Size for Machinist table

Pretty much completed this weekend!

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Good job Bill, looks great!

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Thanks Larry! Had a bit of a struggle with the wiring, but worked through it today.

Bill, did you find the dimensional drawings provided by OF to be accurate with respect to hole spacing of the aluminum mounts? If so, I would use the drawing they provided for the “Woodworker” to locate the holes for a metal base.
Thank you,
Tom

Hey Tom, yes, it definitely proved to be accurate enough. The Y axis block holes are 8mm, and my attachment hardware is 5mm, so there’s that. But the alignment seems very good. At the moment, I just have 1 bolt in each corner, as I was more focused on getting everything else put together & working. I will need to go back & finalize the mounting.

Thank you. It looks like there is also an expanded area at the top of the bolt holes. Is the through hole diameter 8mm, and room for a washer on top? if yes, would you know the diameter of this top circular area?
Thank you,
Tom

Just ran out & measured it: the c’bore diameter is 15mm, and the length of the 8mm hole is 15mm top to bottom.

Thank you so much for the information - I appreciate it. You must be excited to start creating work that maximizes the functionality of the OF. Maybe you will have time to show some of your finished work in the future.

You’re very welcome Tom, anytime! Yeah, I’m anxious to get going on it. It took all day, well, basically all weekend to sort out a wiring issue I had, but now that I’m done with that, I can focus on getting things aligned & calibrated. Will definitely share work, but mine tends to be more simplistic than a lot of the intricate 3D carvings I’ve seen pics of. But yes, definitely anxious to cut something with it!

Thanks Tom for the follow up question about the size of the countersink hole and thank you Bill for measuring everything for us. I definitely know what length I need to get now. Some of my table frame work is under some of the mounting holes so I didn’t want to go too long( I know I could cut them). Good luck today fine tuning everything.

Thanks Larry, today’s project (well, probably today & tomorrow) will be to add some alum. extrusion rails between the bearing block & Z axis assembly to get the additional depth required by not having a wasteboard. Will supply pics if you’re interested. This won’t be an issue using your vise, but anything down close to the table surface (where I typically work) will require the extra reach down. This will be the cheap & easy way forward to get up & running, but I may revisit this in the future for a better solution. I don’t know… I’ll see how this works out first. May be no need for anything more elaborate.

Yes, I would like to see pictures of the extra rails. I wanted my machine mounted to the aluminum plate so it would be perfectly level side to side and front to back. I believe that will mean anything I surface will also be perfectly level. I’m planing on building up the work surface to the 2.5 to 3 inches high that is mentioned somewhere on the web site. Will the shortened z travel help, I’ll let you know. I have material on hand to do it so its a free experiment. The times I would not have any waste board would be , like you said, if I’m using the vice, if I’m cutting dovetails or if I’m cutting something really thick like a 4x4 post. But I still want to see your extension because maybe building it up isn’t the way to go.

@Laserlarry, I did end up getting it completed this afternoon. I placed 6mm dowel pins in the middle hole positions of the Z axis that keep the assembly aligned by engaging the 6mm slots in the alum. extrusions. Not necessary, but very nice for keeping the Z axis aligned vertically. I used M5 flanged-head screws to attach the 20 x 20 extrusion pieces to the X axis bearing block, and then used screws in 8 locations (upper & lower hole positions) to attach the Z axis to the extrusions.

It would ultimately be better to mount the z axis in the center position, but that would require another smaller baseplate & frame assembly on top of my existing base. I may still opt to do this later, I don’t know. Note that this modification will complicate dust shoe mounting, but I don’t use one so it’s no big deal to me.

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That’s really clever. The pictures you took do a great job of showing how you did it. I don’t have any of the aluminum extrusion but if raising my work surface up doesn’t work it won’t be hard to get some. I was reading another post about tramming the router, is that what you’ll be doing tomorrow? Good job, thanks for sharing .

Since I squared the aluminum extrusions when I put them on, the z axis was/is essentially self-tramming thanks to the 6mm pins that engage the 6mm slots in the extrusion. I will double-check it though.

Raising your work surface is ultimately a better, more stable solution. While what I did seems pretty solid, it’s still a compromise solution. Keeping the Z axis assembly more vertically centered to the gantry is preferable.

Well, I couldn’t resist (re) designing the base, and came up with this configuration that raises the steel working surface 1.75" which should allow me to use the middle mounting holes. The biggest challenge will be cutting 4" off each edge of my steel plate if I decide to do it.

I am joining your design part uninvited - so my apologies up front.
What if you kept your existing table as it is truly a solid well thought out base, and designed a smaller raised accessory base (much like the redesign that you posted) that could be bolted to the existing base when needed/wanted. You could place it on aluminum extrusions that would make use of the tapped holes you have, and the additional cost would be of a smaller metal base that would be bolted to the extrusions. It shouldn’t take too much time to add or remove it for the different project applications you have.

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Welcome aboard Tom! Now I’m going to add my 2 cents. Bill as far as cutting the 4" inches off, I looked back and you said a vendor of your company made the plate for you,right? If they have a laser and large router I bet they also have a shear that could cut 7ga CRS. You are probably +/- .0625 on the finished size so it should be real easy, If you decide to do it. Tom’s idea is good. Correct me if I’m wrong but you both want to machine Aluminum and therefore are staying away from wood for a base, right? How consistent is the size of the extrusion over a long length? I’ve never worked with it so I don’t know. If it varies to much your work could be sitting crooked. Could you bolt the extrusion to the 7 ga plate and “surface it” with an end mill before attaching the second level? It’s a good idea to make the machine flexible when it comes to the thickness of the material you’ll be cutting. I’m interested in what you think about the surfacing idea.
PS Tom, I don’t know if you realize that I live just south of Niagara Falls NY. If only the border wasn’t closed

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Hey Tom, you are absolutely invited, no apologies necessary!
What you suggested was actually my first thought. However, it was going to be cheaper/easier for me to modify my existing plate. Additionally, I like the new design better. My biggest hesitation was trying to figure out how to cut the 4" off each side of the plate, and then realized I could actually do it on my mini mill, in a 3" vise, no less! Time-consuming, but doable. Got the extrusion ordered as well.

I could probably have had the vendor that made it in the first place do it for me, but that would be extra time & $$, and wouldn’t be able to have it done until after the first of the year. This way, I should be able to have the steel plate done tomorrow.

Larry, the alum. extrusion is actually very straight, and especially so in the relatively short lengths I’m using. The stackup between the steel plate & alum. extrusion is extremely accurate, so no need in surfacing it (it would probably not even be as good after the fact). Any slight inaccuracy could be handled with shimming, but I don’t think that will be necessary. Anyway, it’s underway now!