[dachopper]

Hello all,

I've decided to share the story of my large DIY CNC/3D Printer build.

Born of the pure frustration caused by a severe lack of 3d Printers and hobby CNC machines sized large enough, but not too expensive, I designed my own machine based on my experiences with the problems a hobby CNC machine causes.

I joined the Fusion 360 fraternity , and have been using it to create, modify, 3d print and CNC my designs from the beginning.

Last weekend I discovered the insert Parts4CAD, which is a depository of thousands, maybe millions of CNC designed off the shelf components available.

The following weekend - after some DIY research during the week, I had completed the frame and mount design as shown below.


Then i ordered
All the T-slot extrusion, nuts and bolts required cut to length $298 USD for
1.8m x2 (160x80)
1.1m x 2 ( 80 x 80)
.92m x 5 ( 80 x 80)
Gecko 540 + 4x380oz+wiring, motor leads and power supply $580
UC400ETH controller $157
HIWIN linear rails 2x1800, 2x1100, 2,450, 12 bearing carts
2 x 1500 1610 precision ballscrew, 1 x 1100, 1 x 1605 350 $600 incl postage
1 x thermister temperature controller, thermister and ceramic heater $80



DAY 1: 3 hours


Make lots of frame brackets for the T-slot. used 5mm angle aluminium for this task as it was all I could get ahold of, and i can easily upgrade to a tabbed version in future if needed.

[pippin88]

Your uprights look very thin. I would mount the long rails on the side of the extrusion (not the top). It will be easier and more rigid.

[manofmanyhats]

I'd consider using a plate to connect the 2 gantry extrusions together on the back so as to help mitigate flex and twisting during cuts. Good luck with it.

[dachopper]

I'd consider using a plate to connect the 2 gantry extrusions together on the back so as to help mitigate flex and twisting during cuts. Good luck with it.

Yep, have a plan to connect the two.

[dachopper]

Your uprights look very thin. I would mount the long rails on the side of the extrusion (not the top). It will be easier and more rigid.

Well I was thinking 10 mm solid aluminium plate for the sides( think this is enough?) , and if needed I can bolt some angle on for extra rigidity. I put the rails on the top because if they are sidemounted there is a lot more twisting force on the frame. So it seemed easier, it also reduced the unsupported gantry side wall height, which increases rigidity( smaller lever by about 80-100mm.

[pippin88]

The cutting results in the forces, not sure how side mounting would increase twisting force?

Re 10mm plates - you need to look at the stiffness numbers (moment of inertia). If it is as stiff as the other elements in your machine it would be reasonable, if it's not, then rethink.

The problem with the top mounted rails is how you connect them to the uprights. If you use a nice chunky block it may be ok, but you show a thin plate, which will have a very weak connection to the uprights.

[dachopper]

regarding twisting... think the actual join onto the frame itself not the gantry twist - like mounting a car roofrack onto the outside of a door, and putting the load of the gantry on it, instead of mounting the roofrack vertically ontop of the cars' door frame.

No ideas about load numbers, I was just looking at what other people had done, and 10mm aluminium plate seemed thick enough. I can always add angle or re-inforcing plate to eliminate vertical bend, rather than increase the plate thickness.

Regarding the bearing connection,
I'm going to use thick plate again - 10mm ontop of the bearing blocks, but also make a couple of 45 angled stiffeners that will sit on the inside, between the bearing block and lock the pad angle in.

Like this picture:

[dachopper]

First Delivery arrived today, the Linear motion components...

Delivered as ordered.

[dachopper]

Party Pack number two arrived today, Frame is on it's way also.

G540, Uc400ETH, motor Plugs/leads, Power supply, Motors and motor mounts in this pack

getting excited..... might have to connect and test power up the motors this weekend, make sure it all works.

[LeeWay]

That is looking like a very nice hoard of parts so far.
Great stuff. I can feel the anticipation building from here.

[dachopper]

Just checked out the DaemonCnC DIY, and noticed they had a similar setup with rail ontop and drive on the side.

I'm thinking of getting aluminium laser or cnc cut for my end plates.

Does anyone know a cheap place around Europe / middle east that will cut with off a simple CAD, or to supply basic 300x500 aluminium plate?

damencnc.com - DamenCNC Router KIT

[wizard]

Just checked out the DaemonCnC DIY, and noticed they had a similar setup with rail ontop and drive on the side.

Ultimately I believe this is an easier arrangement to get the rails parallel with each other and keep them in the same plane. It does add challenges to the design of the riser to keep in rigid. as such I might suggest using steel tubing in this location.

I'm thinking of getting aluminium laser or cnc cut for my end plates.

That is one approach. You could also cast your own. You should also consider building up something out of steel plate or tubing. Strength is important here.

Does anyone know a cheap place around Europe / middle east that will cut with off a simple CAD, or to supply basic 300x500 aluminium plate?

Cant help with that as i'm in the USA. Around here people have Bridgeports in their garages. If you have local full service metal suppliers you can have them cut the material to size. otherwise look for a jobber that specializes in prepping plate for the machine tool industry. By the way aluminum plate can be cut on a table saw if you really want to. do wear hearing protection though.

[dachopper]

Ultimately I believe this is an easier arrangement to get the rails parallel with each other and keep them in the same plane. It does add challenges to the design of the riser to keep in rigid. as such I might suggest using steel tubing in this location.

That is one approach. You could also cast your own. You should also consider building up something out of steel plate or tubing. Strength is important here.

Cant help with that as i'm in the USA. Around here people have Bridgeports in their garages. If you have local full service metal suppliers you can have them cut the material to size. otherwise look for a jobber that specializes in prepping plate for the machine tool industry. By the way aluminum plate can be cut on a table saw if you really want to. do wear hearing protection though.

By riser, do you mean the gantry end plates ?

For me it's trickier to get specific metals, we have standard angle iron and 10x10 steel tubing, I think only 2 mm wall thickness.

I've got 13 mm aluminium plate, and 50x50x5 aluminium angle. Was contemplating using both together, with the angle running vertical or diagonal on the outside of the gantry end plates. 80 series cross pieces in the post. And dabbing up some bearing mount plates for the t slot.

[dachopper]

So over the past week I've been finalizing the linear motion design, based on my CAD, but I found a pencil and ruler was much quicker to figure out the clearances and spacers that would work,

In the end, my Nema motor mount had the axis at 39mm above the mount, so I needed a 14mm spacer block for the bearings, and I had some 13mm 6000 series plate, and will use a 1mm spacer

So I tapped out all 26 bolt holes to fasten the bearing blocks to my plate, and I now only need drill the holes that allow me to fasten and manoeuvre the spacer block on the 40 series T-slot.

I have decided this is probably the best part of my design, in that the motor mount, the fixed and the floating bearings will all have up to 2mm adjustment, as well as sliding up the T-slot, allowing me to get them in perfect alignment.

Below is a pic of the 6000 plate with 4 of the Fixed bearing spacers tapped, with the T-slot holes market but not yet drilled - job for tomorrow perhaps

Co-incidently I also found out the hard was how difficult it is to drill a hole in titanium rod. I was trying to make a barrel nut, and destroyed about 6 drill bits before I figured out the right technique

Now I have to cut the rod - and I destroyed 1 x new hacksaw blade without any penetration. This stuff is dam tuff !

My T-slot arrives tomorrow, so Should have some pics of the X-axis linear setup for comment shortly.

Nick

[dachopper]

Finished the bearing mounts today, still trying to decide how to do the Gantry end plates.

I have two options.
Option 1. The Gantry end Vertical plate sits on a wide plate fitted with Larger Gussets both sides.
This requires a large spacer block fitted to the Ballscrew mount underneith ~ 55mm

Attachment 338432
Attachment 338434

Option 2. The Gantry side plates extend all the way down to the ballscrew mount.
This will have smaller Gussets, and only on the inside side of the Vertical gantry support
Also requires Bearings/motormount pumped out by a further 3.5mm

Attachment 338436


What do you guys think?

Or is there another option?

[dachopper]

Big day Today,

My Aluminium Extrusion order finally arrived from China.

Really happy with the quality, and it all seems to be the thicker stuff............ or so I thought, turns out they sent the wrong sized T-Nuts, but after a quick e-mail, I have 300 replacement T-nuts inbound !

Some pics below of the rough layout,
I'm still debating weather to put the center supports at the end and space them, or go from the ends of the cutting zone, which will be 150 in from each end ( no end plate in my design )

You can also see the Mock X axis setup, which is designed to fit in between the gantry end plates.

I think I have decided to go with the 2nd design from above, but instead of spacing the ballscrew furth out, I will mill 3.5mm off the side plate that contains the gantry, to mount the ballnut directly to the outside of the gantry end plate.

Some Pics



Nick

[pippin88]

Can you post a link to the extrusion seller?

[dachopper]

Yep

I got in contact through alibaba or aliexpress

https://sytoshine.en.alibaba.com/com...o8#top-nav-bar

The guy I was dealing with was Sunny toshine


So far a good experience - except for the T-nut which I subsequently figured out had 1 incorrect measurement.

Sunny traced it back to a replacement nut they purchased, that had the manufacturing details changed - which was not picked up.

They have agreed to send me 300 replacement T-nuts free, so I am happy as I originally ordered 170, but then realized I would probably be short.

They have been fast - order out within 5 days, and replacement nuts sent two business days after I figured out what the issue was.

Nick

[dachopper]

Not a huge amount of progress this week, owing to the replacement T-nuts which are only leaving China today, I had to re-enforce some carbon fiber joints on a project bike I'm working on too

but

I managed to sand and fit together all of the bearings, shims, spacers and precision screws.

You can see the basic design here, mount the motor and bearings to a bracket, then adjust the bracket sitting on the T-slot to gain correct alignment, and correct position.

[dachopper]

T-nuts arrived from China today, bolted the 1.8 meter 20mm Hiwin rails onto my 80*160 Y axis extrusion.

I suspect I'll get a better alignment after driving the y axis up and back at a later time.

Base frame together tomorrow hopefully, too heavy to sort out a table tonight !