how would you fix it

[tanii51]

i recently bought an XY drill press vise at the right price ( a few dollars) it had a manufacturing fault with the cross slide nut... the small bit that sits in the slide is about 5mm too short. i thought of brazing on a small piece and turning it to the original diameter but maybe theres a better way????

[Dave J]

Hi,
Not quite sure what you mean,:? but I will try to answer. Is it the smaller round portion of it that needs extending? If so why? Is it that the tread not long enough or is it the slide screw is out of alignment with the nut?
If it is, one way would be to put a spacer in there even some washers would do.
Sorry for all the questions, I am just trying to get a better idea of the problem to help you out.
Dave

[tanii51]

thanks dave neither of those the smaller diameter is supposed to fit into a hole in the base of the cross slide but it only fits in by about 1 mm and jumps out when pressure is applied so i think it should be about 5 mm longer
john

[tanii51]

heres a pic of the vise upside down you can see the small part of the nut only just fits into the hole of the bottom of the slide

[Dave J]

Is it held in there by a bolt from the other side, or is it supposed to be a press fit to hold it in?
If it is press fit is there any way of putting a counter sunk head, bolt in from the other side, then drill and thread this piece to suit. You would then be able to use a spacer (or washers) on the collar to raise it to the right height.
Dave

[pipeclay]

If you wanted cant see why you couldnt either machine the spigot completely off,drill and tap the remainder of your nut,it appears that you have plenty of meat between the threaded hole and the end,and the machine a new spigot piece to desired size.

Allternatively drill and tap what you have now and machine a suitable extension piece and face to length.

Your choice if you use a screw of some type or a stud.

[tanii51]

no that wouldnt work it would pull the thread sideways and bend it .if you look at the end of the thread it is already on one side of its locating hole (hmm probly needs a brass bush in there to take up the slop)

[krisfarm]

tanii51
I would do as DaveJ has suggested and drill and tap into the end of the nut and hold it in place with a countersunk allen screw from the other side, with packing under the nut to align it with the centre of the thread. I would also improve the fit of the spigot end of the threaded rod into the cast body, it appears from the photo to have an excessive amount of play, which would be causing the nuts spigot to come out of location as soon as you turned the thread.
Bob

[Dave J]

You could make a whole new nut assembly. It wouldn't take that long to make, and at least then it would fit properly.
Dave

[RayG]

Hard to tell from the pictures, but it looks to be missing the bearing at the end of the threaded rod, that would allow the leadscrew to move up and down enough to cause the pin to disengage. Might be as simple as fixing the bearings.

Making a new nut may or may not be easy depends what the profile is, looks like a buttress thread, or is it acme?

Regards
Ray

[tanii51]

thanks every for your input i have decided to drill and tap a thread to take a 6mm cap screw. i will have to remove the knurling only on the head to make it the same size as the spigot part ,,much easier than the way i "was" going to do it
it pays to ask first
john

[Dave J]

thanks every for your input i have decided to drill and tap a thread to take a 6mm cap screw. i will have to remove the knurling only on the head to make it the same size as the spigot part ,,much easier than the way i "was" going to do it
it pays to ask first
john

Good idea John, never thought of doing it that way with using the head of the bolt as the extention.
Let us know how it turns out.
Dave

[tanii51]

well it worked a 10mm cap head trimmed down to length.drilled a hole in the spigot and tapped a thread and 'voila" it worked
also drilled the hole out where the thread goes throught the caste and made a little brass bush to take up the slack.
Its not the best XY vise in the world but for 10 dollars its better than none. I had to do a bit of work getting the black tar like paint of the sliding parts to get it to move freely

[krisfarm]

tanii51,
That looks like a good fix and should now give you good service.
Bob