Stripped thread in old jointer head

[gtvone]

Not sure if I'm using the right name for the part, but the blocks that hold the blades in place in my old 6" jointer, the bolts appear to be stripped (At least one of them in each of the three blades) has anyone dealt with this before, how did you do it? tap it? Any thoughts appreciated. The photo isn't of mine, it's of a restoration from Youtube (the font of knowledge..)

jointer.jpg

Many thanks!

Simon

[Bohdan]

Buy a helicoil kit and repair the stripped threads.

[gtvone]

Thanks, you wouldn't tap it and put new bolts in?

[Bohdan]

Tapping it to a new larger size might result in bolt heads that don't fit.

Apart from the initial cost of the kit it is the same amount of work with helicoils and you retain the original bolt size.

[gtvone]

Tapping it to a new larger size might result in bolt heads that don't fit.

Apart from the initial cost of the kit it is the same amount of work with helicoils and you retain the original bolt size.

Understand, appreciated. Looking at the bolts that are in there, the previous owner has.. err.. mixed them up a bit anyway! I'll have a play around and see what I come up with. Again, thanks for your help!

[orraloon]

For peace of mind I would just get all new oversize bolts and retap to suit. I am mindful that they are holding blades spinning at few thousand revs.
Regards
John

[tony_A]

Presuming that the thread in question is in the metal strips where the bolts are currently (like my planer) I would take the strips to a engineering shop and get new ones made. May not cost a lot more than a helicoil kit.
If one thread is stripped the others are likely worn. All threads for high speed machinery like this should be in A1 condition and that includes the bolts. Get new ones there as well.
The thread below by LS Barker gives a few of his thoughts on setup of square head machines, but many of the principles apply to all, see paragraph about 2/3 of the way down the first post. (4140 is a high tensile steel)

Tony

The Square Head Thread.

[gtvone]

Presuming that the thread in question is in the metal strips where the bolts are currently (like my planer) I would take the strips to a engineering shop and get new ones made. May not cost a lot more than a helicoil kit.
If one thread is stripped the others are likely worn. All threads for high speed machinery like this should be in A1 condition and that includes the bolts. Get new ones there as well.
The thread below by LS Barker gives a few of his thoughts on setup of square head machines, but many of the principles apply to all, see paragraph about 2/3 of the way down the first post. (4140 is a high tensile steel)

Tony

The Square Head Thread.

Tony, thanks, that had certainly crossed my mind. I have checked and have found three worn so far, and with a variety of random bolts. I'll get them re-made.

--S

[Treecycle]

Make sure you get high tensile bolts to put in the new strips as they prevent the threads from stretching which leads to stripping.