MechMate CNC Router Forum

Go Back   MechMate CNC Router Forum > Personal Build Histories > Introduce yourself and start planning
Register Options Profile Last 1 | 3 | 7 Days Search Today's Posts Mark Forums Read

Reply
 
Thread Tools
  #1  
Old Thu 29 November 2012, 08:37
PhilipA
Just call me: PhilipA
 
England
United Kingdom
Just about ready to start in the UK

Hi guys, another UK machine about to start, I'm ready to hit the go button on the saw....I've studied this for a while now and reckon I have a basic understanding.

Though the main problem I have is deciding on the table size, I work with perspex (up to 3m x 2m and composite aluminium 3m x 1.5m. I had settled on the 10ft x 5ft, then thought why not just go for the bigger table for the occasional full sheet job.

My question is, is there any loss of performance or accuracy with the 3m x 2m over a 3m x 1.5m?

Or any issues that I should consider, I want to build a well spec'd machine that will be used everyday?

Regards

Phil
Reply With Quote
  #2  
Old Thu 29 November 2012, 21:45
pblackburn
Just call me: Pete #98
 
South-Central Pennsylvania
United States of America
The accuracy will not decrease as long as your build quality is good. This is a solid machine. I have not said enough on this forum and mainly stick to my thread. The only thing I can say is read, read, read the posts and be flexible when you are building so you can adapt to different problems that will present themselves on the way. The only thing I will say about aluminum is it is light. Gerald made a post on one of the thread that even the heaviest of these machines will bounce. Mine is heavy. All steel, extra thick cross tubing on the gantry. I have a metal background with my occupation being electro-mechanical repair. The best thing is take your time, build it as true and accurate as you can, then the small problems later will not be so big. I took some slack for extra detail on exact leveling, twist over the entire machine. It is a fun build and very rewarding. Little problems come and go but that is what the community is for and questions will answered as people have time. There are many aluminum machines here, just takes planning and care. Your machine will work.

As far as everyday usage. There are many who use there machines every day. I have used mine lightly but a 10 day of cutting is not unusual for me on the day I use it. It is at least started every day.
Reply With Quote
  #3  
Old Fri 30 November 2012, 06:08
darren salyer
Just call me: Darren #101
 
Wentzville mo
United States of America
I use mine everyday.
Usually much less than the 5x12 cutting area, but I don't regret building it that size, because I have needed the whole table enough already to justify it.
Having said that, when it comes time to expand, future sizes will be 4x8, and possibly even a 4x4 for ease of loading smaller jobs, which seem to be the most common, and profitable.
Reply With Quote
  #4  
Old Fri 30 November 2012, 06:46
PhilipA
Just call me: PhilipA
 
England
United Kingdom
Thanks guys for your comments.

I nearly settled on 10 x 5ft for the composite, then sod's law I need to do something on a full 3 x 2m sheet....so it's the big one first!

The idea of running a smaller table as well is a good one! I'll have extra steel left over which could be used, and if my laser cut guy is in a good mood, I might get two sets for not much more money than one set....Once the learning and sourcing is sorted on the first the second should be mighty handy.

I wonder can two be run from the same pc?
Reply With Quote
  #5  
Old Fri 30 November 2012, 08:15
pblackburn
Just call me: Pete #98
 
South-Central Pennsylvania
United States of America
I do not know if 2 can be run from the same pc at the same time. I know mach takes great control of the windows resources and I do not think that would be possible. Even if it could your limitations are going to be your parallel and serial ports. I do not think it would be wise to use the same pc for multiple machines running at the same time. However if only one machine was run at one time then you could just load different profiles and switch cables but this adds an area of complexity that would surely lead to a mistake in the future. Someone else may be able to answer this better.
Reply With Quote
  #6  
Old Fri 30 November 2012, 08:26
darren salyer
Just call me: Darren #101
 
Wentzville mo
United States of America
Labor costs are something I'm trying to reduce all the time.
In the overall scheme of things, a PC and software capable of running a MM is cheap.
Trying to train a helper to switch things over and pay him to do it is a false economy, in my mind.
Only being able to run 1 machine at a time, because of shared components, would seem foolhardy as well. Just run everything on the biggest machine.
I really think it would take 3 MMs running daily to keep a semi-skilled helper really busy.
That would take a full time person selling and possibly another one programming, though.
Reply With Quote
  #7  
Old Fri 30 November 2012, 08:44
pblackburn
Just call me: Pete #98
 
South-Central Pennsylvania
United States of America
I would agree with Darren. Build one machine to cover your base. To enlarge the machine is not a huge cost. The electronics are what bite. My basic steel cost was $700 US, my laser cut parts I got from metalhead (around $420 don't remember but close) and I used induction hardened rails on every axis that cost total $210 US. The basic steel cost is the one that will affect your length.
Reply With Quote
  #8  
Old Fri 30 November 2012, 09:04
smreish
Just call me: Sean - #5, 28, 58 and others
 
Orlando, Florida
United States of America
...while choosing on different lengths, make sure your choice on Gantry width stays the same. It's easy to extend a table from 10' to 20', but hard to change that 4' width to 5' without a significant changes.

Good luck
Reply With Quote
  #9  
Old Fri 30 November 2012, 11:13
PhilipA
Just call me: PhilipA
 
England
United Kingdom
Is there any additions or tips that you may suggest for my 2050mm cutting gantry. I was going to settle on 3mm wall thickness, but then did I read somewhere that too much weight then can be an issue? (standard rack and pinion, with belt reduction)
Reply With Quote
  #10  
Old Fri 30 November 2012, 11:55
smreish
Just call me: Sean - #5, 28, 58 and others
 
Orlando, Florida
United States of America
Personally, I used gearboxes on all the machines I built. 7.2:1 OM with 20T or 30T pinions. The 30T machine jogs a bit faster, but all three cut well at 180-280ipm in wood. The reason I mention this is because they are all 5x10 machines with a 3/16" wall tube for gantry which is almost 4.7mm thick. I never noticed the extra mass being an issue at all. The thicker tube allowed me to omit the clamping strip internally to the gantry for rail attachment by just tapping the wall. This was the real time saver!
Reply With Quote
  #11  
Old Fri 30 November 2012, 18:15
pblackburn
Just call me: Pete #98
 
South-Central Pennsylvania
United States of America
PhilipA,
Weight should not ever be an issue with this design. You are running on linear rails. Only if your running surface was not smooth would this be an issue. Maybe if the weight was so extreme that it distressed the radial bearings (I highly doubt you would built it that heavy) would you notices a chopping action. I would be more worried about being to light and the cutting action causing lift with a higher feed rate. This is where weight is a plus to stop this from occurring.
Reply With Quote
  #12  
Old Fri 30 November 2012, 18:24
pblackburn
Just call me: Pete #98
 
South-Central Pennsylvania
United States of America
The belt reduction with the right stepper and gear reduction will give no problem with moving the gantry. To be truthful, the only one I would worry about using a belt reduction would be the z axis. The gearboxes do have a very minute about of play. But for V carving and standard work you will never notice it. I have even seen excellent work with 3d with the 7.2. It is less expensive to do belt reduction but more places you have to exact with your plans. You can get ungodly speed out of the 7.2 motors. I also have the PK296A2A-SG7.2 gearboxes on all my axes. In the end, it is what you are most comfortable with however I would recommend the Z be belt reduction and not gearbox.
Reply With Quote
  #13  
Old Fri 30 November 2012, 21:03
darren salyer
Just call me: Darren #101
 
Wentzville mo
United States of America
When I do 3d raster carvings, if the size will allow it, I set the material grain parallel with the Y axis, and raster along the Y. (which is a good benefit of the 60" width)
Rapid changes in the X-direction can cause lost steps as the entire weight of the gantry has to change directions.
Way less inertia and mass to reverse in the Y-car, as opposed to the entire gantry.
I 3d carve around 150-175 IPM, with 300 IPM rapids. This works for me, your results may vary.
Reply With Quote
  #14  
Old Tue 04 December 2012, 17:03
pblackburn
Just call me: Pete #98
 
South-Central Pennsylvania
United States of America
Everything you need to know about belt reduction is here
Reply With Quote
  #15  
Old Tue 04 December 2012, 17:04
pblackburn
Just call me: Pete #98
 
South-Central Pennsylvania
United States of America
That will help you when setting up your x, y, and z drives. A lot of good information is there.
Reply With Quote
Reply

Register Options Profile Last 1 | 3 | 7 Days Search Today's Posts Mark Forums Read

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Awesome cut ready DXF files custom dxf file Dxf Library 1 Thu 21 February 2019 19:09
First Cuts #108 - Willemstad,Netherlands parrulho MechMates already cutting 154 Sat 15 November 2014 12:14
Individual Cut Ready DXF Files Now For Sale! custom dxf file The Market Place 9 Mon 22 November 2010 11:27
Ready made water cooling system gixi 50. Toolheads 3 Sun 20 September 2009 16:40
Ready to Begin - Weiser Idaho Bill McGuire Construction started, but not cutting yet 1 Sat 16 December 2006 20:54


All times are GMT -6. The time now is 09:10.


Powered by vBulletin® Version 3.8.3
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.