Handscrew grip 487554 - the outer diameter

[HankReardenJr]

Hello dear woodworkers and Festool fans,
I am designing a holder for my MFT SP grips in Fusion 360. I do not have the grips at hand, they are in my garage at another location I visit bi-weekly. I have most of the dimensions needed to do that by searching the net, but I am not able to obtain the dimensions for the knobs (for securing the grips from under the table).

You can see the part here: https://www.sparepartsworld.co.uk/product/FES487554

So, I was hoping that someone here can help me and measure the knob for me. I only need the outer diameter of the knob, the widest part. The knob is used in various Festool products. The knob itself is the large one (there is an extra large version too) and should be the same in all those products, only thing that varies is the length of the threads (which doesn't matter to me).

Thank you so much!

 

[luvmytoolz]

If the grip knobs are the same as the ones used to secure the legs of the MFT, mine measure 52.4mm diameter.

 

[HankReardenJr]

I think they are! Thank you very much!

 

[luvmytoolz]

Happy to help!

 

[Packard]

Help me to understand. You want to add a grip to the existing hand screws pictured below?

There are several reasons that machine designers set for the diameter of the grips.

Without prioritizing:

1. Ergonomics.
2. Torque limitations.
3. Space allotment.
4. Pressure limitations

The big issue, as I see it (#2), is will increasing the diameter allow for too much torque for the manner in which threaded rod or threaded insert were installed. In other words, will this promote premature failure of the knob.

Almost as significant is (#4) the ability to create too high of clamp pressure. The larger knob will not only allow greater torque on the inserts, they will allow greater clamping pressure. That pressure might exceed the design limitations for the clamping elements.

“Stronger-is-better” is not always the case.

In any case, I would check to see if you are providing torque overload with the increased diameter. If you are just trying to improve the grip, perhaps a really wide rubber band in the correct size would do what you need.
D

 

[HankReardenJr]

No, no, no. I am just designing a stand for the clamps and all related parts. A stand that will be attached to the aluminum extrusion on the MFT's side. Something like this:



, but not just for those clamps in the video, but for MFT SP and MFT-HZ 80, and for more benchdogs etc. I do not like the model shared in the video so I decided to do my own version suited for my needs.

 

[Packard]

No, no, no. I am just designing a stand for the clamps and all related parts. A stand that will be attached to the aluminum extrusion on the MFT's side. Something like this:



, but not just for those clamps in the video, but for MFT SP and MFT-HZ 80, and for more benchdogs etc. I do not like the model shared in the video so I decided to do my own version suited for my needs.

My bad. Jumped to a conclusion.

My recent experiments with rare earth magnets has left me extremely impressed. This might be an application for that.