Question about: Extended Length Base (y-axis) for V2 Handibots

I just read the new blog update and noticed that the Extended Length Base (y-axis) for V2 Handibots has a Handibot Store targeted release date of 12/2016.

Can we get a description of this new accessory?

Will this be available on new orders for the V2 Handibot or will this only be available as an upgrade to the V2?

I'm thinking of placing an order for the new V2 Handibot but if I can get one with the Extended Length Base, I might wait a little longer before placing an order.

The handibot will still be sold in its standard 8" length. The V2 was designed to make it easier to remove the base and Y motor just for that purpose. We're going to start out with a 24" long handibot that will give you the ability to cut up a 2' x 4' piece of plywood with a lot less tiling effort than is currently required with the large material jig (8 tiles versus 24 tiles).
I'm designing the 24" base right now with some built in fixturing that will make it easy to slide the handibot frame off of the 8" base and onto the 24" base when you want to use the long version.
The motor for the 24" Y will attach right into the current Y motor position...but it will be a unique kind of motor with an internal threaded nut--so the motor spins the nut rather than spinning the lead screw. This prevents the "spear" effect when a long motor is being used. It also means that the same motor could be used for multiple lengths of base--just with a lead screw cut to a longer length. I'm working with our motor vendor to get the backlash down on this motor (currently there's about 0.003-0.005" backlash because the split internal nut is not preloaded adequately).
So to answer your question, people who already own handibots or are about to purchase them will have the same tool as what will be sold after the 24" base is released. They're meant to be interchangeable depending on what you're working on.

Here are a few videos of some earlier prototypes of this long handibot:
first try, a quick sketch on a friday using a regular motor (the spear effect is the problem): [www.youtube.com]
second try that I made for cutting some trail signs...too many machined parts would have cost a fortune: [www.youtube.com]
48" long tool...was too flimsy when it was only supported on the ends: [www.youtube.com]
24" tool with a plywood vacuum table and rack and pinion positioning, the end opposite the drive side would lag behind making horrible backlash...decided that the tool needed to lock on both sides after getting into position: [www.youtube.com]

I decided that it would be good to offer a manual positioning version (which is how I use my tool most of the time) and a motorized version (a re-imagined "crawler") and that the manual version should be upgradable to the motorized version without having to replace any parts, just the addition of a motor and some wire. So that's where I stand at the moment; almost done with another iteration. Hoping to eschew distractions this week and get it built.

Thanks for the update, Brian.

I hadn't seen those videos.

Those are some nice ideas. Glad to see this accessory offered.

Gil

Always thrilled to see anything you guys are working on.

Even without an X sled, a long Y, and some imagination could go a long long way.

That's true Mark...glad to know its not just me who finds that his "big" parts are usually just long. I've made a number of things on long handibots with no tiling at all.

Wow!

Can't wait to get that guy.

Testing out a new design today. This one is built on top of off the shelf extrusion with all custom parts made from HDPE (this should bring the cost down and also make the design flexible if we want to offer it in multiple lengths...12, 16, 24, etc...)
I don't have the right length rails yet so it still has limited travel, but I'm testing out the manual style tiling by cutting all accessory parts for orders this week on the new handibot.

[www.youtube.com]

Brian Owen, ShopBot Wrote:
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> Testing out a new design today. This one is built
> on top of off the shelf extrusion with all custom
> parts made from HDPE (this should bring the cost
> down and also make the design flexible if we want
> to offer it in multiple lengths...12, 16, 24,
> etc...)
> I don't have the right length rails yet so it
> still has limited travel, but I'm testing out the
> manual style tiling by cutting all accessory parts
> for orders this week on the new handibot.
>
> [www.youtube.com]

And here is a little video of me watching your little video.

[www.youtube.com]

What kind of time are we looking at to swap from standard base to extended base?

thanx

Nice idea.

Is there a way for this new sled to index in the X? Looks like you aren't worried about indexing at all in this video.

Mark,

There are only 2 screws that need to be removed in order to take the stop off the back and slide the handibot frame off of its base. Then four screws to remove the Y motor...the trick is going to be finding a way to make the motor removable without too much headache. I feel like I want to put a plug-able connector on the Y axis cable and just let the motor switch be a matter of unplugging the old motor and plugging in the new...it's going to be tricky to make balance making it easy to switch back and forth and not making it too much of a pain to set up the first time.
Sliding the frame onto the extended base is easy because I've machined little plastic guides that you just set the bearings on...then you push forward and the tool just slides onto the new rails.
I'd like it to be just a couple of minutes to make the change over.

RS,

Ted and I have gone back and forth about how to achieve the indexing. It's looking like we're going to go with grippy drive wheels that support the tool above the material, and are driven by a fourth axis motor. In the video, you can see the fourth motor far off to the right on the new frame. I want to make the design generic so that it can be purchased without paying for the motor and wheel system if someone wants to save some money or doesn't need it...but that it will be easy to add in later without replacing a bunch of parts if they change their mind. So in the manual indexing version there would still be a place for that motor.

Brian

These look great.

Grippy wheels would be nice - I can imagine putting it on a pair of U-channel grooves and driving it in the X-direction or just running it along a piece of plywood for cutouts - similar to how I would use my tracksaw.

Still shooting for a December release to the store?

RS,

Yes! Still trying for a december release...LATE december. I just finished another prototype of it last night--trying to address what some people had commented on here about the need for a better way to manually index. It'll be easier to show in video than to explain...so I'll try to get something up by the end of the week.

This thread plus the one about cutting on a 4 x 8 sheet with the large material jig really makes me want to design this thing as an improved large material jig at its most basic level--a slightly more sophisticated, accurate way to move your handibot around a large sheet. To that you could add rails and a long motor for the extended Y and then go further and add a 4th motor to drive the tool up and down the board.

I think that what we will have this month is the base model--plus the long motor/rail upgrade. We're exploring ways to give position feedback to the fully motorized version, hoping to make it very reliable.

Brian

Hi Brian,

I must say that I'm very excited for this new version of the Handibot with extended Y and the future ability to automatically extend the X. In the version that would be automated, do you still imagine things would be tiled? Or would you be able to do cuts that covered the full range of motion in both X and Y?

I ask because I recently finished my first, large scale project the Handibot: a Paulk workbench. (If you're not familiar with this bench, check it out here: [www.paulkhomes.com]. By the way, I freely admit that using the Handibot in nearly every step is not necesssarily the most efficient way to build the workbench, but I wanted to practice for other, upcoming, large scale projects.) While building the workbench, I ran into challenges indexing in X that I would best describe as "stair-stepping". I did figure out that I was slight misaligned on the base, but even after squaring it several times, I never got it perfect. Thus, in cuts that extended over a number of tiles, the intersecting edges were off by 1/16" or so and had to be sanded out. Is there something in the newer Handibot versions that makes this less likely or is it something to consider for this new version?

By the way, I've been meaning to write up a newbie/"lessons learned" post about building the bench so that others can learn from my mistakes. I'll try to do that in the next week or two.

Best,

Eric

Eric,

The automatically indexing handibot would still do its work in tiles. The idea behind the longer handibot is to use an inexpensive, lower quality drive system for the gross movements (it would be good enough even if it only had a 1" resolution!) and then to use the much more precise, lead screw drive for actual cutting. The problem that we often face is that something like rack and pinion is the only practical way to get axes longer than 3 or 4 feet--but you give up precision to the backlash in rack and pinion systems. By doing the cut in sections, we hope to be able to create very accurate, low backlash cuts over an unlimited length of material. The handibot would use its fourth motor to get into position for the next cut, park itself, then begin the next tile of its job.

The "stair stepping" can be caused by a lot of things, some of which will be automatically corrected by the long style handibot. Using the large material jig, you have to be very careful once you begin to stack the spacers along the wooden rail to get the second and third rows of handibot cuts. If you're skewed even by a fraction of a degree, then you may be off by a tenth of an inch in the x or y axis. This would no longer be a problem because you would only need to do one row of cutting on a tiled job with a 24" handibot (assuming you're cutting things out of 2' x 4'+ sheets).
The other cause of the stair stepping could be a slight lack of parallelism between the X axis and the front edge of the handibot. If x=0 is 0.01" closer to the front edge than x=6 then you will find that the end of one tile and the beginning of the next will always be out of line by 0.01". Handibots are all aligned at the factory but its possible that over time that alignment may need a bit of tweaking. You can do this at home by either taking the Y bearings loose (4 screws each visible from the top) or by removing the rubber base pads and taking the two Y rails loose--you could then bump the handibot around until you're all lined up...this kind of adjustment will be much easier to make with the design of the 24" handibot--everything is much larger scale and its easier to get in to make tweaks.

Still hoping to find time today to get a video made about this newer design...!

Brian

E Furie Wrote:
>
> By the way, I've been meaning to write up a newbie
> /"lessons learned" post about building the bench s
> o that others can learn from my mistakes. I'll try
> to do that in the next week or two.
>

We'd love to see it!

M

Well, obviously the video didn't happen! We decided try to draw in our lead time to make sure anyone who ordered for Christmas got their tool in time--and people have responded by placing a bunch of orders! So now we have more tools to build--in less time! Good problem to have of course...but I'm going to be trying again to get an update out about this!

Alright! Pulled an all-nighter yesterday and got the next version built! For this test cut I just used a tape measure to mark out 6 inch increments on my board--then used the mark on the tool frame to line up each tile. The yellow piece next to that mark on the frame is an idea I'm working on to semi-automate the 6 inch moves between tiles. It's a slide with a 6 inch travel--it's pressed down to grip the material that you're cutting--and you then slide the tool until the slide reaches a pre-set hard stop (set to exactly 6 inches)--then you lock the tool down and start your next tile. It doesn't slide as smoothly as I'd like so I didn't use it today.
When I moved the tool it was riding on those wheels attached to either side. Currently they're set to be rotated manually by twisting a knob on the tool frame--but the eventual idea is to have them motorized (the extra motor next to the Y axis motor).

Anyway--here's the latest! [www.youtube.com]

Glad to hear that more Handibots are getting out there.

Now that you have the latest video up I am a bit giddy. Very nice.

So - in the first 10 seconds of the video - is the machine just hanging off the edge of the plywood or are the wheels supported somehow?

Since the Handibot can't cut the area right in front of the pointer to index - maybe you can do some pilot holes for a drill - similar to a Kreg shelf pin jig. Then you could drill holes at whatever point you want to index and just use a spare 1/4" bit to index the machine to the next hole in the material.

Yes--that is one reason I was less excited about the wheels--they make moving easier and also set up the way that we'll eventually automate the indexing...but they give the tool a really wide stance. At the beginning I'd just grabbed a scrap piece of 3/4" plywood and set the wheels on top of it. There are two clamps on the back of the tool and you really only need to have one engaged to keep the tool square and stable during the cut--so it worked out (while being a little annoying).

And--yes you lose about 0.25" at the front of your material to make room for the little mechanism that sets the tile width...I'm going to re-design it a bit today and maybe its utility will make more sense.

RS Wrote:
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>
Right?

This extended length model is looking better and better. One thing I can't tell from the videos: how big are these versions? And what are they weighing in at? I see in the latest video that there are end handles, but is it getting so big that it's too unwieldy for one person to pick up and move?

The latest one has a Y travel of 24". I've carried it around by myself a few times, taking it out to jobs at a friend's house, and it's more awkward than heavy--I'd guess around 60lb...The front has a rounded surface so that once you have it in your garage you can lift one end and pull it around like a dolly--may need some wheels there as well just so that it can be moved up and down a driveway when you're taking it somewhere.

Thanks, Brian. That's good to know.

Something about your response raised another question for me, though it's not unique to this Handibot. I'm curious though: why is indexing only really supported along one axis? Does it have to do with visibility into the frame? Especially with this new version where the aspect ratio of the cutting area is so much larger than the original, it makes me wonder if you'd want to be able to index (even manually as in the early method with a pointer and a jig) along the 24" axis of you were cutting a single long line to reduce tiles.

Does that make sense? Am I missing something obvious as to why that's not ideal?

Oh no, you're exactly right. As it is now, handibot is indexed in both X and Y when doing a large cut. What often happens is errors stack up when you return to the beginning of your X indexing line each time, and people have seen jagged edges on their indexed parts. 24" seemed like a good compromise to me, allowing the full width of a 2'x4' piece of plywood to be cut during each tile. Reducing the number of tiles required from 24 to 8 and getting rid of the mis-alignment issue when the spacer plates are used in the current large material jig.

This year, I just noticed on the store that almost everyone was buy a large material jig with their handibot--and I thought that might mean that a few people would like a more sophisticated solution to that problem.

How are we making out with the extended length base, do you think it will be for sale soon?

Until Brian can get back here and give us a better estimate I can say that they got a lot of Xmas orders that needed to be got out so I'd guess it has been pushed back at least a month.
Also, I know these guys well enough to say that they won't go out until they are sure it is right no matter what the time table.
I want one yesterday as well but let's try to be patient and let them get it right.

Mark Evans Wrote:
-------------------------------------------------------
> Until Brian can get back here and give us a better
> estimate I can say that they got a lot of Xmas ord
> ers that needed to be got out so I'd guess it has
> been pushed back at least a month.
> Also, I know these guys well enough to say that th
> ey won't go out until they are sure it is right no
> matter what the time table.
> I want one yesterday as well but let's try to be p
> atient and let them get it right.