Build Thread 1

[groswald]

Well,

First thread in the new forum. What fun!

My build is coming along. The case is done and being painted. The first three metal parts have been blued, laid out, and cut. Drilling and tapping is in progress (slow progress).

I'm trying to do get the best precision I can, so the drilling process is:

• Put the part in the vise.
• Locate the center-punch mark with a center finder.
• Lock down the vise.
• Remove the center finder and start the hole with a spotting drill.
• Remove the spotting drill and complete the hole with the correct size drill bit.
• If the hole is threaded, remove the drill bit and install a dead center to keep the tap aligned.
• Tap the hole.
• Move the part to the next hole and start over!

Part number 3 took about an hour from start to finish. Doing all operations on one hole before moving the part adds time, but ensures everything stays concentric.

One note. A decent drill press vise really helps, especially when you need to drill several holes with a common center-line as on parts 1, 3, etc. Locate one of the holes with a center finder and then bolt the vise down securely. Now you can move the part side to side to drill the other holes knowing that they will all line up.

I'll post some pic's as soon as I can.

Regards,

Randy

[kemper45]

Randy,

Great first build post to our new Momus forum.

I hear you when you talk about the amount of driling and tapping. I went out and bought myself a very basic bench top drill press and can't imagine doing all drilling without it. I would spend a couple of hours at night working on a piece or two. Any more than that then I would start rushing things and that was not good. Eventually I go them all done and it was really cool to see how the pieces scattered about my work bench came together.

It was all worth it when I finished all the components and put them together to look like attached photo.

Next step for me is the wood base and then the electronics.

Dave

[groswald]

Dave,

Wanna swap - your carriage for my case?

I agree, a drill press is pretty much required if you want to get decent precision. I've got a decent one having put together a fairly nice wood shop over the years. I can only work an hour or two at a time as well. I want to get at least as good as the +/- 0.005" Bob says the machine is capable of, but my precision suffers if I push too hard.

I ordered my electronics package today. I got the NEMA 23 kit from CNCRouterParts. It should be here next week. I still need the drive bits and switches, and then I will have everything. It should come out right at $800 by the time I'm done (minus software). Not a bad price for what should be a pretty good machine.

I hope to make a fair bit of progress over the weekend, but I expect it will be at least a full week before all the metal parts are done. It should go together quickly after that though.

Pictures tomorrow. Gotta play golf this evening...

Randy

Randy

[louieatienza]

Glad to see you guys got the sub-forum going... although I might not go this route just yet, I do plan to build one to use in my office as a prototype machine, and the enclosure design fits right in.

I have been cutting aluminium on my CNC router for a while now, and was gound to cut the parts for this machine with it. I have all the metal for this as well as the steppers, plywood, bearings, etc. but am planning to build a mini-mill first, then use it to cut parts for this machine...

[momus_cnc]

I'm trying to do get the best precision I can, so the drilling process is:

Randy, your drilling procedure is impressive. I don't know if I would have the patience for that! But the results should be well worth it. Any photos of the base?

I ended up marking out all the holes on all of the pieces first. Then I drilled all of each size hole. For me at least, I found it was quicker to unclamp one part, and drop the next one in place, rather that constantly switching drill bit sizes.

Dave, that gantry assembly is looking good.
I also did all of this with a cheap bench top drill press. It was like $99 at Home Depot. If I had it to do over again I would probably take some time to find a higher quality used one. When drilling a hole with this one I can watch both the column and the table flex considerably. To the point that even with moderate drilling pressure the drill bit is suddenly no longer perpendicular to the table! One addition that was worth the money was a cheap cross slide vice I picked up at Harbor Freight. It is typical HF quality, but it is very handy.

Keep the photos coming.

-Bob

[groswald]

All,

It's not Friday, late again, sorry. Here are a few shots anyway.

The base is done.



Well, it is done but for the rear flange, rear door, and cover. Done enough to want to start working on the metal bits anyway. Mine is almost exactly per plan. It is 1/4" short from front to back due to significant variance in the size of big-box "Handy Panels". Only one of the 24" x 48" panels I bought was actually 24" wide. By the time I trued them up the best I could do was 23.75" so that became the depth of the base.

I goofed reading the plans and the relief cuts on the left side are not in the right place. They are spaced the right distance apart, just not located correctly fore and aft. I could not find 3/8" ply locally either. Actually it's all metric anyway. I used 1/2" which is closer to 7/16". It worked out just fine. I did use the panel-raising bit in the router to make the bearing tracks. It worked great.

As for the drilling process, I have decided I don't need to do it with most holes as it is very time consuming and Bob has made most things adjustable so dead-on precision is not needed. I am doing it where two or more parts join and there isn't a lot of room for adjustment. Stepper motor mounts for example.

Here are a few pic's of the process.



I do tap all of the holes this way. It keeps the tap straight. Also, by providing support to both ends of the tap and wrench it greatly reduces the possibility of breaking a tap. Getting taps out of aluminum is miserable process. It's usually easier to just scrap the part and start over.

I learned this process from a series of videos produced by MIT. They have a Machine Shop course for people who must produce prototypes for their coursework. If, like me, you are not a machinist these videos are great. There were two on drilling and tapping holes alone. You can find them by doing a Google search for "MIT Machine Shop Video. There are 10 in total. Here's a link to the first one: MIT TechTV – Machine Shop 1

Regards,

Randy

P.S. A question. How does one post those expanding thumbnail photo's that most people seem to use?

[groswald]

Bob,

Your method for making the parts is certainly the most efficient way. Unfortunately, my psyche won't allow it.

I can't stand to do the same thing over and over, and I have to see progress. Making one or two parts at a time from start to finish fills both needs and keeps me sane.

It's even worse that that though. If I were to show you a picture of my shop you would see three projects in progress. A tall-clock for my wife, a 1/4 scale Rearwin Speedster airplane, and your router. The lattice-work looking thing behind the tap picture in my previous post is one of the wing panels for the Rearwin.

Regards,

Randy

[Bubba]

"P.S. A question. How does one post those expanding thumbnail photo's that most people seem to use?"
Save your photos to a convenient spot on your drive and then in the advanced mode, use the attachments tool (paper clip) to upload the pictures. It will then put them as thumbnails in your message.

[louieatienza]

Randy that looks great so far! I wish I had your patience as far as tapping. Some people cringe when they see me tap; I just chuck it on the cordless drill and go at it! I have one drill with a tapered tap, and another with a bottoming tap, and they come out pretty straight...

Actually I did use to use the drill press; but I would put it at the lowest speed, then I would put my piece in the clamp but loose, and start feeding the tap. I have to keep another hand on the off switch, because once I sense it's about to lift I shut the drill press off right away and manually reverse the tap. But the cordless drill works faster...

The guys on American Chopper chase tapped holes all the time with the cordless drill, so I guess it's almost OK...

[groswald]

Art,

Thanks! I never thought of using the attachment feature. Makes sense though. I'll do that in the future.

Louie, I've done that a time or two myself. But I've broken a few taps that way too...

Randy

[bjesson]

Ok gang, My ACETAL (delrin) showed up in mail on thursday along with a chunk of ABS plastic. I wanted to try out delrin clamps to see if they would be rigid enough and yield similar results as the aluminum version. I also wanted to test out my custom designed clamps for the Rigid 2401 router so delrin was a good way to prototype quickly and costwise wasn't too bad. Aluminum was supposed to show up friday but it didnt make it. So will only post pics of the delrin version.

Here's a shot of the clamps after initial cut and then after I seperated the halves and drilled/tapped/slightly de-burred everything...

[bjesson]

next up you can see the router with the clamps attached and a close up of the new mounting location on the z-rail. The new mounting location is a must because of the contour area on this router is in the way if you use the plan mount locations. Also Lowering this mount makes it a lot easier to square the bit.