X-axis t-slot guides for mill samples

[Suzuki4evr]

Hi guys.

I need some examples for guide stops for the mill bed for a job a must do next week. I need to drill and tap repeated holes on 6 25×25 bms shafts inline and I want good way to clamp the shafts at the same place every time so the holes is center everytime.

Any pics is very welcome or a link on here if this was posted befor.

Thank you in advance.
Michael

 

[mmcmdl]

Are you using the T slots for mounting ?

 

[Suzuki4evr]

Yes,the square bar will be clamped flat on the bed and must push against the stops to keep it in a straight line everytime.

 

[wnchstrtnfldvlle]

What if you just turn some cylindrical “posts” with a threaded end to screw into the t-nuts to create backside stops? Then clamp a straightedge for the x-axis stop.

I will admit I have no idea what these shafts look like though.

 

[Suzuki4evr]

What if you just turn some cylindrical “posts” with a threaded end to screw into the t-nuts to create backside stops? Then clamp a straightedge for the x-axis stop.

I will admit I have no idea what these shafts look like though.

Sounds good. The shafts are just 25mm×25mm by 1 260mm long and must get 3/8"-16 tapped holes in every 98mm appart for the first 4 holes and thn 58mm appart for the next 4 holes on 3 of the shafts the other 3 are 660mm long with 4 holes 58mm appart. There is also milled section at the end with a through hole at the end. I can post a pic of the end of the shafts I did last year,but is not the image of the total length. I took it back then to send to the customer of a mistake I made. These shafts actualy work as runner shafts inside a hey baler and they must be nitrided too. I just want to find a quicker way to shift the shafts after doing a few holes because my bed travel is not long enough to do all the holes in one go. Thats why I want back stops to just move the shafts and clamp again.

Sorry for the long breath.

 

[Asm109]

On bridgeport, 5/8 diameter dowel pins are a tap fit into the slot. A couple of those for alignment and a regular clamping setup for hold down. Done.

 

[Firstram]

If you’re drilling through holes, you’ll need a spoil board anyway. Why don’t you bolt down a piece of 3/4” MDF on the front half of the table and machine a 25.1mm x shallow groove to locate the stock. That leaves the back Tslot open for clamping down. With a little layout you could cover the whole table and have hold down studs poking through wherever needed.

 

[compact8]

How about bolting two or more 123 blocks onto the bed ?

 

[B2]

Here is how I fastened my backer board down to the table. I used a piece of 1" thick nylon for the backer board and milled recessed holes with custom bolts to holed it in place via the T-slots. You can probably modify something like this. For long work pieces, that are longer than my table motion, with repeating drill holes I commonly use the previously drilled holes as register positions for the future holes, where the pins are fastened to the table or the backer board. Most backer boards are of somewhat soft material so the registration holes maybe b off a bit. It depends on your allowed tolerances. However, you could make a board from Al. It would be heavier than my Nylon.

I should post my backer board that I used to make the

You will see the T-slot bolts that I made in the photo. I turned the shoulder down so that the top was thin and did not stick up.

https://www.hobby-machinist.com/attachments/imag2920-jpg.381402/

I also used some drill rod as pins through the backer board to allow the backer board to be quickly aligned to the table. In spite of the fact that the Nylon is rather soft, because the backer board alignment pins are far apart, the length of the mill table, the error over short distances is pretty small. The drill rod pins fit very tight into the backer board and can protrude out the bottom and top. Since the Nylon is slick and a little soft I drilled holes that are tight to the drill rod diameter and beveled the ends so that they would start. I can then push them in with some force. Likewise they can be removed after T-slot clamping the board.... if they are in the way.

One last thing is that you can permanently fasten a hard surfaces near to at the ends or sides of the backer board to use for more accurate alignment. However, my pin technique gets my backer board to reasonable position very fast.

Good luck.

Dave

 

[Suzuki4evr]

If you’re drilling through holes, you’ll need a spoil board anyway. Why don’t you bolt down a piece of 3/4” MDF on the front half of the table and machine a 25.1mm x shallow groove to locate the stock. That leaves the back Tslot open for clamping down. With a little layout you could cover the whole table and have hold down studs poking through wherever needed.

This is a very good idea,but I want something for future projects like this as well. Thanks for the idea.