How would you mount this bearing block?

[HereinCS]

The thread on my ball screw is longer than the standard spacer on my mounting block. I have to buy a second spacer. A couple of questions:

1. Should I place the spacer on the screw side or the milled side? Or should I put one on the screw side and one on the milled side?

2. I used 25 series 8020. The mounting holes on the bearing block is a perfect match spacing-wise. Problem is, it takes m8 bolts. The 25 series takes max of m6 bolts. Should I make a mounting plate to fix the screw or is there some sort of adapters that will allow me to use an m6 screw with the m8 holes?

Thanks.

[HereinCS]

anyone?

[hemsworthlad]

Hi,

1st I would put the spacer on the outer milled side, closer gap between bearings that way but it's so tiny a differance dont think it would make a great deal of differance either way thou.

2nd: Not sure but think you can buy shoulder bolts that have differant shoulder sizes to the thread size.? The other way would be to turn the end of a M8 down to M6 and re-thread.?. . . . Or buy M8 T-nuts.?

Edit: I use these BK/BF regular and think you'll find they are ok with M6 bolts and so long as you tighten them down properly then they wont move. Marking them with registration marks will show at glance if they do. If alignment is an issue then just referance both ends of a straight edge then tighten down.

[jsheerin]

Another idea - make or find a tube with ID 6, OD 8 so you can use M6 bolts and still have them locate the bearing block.

[metalworkz]

You could probably use washers that fit the counterbore diameter on the mounting plate and ream them to fit the M6 bolts on the ID? It would not take much to make some to fit from flat stock either, but I am not sure what machines you have to work with?

[HereinCS]

Thanks for the great suggestions. I just looked at my mounting block again. The bolt hole is 10.5 mm wide by 30 mm long. The largest screw that is available to a 25 series 8020 extrusion is an m6. Please excuse my ignorance. I have zero machining background and am learning with each step. I have almost zero access to any machining so I'm stuck with off the shelf products.

The shoulder bolt is a great idea. I've looked everywhere and can't find the proper size. It seems that a m10 size shoulder bolt will only taper down to m8 size thread. Perhaps I'll use the spacer idea. Maybe I'll not use a tnut afterall and use a m8 bolt, with the head inserted into the tslot. On my way to Lowes right now to see how it'd fit.

thanks again.

[metalworkz]

Good idea, maybe you can make the M8 bolt head fit in the slot with a little grinding.

[langwadt]

Originally Posted by hemsworthlad Hi, 1st I would put the spacer on the outer milled side, closer gap between bearings that way but it's so tiny a differance dont think it would make a great deal of differance either way thou. 2nd: Not sure but think you can buy shoulder bolts that have differant shoulder sizes to the thread size.? The other way would be to turn the end of a M8 down to M6 and re-thread.?. . . . Or buy M8 T-nuts.? Edit: I use these BK/BF regular and think you'll find they are ok with M6 bolts and so long as you tighten them down properly then they wont move. Marking them with registration marks will show at glance if they do. If alignment is an issue then just referance both ends of a straight edge then tighten down.

or use countersunk screws, contact area isn't ideal but it'll align itself.
or use a small piece of 8mm od 6mm id tubing it is a standard size