for the default frame available somewhere? The most recent change in the image (mainpicture.jpg) are 6 days old but none of the models are that recent. In addition the link at the bottom goes to the Bolt Together Frame.

I have not created a model showing bar’s modifications, but it’s pretty close to
the last model I made.
k

1 Like

I have a quick question. For the default frame, the “beam” is shown as being 8" long. This length defines how far the chains are offset from the surface (plus 1.5" from the top beam). When I line everything up, that seems to be too far. When I line up the chains such that they are parallel to the worksurface, I get something more like 6 to 6.5". Could someone provide some information on whether or not 8" is correct?

Thanks

Great question!

8" is correct, but keep in mind that you loose 3.5 inches to the post the beam attaches to, but then gain back 1.5 where the top beam attaches like this:

image

So the 8" length really gives 6" just like you guessed :grin:

3 Likes

I did some calculations to understand how far off the sled the ring should be mounted. I wanted to understand how far off the surface of the sled I should set the ring. I added all the distances spacing the chain out, and subtracted all the distances that space the sled out. I think I accounted for everything.

When I do the math, it looks like this:
8" length of “beam”
+ 1.5" width of 2x4 top beam
+ 0.5" distance from front surface of top beam to sprocket center
- 3.5 depth of vertical top beam
- 0.75" thickness of frame plywood
- 0.25" thickness of sacrificial plywood
- 0.75" thickness of plywood being cut
- 0.75" thickness of sled base
= 4" distance from surface of sled base to ring surface

This distance was too much for my ring system; it was extended all the way out. When hanging, the sled wanted to rotate forward.

I have a quick question. For the default frame, the “beam” is shown as being
8" long. This length defines how far the chains are offset from the surface
(plus 1.5" from the top beam). When I line everything up, that seems to be
too far. When I line up the chains such that they are parallel to the
worksurface, I get something more like 6 to 6.5". Could someone provide some
information on whether or not 8" is correct?

when you suspend your sled in the air by the chains, does it hang straight or
does it tilt forward or backwards?

I suspect that you are going to find that it tilts backwards (towards the
router) and that you should raise the ring from the sled a couple inches (which
will put you at about the right distance)

1 Like

I adjusted the height of the ring, off the sled base, such that it hangs parallel to the work surface. This is about 12.5 degrees from vertical. When I did this, the ring was closer to the sled than the calculated 4". The calculated 4" was what made the chains parallel to the work surface.

3 Likes

I would like to re-visit the topic of the “beam” length. I think it is something that is off, and is somewhat foundational to the frame design.

When I build the frame in the default configuration with an 8" “beam”, it appears to be too long. I have cut mine shorter, and it looks better. I did some math (previous post) that shows that an 8" beam required the ring to be set 4" off the surface of the sled. This math included the 3.5" 2x4, as well as the other things that affect this length. The 4" offset was too large in my sled.

For anyone who reads this, and is using an 8" top beam, I have two questions:
1) How far is from the surface of the sled is the ring? (Mine is about 2")
2) When viewed from the side, do the chains appear to be parallel to the working
surface?

The 8" piece doesn’t have to be attached with its end aligned to the edge of the post, that’s just a convenient landmark. I like that it offers adjustment.

1 Like

Is that in the instructions? In the photos, it is shown as being aligned. Once the glue dries, it is pretty much set in place.

When I was working on the “new stock frame design”, I had always seen the top beam resting on the arms. I just looked at the design in the instructions and it shows it mounted into the arms (through the beam). If the length of arm is the same, then it would be about 1.5-inches too long

Edit: @dlang had those pieces originally 10-inches long… so maybe @bar accounted for it.

No, you’re right, the instructions glue it down. As you can tell, I “don’t take instruction well”. :grin:

Can you post a picture from the side of your maslow that shows the alignment of the sprocket and the sled. What did you cut the beams to in order to make it look better (as you say)?

I can. I will try to remember. I cut the beams to 6".

You might consider leaving the 6" beams glued in place as support/alignment blocks for longer beams attached to the horizontal top beam. That setup would have the adjustability I mentioned along with the firm support of the glued blocks. It would add 3.5" to the motor height above the workarea, though, so use a bit more of the chain.

1 Like

I like the idea. However, it is very close to being functional, and I would like to get it fully functional, so that will have to wait.

1 Like

what I would suggest that you do is get a pair of 2484 unistrut angles, attach
them to the front of each of the legs, and then have a piece of unistrut (could
be as short as 6", or up to a foot or so) that is open-side down over the angles
and the top of the legs (you can shorten the legs by ~5" when doing this)

bolt the top beam to the top of the unistrut.

it’s now easily adjustable and very strong.

This was deemed ‘too complicated’ for the stock frame, but is a good idea if you
want to be able to handle extra thin or extra thick stock well.

1 Like

Good idea! I would like to do this at some point.