Lowrider CNC

[rockyboy]

So I've been lurking on the awesome needle cutter thread long enough, and want to try my hand at CNC routing / needling of both foam and wood. The popular option for the machine is of course the MPCNC - but that takes up a lot of room that is dedicated single use space just for the machine. And I have a very small work shop.

So I'm going to tackle the Lowrider CNC by the same guy who designed the MPCNC.


The big advantage of this design for my workshop is when I'm not actively cutting something, I can push the carriage off to one side and use the open space as a work bench. I'm still working out the final dimensions, but I'm not looking to have a useable space much larger than a sheet of dollar tree foam. Right now the rough overall machine dimensions are looking like 36" x 50", and if I build the table top it rides on up at a comfortable standing workbench height, I'll have plenty of room for storage underneath.

I'm saving some money on this project by reusing components from my first 3D printer like the stepper motors, RAMPS board, limit switches, etc., I even have a pile of bearings on hand - accidental order of 10 sets of 10 instead of just 10 bearings a while back. But the first step was to see if it's feasible for me to make this with the equipment I have on hand. So I tried to print out some of the parts on my trusty Folgertech 2020 i3 printer.

Here's the parts for the primary carriage - and what do you know, the bolts and bearings all fit! :applause:


After printing the carriage template on paper and taking a sheet of 1/4" mdf to the band saw I was able to get the first assembly put together tonight.



So I dropped an order with http://www.vicious1.com/lowrider-cnc/ for the wheels, lead screws, and other miscellaneous parts I'm missing and started trying to figure out where I'm going to get the stainless steel tubing from. There is one supplier I see locally, but by local I mean an hour away on the other side of the city.

And when I mentioned this project in the earlier mentioned awesome needle cutter thread, jhitesma turned around a modified needle cutter design in an afternoon! So yeah, this needs to happen.

Anyway, other than getting the tubing, and some lumber for the table, I think I have everything I need to build it - except the space to build it in of course. Really need to get to work cleaning and rearranging the shop...

 

[dkj4linux]

A great start, Rockyboy. Welcome to the party!

 

[jhitesma]

Wow, you're making quick progress! Glad I made quick progress on the cutter modification now that I see how far along you are already!

I was starting on an article about the needle cutter...but it seems the FT article system is having issues and not dealing with photo uploads currently...so I guess I should finish refining that cutter design instead

 

[jhitesma]

Ok...here you go: https://drive.google.com/open?id=0B5JVPXZ3vDfBTWtrSHQ2ejNMV2s

That should be a usable design. I included the STL's for the flywheel and the new cutter as well as DXF's for two different insulator options.



I'm not 100% happy with the aesthetics of the guide bearing mount (I should have made it a hair taller and it bulges a bit)...and I'd rather the spokes on the support be 8mm wide so LED strips can fit under them easily...but that may just be my LED strips But it should be a fully usable cutter.

For those who don't want to wade through all 140 pages of the main needle thread here's the link to my Onshape document if you want to explore the design in 3D or modify it yourself:
https://cad.onshape.com/documents/0...374883adf8d46d6f90/e/ec7044d90b323723ca2e806a

This is all in the "611 mount" part studio in the '611 Mount - V2' branch

The insulator part is designed to be cut from wood - or printed in a higher temp capable material - since it holds the needle guide which can get warm enough to melt PLA. In this case I also designed the insulator to fit inside the 70mm circle in the router mount of the low rider. You could just use a small random scrap of wood attached just to the small central circle with the two bolt holes provided. I didn't bother with nut traps for those like I did on my hicwic mount cutter...because I haven't bothered to use the nut traps on my own

 

[PsyBorg]

You are more then welcome to store it at my place partner.

 

[rockyboy]

@dkj4linux - thank you! Really appreciate all you've done for this aspect of the hobby, and the grace and skill you show in moderating your thread. Hat's off to you my friend!

@jhitesma - that's awesome! Thank you so much for a lightning fast turn around - and it looks really cool too! I was going to work on printing the XZ carriage parts next, but that needle cutter looks so cool I think I'll give it a go first!

@PsyBorg - but where? I think your place is pretty small too. I guess kitchen counter space is overrated, right?

 

[PsyBorg]

I am NOT sacrificing my toaster and coffee pot space. I will however be willing to sell my bed and make the bedroom the official build cave since I have only actually slept in there twice since I moved in 4+ years ago now..

 

[rockyboy]

I am NOT sacrificing my toaster and coffee pot space. I will however be willing to sell my bed and make the bedroom the official build cave since I have only actually slept in there twice since I moved in 4+ years ago now..

LOL!! Good to have priorities! :applause:

 

[Timmy P]

Awesome.. Its good to see people make a leap that further imbeds them into a hobby that they enjoy.. I have wanted a cnc router table for a while now, so I can imagine how exciting it is to actually get started. and doing silly tests to learn the process.

Also it was cool meeting your at FF. You were nice enough to "spot" for me while you asked questions about my plane.. I should have let you fly it.. I was trying to keep her fresh for the FT guys..

I am with the crowd that is here to see the results of your setup.. I like that lopro table you got..

 

[jhitesma]

Shhh, Don't tell my wife.

I may have accidentally started building a low rider:



I can pretty much guarantee Rocky Boy finishes first though...I have a number of higher priority projects and almost no budget. I have a spare ramps/lcd on hand, maybe enough conduit, and more plenty of PLA...but would need another set of steppers, bearings, hardware, wheels.....Actually when Ryan first released the low rider I started designing a printable wheel for it...but set it aside because I couldn't figure out a way to print it without support and since I planned on printing it in TPU supports weren't a great idea. But...this morning in the shower I had an idea about doing it as a TPU "Tire" around a 2 piece PLA hub so it could be printed in PLA. So...I might experiment with printing the wheels.

Funny thing is...I use the MPCNC for cutting foam so much I kind of forgot that it's a freaking CNC and I have 2 routers I can attach to it to cut other stuff with In fact now that I cut this I'm thinking I should use the CNC to cut a nicer insulator for my hicwic mount needle cutter.

Though, cutting this little guy reminded me why I much prefer working with foam. First attempt out of....well, I'm not sure if it's hardboard or really cheap MDF...I think it's just hardboard:



On the first cut the power cord for the router got caught on one of my steppers. It's really a pain to work near the origin...but it's the stiffest part of the machine and makes it easiest to keep the machine square. Rest of the cut did ok...but once again my ability to judge scale in CAD proved to be....terrible.

This insulator is WAY smaller than I pictured it. Working on the low rider needle cutter it seemed so huge...but look at this little guy next to my existing cutter:



That...that can't be right can it? I mean in CAD the low rider cutter looks HUGE. Where's that 611 router...how does this compare:



Well, I guess it's right after all! Fits right in there, was actually kind of snug getting it in. And my calipers peg it at 69.98mm with less than .4mm difference across various points...and that's probably my $13 harbor freight calipers being inaccurate. So...yeah it's the right size!

It's just that the actual cutter body that goes on top is larger:



That's the earlier simpler design...but..that 2.5mm outer rim looks a lot thicker on the screen....To be fair I'm not sure this is actually 1/4" ply...it may be a bit thinner. I thought it was 1/4"...it's more than 1/8"...maybe it's only 3/16". Oh wait...there's a ruler...yeah 3/16". That explains why my 1.5mm retaining tabs didn't work

Guess I'll have to pick up a sheet of actual 1/4" this weekend if I want to cut actual low rider plates....hmmm....

 

[dkj4linux]

Thanks, Rockyboy, for the kind words.

If y'all don't mind, I'm just gonna sit over here in the corner and piddle around with Onshape -- and a more conventional-looking needle cutter -- and keep an eye on what you and Jason are up to... :applause:

 

[rockyboy]

Awesome.. Its good to see people make a leap that further imbeds them into a hobby that they enjoy.. I have wanted a cnc router table for a while now, so I can imagine how exciting it is to actually get started. and doing silly tests to learn the process.

Also it was cool meeting your at FF. You were nice enough to "spot" for me while you asked questions about my plane.. I should have let you fly it.. I was trying to keep her fresh for the FT guys..

I am with the crowd that is here to see the results of your setup.. I like that lopro table you got..

Thanks Timmy! I'm perfectly happy keeping my crashy thumbs on my own plane, thank you very much! :black_eyed:

Shhh, Don't tell my wife.

I may have accidentally started building a low rider:
.............

Well, I guess it's right after all! Fits right in there, was actually kind of snug getting it in. And my calipers peg it at 69.98mm with less than .4mm difference across various points...and that's probably my $13 harbor freight calipers being inaccurate. So...yeah it's the right size!

.................

That's the earlier simpler design...but..that 2.5mm outer rim looks a lot thicker on the screen....To be fair I'm not sure this is actually 1/4" ply...it may be a bit thinner. I thought it was 1/4"...it's more than 1/8"...maybe it's only 3/16". Oh wait...there's a ruler...yeah 3/16". That explains why my 1.5mm retaining tabs didn't work

Guess I'll have to pick up a sheet of actual 1/4" this weekend if I want to cut actual low rider plates....hmmm....

I can keep a secret - especially as you're kicking butt on this needle cutter design! Very excited to try this out - not sure which print to do next, the XZ axis for the lowrider or a needle cutter frame cause it's so cool!

Thanks, Rockyboy, for the kind words.

If y'all don't mind, I'm just gonna sit over here in the corner and piddle around with Onshape -- and a more conventional-looking needle cutter -- and keep an eye on what you and Jason are up to... :applause:

Very glad to have you keeping an eye on us - your input has been incredibly insightful on all things needle-y and I'm sure we are going to run into more snags that need brain sweat applied as this moves forward.

So next up for me this weekend is a combination of cleaning the shop and printing more Lowrider parts....

 

[jhitesma]

Thanks, Rockyboy, for the kind words.

If y'all don't mind, I'm just gonna sit over here in the corner and piddle around with Onshape -- and a more conventional-looking needle cutter -- and keep an eye on what you and Jason are up to... :applause:

Did someone say conventional?



Didn't like my hacked together 525 mount version so had to improve it a bit Still need to add fillets...and not sure how well the mount works without the curved part since I don't have a 525 to test on....

Oh wait...this is a lowrider thread. Sorry

 

[jhitesma]

So...I mentioned yesterday that I had considered the possibility of printing wheels for the low rider instead of buying them. But figured they should be printed from TPU and that meant not being able to use supports which made things tricky. Except I had come up with an idea to solve this.

Here's my idea:



I may be hard to tell...but basically it's a 3 part wheel. The two inner parts are printed in PLA for stiffness - and as two parts so they can be printed with no support. The outer wheel is printed in TPU. Angles are kept so it all prints with no support and the idea is that the design should self-assemble with the TPU tire holding the two inner parts together.

In use it would have a bolt through the bearings in the center as well which should also help keep it all together.

I also did a fancier version with pins/holes to help the two inserts join together and not slip:



But that would require support to print and I don't really think it's necessary.

I don't have time to print this tonight...but will be trying it this weekend to see how it does. I think with the right print settings this could make for a usable wheel....

Any feedback?

 

[jhitesma]

It's after midnight...so...technically it's tomorrow now right?

Hey, it's Friday and I can sleep in tomorrow...I couldn't let this design just sit and not get printed:



I think this might be viable...It does squish a bit much...but I only printed the tire at 15% infill and 3 perimeters. At 6 perimeters it would be basically solid through the center where most of the load is.

Getting the tire on was a bit tricky but not overly so...getting it off...I don't think is going to happen. With more perimeters getting it on will be trickier but I think still doable.

Though I think the center needs to be modified a bit...there's no room for a spacer between the bearings...but would I even need one...I need to find a "real" wheel to compare with...

 

[rockyboy]

Very neat! I haven't worked with TPU before - might need to pickup a roll to experiment with.

I don't think you'd need a 'real' spacer between the bearings if there is a lip that prevents them from moving any closer together. I don't think the spacer provides any other function

 

[jhitesma]

I reprinted the tire with 6 perimeters - it's now MUCH stiffer and along the load bearing part barely squishes at all as it's solid TPU between the "top" of the curve and the PLA parts. It's also MUCH harder to install on the PLA hubs!

And even the 3 perimeter soft version was impossible to get off the hubs without destroying it.

This is a far more viable wheel than I ever expected! Going to print up a full set of 4 today, pick up some bolts and machine a Y plate to see how it rolls on my table....

 

[PsyBorg]

That looks nearly exactly what the wheels on my old roller blade hockey skates look like. If that printed one does not work for you maybe try those as a viable option. Kinda what I thought it was for when I first saw the picture. If it fails at the printer job it was designed for maybe put em on the file sharing place for replacement wheels for kid skates.

 

[jhitesma]

That looks nearly exactly what the wheels on my old roller blade hockey skates look like. If that printed one does not work for you maybe try those as a viable option. Kinda what I thought it was for when I first saw the picture. If it fails at the printer job it was designed for maybe put em on the file sharing place for replacement wheels for kid skates.

That's because that's exactly what they are The lowrider uses 60mm inline skate wheels...but when I priced them I was kind of surprised how much they are now! And back in January when the low rider was first released I speculated about the possibility of printing wheels instead of buying them.

The problem was - how to print them and still have the bearing recess. The one facing downward can't print without support. Now...you could probably just print them solid in petg and for this they'd be fine....but I wanted to do them in TPU so they'd be more like regular urethane wheels.

There are two designs on thingiverse....but one is a 80mm wheel and it's only a model not designed to be printed. The other is 70mm and it's actually a model for a mold to cast your own wheels. https://www.thingiverse.com/thing:746527

But then yesterday morning in the shower it hit me - Print the central hub in PLA and the tire in TPU! And by splitting the hub in half it can print with no support. So I tested it last night and today I've been printing wheel parts...2 more hubs and I'll have 4 usable wheels

I'm not sure just how well they'll actually work...in practice but I'm fairly impressed by them so far. In fact if i still had rollerblades I'd put these on and take them for a skate just to do it. They wouldn't last very long..the TPU would wear out quickly...but I think I'd trust them to support them and for the tires not to come off the hubs.

Getting the tires on is very tricky...I have to put a rod through the center of the hub to get extra leverage to twist them on. And once they're on the only way to get them off is to cut them off.

I also did one version where I put some holes through the hub similar to commercial wheels - and it should be stronger due to the extra perimeters around those holes...but for the lowrider that strength isn't really needed and it almost doubles the print time.

Speaking of rollerblades....I got my first pair back when they first came out and no one had heard of them. They were only sold by licensed dealers and only high end ice skate shops were accepted as dealers since they were considered an off season training aid rather than a consumer product I pretty much grew up on the ice and played hockey for a few years while my sister was a competitive figure skater until she reached high school. She actually trained with the same coach at the same time as Lisa Ervin and Tonia Kwiatkowski and a few others who were competitive on a national level but who's names I can't really remember. (Honestly 98% of the competitive skaters she hung out with were incredibly unpleasant to be around - Tonia was a big exception and a genuinely wonderful kind hearted person. Lisa was pretty nice as well and being the same age as my sister they hung out a lot away from the rink as well.) Unfortunately my sister reached a point where she couldn't remain competitive and had to give it up.

I actually still have that original pair or at least did until very recently...I suspect my parents finally got rid of them while preparing to sell their house. They were VERY well made and took a LOT of abuse over the years. That was when the boots were still laced instead of the clasps they use now, and the runners that support the wheels were steel instead of cast plastic.


Ok...enough reminiscing....back on subject. I cut one of the Y plates today Came out great! About to go cut the other one and maybe a few other pieces too. Need to decide which colors of filament I want to dedicate to this too...

 

[rockyboy]

Very cool! I was able to get all the printing done for the Z axis pieces, and one of them put together. But what hobby time I had this weekend went mostly to cleaning the shop so I can put the lowrider somewhere - filled 7 of those big 55 gallon trash bags - it's looking like a whole new shop now