Parallel sawing with the Z-saw guides

A follow up to discussing the Z-saw guide. This time I'm doing parallel cuts.

Here I needed to saw 6mm MDF and I expected it to be quite easy. It was not entirely without difficulties. I picked the smaller Z-saw guide and the mini 175 saw.

After the cut.

Using similar-sized 450x800 MDF boards on top of another, I could make a fence for moving the guide smoothly and check the 90-degree by aligning the top board as close as possible. This works only if the boards have been cut accurately enough in the factory!

However, my first cut didn't really succeed. From the ends, the piece has the correct measure, but something happened near the middle, resulting in a long curve, deviating about half a millimeter.

I had a few ideas of why it happened. The third one is the important one.

Firstly, I may have pulled the guide against the fence with too much force. After all, the fence was only clamped from the ends. This couldn't really happen inwards, but perhaps vertically, just enough to disturb the guide.

Secondly, sawing ahead of the guide can result the blade veering just a little bit, and from that moment on the board itself can force the saw into misalignment that's neither easy to see or correct. If everything else is right, speed in itself shouldn't matter all that much.

Left: wrong. Right: right.

Thirdly, and most importantly, I sawed with a too steep angle. Using a lower angle should create more surface between the saw and the guide. This also makes the cut in the board act as a better guide. The saw point where the "decision" is made is closer to the guide midpoint.

For the later cuts, I tried to keep the angle low, adopted a routine for moving the guide, sawing as much as by ear as by eye. I tried to hold the guide in place, only pulling it gently and checking it is firmly against the fence.

It is important to have a good, comfortable position from where you can also see the saw alignment. The blade shouldn't bend at all against the guide.

The later cuts were about as perfect as I could hope for.

Measure and mark, use the dummy plane, dummy.

Repeats, as I've already observed, are not very simple to do with these guides.

Ideally, there would be a jig for making similar cuts without measuring each piece separately. But for that I'd have to build a rather large jig.

Fortunately I think it is enough for most cases to do an accurate marking and measurement, and use the dummy blade to simulate the cut. You have to choose how the dummy is placed in relation to the marked lines, and be consistent with this choice.

Errors might compound if pieces are sawed off from the same board, and the new measure is each time marked from the previous cut. The pieces could end up correct width but no longer precisely rectangular. This compounding should not happen if the fence can enforce the 90 degree angle for each cut.

Drawing all lines for all cuts beforehand isn't viable, as the blade thickness is difficult to factor in.

With these techniques I began to make a 38x220x89mm box using MDF slices from 800x450 boards I ordered. (The box is intended to fit a 19 inch standard rack, taking two rack units.)

Spot the mistake

The plan for sawing the material was made in Librecad. This doesn't take into account the saw thickness, so it is just an approximation of whether the material is enough for a box.

After the shaky start described above, the rest of the wall pieces were accurate.

I glued the box together using four Wolfcraft (that brand again) corner clamps and two Cocraft clamps. As the wood glue doesn't dry instantly, there's some time to adjust the corners. Much like with artists' oil paints, the slow drying is a feature, not a bug.

The corner clamps are more for keeping the pieces up and do not itself produce an accurate position.

Corner clamped

Although the Cocraft clamps only give a gentle pressure, without them the box would fall apart.

The bottom was then glued and held together with six small clamps.

I was initially well pleased with the box. But, considering the box was intended to fit a rack mount, I had made a crucial mistake.

For some reason what was meant to be the outer dimension (438) had become the inner dimension and the box ended up being 450mm wide instead of 438. This mistake was made early and I had ordered the MDF material already in wrong size.

Corner clamped and glued

What's even more unfortunate is that I'd already added reinforcing pieces to the inner corners of the box.

I pondered if I should simply build another box, but I couldn't foresee any use for the wrong sized one. The Z-saw guide and the saw came to the rescue. I cut away the ends from side and yanked them off using a clamp as leverage. Then I cut 3mm MDF to size and glued them to the ends.

The end result is not 438mm, and not as clean as the original box, but at least I can continue prototyping. Some day.

Zoo 2024

Pit Stop

A weekend was well spent at the Commodore 64 demoparty Zoo, hosted at Orivesi.

I'll mostly focus on my game release The Last Z-8, and avoid doing a separate post about it.

Ok, at least something about the demoparty. We took the partybus from Helsinki, which turned out to be 1-2 hours late! It was alternatively amusing and not-so-amusing in the cold, grey sleet of Helsinki.

Elite

In the warmth of the bus it was already fun to reflect on, but the gods of Murphy do not look so kindly on such frivolity, so a tire fell of from the bus before it even got out of Helsinki.

Fortunately a replacement bus arrived promptly and eventually, finally, we got to the party place.

Lopussa kiitos seizoo

What can I say? The concept was largely the same as 2022. The lobby greets visitors with Reprocade arcades and an exhibition of pixel art. The main hall and a second hall are filled with tables for computers and the audience.

The program was filled with compos, talks, music acts and other party features.

Pixeled Years

The pixel art exhibition was the Pixeled Years on tour, with one piece from yours truly too.

With the Party Feature, the "computer fair" elements could compete too, for example AK rigged a C64 to work with a high-end car simulator gear courtesy of Simucube, SIDrock had a matrix printer digitized image service, and so on. Also the usual market of C64 extensions, parts, magazines, stickers and games.

Stunt Car Racer

The crowd did feel a little more international than before, perhaps an indication of how party has grown from the 2013 days, becoming a more credible outlet for big name C64 demo releases.

The number of productions was quite staggering. (Demozoo link)

The Main Hall

I'm no longer very surprised by all the graphic talent, but I have to admit Worrior1's Binary Saint is a grand piece of PETSCII and Sarge "did it again" and maybe exceeded himself with SLOBBER. 

According to the slides, Multipaint still had a strong presence among the pixeling tools, but Albert is becoming more and more popular I think.

All the Young PETSCII

As my attention had been on creating a game, I could only patch together one PETSCII at the party place, All the Young PETSCII. Given the circumstances I'm strangely pleased with it. Maybe I managed to come slightly outside of my usual style. It landed on the respectable 8 out of 21 position in the compo.

I went all in and submitted a Nick Montfort-inspired Illegal, a 10 PRINT poem, an attempt at teasing something out from the BASIC ROM area where the error messages are contained. Obviously it's not a thing to win any prizes, but it was interesting to try.

Illegal, a 10 PRINT poem

From the main demo event I can't highlight a particular all-round favorite, it looked like one demo excelled in one area whereas some other might exceed in another. Possibly Artline Designs really deserved the win with their coherent Nightfall package. Stereo by Phonics was memorable in using some more unconventional cuts, and the A-side/B-side concept was brought to full fruition with music taking the center stage. Pretzel Logic's Papel is an example of showcasing huge amount of creative talent, but it was perhaps tad too long at that time and hour. Yes, the democompo ended about 3AM, with Extend's demo failing to properly load.

The Last Z-8

For the game dev compo I made The Last Z-8. (csdb link) This took about one month to create, using reasonable time on evenings and weekends, and a couple of crunch sessions near the end.

My workflows and pipelines are rather well established, and I took a relaxed attitude. For once I did not dedicate a whole lot of effort on laboring some technical point. Just sprites, PETSCII graphics as background, no multiplexing, single raster interrupt, some Goattracker tunes and effects.

I also refrained from creating any specific tools, instead using Spritemate and/or editing sprites directly in the source code for the graphics.

Intro Screen

For The Last Z-8, I mixed and mashed various games, but ultimately what it looks like is a Ghostbusters-remake, which is misleading as it's actually not very similar. 

But especially it has nearly nothing to do with The Last V-8, as I decided on the name rather late in the process.

You are first confronted with the post-apocalyptic city map, from where the other game parts are then accessed.

The City map

The car driving sequence is a Moon Patrol-style minigame paying homage to the Parker Brothers' James Bond game, and some elements may be more reminiscent of Ocean's Miami Vice.

In fact, the game started growing from trying to make some kind of send-up of that Bond game.

In contrast to Ghostbusters, you need to avoid the ghosts even in the parts where you'd be vacuuming them in the original game. Instead of trying to keep the "city energy" level low, you are encouraged to maxx it as soon as possible. There's no money and no business and no shop.

Driving to the location

All in all I tried to combine elements from as many games as possible. At beginning, the ambition was larger and I intended to have more silly minigames, but the end result only has two distinct sequences apart from the repeated map/driving/trapping screens.

The map screen has a very minimal effect on how the game plays. You may lose just a slightly more zonk energy if you choose a less optimal route.

Trapping them ghosties

Though I feel releases should be fire-and-forget, I may still want to return to this and tinker the game balance and other aspects. There's still memory left a-plenty. But no promise, really.

The games could be pre-released to the audiences already before the party. After I saw herra47 from Jani Parviainen (link) and Aquarius from Aleksi Eeben (link), I knew one of these would win and my work would place third at best. Which it did!

A detail: my game had a small Leisuresuit Larry -tribute in place, but seeing that Jani was making an entire Larry-based game, I removed it. But the reason the guy sprite is as tall as it is, is kind of because of that Larry reference!

The video could have been better edited, showing more of the game content (there is more) but I sort of doubted it would help, so I just let it show the first few minutes of the repetitive gameplay.

I also participated in the panel discussion led by Mikko Heinonen of Skrolli and V2 "let's play" videos fame, joining with industry veteran Miha Rinne and all-round clever guy Aleksi Eeben. Perhaps there were no huge surprises to the audience, but at least fun was had by the panelists. The enthusiasm tends to be infectious, and suddenly you can see the productions are important to the authors, unlike the typical Finnish "I just did this blah blah nerd thing and it was really nothing".

More Zoo next year!