Parf dogs size discrepancy

[Woodmonkey]

I bought some parf dogs a while ago and only just round to using them, and they are not the same size. One is 19.83… exactly the same size as the smaller bench dogs, but the other is 19.63. I know a fifth of a mm doesn't sound a lot but it's enough to make it noticeably sloppy in the hole. Anyone else had this issue? I had assumed they would be more accurate than that....

 

[adidat]

I think there was a debate on them on the festool owners group some time ago. They where being made badly by a third party.

Adidat

 

[Woodmonkey]

Just called Axminster, they are sending me out another pair foc, great customer service as usual.

 

[SteveF]

have to go and check mine now
not used them yet

Steve

 

[Distinterior]

I bought a full set of them when they were first available (both short & tall).

I was a bit disappointed in the fit of them in my MFT table, to the point where I e-mailed Peter Parfitt about them.
I felt there was more movement when they were fitted in the holes than I would have expected.

After talking to Peter about it, I now tend to fix them in position with the use of knobs & washers from underneath.

Belt & Braces really, but the cuts with my plunge saw have always been accurate enough for my needs.

I never bothered measuring the dogs with a vernier though!

 

[Woodmonkey]

Yes I think had they both been the same then I would've accepted that I just needed a bolt underneath. It will be interesting to see if there's any variation in the new pair.

 

[custard]

had they both been the same then I would've accepted that I just needed a bolt underneath

I'm not sure I agree with that. A bolt might stop it rattling, but it won't improve the linearity of a line of dogs.

When everything's set up properly you can get stellar precision from an MFT. There's not much point spending all that money unless you are getting, and using, its full potential. Otherwise you might as well buy a folding wallpapering table.

Dogs should be a very snug friction fit with zero play, a top quality straight edge should be able to pinch a cigarette paper between each individual dog in a row of dogs. That's what all mine can do so I know it's possible.

Top man for having the resolve to return them, and good luck with the replacements!

 

[SteveF]

I guess if they were all the same size even if slack it would not affect performance
but difference size would never work

Steve

 

[custard]

I guess if they were all the same size even if slack it would not affect performance
but difference size would never work

Steve

I'm not sure I buy that either. How could you be sure that you had clamped them all down uniformly? And even if you were up for trying on a horizontal or vertical line, what about if you were using a line of dogs at 45 degrees for mitring?

In any event why bother with all the faffing around, I've got a wide selection of dogs in different heights, threaded and unthreaded, and they all have that perfect friction fit; even though it took a fair few returned items before the manufacturer did their job properly!

 

[Benchwayze]

had they both been the same then I would've accepted that I just needed a bolt underneath

I'm not sure I agree with that. A bolt might stop it rattling, but it won't improve the linearity of a line of dogs.

When everything's set up properly you can get stellar precision from an MFT. There's not much point spending all that money unless you are getting, and using, its full potential. Otherwise you might as well buy a folding wallpapering table.

Dogs should be a very snug friction fit with zero play, a top quality straight edge should be able to pinch a cigarette paper between each individual dog in a row of dogs. That's what all mine can do so I know it's possible.

Top man for having the resolve to return them, and good luck with the replacements!

Precisely what I would have thought.
About the best way I can describe the fit of my first set is to say they are an engineering fit.
The second set I bought to go with an aftermarket MDF top are just as good. I think I have been lucky then.
Phew! That's a new one pour moi!

John

 

[Paddy Roxburgh]

I just use 20mm electrical conduit that I had lying around cut to length and it fits totally snug. I filed the leading edge to make them easier to put in. I haven't measured it but may put some verniers on them at work tomorrow (anything to delay actual work)
Paddy

 

[Roughcut]

I must admit i've never needed to measure my Parf dogs as they feel as perfect a fit as I could ask for (a very light friction fit) in the mft.
When using the dogs to square the rail against cuts come out spot on every time.
I think you may of just been unlucky Woodmonkey and maybe a rogue reject dog got in with a good batch.

 

[Woodmonkey]

Replacements arrived and glad to say both are bang on 19.9mm so I guess I was just unlucky. Fair play to axi for sending them out so quick, and they didn't ask for the old ones back so I now have a spare

 

[JandK]

I bought a MFT top and dogs from a seller on eBay (3rd party manufacture) I am very pleased the dogs are nice and tight fitting and having spend an hour checking all the holes and alignment with a straight edge and an engineers square all are spot on.

I have noticed that another seller is making templates to enable you to produce your own MFT tops with a router, this maybe handy if it proofs to be very accurate and you can find snug fitting dogs. If this is the case you could produce custom tops for your own use.

 

[SteveF]

i have had a template made
not tried it yet

Steve