[diamus]

Hello All,

This is my first post here and I would like to start by saying this place and the people here are awesome. You guy's are so helpful and knowledgeable. I have been reading for a while and finally worked up enough guts to post without feeling stupid.

I am a mechanical engineer with experience in manual and CNC machining. I have been working on a design for a while and have enough to post some images from the CAD software I am using. My intention here is to develop an entry level machine, with good accuracy, and easy to build with minimal skill and tools. A electrical engineer buddy of mine is working on the motor controller for this design. We plan on releasing this design as an open source one once it is more complete. Here is what we have so far.

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Here are the specs I am designing for:
14" x 9" x 3" Range of Motion
+/-0.003" Accuracy
Fixed Gantry
$300-$400 Price Range (Including Motors and Controller)
PC Controller
Dremel or Small Router Spindle
MDF Frame
Rollerblade Bearings
NEMA 23 Motors
5/16" Allthread leadscrews
3/4" Drill Rod Rails

I know there is more but it is late so I will post them as I think of them. The purpose of this post is to solicit feedback on the design. You guy's have a tremendous amount of expierience and any help would be greatly appreciated.

Thanks in advance

Diamus

[jckstrthmghty]

You're y-axis adjustment blocks are the inside of the table. Might be easier to adjust them if they were on the outside.

[diamus]

Yes I need to add that to my todo list. Originally I had been trying to use less drill rod and this gave me 1.25" of extra travel without using any more rod, due to the thickness of the MDF I wasn't having to pass thru. I have since economized on rod elsewhere and need to lengthen the rod and move the adjustment blocks.

[nda22]

Moving the gantry instead of the table would give you more work space without increasing the footprint of the machine.

[diamus]

When I started setting criteria for my design I contemplated a moving and a fixed gantry. I finally decided on a fixed gantry for multiple reasons. A fixed gantry simplifies rigidity as you don't have to support the weight of the gantry on the Y axis rails.

A fixed gantry also simplifies construction as I don't have to create a fully supported set of rails. One of the goals was to be able to build this with simple hand tools. Right now I think the most advanced tools you will need are a router, a drill, and a circular saw.

Space constraints weren't my first concern with this design and when I started comparing material costs MDF was cheaper than most of the other materials. Given those two factors I decided to economize on other materials first (i.e. the rails).

[Labidus]

Really nice design.

I think its one of the design I would need for my first machine, small enough too for my step motor.

The moving plate can also be larger (just before they touch the side) ? The reason I say this is for the dust.
All the dust will go on the piece of metal beside the plate if the plate is not big enough.

[diamus]

When you say moving plate do you mean the table. And are you talking about making the table top wider to protect the linear rails and bearings?

[Labidus]

When you say moving plate do you mean the table. And are you talking about making the table top wider to protect the linear rails and bearings?

Yes its what I mean sorry. To protect the bearing against the dust that will come while milling.

[diamus]

Hello All,

Sorry I have been quiet but I just got a new vehicle and I have been replacing the transmission, clutch, transfer case, man what a time drain. Anyway back to router design.

I am working on the drawings for the router parts and was wondering popular opinion on dimensioning. What would you all prefer to start with:

Decimal
Fractions
Metric
Dual dimensions with decimal & detric
Dual dimensions with decimal & dractions
Mixed dimensions depending on tolerance

Would you prefer a standardized tolerance or would you like the tolerance on every dimension or a mix of the two.

Attached below is an example of what I have started with.

Just thought I would ask before I got too far.

Diamus

[twistedfuse]

Diamus,

This is just my opinion but i would stick with whatever you find easiest. It doesn't matter if you ask or not there will be plenty of emails for you to have done it another way. You can only spoon feed so many people and being an entry level machine they will get frustrated with little things(i know i did). Your CAD skills are great. People will learn alot from the drawings and photos and will adapt their own machines to reflect certain design points. That was the same with my router.


I think the design is great for beginners. I think the ridgid gantry is best to learn. I read a while back that these are truely the best type router out there. Anyway keep up the great work, Look forward to seeing the plans and machine up and running soon.

Daniel

[cely]

If your Dremel Tool can connect to a flexible drive shaft, then you can mount the Dremel Tool to your router using the 20mm diameter, 2mm pitch threads on the end of the Dremel Tool. As in your case, where the tool only goes up and down, you may not need anyother mounting brackets.

I mounted my Dremel Tool to my Z-AXIS with 3"x3"x.25" extruded aluminum angle profile stock (for example 8020 part number 8235).

[Regnar]

You could make your y axis supports full lenght and height to be able to make a enclosure to stop the spread of dust. You would just have to add a top and front and back and your set.