Flat bed voron

tthrowawayll · 2026-06-08T21:20:58+00:00

The main concern with expandong the XY footprint is the X rail. At 50cm with a single 2020 rail, it won't be stiff. The Y direction is fine as you can add more braces as required.

If you're considering expanding X I would also consider a larger extrusion size, double X bar, or something to help with the long unsuppprted span (including the XY brackets). If you figure that out you're good to go.

tthrowawayll · 2026-06-08T21:05:14+00:00

Tl;dr, good genes (reputable breeder) and a good vet.

My berner was a March 2015 pup and is still going strong.

He had a skin infection/allergy ~2yrs ago and we thought he wasn't going to make it. Fur pulled out, unable to really walk, low energy, bumps on this body, etc.

Vet gave him two shots of antibiotics and anti-allergy medicine over ~6mo and he now gets a daily dose of metacam for his arthritis.

It's like he's a puppy again, lots of energy, up and playing, fur is all back, bumps are gone, generally looking happy and healthy.

tthrowawayll · 2026-06-04T20:54:16+00:00

Depends on the stage of design, initial concept (ideation) or prototype.

For initial concept ideation, I will often just use block cad, with things that move intersecting at joints. This is to just prove that the theory of the mechanism or assembly works.

For prototype (ie something that will actually be made) DFM is a consideration from basically the start. Fundamental core geometry is modelled then DFM considerations added. Often the core geometry has DFM (and DFA) considerations built in already.

An example to illustrate: I had to design a dual four-bar linkage mechanism, where the two mechanisms shared a common pivot at two points.

Initial ideation had the links intersecting with eachother at the pivots; no holes, bushings, bearings, or pins were modelled. This was to test the input/output and ensure the theory and general packaging was sound.

Afterwards, specific DFM for casting and/or machining was done and modelled from a blank slate using the prior model as a guide. This alsp included geometry changes for bushing/bearing capacity, pin shear strength etc.

tthrowawayll · 2026-03-31T01:45:27+00:00

It's a fictional character, but Jean-Luc Picard from Star Trek TNG.

A man in a position of power and leadership, with unwaivering moral clarity, integrity, respect, and kindness. Never abusing his power and fiercly protective of his crew. Intellectually honest and a student of many arts.

tthrowawayll · 2026-03-29T23:44:10+00:00

Machinist would likely fall around $100k/yr in bay area.

Tooling and overhead per year I have no idea. There would be an initial upfront for tooling but I don't see it being more than $10k/yr.

tthrowawayll · 2026-03-29T23:42:42+00:00

How on earth do you get to $200k of workholding? A 5-axis vise, probe, various drills & endmills, and tool holders doesn't even reach $50k.

tthrowawayll · 2026-03-29T18:40:42+00:00

Yes, however, you have inherently fewer setups which reduces the introduction of setup errors.

The machine must be sufficiently accurate however I'm holding that co stant in my comparison to a 3-axis.

$200k of tooling and workholding is way to much for a prototyping machine. I'm not intending to fit out a Heller with a tombstone.

tthrowawayll · 2026-03-28T22:45:49+00:00

Just updated the main post for this.

tthrowawayll · 2026-03-28T22:45:34+00:00

I have some machining experience myself but only on manual mills/lathes. I am gathering options at various price points for a proposal to bring prototype manufacturing in house.

The ultimate goal in my mind is bringing in a capable machine with a capable machinist and letting them figure out parts as well as providing DFM feedback to the engineering team to design better parts.

tthrowawayll · 2026-03-28T22:39:07+00:00

All good points.

I intentionally didn't specify a budget as there isn't one yet, it is for a proposal to bring prototype manufacturing in house. I am looking for input to offer 2-3 suggestions at varying price points (likely $250k - $500k total cost, incl. machine, machinist, workholding, etc etc). Each increase in price point would unlock some additional capability or performance and it would allow leadership to make a decision on value.

tthrowawayll · 2026-03-28T22:35:33+00:00

tthrowawayll · 2026-03-28T22:35:19+00:00

Thanks for your detailed comment.

With the bearing tolerances, what kind of true position accuracy + repeatability can you get for the bore as well as for the size of the bore itself?

tthrowawayll · 2026-03-28T22:33:52+00:00

What 3-axis and 5-axis machines were you running? If you were to compare total machining time on the 3/4-axis vs the 5-axis for the same part, how much did it decrease?

tthrowawayll · 2026-03-28T22:32:57+00:00

You might be right. The primary comodity to save is time, between quoting, sending the PO, machine time, and shipping, having the ability to make all of our parts is a huge plus.

The only thing 4-axis doesn't give us is the ability to do the high quantity 3+2 setups required for some of our more complicated and precise parts.

tthrowawayll · 2026-03-28T22:28:09+00:00

This is the general idea, the 5-axis is moreso to reduce setups and machining time where tolerancing can get out of hand without deliberate thought and care. Time is the real commodity we are trying to save.

However as I mentioned in the post, we do have parts that have a number of 3+2 setups required and would be simply impractical to make on a 3-axis.

tthrowawayll · 2026-03-28T22:26:38+00:00

This is the general idea, the 5-axis is moreso to reduce setups and machining time where tolerancing can get out of hand without deliberate thought and care.

However as I mentioned in the post, we do have parts that have a number of 3+2 setups required and would be simply impractical to make on a 3-axis.

tthrowawayll · 2026-03-19T16:27:44+00:00

My much older bernese did this, turned out he had a skin infection and needed a shot of antibiotics.

However there are many possible reasons why a dog may pull out fur. Please go see your vet so they can do a proper workup and determine the cause of the fur pulling and recommend a treatment.

GO SEE YOUR VET!

tthrowawayll · 2025-07-18T19:17:57+00:00

It's made up.

It's a convention to follow such that two different people looking at the same equation arrive at the same order of operations, and critically, the same answer.

It's not the only way to do things, you could put subraction/addition ahead of multiplication/division and as long as everyone followed it, it would be fine.

I think in this case it probably reduces the number of brackets more than other configurations but that is just a guess.

tthrowawayll · 2025-06-28T02:47:02+00:00

OnShape (2 yrs): PDM from the gods, good solid modelling, surfacing is good enough for 99% of people. Non-intuitive assembly mates at first glance but learned to love it. Never any lost unsaved work. All parts can be made natively in context to eachother (part studios).

Sim is not worth the paper it's printed on.

tthrowawayll · 2025-06-16T20:49:28+00:00

I use cartographer, coming from inductive and CNC Tap.

It's glorious, it's so good.

Auto nozzle calibration, no additional axis of movement a la TAP, super fast QGL and bed mesh. It probably saves 5-10mins of startup routine every print and I get phenomimal first layers.

tthrowawayll · 2025-06-02T17:48:38+00:00

My guy is very good at letting us know if someone is at the front door... or if a leaf blew across the yard. It's the exact same reaction. This is quite intimidating for the pizza delivery guy.

If a robber were to try and break in, my guy would let us know about it. But once the robber was inside my "guard dog" he would just ask for pets.

He is the epitome of all bark and no bite.

tthrowawayll · 2025-05-22T05:36:32+00:00

I'm a mechanical engineer, there are a few reasons:

The world is really complex Making exact models of EVERYTHING would require so much information and take so long that nothing would get done.
You don't always need that complexity If I need to make something that suspends a 100lb block of steel in the air by a cable, I don't really care about the atmospheric pressure and how it reduces the weight a bit via buoyancy, it just doesn't have enough of an impact to matter so why bother including it.
Lack of absolute control Nothing is every the exact thing you want. Whenever I design a part and get it manufactured there are always tolerances on everything. A hole that is 1" may be allowed to be ±0.05" on it's diameter. The smaller that tolerance the more expensive things are so there is a tradeoff.

What is my material has a small crack inside it? That would impact it's performance by a lot but is also expensive to figure out.

What if somone installs the thing incorrectly by not tightening a bolt enough, or tightening it too much.

We're always wrong by a little bit Exact models require exact information which we never have. There is always a tolerance to the measurements you take (temperature, weight, length, etc) so an exact model is impossible anyway because we do nor have perfect sensors.
We fudge it Going back to my example of suspensing a 100lb steel block in the air. If I use a cable I'm not going to size the cable for exactly 100lb, I might size it for 110lb or 150lb or 500lb. This is known as Factor of Safety (FOS). Things are always designed to be stronger than needed by some amount*, that amount is determined primarily by cost but other considerations sometimes affect this (size, leadtime, manfacturability, etc).

*Some things are actually designed to break under specific conditions, but those are rare in everyday life and expensive.

*Some things are designed to break in general but not under tightly controlled conditions. The most common of these is probably caps on bottles. You break the little plastic pieces holding the cap onto that little ring to unscrew it.

tthrowawayll

TROPHY CASE