[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

[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...

[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.

[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.

[bjesson]

finally, testing the rigidity of the delrin clamps by machining another set of clamps from ABS. I am scrapping the ABS clamps as the finish isn't all that great. the high RPM is melting the plasic a bit. I have not tried any aluminum cutting with these clamps but they are very sturdy and in wood and plastics they are performing as well as the aluminum clamps did.

[louieatienza]

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.

Hey bjesson, those came out great! I just thought of this; on my CNC table, I used black paper-based phenolic for the entire frame, including the notor mount, and it has proved to be very solid. I can check to see if I have some chunks wide enough to try on. Thye're 1" thick also, so there should be evevn more clamping force and support...

[groswald]

bjesson,

Way cool!

Wanna sell me the delrin set once you get your new aluminum ones done? I could use 'em to make an aluminum set for myself, and then pass them on to someone else.

Regards,

Randy

[momus_cnc]

One issue I am having with the design is the 1/4-20 bolts for the main carriage. If I try to remove too much material from a part it shifts the carriage. Tightening the four bolts works for a bit but eventually the studs (cap screws in my case) snap. I just cant torque them down enough because they are too small. So, I have bought 5/16-18 cap heads and once I finish the bosch clamps I am taking the carriage off the machine and modding it. Hope this will stiffen it up a bit more.

Bill, can you explain this one again, I'm not sure I'm understanding exactly what is happening. Are you saying there is movement at the four studs (your bolts) that hold the front vertically oriented carriage parts (parts #22, 23) to the rear horizontal ones (parts #16)? So are these parts moving so that they are no longer exactly perpendicular to each other? Or are they moving so that they spread apart (like the two part #16, for instance) and are no longer parallel? I've pushed my machine pretty hard, to the point of having the belt skip, without running into any problems with anything shifting anywhere on the carriage.

-Bob

[bjesson]

Bob, the four bolts that sandwitch #16,#22,#23. If I plunge too deep or move too fast on hard materials #22 and #22 rotate on the four bolts so they are no longer perpendicular. I dont have this problem in wood just when cutting hard plastics plunging anything more then 1/4 inch into the material and aluminum I can only go about 1/16th on a pass, Both around 6 IPM. above 6 IPM and it tends to happen. But not an issue anymore. I just spent several hours machining clamps for the Bosch router, then removed the carriage, drilled and countersunk for the 5/16 bolts, remounted carriage and re-aligned all axis' and mounted new clamps and bosch router. Right now I am much more comfortable with the bolts. I was able to clamp them down pretty hard without anything snapping. the only issue I had was with the new clamps, I had to add shims because the router head hit the flange mount bolts. I will throw some pics up of the whole thing tomorrow. Nappy time now!

Billj

[bjesson]

Ok here are the pics as promised. I used the Ridgid router to cut the clamps for the Bosch router. I have not tested cutting anything yet since I tore the carriage down to modify it. Enjoy!

billj

[bjesson]

in this pic you can see the 5/16-18 cap head screws where the 1/4-20 studs were originally to sandwitch the carriage together. You can just make out the spacer I used on the new clamps as well.

billj

[bjesson]

OK, so I loaded up some aluminum to test out the performance of the Bosch router, the modified carriage bolts, and the delrin router clamps. It is an easy 10 out of 10 now. I have this machine performing about as perfect as can be. I am getting damn near mirror finishes on aluminum and I am able to cut easily twice the depth and twice the speed as before without a hickup. I accidentally had the feedrate at 138 IPM but it did not hurt the machine in any way and easily cut the aluminum. The edge finish at that speed wasn't great but it still cut without issue. Lowering IPM to 20 made a clean edge for my rough cuts and lowering to about 12 IPM for finish cutting produced a near perfect finish. I am extremely happy at this point with this machine and will load up some 3/4" aluminum tonight to see if it can handle cutting clamps out of metal this time. Last thing, I wasn't going to bother with the Bosch router before since I put the Ridgid in but now I am happy I spent the time making the clamps for the Bosch and mounting it all up. It outperforms the Ridgid mostly I think because the Bosch has a metal casing as opposed to the 2401 which has a completely plastic shell. I would recommend the Bosch if you dont mind modding your setup.

Billj