Moderators: Random Orbital Bob, nev, Noel, Charley, CHJ

 Reply
By NeverGiveUp
#1198738
Hi Everybody,

I am looking for advice on purchasing a scroll saw. I am working on a project where I need to cut and slit 50mm thick Acetal, this should lead to ongoing work hence the reason to purchase. There are internal cuts required so a bandsaw cannot be used. The slot thickness of cut on this job is not critical but I would prefer if it could be around 1mm. I am aware that the thicker blades are probably better for thicker material. I have experimented with a jigsaw mounted on an inverted baseplate. This is fine for thinner section material but not surprisingly the end of the blade wanders about on the thicker section material. I had a look on Ebay and noticed that numerous manufacturers have scroll saws that all seem to use identical casings, and I presume are coming form the same Chinese factory. I then came across reviews posted on your forum and from what I have read on previous posts it would look like I need a decent quality saw like a Hegner or one of the Axminster AWS or EX models to handle the depth and accuracy. I would appreciate advice on the saw and also should I be looking for variable speed, what sort of blade I should be using for cutting 50mm thick Acetal and hints on cutting this material. If any member has a suitable saw for sale please let me know.

Thanks

Philip
User avatar
By Droogs
#1198776
Hi and welcome, There is a Hegner for sale on the site at the moment. An excellent machine and used by many and seen as the rolls royce of scroll saws, but then I have an EX which you could say is the maybach of saw. Both excellent and but different to use. The smaller chiwanese ones that you mention ar e all much a muchness so to speak. If you are looking to purchase this saw for work then I would recommend you buy the best quality and largest you can invest in to give the most flexibility. It does take a good while to get proficient with using the the saw, especially to follow a pattern accurately. The basic rule to remember visa vie blades is the thicker the work the higher the blade number and the choice of toot pattern is up to your particular way of using the saw. You just need to use the different patterns until you are happy with a style for the particular material and use that. I have found Pegas and Niqa blades to be good though my preference is the Pegas blades as I use them on both my machine and in my hand scroll saws
By NeverGiveUp
#1198811
Thanks for the advice, I have seen the Hegner for sale and might be interested but wonderd if the speed control would be necessary for plastic/ acetal and is there any special blades for acetal, I have read about problems with material melting onto the blade and wondered if anybody has had experienced cutting this sort of thickness (50mm) of acetal or is it simply down to taking your time?

Philip
By AES
#1199560
First welcome, lots of help to be had here, and a very friendly bunch.

But if you go to the Forum Board Index (1st page), you'll see there's a separate section for scroll saws alone. Not that it really matters, (there are no "penalties" or anything!!!) but the chances are that if you post there you'll get more specific replies than in this section as it's more for "general" tool buying advice.

Now to your specific questions - I'm not sure what "Acetal" is, sorry, but as you mention plastic also, I assume this Acetal is also a plastic, right? If so, the answer is YES, you certainly can cut all sorts of plastic with a scroll saw. BUT the big trick is to stop the 2 sides of the cut melting back together (the few times I've cut plastic when I first started with a scroll saw, I darn near welded the 2 bits back together again!!!). So you definitely DO need a saw with multi speeds (which you set to the slowest speed for cutting plastic). Keeping the speed right down keeps the heat down which stops the 2 parts welding back together again.

I haven't looked at the Hegner for sale here, but if it's variable speed then I'd buy it because they really are excellent saws (although I own an Excalibur myself).

Re blades, there are many. The blades I mainly use are called "Pegas" and the UK dealer for those blades is Axminster Tools. They do mail order if you don't have a store near you.

As to blade size, the basic rule is the thicker material you're cutting, the higher the blade number you need. For example, for any soft material 6 mm thick (soft wood, plastic, etc) I'd probably choose a No. 5 blade. But as always there's a bit more to it than that. (!)

So below I've given you 2 links, the first is for the Pegas blade manufacturer in Switzerland, where you can download (free) loads of blade charts explaining all the various blades. The 2nd is for Axminster where you can order the blades you decide on. In English BTW.

Pegas blades: http://www.scies.ch/
Axminster: http://www.axminster.co.uk/

There are other blade makers (Hegner sell their own brand I believe, just one example, and there's several others) but personally I like Pegas, as do several other regular posters on the scrolling section here.

Likewise I THINK there are other places where you can buy Pegas blades (not sure who/where in UK - you cannot buy direct from Scies themselves) but I've dealt with Axi several times and their service is excellent.

Usual disclaimers for both.

HTH

AES
User avatar
By Droogs
#1199565
Would have thought you would just have a day trip to Vallorbe AES, rather than order from Axi.
By AES
#1199568
A day trip would be great Droogs, but they won't sell direct to the public (fair enough I suppose, it is a factory). They don't sell files direct either, BTW. Pity. Anyway,

If you want a "funny" story here goes:

There is a Pegas dealer in Switzerland. He has precisely NIL stock of scroll saw blades, and IMO is otherwise pretty useless unless you want to talk wood turning which I'm not into (so why they "allow" him to say he's a Pegas dealer Gawd knows). Anyway, when I wanted some of the "new" revised geometry blades, the dealer didn't know what I was talking about, so I had to go to Pegas direct. They accepted my order as if it had come from their dealer and they then sent my blades to the dealer who then sent them to me! (I had to pay the dealer). Convoluted or what.

I have ordered Pegas from Axi in the past (only to get the shipping break points) and Axi are very good to deal with, but if I just want a few blades I normally order from Dictum in Germany (another excellent company to deal with, they do have stock, and no shipping charges for small stuff like blades).

AES
By AES
#1199569
A P.S for "NeverGiveUp":

Sorry, I mis-read your post about the thickness of the Acetal. If it's 50 mm then I'd PROBABLY be thinking about a No 7 or even 9 blade, and probably skip tooth configuration.

AES
By novocaine
#1199602
normally for cutting plastic I'd want some flushing fluid running, I can't remember as I haven't worked with it in a while (got a load of it in rod I used for making bushings on something) but seem to recall it acts more like brass than plastic and doesn't easily adhere to itself when cut hot.

not sure you'll get 1mm cuts from any scroll blade, that's a big kerf, I can't think of a better way of doing it though unless you want to splash out on a laser (and worry about undercutting), a water jet or (I'm not sure about this one) a hot wire cutter.

Andy you might know Acetal as delrin (a proprietary blend of the herbs and spices) or polyoxymethalene (POM)
User avatar
By MikeJhn
#1199603
I'm just guessing here, but could you use a router table with a straight cutter?

Mike
By AES
#1199624
Thanks novocaine. Yes I have heard of delrin (but not of POM). I have to say that my knowledge of plastics is pretty slim - if you put a bit of delrin in one of my hands and a bit of a different plastic in the other, I doubt that I could tell the difference!

I seem to remember machining some delrin on my little (metal) lathe a while back and it was OK I think, but I can't remember if I used a lubricant. But if you say lubricant is needed and/or better for cutting, then I certainly don't know enough to doubt what you say.

To NeverGiveUp: If novocaine says you need lubricant to cool that Acetal when cutting it, then clearly a scroll saw is NOT the way to go!!! If/when you down load the Pegas blades info I suggested yesterday then you'll see that you'll find it difficult to get a scroll saw that will give you a 1mm kerf.

PERHAPS Mike Jhn's idea of using a router is better than a scroll saw, I just don't know enough about plastics to say much more. Sorry.

AES
User avatar
By Brandlin
#1199675
MikeJhn wrote:I'm just guessing here, but could you use a router table with a straight cutter?

Mike



i understood the OP needed to cut a 1mm wide slot, 50mm deep. You're not going to find a router cutter or end mill that size (i think)
By AES
#1199851
Router? Several passes will give him the depth, but correct me if I'm wrong, there's nothing as small as 1 mm (for the kerf) is there? And anyway, is there any router that would go slow enough (even with a V small dia bit) that it wouldn't automatically just melt the stuff he's cutting? As novocaine says a coolant/lubricant would be needed, and if so, personally I think that would be just about as "successful" on a router/table as having liquid running all over a scroll saw!

I stress I'm NOT being sarky here, I genuinely don't know the answers and am purely speculating, so no one take offence please.

Novocaine (or anyone else): How is this stuff cut in industry?

The little bit of "perspexy" stuff (no idea what it's really called) I've cut in the past has always been straight lines, sometimes with the scroll saw (going DEAD slow), but usually with a home-made "scrawker", and NEVER a thickness like 50 mm - more like 10 mm max in my case.

As above "I dunno", sorry.

AES
By novocaine
#1199958
AES wrote:
Novocaine (or anyone else): How is this stuff cut in industry?

AES


it wouldn't be is the simply answer, if it's mass produced then it's injection or spin molded. it is free machining so for simply things like bushing and such it can be turned.

I think a scroll saw is a good option as any for small scale machining, I'd suggest a few tests to see if you can get the cuts without rebonding.
User avatar
By MikeJhn
#1199959
Brandlin wrote:
MikeJhn wrote:I'm just guessing here, but could you use a router table with a straight cutter?

Mike



i understood the OP needed to cut a 1mm wide slot, 50mm deep. You're not going to find a router cutter or end mill that size (i think)


He actually said the slot thickness is not critical.

I'v cut perspex at only 10mm admittedly on my table saw, bandsaw, router and cross cut saw, even shaped it on the bobbins sander, but I can see the potential problem of cutting something 50mm thick and it melting as its being cut, it took careful adjusting of the speed to get the router to work.

Saw guard.jpg


Mike
User avatar
By Droogs
#1199971
Mike, i would recommend you go allong to an axi store with a piece of the plastic and try it out on a demonstrator. There are Axminster stores in Sittingbourne and High Wycombe. The ex range have speed control. The only real sticking point is: how straight do the slits need to be over their length or how accurate in curve etc? This is the part that will take time to be proficient in. You can't really attach or use a fence due to the thinness of the blades, they'll snap due to the stresses. You could consider using a hand fret saw mounted in a guide jig, which uses a drawer runner to ensure accurate vertical movement of the blade. I have drawings somewhere and am happyto send them to you for your consideration if you like, just PM me.