Cutting foam sheets... with a needle!

[dkj4linux]

You know what's way better than thumbs up on a video or even positive comments - seeing someone actually put the info in a video into practice

Love it David!
...
But things will probably have to change some more since right now there's no way I'd be able to put a nut on the pivot bearing screw as it would interfere with the motor. So trying to rethink the flywheel design a bit more - kind of tricky to keep it printable with what I want to do since I need recesses for the mounting screws on front (so they won't interfere wtih the needle/bearing) and one on the rear so it will fit over the lump on front of the motor and mate up properly. But...got some ideas just need to play around a bit more. Will probably shift the flywheel out another 5-8mm though so will have to move the guide mount as well.

Idea is coming together though.....

Thanks, Jason. I just need to keep practicing now and try not to forget everything I've learned between sessions.

With regard to the flywheel... I've never seen it necessary to put nuts or any captive hardware on the screws going through the body of the flywheel. It's relatively thick and all the holes are sized so that 3mm machine screws thread themselves nicely into the plastic and stay sufficiently put... and I've never had any back out on their own. I've also considered putting a spot of superglue, bubblegum, or somesuch on the threads but laziness has prevailed and it's never happened

-- David

 

[jhitesma]

Thanks, Jason. I just need to keep practicing now and try not to forget everything I've learned between sessions.

I'm just still really struggling with getting mates to work for me. I keep thinking I've got the concepts figured out...but then try to do it and it doesn't work the way I expect it should Just need to watch a few more training videos I guess.

With regard to the flywheel... I've never seen it necessary to put nuts or any captive hardware on the screws going through the body of the flywheel.

Ahh, good to know. For some reason I thought you had one on the screw that mounts the bearing at least. I just worry about the force on that screw with the needle going up and down potentially causing it to vibrate itself loose. Maybe I won't worry about it and see how it goes....Hoping I can get this thing on the printer tonight, but probably won't have time to actually try building it up until tomorrow even if I get it printed tonight.

 

[jhitesma]

Well think I've got it ready to print...but...not in time to get it printed tonight Well, the flywheel is printing right now but that's only a 20 minute print



Designed it to use 4 - 8mm bearings similar to what basscor did on his: https://www.thingiverse.com/thing:2104900

Which works well since the 3 trashed quad motors I have sitting here have 8mm bearings.

I'm just not 100% sure my spacing on the bearings will be optimal. I put them 9mm apart so there should be 1mm between them and last time I measured my needle it was around .9mm IIRC. So should work...but may be a bit tight. Worst case I figure I can try grinding a small groove into the bearings to help clearance/guide the needle between them.

Despite being taller than any cutter I've printed yet the print time is about the same since it's shorter and I eliminated most of the bottom. I could probably eliminate more of the sides still too. And actually already have an idea on an even better way to draw it...but...want to test this first

Then again since I won't be able to print it until tomorrow evening I may end up completely re-drawing it again first

 

[dkj4linux]

Well think I've got it ready to print...but...not in time to get it printed tonight Well, the flywheel is printing right now but that's only a 20 minute print

View attachment 90935

Designed it to use 4 - 8mm bearings similar to what basscor did on his: https://www.thingiverse.com/thing:2104900

Which works well since the 3 trashed quad motors I have sitting here have 8mm bearings.

I'm just not 100% sure my spacing on the bearings will be optimal. I put them 9mm apart so there should be 1mm between them and last time I measured my needle it was around .9mm IIRC. So should work...but may be a bit tight. Worst case I figure I can try grinding a small groove into the bearings to help clearance/guide the needle between them.

Despite being taller than any cutter I've printed yet the print time is about the same since it's shorter and I eliminated most of the bottom. I could probably eliminate more of the sides still too. And actually already have an idea on an even better way to draw it...but...want to test this first

Then again since I won't be able to print it until tomorrow evening I may end up completely re-drawing it again first

I'm really liking the look of that, Jason. Melding the side supports with the bearing-block supports and softening all the edges really looks cool. I'm thinking I should be able to readily adapt it to sideboards already

Also, I'm wondering now if the needle guide might stay cool enough with the near-straight line needle motion that we can do away with the wooden sub-platform. I'm printing my first Onshape-modeled needle cutter and flywheel right now so may try that and see how it holds up.

I can't see enough detail yet... does your flywheel use a prop-saver setup on the backside similar to mine? Also, what motor is your cutter going to use?

I'm still excited about my progress with Onshape... still a lot to learn but, like coding in any "new" language, it's pretty amazing what you can do with a relatively small set of basic commands

UPDATE: I just found your Onshape model and made a copy to play with... I can see all the detail now

 

[jhitesma]

I'm really liking the look of that, Jason. Melding the side supports with the bearing-block supports and softening all the edges really looks cool. I'm thinking I should be able to readily adapt it to sideboards already

Thanks, that's the idea I've had in mind for awhile...but hadn't got around to trying. I'm liking where it's going but have a few ideas on how to make it a bit more aesthetically pleasing...but will try this version first to test functionality.

Also, I'm wondering now if the needle guide might stay cool enough with the near-straight line needle motion that we can do away with the wooden sub-platform. I'm printing my first Onshape-modeled needle cutter and flywheel right now so may try that and see how it holds up.

I'm wondering that as well...though...mine doesn't really get that hot anymore with the oil soaked cotton ball. Even so that was what failed on Saturday night and caused those wandering lines I haven't fully explained yet. The needle guide came loose in the wood. I had just used some soft pine for the wood and made a new piece out of red oak that should hold up a bit better...

But on the new one I'm thinking about going back to the mig tip. The air needle works...but I'd like to use a shorter guide and for no good reason don't want to cut the air needles down that short. Plus I've had at least one come loose where the needle meets the screw part and have had at least one wear through the sides. The mig tip just seems more robust overall so I'm hoping with the bearings to give straight line motion before the guide and the oiled cotton friction/heat will be minimized enough I can go back to the mig tip. For now I'll be keeping the wood...but it has crossed my mind that it might be possible to eliminate it at some point. (and with the rounded front it will be harder to make the piece of wood so being able to eliminate it will be nice.)

I can't see enough detail yet... does your flywheel use a prop-saver setup on the backside similar to mine? Also, what motor is your cutter going to use?

I eliminated the prop-saver mount as the shaft on the motor I'm using is too short for me to trust that style of mount. Plus I wanted to keep the length of the cutter as short as possible and keep the flywheel as close to the motor body as I could to shorten the lever arm and try to minimize force from the needle.

Instead it has 4 2mm threaded holes in the face and I added holes with recesses for screw heads to use those instead. The motor is a "jDrones" with no specs marked on it that was given to me by another forum member who retired it from his 450 sized quad. A did some digging and am pretty sure it's 850kv which should let me run it off 12v and dial in the speed reasonably. With my current higher kv motor running off 12v I hit my target speed at about 2 on the servo tester and don't have much resolution. This motor should put me back in the mid-throttle sweet spot with good resolution on 12v so I don't have to run a second power supply just for the needle.

I'm still excited about my progress with Onshape... still a lot to learn but, like coding in any "new" language, it's pretty amazing what you can do with a relatively small set of basic commands

UPDATE: I just found your Onshape model and made a copy to play with... I can see all the detail now

[/quote]

It took me a few days to get the basic concepts of Onshape down...but once it clicked I'm really loving it. And almost every time I use it I find some new trick. I keep trying to think of new things to draw and design just to give me excuses to learn new things with it since I'm enjoying it so much

I'm still REALLY struggling with mates though...(which is why I didn't add the position bearings in the model) and need to put some time into learning them better. Which is kind of funny since that's the thing that really drew me to a more advanced CAD package in the first place - being able to assemble things and test motion in the computer I can use translate easy enough to position things - but I want to be able to more accurately position them by referencing features on one part to another...mates in other words Just every time I try to use them they don't work like I think I understand they're supposed to.

I didn't share the link yet since this is such an early work in progress and is designed around a specific motor...though it's a common enough motor design that I'm sure there are plenty of others it will work with (it's a standard m3 16mm/19mm mount pattern that most quad motors use.) And I figured that the name on it is obvious enough anyone who was curious would probably be able to find it like you did

But I'm feeling fairly confident in it so here's the link for anyone else who's curious and wants to take a closer look at where I'm going with it: https://cad.onshape.com/documents/0...e09afff0c3dfe212b1/e/0282404df574b68957c362e8

Wish I didn't have to work today...really want to print this thing up and build it! The flywheel came out well last night, Just had to cleanup the center hole a tiny bit (ran an allen key through it to ream it) and it popped on the motor perfectly. I didn't have time to dig out any m2 screws but it's a snug enough fit I'm half tempted to rev it up without screws...though I wouldn't try to cut with it without them.

My big worry is if the guide bearings will work well. I'm already thinking it may be better to use 3 bearings, 2 on one side and 1 in the middle on the other - with the 1 by itself on a slot so it can be adjusted.....hmmm....even so they'll probably need some washers behind them to get them to align well. But I planned on that since they need at least one washer so they'll run smoothly and not rub against the support wall.

 

[Basscor]

Hey Jason,

I'm glad to see you are trying out the bearing idea. I went back to my original model of the block and the spacing is 9mm for the top pair and 8.75mm on the bottom pair. Though I didn't measure the final product to see if that is true.
My thought process was to gradually straighten the path to the tip as best as possible with just 2 sets of bearings. Then I adjusted the block placement to get the needle to ride in the center of the mig tip while unloaded.

Of course that was all while I was using tinkercad. I'm in the process of learning Fusion360 so I'm interested in seeing how your all in one cutter works out.

I'm just super stoked that I contributed an idea that is now being integrated and adapted!

 

[jhitesma]

Hey Jason,

I'm glad to see you are trying out the bearing idea. I went back to my original model of the block and the spacing is 9mm for the top pair and 8.75mm on the bottom pair. Though I didn't measure the final product to see if that is true.
My thought process was to gradually straighten the path to the tip as best as possible with just 2 sets of bearings. Then I adjusted the block placement to get the needle to ride in the center of the mig tip while unloaded.

Of course that was all while I was using tinkercad. I'm in the process of learning Fusion360 so I'm interested in seeing how your all in one cutter works out.

I was thinking about measuring your STL...but figured from the filename they were 9mm between and I assumed you're also using 8mm bearings based on that.

I may just print a test fixture for the bearing block first since you've got me thinking about this a bit more now and hadn't noticed that your second set were closer - though the reasoning for that makes a lot of sense to me.

I just assumed that 1mm gap between bearings would be pretty tight on the needle as is, hadn't considered going to 8.75.

I also debated making the bearing block a separate piece that could be moved in slots to position it...but am kind of hoping I'll have enough adjustability with washers. Part of me wants to make things all one piece so it will be as solid and rigid as possible...but part of me wants to make things adjustable as well - the inner struggle is real

I'm just super stoked that I contributed an idea that is now being integrated and adapted!

Isn't it great I love seeing my ideas expanded upon and modified. And the fusion of all the different people here working on their different approaches is amazing!

 

[Basscor]

I just measured everything for you so we have some hard numbers to go off of. The bearings are 8mm by 4mm with a m3 sized hole. They were leftover from a hexapod project.

Total spacing of the top set is right at 17mm and the bottom is 16.65mm measuring from the outsides of the bearings, so I guess my printer is fairly accurate.

 

[jhitesma]

Well, the 2.5 hour print actually took 3 hours...and I had to take my kid to her swim class tonight so I didn't even get to start printing until after 7. And then when I did my CHIP which has been rock solid stable for several months crashed 3 times Installed a few debian updates on it and seems happy again (except the kernel which is way out of date and can't update because I'm on a custom build and can't be bothered to build a new custom kernel but apt-get won't install a new stock kernel over my custom one...I need to just do a full wipe on this thing but am too lazy to do it.)

Anyway...finally came off the printer around 10:30 tonight and I did some mockup building. It's looking pretty good...but definitely a few things I need to tweak.

The holes in the flywheel are too loose for 3m screws. I copied David's flywheel with the technique from my video...but the cleaner 3mm holes have just barely enough meat to thread a screw into. not nearly enough for me to trust it at speed. Checked my metric taps drill size and they suggest 2.5mm holes for a 3mm tap...so I redrew the flywheel with 2.6mm holes as a compromise. We'll see how it does...may need to open those back up a bit but at least the flywheel is a quick easy 20 minute print. (The new flywheel is printing now.) I also changed it to have 16 "balance" holes instead of 15 because that allowed me to use a circular pattern in onshape to create them really quick and easy. Then I realized I had just miscounted the holes on David's original

The actual mount though is looking pretty good:





I need to trim down those 2mm screws that will attach the flywheel. Also I guessed on the size of the countersink holes for them and was off by about .5mm so had to make them a bit larger on the reprinted flywheel as large.

You can get a bit of a feel for how it's shorter than the old one and there's less to "wiggle" unsupported out off the lever arm of the motor. And how it's taller.

I used Basscor's spacing for the bearings and it looks pretty good...I'll have more details on that tomorrow. But I tested it with both 0.62mm and 0.8mm wire (the 0.8 is what I've been using) and with the 0.8 the two lower bearings give very slight tension against the needle while the 0.62mm wire fits just slightly loose.

It's hard to show in a photo but the bearing on the flywheel with a single m3 washer behind it lines up perfectly with the hole for the guide:


The guide bearings though...don't line up so great. They're too far back. I could stack some washers behind them...but after looking closer at Basscor and Verris's setups I decided I wanted to lower the bearings closer to the guide to give more length on the unflexed needle. So I'm probably also going to push that part of the "frame" out a bit over the hole so the bearings line up better. The holes for the bearing bolts are also 3mm and screws do thread into them and would probably be safe...but I'm making them a little smaller too so I can tap threads into them...I'll probably still put nylocs on the back just for peace of mind.

I also have to take 1.5 more motors apart for their bearings and pickup a few more metric screws and washers for final assembly.

Oh...and I need to modify the quick mount a little...it's just a little loose in my machine. I need to thicken the V part up just a hair.

Overall I'm hyped though. The frame feels VERY solid removing the bottom doesn't seem to have hurt at all. In fact with the bigger sides it almost feels more solid than my original cutter body.

New flywheel just finished printing...we'll see how the hole sizes are...so I can decide what size to go with on the bearing mounts before I do a "final" reprint.

Oh...and may choose a different filament...this translucent green is neat for thinwalled stuff...but looks lousy on thicker things where you can see the infill showing through

 

[dkj4linux]

Well, the 2.5 hour print actually took 3 hours...and I had to take my kid to her swim class tonight so I didn't even get to start printing until after 7. And then when I did my CHIP which has been rock solid stable for several months crashed 3 times Installed a few debian updates on it and seems happy again (except the kernel which is way out of date and can't update because I'm on a custom build and can't be bothered to build a new custom kernel but apt-get won't install a new stock kernel over my custom one...I need to just do a full wipe on this thing but am too lazy to do it.)

Anyway...finally came off the printer around 10:30 tonight and I did some mockup building. It's looking pretty good...but definitely a few things I need to tweak.

The holes in the flywheel are too loose for 3m screws. I copied David's flywheel with the technique from my video...but the cleaner 3mm holes have just barely enough meat to thread a screw into. not nearly enough for me to trust it at speed. Checked my metric taps drill size and they suggest 2.5mm holes for a 3mm tap...so I redrew the flywheel with 2.6mm holes as a compromise. We'll see how it does...may need to open those back up a bit but at least the flywheel is a quick easy 20 minute print. (The new flywheel is printing now.) I also changed it to have 16 "balance" holes instead of 15 because that allowed me to use a circular pattern in onshape to create them really quick and easy. Then I realized I had just miscounted the holes on David's original
...

I need to trim down those 2mm screws that will attach the flywheel. Also I guessed on the size of the countersink holes for them and was off by about .5mm so had to make them a bit larger on the reprinted flywheel as large.

You can get a bit of a feel for how it's shorter than the old one and there's less to "wiggle" unsupported out off the lever arm of the motor. And how it's taller.

I used Basscor's spacing for the bearings and it looks pretty good...I'll have more details on that tomorrow. But I tested it with both 0.62mm and 0.8mm wire (the 0.8 is what I've been using) and with the 0.8 the two lower bearings give very slight tension against the needle while the 0.62mm wire fits just slightly loose.

It's hard to show in a photo but the bearing on the flywheel with a single m3 washer behind it lines up perfectly with the hole for the guide:
...
The guide bearings though...don't line up so great. They're too far back. I could stack some washers behind them...but after looking closer at Basscor and Verris's setups I decided I wanted to lower the bearings closer to the guide to give more length on the unflexed needle. So I'm probably also going to push that part of the "frame" out a bit over the hole so the bearings line up better. The holes for the bearing bolts are also 3mm and screws do thread into them and would probably be safe...but I'm making them a little smaller too so I can tap threads into them...I'll probably still put nylocs on the back just for peace of mind.

I also have to take 1.5 more motors apart for their bearings and pickup a few more metric screws and washers for final assembly.

Oh...and I need to modify the quick mount a little...it's just a little loose in my machine. I need to thicken the V part up just a hair.

Overall I'm hyped though. The frame feels VERY solid removing the bottom doesn't seem to have hurt at all. In fact with the bigger sides it almost feels more solid than my original cutter body.

New flywheel just finished printing...we'll see how the hole sizes are...so I can decide what size to go with on the bearing mounts before I do a "final" reprint.

Oh...and may choose a different filament...this translucent green is neat for thinwalled stuff...but looks lousy on thicker things where you can see the infill showing through

Very nice, Jason. Thanks for the update. Once you've got everything tweaked just right I'll probably just download it and give it a go. I may have to do some real scrounging to find enough bearings -- which is the primary reason I've not done a bearing-based version before -- but it would seem a lot less work, at least initially, than reworking your design for sideboards right off the bat.

Although, my Onshape skills are improving to the point it might be another good exercise to work through. I spent a few hours yesterday working on a 4-legged "truck" (vs the 3-legged C-Roller used on MPCNC) for our EMT. I want to now add feet, flip them upside-down, and use them on my latest CoreXY laser machine to replace the yellow kludges that are there now...





-- David

 

[dkj4linux]

Alright!! Just discovered how to create Drawings in Onshape. Now we're cooking...

 

[jhitesma]

Very nice, Jason. Thanks for the update. Once you've got everything tweaked just right I'll probably just download it and give it a go. I may have to do some real scrounging to find enough bearings -- which is the primary reason I've not done a bearing-based version before -- but it would seem a lot less work, at least initially, than reworking your design for sideboards right off the bat.

I was thinking about just adding a few more holes to optionally allow using sideboards instead of bearings. Shouldn't be that hard to do...though if I do push that face out further to support bearings it may be a bit trickier - may just take two different versions that are slightly different. Thankfully onshape can do that

I almost designed it for even smaller bearings because I have a bunch I bought for some 1806 motors that had junky bearings right from the factory...but...those bearings were pretty junky themselves Then I remembered these bent up 2204 motors and figured their bearings looked "just right"

I kind of wish I had a lower kv 1806 or 2204 motor instead...the cutter doesn't need the power of this big 2212 (which I'd rather put on a plane or something) and a smaller motor would let me make the whole thing smaller....but all of my smaller motors are higher kv and I really want to keep everything on 12v for wiring simplicity which means having to keep the kv low so I have enough adjustment on the RPM.

Although, my Onshape skills are improving to the point it might be another good exercise to work through. I spent a few hours yesterday working on a 4-legged "truck" (vs the 3-legged C-Roller used on MPCNC) for our EMT. I want to now add feet, flip them upside-down, and use them on my latest CoreXY laser machine to replace the yellow kludges that are there now...

Wow, beautiful prints! Looks killer. Look forward to seeing the completed project for sure.

One of my big issues is still a matter of scale. Working in the "Void" of a CAD screen it's hard for me to visualize how big/small things are. This is the first thing I've done more or less from scratch that wasn't pretty far off from what I expected as for size. It's still not 100% what I visualized...but it's very close so maybe my brain is getting better. Having the motor in there for reference probably helped too.

 

[jhitesma]

Hmmm....



Slightly trickier to print...but the angles should be ok...the very top of the cutout is the only really tricky bit...

Just not sure if that would weaken it too much. Doesn't seem to save any print time on the estimate. But I do like the more open look.

Also - added some bumps for the bearings (and included the bearings in this mockup).

Still need to make the QC V just a tiny bit thicker...forgot about that. Feeling pretty good about this though.

Oh - and I did test the flywheel with the smaller holes last night. Tapping them wasn't great...they were a hair to small to tap well and the screws fit slightly looser in tapped holes than when they just cut their own threads into the plastic. So I may open the holes back up to about 2.8 as a better compromise. I was able to get them to self tap in this but it was tricky.

Also tried printing with support to get the recesses for the 2mm screw heads to print cleaner...but removing the support from an area that small was almost impossible. Usually support in screw holes is pretty easy - just push something through from the back and it pops right out. But this was such fine detail that didn't work. So will just print without support again and deal with the countersink holes being a little messy.

Maybe tonight I'll be able to test this.

One thing I still would like to do is figure out a way to include a place to mount the ESC to clean up the wiring.

And...I'm already envisioning a different version....where the shape of the back echoes the shape of the foot. Instead of the circle on top of a square with shoulders that give it a tombstone kind of look I'd like to do a rounded over V for the top and bottom. The tricky bit there is how to create the sides...I can't just extrude them up from the bottom like I am now since they won't taper. But...I've got a few ideas. May try drawing that idea up tonight while this version prints.

 

[moebeast]

After seeing your setup in person at Flite Fest East 2017 on Saturday, I am so very impressed with the upgraded parts that I now know that I must update my MPCNC soon. Downloading the print files is underway. Thank you for answering my questions and sharing your talent with the Flite Test community.

You are very welcome. I was happy to share what this little family has developed with our larger FF family.

 

[Michael9865]

View attachment 91044

jhitesma,
That looks awesome.

moebeast,
I think you have inspired some people to try this wonderful machine.

Now I need to figure out how to balance the flywheel. So far it is winning the battle. LOL Looks like a fun fall and winter of upgrading my setup.

 

[Michael9865]

moebeast,
Which program do you use to organize you G-Code cuts? Your machine seemed to follow a much more logical path of cutting. When I create the G-code in Estlcam V9 it skips around in a non efficient manner, it is probably logical to it's programming, but not to me. I was watching you cut a plane, I believe it was a Baby Baron, out and as it went down the line on the X-Axis or Y- Axis and it would change the Z-Axis to cut the different depths in one pass. If I cut a FT Bloody Baron or Baby Baron, for example, mine will make multiple passes over the same line to create the different depths of the fuselage and motor mount. It also does not do them in sequence. It may make on pass early in the cut procedure and may finish the part near the end of the cut procedure.
Please excuse me if I am using the wrong terms, before the MPCNC I last touched G-Coding in 1982.

Thank You for any help that you can give me.

 

[moebeast]

moebeast,
Which program do you use to organize you G-Code cuts? Your machine seemed to follow a much more logical path of cutting. When I create the G-code in Estlcam V9 it skips around in a non efficient manner, it is probably logical to it's programming, but not to me. I was watching you cut a plane, I believe it was a Baby Baron, out and as it went down the line on the X-Axis or Y- Axis and it would change the Z-Axis to cut the different depths in one pass. If I cut a FT Bloody Baron or Baby Baron, for example, mine will make multiple passes over the same line to create the different depths of the fuselage and motor mount. It also does not do them in sequence. It may make on pass early in the cut procedure and may finish the part near the end of the cut procedure.
Please excuse me if I am using the wrong terms, before the MPCNC I last touched G-Coding in 1982.

Thank You for any help that you can give me.

I think Estlcam orders cuts by engraving, inside, outside... I use engraving for all cuts. Then, under the edit menu, edit machining order. Select "From beginning" and click through in what seems to be the most logical order. I do the scores and holes then outline for each part. When I watch the preview, I usually see I missed something like a control horn slot. You can use "at the end" to order cuts if what you want to add is closer to the end.

If you are getting multiple passes to get full depth, check the settings on your tool in the tool list. There is a depth of cut setting. I set mine to 10mm.

I still haven't got the rapids to work straight out of Estlcam. I am using notepad find and replace to bump the G00 speed to 3500. It looks like it could go faster.

 

[jhitesma]

I think Estlcam orders cuts by engraving, inside, outside... I use engraving for all cuts. Then, under the edit menu, edit machining order. Select "From beginning" and click through in what seems to be the most logical order. I do the scores and holes then outline for each part. When I watch the preview, I usually see I missed something like a control horn slot. You can use "at the end" to order cuts if what you want to add is closer to the end.

Estlcam 10 seems to do a more optimized default order than 9. I just finally started using 10 last weekend and the first things I did with it the automatic cutting order seemed much more logical than what 9 does. I've considered doing them manually...but I'm lazy and I figure there's probably some logic behind what estlcam does that I'm not cognizant of I don't usually cut more than 1 or 2 of any given set of plans so I just doesn't seem worth it to optimize things to the nth degree.

Plus machining order doesn't seem to matter nearly as much as with milling for example. With milling it makes a lot of sense to do the "inside" operations like scores and holes first since there's a risk of the part coming loose when you do the outside. But since parts stay in place even after being cut...there's a lot of room for slop with machining order.

I do get annoyed sometimes when estlcam picks an order where it ends up doing rapids back and forth across the work instead of doing everything in one area - but 10 seems much better about that.

If you are getting multiple passes to get full depth, check the settings on your tool in the tool list. There is a depth of cut setting. I set mine to 10mm.

Yep, I've messed that up before

I still haven't got the rapids to work straight out of Estlcam. I am using notepad find and replace to bump the G00 speed to 3500. It looks like it could go faster.

I'm sure my rapids could be quicker...but again I haven't put much time or effort into optimizing things...it is on my list to look into at some point but my laziness really is pretty off the chart

 

[dkj4linux]

jhitesma,
That looks awesome.

moebeast,
I think you have inspired some people to try this wonderful machine.

Now I need to figure out how to balance the flywheel. So far it is winning the battle. LOL Looks like a fun fall and winter of upgrading my setup.

Michael,

Check out post #1050 in this thread (http://forum.flitetest.com/showthre...with-a-needle!&p=325092&viewfull=1#post325092) for the flywheel balancing procedure I use. It's not difficult and is made easier if you have an electronic scale that has a "grains" (gn) mode but you can get by without it. Simply use parallel "knife" edges -- or the sides of a plastic parts drawer -- to get it close... just like arranging kids on a "seesaw"





Once you get a pretty good "static" balance, chuck it up in a variable speed dremel and -- at lowest speed -- check the vibration in your hand. Add a counterweight washer(s), use a shorter/longer counterweight screw, etc. to reduce vibration until "comfortable" to hold. Then run the speed up until "uncomfortable" again and add/remove a little counterweight. Stop messing with it when you can get 7000-8000 rpm or so while still reasonably comfortable to hold.

-- David

 

[jhitesma]

So new cutter is getting very close! Printed the latest body revision last night and the tweaks from yesterday seem nice. Cutting out the sides didn't seem to affect the rigidity noticeably - but also didn't speed up the printing any. In fact...for some reason it increased the print time. Octoprint estimated it to be a 2.5 hour print - same as the last design (which actually took closer to 3 hours) but it ended up taking 4 hours to print now



I do like the more open look though, so I'll stick with it even if it takes longer to print (I'm guessing the slower printing is because I have cooling enabled which slows print moves to make sure layers take a certain amount of time. So by removing material and making the layers smaller they hit the point where they trigger the cooling slowdown. At least that's my theory.)

The resized holes seem "just right", m3 screws self-tap great for the bearings (the motor holes are slightly larger since I don't want them threaded - they still bite just a tiny bit but they aren't meant to be threaded like the bearing mounts.) If the bearing bolts come loose in their threads I can always switch to longer screws (I'm using 10mm right now which is just about perfect) and put nuts on the inside - the open sides would make that nice and easy

The bumps for the bearings printed well and seem good...I may shrink them back just a bit though, I wanted washers behind them for the bearings to ride on and the washers were just a hair thicker than I expected. It should be ok...but if I'm going to print one more I may as well tweak it.

The bearing spacing seems about right. With my current 0.8mm needle:



The top bearings just barely touch while the lower bearings actually grip the needle just a bit. I'm actually slightly worried that the lower bearings may be too close for a 0.8mm needle. In Onshape the gap between them measures 0.75mm so there's theoretically a 0.05mm interference fit against the needle.

The 0.6mm needle fits a little looser of course:



You can easily see the top bearings are loose...the lower bearings are about as loose as the top ones are on the 0.8mm needle...which based on the sizes and the math makes perfect sense.

I may switch to a 0.6mm needle on this setup...

I was hoping to try eliminating the wood on the guide mount, but....



I never bothered to measure the MIG tips. Oops. Guess I'll have to make up a wood piece and give it a go just to see how warm the tip gets. Then I'll know if I want to reprint a direct mount version. If I can direct mount that may be quite nice - could make the front smaller not needing the mounting holes for the wood piece.

The latest attempt at the flywheel seems good too. I changed the "XY separation between an object" for supports in slicer which I've never messed with before. Instead of the default 50% I set it to a fixed .5mm which left a larger gap between the support and the part. That made the support much easier to remove. Other than the one where the first layer squished a bit more (must need to fine tune my UBL mesh a bit more) the other three I just poked some very fine tweezers through and the support popped right out, the last one I had to use a 1.5mm allen key and give it a tap with a screwdriver handle to get it to pop out.



I also found some old mounting screws from 1806 motors which were the perfect size so I didn't have to cut down the big long screws I was using the day before to mockup.



The flywheel attachment screws countersink perfectly!

All that's left really is to groove the flywheel bearing and bend up a new needle...oh and make the wooden guide mount.



I gave it power and spun it up....even though I haven't balanced it yet and it doesn't have a needle. The imbalance does cause some vibration but it's already smoother feeling than the crank version was. Looking forward to balancing it out better and hopefully giving it a go on some foam tonight! I've got the baby bugatti plans all set to go