6 Attachment(s)
Small rigid router - Design advise needed
Hi, this is my first stab at the design after having a good look at some of the great builds here. Any advice or comments would be greatly appreciated! Requirements for the machine as following
Exclusively for machining aluminium
Cutting area: 600mm x 450mm x 150mm.
Speed is not a great issue
I got hiwin HGR15 rails and blocks and Chinese 1605 ballskrews and ballnuts so I'll use those.
Since aluminium is not cheap here I'm going for a welded steel design and then alu on Z because there's a bit of machining required there.
Some basic dimensions for reference.
Distance between gantry side rails: 800mm
Distance between top and bottom rails on gantry: 300mm
Z plate with 250mm
Box section used is 160x80x3mm and 120x80x3mm
10mm 10mm sheet for flat parts to be laser cut
Y carrage and Z assembly is 25mm alu with a 10mm plate at the back
A few questions:
Will the long belts (+-650mm on Z and 550mm on Y) cause any issues? HTD 5mm pitch x 15mm width with 20tooth pulleys
The gantry is very rigid and HEAVY but I'm worried about ressonance. Can one fill it with something that's not going to add a lot more weight that will help with resonance.
Does the 3 rails on the gantry make sense? I've got 1 on top and two at the bottom.
Please comment if you spot anything that's not going to work or things I can improve without adding major cost
http://www.mycncuk.com/attachment.ph...id=13201&stc=1http://www.mycncuk.com/attachment.ph...id=13202&stc=1http://www.mycncuk.com/attachment.ph...id=13203&stc=1http://www.mycncuk.com/attachment.ph...id=13204&stc=1http://www.mycncuk.com/attachment.ph...id=13205&stc=1
http://www.mycncuk.com/attachment.ph...id=13206&stc=1
Re: Small rigid router - Design advise needed
You could shorten the z belt by moving the motor and turning it the other way up so that the pulley if facing down. ..Clive
Re: Small rigid router - Design advise needed
Thanks Clive, I'll give that a go then I can also move my Y stepper up a little bit to shorten that belt.
Re: Small rigid router - Design advise needed
ja ja wat se jy :P
why even go with belts ? are you going to have a step down ratio ?
i wouldnt bother with the 3rd rail, i think it will just make it harder to clock up ...
what or how are the two bottom rectangle tubes fastened ?
looking good :D
Re: Small rigid router - Design advise needed
Looks pretty good but to make life easier later I would draw in your energy chain, drag chain, whatever you call it because it could affect some aspects of the design such as , mounting brackets, length of travel in X direction. Also consider limit switches and homing switches locations.
Re: Small rigid router - Design advise needed
:-)
No, its just 1:1 ratio. My understanding is that belt drive will make the machine a little smoother. X and Y would be possible to do direct drive but Z will be difficult as I'm trying to keep it as flat as possible.
Not sure but I'm thinking of welding on tabs or a piece of flat bar on both sides that will allow me to bolt it to the table.
Quote:
Originally Posted by
Blackrat
ja ja wat se jy :P
why even go with belts ? are you going to have a step down ratio ?
i wouldnt bother with the 3rd rail, i think it will just make it harder to clock up ...
what or how are the two bottom rectangle tubes fastened ?
looking good :D
Re: Small rigid router - Design advise needed
Thanks for the advice EddyCurrent. I will start adding those as I can see it might be an issue with the design as it is now, especially the drag chain running on or behind the gantry.
Quote:
Originally Posted by
EddyCurrent
Looks pretty good but to make life easier later I would draw in your energy chain, drag chain, whatever you call it because it could affect some aspects of the design such as , mounting brackets, length of travel in X direction. Also consider limit switches and homing switches locations.
Re: Small rigid router - Design advise needed
belts aint gonna make it any smoother .... id run a coupler on the two axis' , so much easier and cheaper
im not quite with you on bolting it to a table ? you HAVE to join either sides , no ways you going to cut ally decently if they are seperate from each other, not to mention the nightmare of trying to get them parallel by clamping to a table
Re: Small rigid router - Design advise needed
I am no expert but if you follow this forum and take notice of the Master's on here, coupling with belts helps to eliminate resonance which can stop a motor dead in its tracks. Try running a stepper with a loose mounting to see the effect. ..Clive
Re: Small rigid router - Design advise needed
Thanks for the feedback Blackrat. I also like the simplicity of direct drive but quite a few people here believe belt-drive is the better route. I don't know how much better?
The table/base will be a very sturdy steel frame so the two sides are build separately but when bolted down they are connected via the base or am I maybe misunderstanding your question. I guess I can also weld them to the table but that won't be much stronger than having several bolts on each side of both or will it? I thought bolting them would make the alignment easier.
Quote:
Originally Posted by
Blackrat
belts aint gonna make it any smoother .... id run a coupler on the two axis' , so much easier and cheaper
im not quite with you on bolting it to a table ? you HAVE to join either sides , no ways you going to cut ally decently if they are seperate from each other, not to mention the nightmare of trying to get them parallel by clamping to a table
