I have loaded, into Sheetcam, an Autocad drawing.
This particular drawing contains eight identical components.
When I look at the tool path, displayed in Sheetcam, I see that these components are shown to be individually machined in what I would consider a rather illogical sequence.
How can I alter these ‘S numbers’ … in other words … Can I select the order that these individual components are machined?
Thanks in anticipation.
Joseph
Hi Joseph,
First of all, have a play with the settings in the ‘cut path’ tab, especially the start position and cut direction. If you want absolute control use the ‘edit start points’ tool. The button looks like an S with a + next to it. Now if you right-click on a start point and select ‘properties’ you have the option to set the start point number. You may also want to try using quick cut sequence. In start point mode, right click and select ‘quick cut sequence’ A dialog box will appear with the number ‘1’ in it. The first start point you select will be set to that number. It automatically increments so you can simply click on the start points in the order you want them to be cut.
Thanks Les,
Great service!
I wonder if you, or one of the people on the discussion board, could possibly help me with another matter…
I am a retired engineer with a small workshop where I make quite intricate models.
I am looking for a small, and not too expensive, CNC mill… with engraving capabilities.
At the moment I am considering machines that are made in China. one that is made in the UK … I am also considering making one for myself…
I feel I have the requisite skills and resources to make a machine myself but a quick look at component prices and it would appear it may be less expensive to buy one off the shelf.
I would be grateful to hear the advice of other similar users .
I live in Derbyshire, England and would be quite prepared to travel a resonable distance to meet up with other engineers using these small CNC machines.
Looking forward to advice.
Joseph
Any mill can do engraving work, though a high speed spindle helps. My mill for instance is limited to 3000rpm so I made a 10000rpm spindle that fits in the taper like any other tool holder. You can do engraving at low spindle speeds but it an be slow and the finish may not be as good.
Building your own machine from scratch is possible but I wouldn’t recommend it unless you just want the challenge of doing it yourself. By the time you have sourced the parts, replaced bits that didn’t work out etc there won’t be a huge difference in the price.
Get the biggest and most substantial machine you can afford and will fit in the available space. You can always do small work on a bigger machine but doing large work on a small machine is a real pain. Large machines tend to be more rigid which is always a good thing. If you can find one, a Denford Triac is a fantastic mill for it’s size. They were built for the educational market and are built as a scaled down industrial machine instead of a light weight hobby mill. The electronics on the older Triacs were pretty poor but if you fit modern electronics they really work well. Unfortunately they are also getting pretty rare these days.
If you are looking at a gantry style engraver, avoid unsupported round rails like the plague. They are the cheapest option but they flex like wet noodles. Supported round rails and square (THK style) rails work well. Try to get a machine with ball screws. Acme screws wear and invariably end up with backlash problems. Software backlash compensation does not work very well.
Les can I have details of your high speed spindle?
Brian.
From: Les Newell <forumadmin@forum.sheetcam.com>
To: problems@forum.sheetcam.com
Sent: Friday, January 27, 2012 7:03:49 AM
Subject: Re: Multiple Components
Any mill can do engraving work, though a high speed spindle helps. My mill for instance is limited to 3000rpm so I made a 10000rpm spindle that fits in the taper like any other tool holder. You can do engraving at low spindle speeds but it an be slow and the finish may not be as good.
Building your own machine from scratch is possible but I wouldn’t recommend it unless you just want the challenge of doing it yourself. By the time you have sourced the parts, replaced bits that didn’t work out etc there won’t be a huge difference in the price.
Get the biggest and most substantial machine you can afford and will fit in the available space. You can always do small work on a bigger machine but doing large work on a small machine is a real pain. Large machines tend to be more rigid which is always a good thing. If you can find one, a Denford Triac is a fantastic mill for it’s size. They were built for the educational market and are built as a scaled down industrial machine instead of a light weight hobby mill. The electronics on the older Triacs were pretty poor but if you fit modern electronics they really work well. Unfortunately they are also getting pretty rare these days.
If you are looking at a gantry style engraver, avoid unsupported round rails like the plague. They are the cheapest option but they flex like wet noodles. Supported round rails and square (THK style) rails work well. Try to get a machine with ball screws. Acme screws wear and invariably end up with backlash problems. Software backlash compensation does not work very well.
Thanks Les,
What you write make good sense!
Unfortunally, I do not have much space.
What I should have written was that I am looking for a bench top model.
Years ago… in the early days of CNC … I purchased a Newing Hall machine.
I was one of the first people to have one of these machines … the CNC programming was very basic … when my machine was first delivered I had to calculate for myself cutter offset… but it was a great machine !
Interestingly, one of the components that I manufactured, years ago, is on the index page of their website.
Joseph
It is pretty basic. I just made up a simple housing with a 30 international taper on one end to fit my Bridgeport and a couple of bearings in the other end. A small 200DA collet holder fits in the bearings with belt drive from a small router that hangs off the side. It isn’t all that accurate but it does the job most of the time. Obviously you have to remember to disable the main spindle motor when using the HS spindle or bad things happen!