finishing flat cut letters cut by scrolling saw.

[Graham Shand]

I would use a hand held dremel with a small sanding tube and also small sanding discs, so you can get to small areas, variable speed for different material, this will get rid of saw cuts and rough edges

[NeilRoss]

I’d agree with Graham, but if you can, fit the dremel pointing up through a table similar to how a router table operates, and run the letters against the sanding drum. I think you’ll find it easier to keep a smooth edge that way.

[Steve Morgan]

Phillip,
There are actually quite a few questions you need to answer that will maybe decide whether you need to finish the edges at all.
What material are you thinking of cutting? How big are the letters? How thick is the material likely to be? Which type of blade? What make of Scroll saw? and lastly, how experienced are you with the saw?

In my experience for what it’s worth. Many years ago I used to cut hundreds of foam pvc letters in sizes ranging from 50mm to 450mm cap height, most if not all were cut in 5mm material. I used a fairly course blade of around 15 tpi and these lasted for several hours of cutting. Foam pvc by its nature is pretty soft, much softer now than then, so it can be cut quite quickly, compared with timber for instance, this means that straight cuts are somewhat easier to control. If you are good with the machine, I’m not trying to be big headed here, you will manage a long straight cut of 200- 300mm with ease and equally outside curves, inside curves are little more tricky, and they shouldn’t need any finishing. On bigger text I used a bandsaw to cut most of the outside stuff, for p’s and d’s etc I used the scroll saw for the insides, it was quicker that way. I very rarely if ever needed to do any edge finishing.

IMO 10mm PVC thick letters will look poor however they are made because the core of the material is too easy to see.
MDF is rarely left unpainted so that will need some kind of filler primer on the edges, above 6mm thick you need a good steady hand and that is where the sanding will more than likely be necessary. Anything over 10mm thick in MDF takes so long to cut, because it’s much harder ie., more dense, that I don’t think it’s worth doing yourself. Metal? probably best buy in, different tools and all that.

Once again, IMO, if you need to finish with a sander of some sort, you want to go for a large diameter to go round the outside of the characters and smaller for the insides. A small diameter can leave the edge with dozens of little scollops, I think you’ll finish up with quite a few different sizes.

So to sum up, up to about 5-6mm thick and maybe 300mm high, with a bit of practice you should be able to produce a good clean edge without need for lots of finishing. Otside those parameters – more than 10off buy ’em.

Also bear in mind, the make and type of blade and the make of machine can also have an impact on the end result and so of course does the level of experience but you can’t buy that 😀

Hope this helps
Steve

[David Rogers]

The time and effort to produce a reasonable finish may outweigh the benefits of just buying some cnc machine ones from a trade supplier.

I’d argued this many times with an ex-employee that faffed about making his own letters for days – materials plus wages & running costs…and all of the lost production time on other jobs.

Not knowing what material you’re using, and if you’ve got nothing else to do 🙂 – dremel…

Dave

[Graham Shand]

Having built a CNC machine from scratch, I prefer using the dremel for certain finishes

[Mike Grant]

In 39 years of cutting out letters by hand I have NEVER had the need to clean up the edges of letters. The only person who sees this is YOU!