Lets have a Parf 3

[Spectric]

The Parf 2 works well but I believe it could be made better and simpler to give better results. Having cut several holes this morning using a 26mm router cutter it was just so easy and gave really clean holes. It made me re think about cutting the 20mm holes for benchdogs and how much easier it would be with a plunge router so I looked further.

The top two drawings show the Parf 2 as it is, the bottom drawing shows how it could be if the drill bushings were just replaced by 30mm holes for a router guide bush to fit in. It becomes a single flat piece of aluminium with nothing more than holes and much simpler to manufacture with no assembly required to fit the drill bushings.

What do people think? Because it is flat and using a plunge router there would be no side to side movement, the raised drill bushings combined with the drill bit and a drill on the end produce a lot of unwanted movement / rocking motion.

 

[Nelsun]

The main problem with using routers is down to the concentricity of the bit; if it's off by a tiny fraction then it's not accurate. The way the Parf system is at the moment with bushing and drill bit is reliably accurate to a horrifying degree - so long as the guide is clamped properly which can be a PITA.

 

[rogxwhit]

Glancing at the drawings & remarks above, it occurs to me that even if the drilling system mentioned ensures accurate spacing, it does little to ensure verticality. A router system ought to be far better in that regard especially if the portion accepting the router base was reasonably broad.

There's a reduced advantage in accurately spaced holes if the dogs you stick in them are leaning ...

And never mind any lack of concentricity - just orientate the router body in the same direction for each cut ...

 

[porker]

The MDF and ply templates for making these tops by the guy in Wrexham uses a guide bush and router method using the standard 1/2" worktop bit. As @Nelsun says though concentricity of the bit is the weak point if this setup but as said, if you keep the same orientation of the router it shouldn't be an issue. Unfortunately when I did my first top I had exactly this issue and had to change the orientation which messed up the accuracy. A better router made sure my second attempt was spot on

 

[Spectric]

The template from RS in Wrexham relies on aluminium foil tape to get a decent fit, with a guide bush and a conical alignment tool you ensure the cutter is concentric to the bush so no issues. The alignment tool supplied by trend with the T10 router is not precise due to being parallel and sits in the 30mm bush with noticeable slop.

 

[Chris Hawkins]

It makes sense to me. I have no knowledge of the concentricity of routers and bits, but the verticalness/verticality (please insert correct word ) of drilling is the weak link in this otherwise superb system.

 

[PerryGunn]

With serendipitous timing @petermillard has just dropped a video comparing the Parf/Trend/RS Pro jigs

 

[Spectric]

Petes footware is not very safety concious, must lead a charmed life. When I wear safety boots nothing ever gets dropped on my feet, forget and wear something lightweight then everything seems to fall on them!

So you can see how quick a router can be, but @petermillard discusses these three options and just drops a hint that he uses something else, please enlighten us so we have all options on the table, thanks

 

[porker]

He uses his LR32 rail which indexes his router. Video #242 to make his tops.
MFT Top

 

[rogxwhit]

When I wear safety boots nothing ever gets dropped on my feet, forget and wear something lightweight then everything seems to fall on them!

In summer I would often wear sandals in the workshop. At bench or machines, heavy timbers - no matter. Any injuries would tend to be minor and to the hands from the wood itself (sharp arris / splinters). A visitor asked 'what if you dropped a chisel?', and a moment's reflection gave the answer - 'My foot can move faster than the falling chisel.'

Given that it was not a building site, but a familiar, uncrowded space without distractions ...

 

[Spectric]

He uses his LR32 rail which indexes his router.

Thats something I am looking at. I get the indexing in the direction of the rail but what about indexing the next row?

 

[porker]

The video explains it better than I could but he routes the top and bottom with semi circular holes ensuring these are completely aligned. He can then use this as the jig and route each vertical row and then trim off his ‘guides’.

 

[Doug B]

Having cut several holes this morning using a 26mm router cutter it was just so easy and gave really clean holes. I

I’ve been saying the same for a while Shop made MFT
& as others have said just keep the router in the same orientation

 

[MikeJhn]

Given that it was not a building site, but a familiar, uncrowded space without distractions ...

Biggest distraction I have found in others workshops are the radio blasting out, when asked what was just said/played on the radio, they can't answer, they weren't listening, its just background unnecessary noise.

 

[Spectric]

Having watched Petes video where he uses the LR32 rail and then looking at the trend jig where both use a 20mm cutter then the LR32 method is more open to making errors if you are not fully concentrating. Rather than make half holes why not just make complete holes which must locate better but his end result shows it is accurate. I think we have to agree that the issue of concentricity of our guide bushes is not an issue, we have Peter using tape to get the right fit with the Rs and Trend jigs and then his LR32 top and all turned out accurate.

So which method is coming out as the all round winner, the template jigs look really easy but they are large, especially the RS pro and so you have storage issues and you don't want them getting damp. The LR32 system is great if you have one, requires more thought in setting it up but a fast method once mastered and then the Parf system which has the extra step of having to drill all those 3mm holes to locate the drilling guide but the only one that is directly accurate as a result of the precision rules, the others rely on the accuracy of manufacture, ie the drilling of the holes and longer term wear.

I still believe the Parf system that allows the use of a router may not be the fastest method but in theory the most foolproof, it is also not a difficult product to manufacture and if there was such a thing as a 25mm guide bush then I think you could use the existing drill guide with a router providing you give the router some extra support as the bar is only 40mm wide.

 

[porker]

I would take the best bits of each. I would use a flat CNC'ed guide like you describe but I would size the holes to take a standard 30mm guide bush and 1/2" worktop cutter to make the 20mm dog holes (like the RS Pro jig). Most routers come with a 30mm guide bush and the worktop cutters are probably the most common cutters available.

I would use the 'parf stick' principle to get the centres on an accurate grid and have 3mm holes at the ends of the jig to register the jig to these holes

If I was making another one I probably wouldn't drill all the holes either but I guess that depends how you use it. I don't use it much for workholding, more for perpendicular cuts with a stop block. The holes can be annoying as all the rubbish and small things drop through them. I must admit for cross cutting one offs I use the rail square more now.

 

[petermillard]

Having watched Petes video where he uses the LR32 rail and then looking at the trend jig where both use a 20mm cutter then the LR32 method is more open to making errors if you are not fully concentrating. Rather than make half holes why not just make complete holes which must locate better but his end result shows it is accurate. I think we have to agree that the issue of concentricity of our guide bushes is not an issue, we have Peter using tape to get the right fit with the Rs and Trend jigs and then his LR32 top and all turned out accurate.

Getting the rail dogs in and out of a pair of holes can be a pain in the neck at the best of times Roy, no fun at all when you’re doing it repeatedly. Cutting half-holes makes this easy simply by flexing the rail slightly, without any loss of accuracy, as the dogs are still locating in the half-holes; it’s as accurate as you make it, basically.

So which method is coming out as the all round winner,

Well, not to jump the gun, but the next 10MinuteWorkshop product might just be the one…

Having had hands-on with all three of these systems, plus my own method with the LR32, I have to say that they all left me wanting, in some way, though the end result - an accurate MFT top - was virtually indistinguishable between the different methods.

My way with the LR32 works very well, but I’d never suggest anyone spend that kind of money just to make their own tops. The Parf guide is definitely an investment, both money and time. Slow but steady, with bits and pieces that are useful (dogs, rules, Forster bit) away from the kit. The Trend was fast, but a little too small, really - too many moves of the jig for my liking - and the extras (corner radii, hand-hold cut-out and bevel) seemed like afterthought add-ons to me. The RS Pro jig was surprisingly physical to use, which made it slower - those little circular motions with the guide bush inside the template became tiresome very quickly, and while I didn’t have any issues I wondered if they would wear the jig over time, or simply cause movement? I’ve already had one person in the comments on that video tell me that this was the case after making four MFT tops with an RS jig, and they’d since switched to a Parf guide.

Anyway, after noodling it around - I’ve had the above jigs for a while - I’ve come up with a design that scratches all those itches, and a few more besides. I have a proof of concept mock-up made and will have a few CNCd prototypes in the next week or two. It uses mostly off the shelf components, though most are adapted slightly, though I am having a bit made specifically for it, which is entertaining.

 

[Spectric]

That sounds interesting @petermillard, the only thing that stands out is that it looks like a non standard cutter if you are having it made, is there no way something could be adapted so it uses a 20mm off the shelf cutter?

 

[petermillard]

That sounds interesting @petermillard, the only thing that stands out is that it looks like a non standard cutter if you are having it made, is there no way something could be adapted so it uses a 20mm off the shelf cutter?

Nothing to stop you using an off the shelf 20mm cutter Roy, but the one I’m getting should give a snug fit with standard benchdogs.

 

[TRITON]

summer I would often wear sandals in the workshop. At bench or machines, heavy timbers - no matter. Any injuries would tend to be minor and to the hands from the wood itself (sharp arris / splinters). A visitor asked 'what if you dropped a chisel?', and a moment's reflection gave the answer - 'My foot can move faster than the falling chisel.'

I've my own technique having worked as a butcher for so long. Not unusual to drop a knife and you get into the habit of doing a rapid backward shuffle with your feet

As to 'Parf Mk3' are we sure there isnt a design copyright on this tool. I mean Trend and the like are coming out with versions, but not copies of the same device. I would have thought a copy would be an exact copy of the parf system parts, not a hole jig for use with a router.
So I would be careful about releasing anything like it for retail sale without first checking where the law stands on it.