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Self Tensioning Frames

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Looking at buying a new stencil frame. We are a small low vo... - Jan 28, 2020 by Spoiltforchoice  

#84291

Self Tensioning Frames | 28 January, 2020

Looking at buying a new stencil frame. We are a small low volume, high mix place & can changeover stencils several times a day.

There are several framing systems out there but most of them are Pneumatic.(VectorGuard,Zelflex,LTC Quattro) I've seen/heard lots of comments that these can require a fair bit of servicing and might not be well suited to a high changeover environment (or even an environment where you don't have a spare).

What are your thoughts, to my knowledge of the readily available systems, VectorGuard does have a mechanical option in the form of the TensoRED frame from Alpha and apart from that the only other mechanical frame is the Genesis from Tecan/Veco (who are not exactly promoting it any more) and some somewhat rarer European ones.

What are your thoughts? Am I right to be wary of the pneumatic systems for our use case or do they bring enough benefits that they are better than Genesis or similar?

Thanks.

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#84292

Self Tensioning Frames | 28 January, 2020

Why not get stencils in frames? I think that is how most of us do it.

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#84294

Self Tensioning Frames | 28 January, 2020

I've always been a big fan of the VectorGuard frame system, especially in high mix environments as it saves a ton of space in your shop storing stencils.

Maintenance hasn't been a big issue for me in the past, just keep spares on hand if it's a concern.

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#84295

Self Tensioning Frames | 28 January, 2020

Stencil foil for a frame £120, 6-11mm thick wallet on a hanger (assuming 1 per wallet and they can easily share)

Framed stencil 30mm+ thick box on a very big sturdy shelf and I have 100s, can be double the price or more.

I would have said "Framed" was rarer based on what I've seen when I've got inside other peoples factories.

I have a very small Genesis already, mostly I'm curious if any of the other systems have particular benefits or if I should stick with the system I know. I can see an advantage to folded or reinforced edges as you get with some of the others, Genesis is just a plain sharp edge much like what DEK had before VectorGuard. However I suspect the foil is more expensive as it has more engineering.

Some of the other systems I've seen mentioned elsewhere I have no idea where you would even buy them. You see a stencil supplier list them as options but no clear home/reseller for the frame maker. Zelflex,Alpha&Tecan are easy to source.

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#84296

Self Tensioning Frames | 28 January, 2020

Guys there are space saver frames available for years. It is the metal frame but with the thickness of a vector guard box. Problem solved.

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#84297

Self Tensioning Frames | 28 January, 2020

Technically they're still thicker than storing the VectorGuard without the box. Never understood why you'd store it in the box either.

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#84298

Self Tensioning Frames | 28 January, 2020

I never understood why people would use foils. I worked at one place where maybe half the stencils were used one time and we got at least 2 to 3 new stencils a week on average. The extra space they took up was well worth not having to handle foils. We started with a rack with slots then went to heavy duty shelving with three levels and no slots. With numbered stencils it made finding them easy.

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#84299

Self Tensioning Frames | 28 January, 2020

What sort of foils are you talking about? Handling VG stencils isn't exactly tough, they're a bit more flexible than standard tube frame, but nothing horrible.

Pair it with a good storage solution and you're set. I'm able to store 165 stencils in my current storage solution.

Attachments:

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#84300

Self Tensioning Frames | 28 January, 2020

Phil from the picture attached you see the challenge - there is no marking to show you which stencil is what. That is why people keep it in a box- to be able to see the number. I used VG for long years and I never liked them. Also with high changeover, you have to constantly fix and rebuild these frames.

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#84302

Self Tensioning Frames | 28 January, 2020

Eh, the stencils have numbers on the labels from the manufacturers and I have yet to put numbered "tick" marks on each shelf, so locating the stencils in this sort of storage solution won't be a problem.

I'm surprised you had so many issues with the frames. I've run VG for probably 5 years on and off (at a job shop, we had about 600+ VG foils when I left) without issue.

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#84303

Self Tensioning Frames | 28 January, 2020

@Stephen The cost here is key, look what I pay for a foil, for established clients that's all I need charge for tooling a new prototype. I can build a pretty decent batch of prototype or low volume boards for less than some places charge for stencil&tooling. The only way I know to beat it is to use those nasty Chinese framed stencils stuck together with tape. For exactly the reason you are against foils, I'm for them. Lots of our stencils are used once, I don't need them taking up space but I do need to keep them for a while in case the next iteration uses the same one or the client needs a pre-production or 2nd prototype run quicker than their main assembler can provide.

Genesis foils have no floppy frame so need the box and 6mm is fine to label, I wouldn't (I don't think) have an issue labelling the edge of a VectorGuard either, if your storage system is indexed on kept in order that's a trivial issue.

However the strength of feeling on both sides is interesting, wasn't expecting that.

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#84304

Self Tensioning Frames | 28 January, 2020

Spoilit.... If you will be the lowest bidder, make your own frame. I suggest metal frame with screws, cut just foil with holes and create the tension with hot air while screwing. You will end up with fraction of the price.

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#84306

Self Tensioning Frames | 28 January, 2020

Phil, I had over 2k stencils VG and 5-6 frames and about 150changeovers per week. Frames get beaten up with time, hoses inside blow, aluminum tensioners change tension, start having nicks, springs inside wear as well. At some point you have to deal much more than you would like. Since I found the thin metal frame with lower price than VG , I figured these frames are obsolete now. Always good tension, less risk for damage, faster changeover and take about same space.

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#84314

Self Tensioning Frames | 28 January, 2020

&gt; Spoilit.... If you will be the lowest bidder, <BR> &gt; make your own frame. I suggest metal frame with <BR> &gt; screws, cut just foil with holes and create the <BR> &gt; tension with hot air while screwing. You will end <BR> &gt; up with fraction of the price. <BR> <BR>

HEHEHEHE Love it

Who makes these low profile frames?

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#84317

Self Tensioning Frames | 29 January, 2020

"I figured these frames are obsolete now."

Naw, VG is pretty popular, and in my experience, the most popular frameless option.

"Since I found the thin metal frame with lower price than VG"

What sort of stencils are you referring to?

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#84320

Self Tensioning Frames | 29 January, 2020

Spoilit... and Phil, it is your regular 29" frame, but it is thinner - 13mm is what I measured. For your vendor this is cheaper as they give you less metal, so usually these have lower price. I assume all stencil vendors will have it nowadays. No need for frameless solution - it is additional operation you do.

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#84321

Self Tensioning Frames | 29 January, 2020

Oh yea, space savers. I switched from those to VG lol. Still prefer VG.

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#84322

Self Tensioning Frames | 29 January, 2020

Funny enough. I did the switch backwards. Just out of curiosity, how much space do the two VG frames on your picture occupy on this specially designed rack? I bet you it is not much different than the 26mm I will need to have two space saver frames.

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#84323

Self Tensioning Frames | 29 January, 2020

> Spoilit... and Phil, it is your regular 29"
> frame, but it is thinner - 13mm is what I
> measured. For your vendor this is cheaper as they
> give you less metal, so usually these have lower
> price. I assume all stencil vendors will have it
> nowadays. No need for frameless solution - it is
> additional operation you do.

I've googled them and found US/Aussie sites selling these things. But in the UK (and also Lingva), where they list frame options they are heavily focused on VectorGuard or fixed frame options with 25 or 30mm profile. One assume the thin frames are specific to the frame adaptor they key on to so if it was an option they should list it. Also that feels like lock-in. However I don't see why there should be much saving the aluminum frame is worth peanuts. When we used to post old ones back to Alpha we got a tiny credit on the next one.

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#84324

Self Tensioning Frames | 29 January, 2020

VG foils are about 5mm thick and two in the rack takes up just under 20mm, so admittedly not a ton of space savings.

That's not the only reason I like the VG system though. It takes multiple failure points (screen tension/mesh adhesion) and reduces it to a single point of failure.

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#84327

Self Tensioning Frames | 29 January, 2020

The 4 places I've worked in SMT all had their own solutions for their own reason. I quit worrying about what worked best if what I had worked OK.

I've only seen (or recognized, at least) tension issues on foils that had been saved well beyond a reasonable lifespan, and those were always 29" x 29" box tube framed stencils.

In my experience the higher cost associated with fixed frames will drive some guys to squeeze the last dime out of a stencil at the cost of quality. Granted, that was an OEM that had to pay for their own stencils.

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