Struggling a bit, right machine?

[James Huggins]

Hi everyone,


i work in the Electrical industry and for the last year kept seeing these engraved panel labels at every customer that I visited, after some investigating and digging around I saw an opportunity.

by chance i found a guy who worked from home making these on a small scale for one or two clients, he agreed to take on some more work so i started putting some work to him and selling them on to a few contacts i have.

That was in Novemember, since then i have manged to make enough money and purchased some equipment.

I have the following.

Routout CNC Machine
Gravograph Beveller
Pillar drill
Bench saw with a carbide blade for cutting to size. not ideal but does the job.

I have manged to produce a few jobs myself but I am having issues with getting the depth of the engraving consistent, Its not been to bad on small lines of text but I have just been given a job to produce 30 logo labels and i am really struggling. The first line starts ok but as it makes its way along the label its not going deep enough and only just marking the material.
Also setting up for each label seems to be taking a while, re-positioning the Z axis and the depth being different to the last label i have done.

This is the only type of engraving I am interested in doing. I this machine ok for this or should i look at a different machine which wont have the above issues, something like a Suregrave Wizard or should I stick with this and try to figure out a better way of doing things.



My machine, MDF bed, the routed out area use to have a vacuum bed

and the below is what i produce

[Joe Hillmann]

I would suggest posting your question in the CNC forum (below the engravers forum) because the engraving forum tends to focus on CO2 lasers. With that said, have you tried resurfacing the bed of your engraver to make sure it's plain is parallel to the tool bit? Is there end play in the router from loose or warn barrings or collet? And how are you holding your work down, is the work bowed at all which would cause the depth of the cut to change? And what materiel are you engraving into?

[Gary Hair]

James,
In order to get consistent depth you need to ensure the material you are engraving is perfectly flat and bed is flat as well. It's pretty easy to do. Get a fairly large diameter bit that cuts on the bottom. You'll use this to flatten the bed of the engraver. Lower the bit to the bed and run it back and forth over the entire bed, until it's all the same level. After you flatten it, attach a sacrificial piece to that surface with two sided tape. I would recommend using MDF for both pieces, it's easy to cut and is more consistently thick than plywood. Now you just need to fasten the material to the sacrificial piece and engrave away. If you use the same thickness material then the Z depth should be the same every time.

Gary

edit: Looks like Joe posted while I was typing. At least we both had the same ideas...

[Ross Moshinsky]

Is that the right machine? Probably not. You really want a spring loaded spindle for engraving. This allows the spindle to ride along the surface and get really consistent results.

Your machine might be salvagable though. You first want to surface your spoil board and see if you can get it dead flat. The best way to test if you can actually get a flat spoilboard is to drop the engraving bit down right to the surface of the spoil board at a corner and then run lines across the table. It will show any inconsistencies. If you're having major inconsistencies, you'll have to diagnose. Most likely it's something with the actual structure of the machine. If the inconsistencies are minor then you need to look at your method of holding down the material, the material itself, and if the load on the router is causing issues.

In the end, this is why laser engraving is becoming more and more popular.

[Gary Hair]

Another thought - what type of bit are you using? If the lettering is some type of single-line font then you could resolve most of the problem by using a straight sided bit. The problem with a "V" bit of any type is that the depth that it engraves dictates the width of the line. The deeper you go, the wider the line and vice versa. A straight sided bit would eliminate that problem because it will engrave the same width at any depth. You can get bits of a pretty small diameter, I use 1/64" quite often for inlays.

Gary

[James Huggins]

Thanks for your replies.

I am using 1.5mm rigid laminate or traffolite as its sometimes called.

I have just run a few lines and it looks like the bed is uneven. So I will try level my spoil board. You mention a bit that cuts on the bottom, what do you mean exactly. Would a router bit be ok?

[Martin Boekers]

Have you taken a micrometer to the material you are using/ I hate to say it, in this industry
our materials aren't always consistant.

[Ross Moshinsky]

You want something like this http://www.mlcswoodworking.com/shops.../bt_bottm.html to surface your spoil board.

As for the bit for doing plastics, you want a 30 degree v-bit most likely.

[Gary Hair]

You want something like this http://www.mlcswoodworking.com/shops.../bt_bottm.html to surface your spoil board.

As for the bit for doing plastics, you want a 30 degree v-bit most likely.

That type of bit is what you need but that particular one is 1/2" shank, your router is probably 1/4" or maybe 1/8", so look for one that fits your router. The engraving bits you want are like this: bitsbits.com/index.php?main_page=index&cPath=4 and have two dimensions to consider - angle and tip size. Check the bitsbits.com website for what those two mean.

Gary

[Michael Hunter]

Suregrave have a sale on at the moment, with big £££s off some of their engravers. Even so, a step in price from the Routout.

Did you get the machine direct from Routout? They seem to be nice guys and should be able to give you lots of help and can probably set you up with the best cutting bit for traffolite.

Meanwhile, the others have already posted the essential wisdom and vital starting point - to get the machine bed completely flat.
While you are in machine maintenance mode, look out for anything else loose, wobbly or worn and fix that too, so that you are starting from a reliable and repeatable base.

[Rodne Gold]

The machine will do fine , level the bed like others suggested. Traffolyte is pretty much consistent thickness so vasriances arent an issue. My shop does this material all the time with similar machines. Far better to put a big sheet down and do all the labels engraving with a V bit and then cut em with the same bit. IE use your machine for both operations.
Lasers work brilliantly engraving traffolyte as well , but lower powered ones struggle to cut it

[James Huggins]

The machine will do fine , level the bed like others suggested. Traffolyte is pretty much consistent thickness so vasriances arent an issue. My shop does this material all the time with similar machines. Far better to put a big sheet down and do all the labels engraving with a V bit and then cut em with the same bit. IE use your machine for both operations.
Lasers work brilliantly engraving traffolyte as well , but lower powered ones struggle to cut it

Yeah this is exactly how I intended to do it as can be a few sometimes. How do you hold down your material? I've struggled with getting the right size hole cuts and outside edge even though the right size is set on vcarve

[James Huggins]

Another thought - what type of bit are you using? If the lettering is some type of single-line font then you could resolve most of the problem by using a straight sided bit. The problem with a "V" bit of any type is that the depth that it engraves dictates the width of the line. The deeper you go, the wider the line and vice versa. A straight sided bit would eliminate that problem because it will engrave the same width at any depth. You can get bits of a pretty small diameter, I use 1/64" quite often for inlays.

Gary

Thats a great idea, although the font can be quite small, isn't a straight bit going to produce a wide font?

[Gary Hair]

You will be limited by the size of the bit, but with the right size and type of font it could work really well.

[Rodne Gold]

I hold down with a double sided tape , the secret is to find a variety that strips off clean without using residue or 1/2 the tape behind , we use a 3m/Scotch Brand.