Announcement

Collapse
No announcement yet.

Table top router/engraver

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Bernd
    replied
    Thanks Karl. More to interesting stuff come.

    It's kind of unfortunate that it takes a while to learn all this stuff if you haven't done it all your life.

    Bernd

    Leave a comment:


  • k9wrangler
    replied
    I figure if I started today, to get that 30+ years experience background I'd be well into the record books of oldest farts fiddling with fabulous fabricating facilities....and this stuff would all be obsolete. And if family background figured in, i'd have forgotten it all anyhow.

    Truly interesting and mesmerizing seeing all this stuff.

    Leave a comment:


  • Bernd
    replied
    For the last several weeks while working on getting the window frames designed and cut out, I've been working on a holder for the Cricut Deep Cut Knife that I picked up up last year at Hobby Lobby. I was originally going to use it in the Sherline, but after purchasing the router I figured I try it out on the router since it has a larger work area than the Sherline.

    First was to come up with design to hold the knife. It's spring loaded and held in by a magnet. Quite ingenious I might add. So, here's what I came up with.

    Click image for larger version

Name:	comgrow71.jpg
Views:	63
Size:	91.8 KB
ID:	988045

    A two-part aluminum holder. When assembled it holds the knife holder in place. There are many ways that I could have designed this, but this was the fastest to make. Maybe someday I'll design a more sophisticated holder. For now, this will have to do.

    So once assembled the tool holder gets inserted in where the spindle motor would normally get mounted.

    Click image for larger version

Name:	comgrow72.jpg
Views:	62
Size:	180.5 KB
ID:	988046

    Tighten the motor clamp.

    Click image for larger version

Name:	comgrow73.jpg
Views:	61
Size:	175.4 KB
ID:	988047

    I've learned to handle the very sharp knife with a pair of needle nose pliers. Have gotten bit a few times.

    Click image for larger version

Name:	comgrow74.jpg
Views:	60
Size:	184.5 KB
ID:	988048

    The hole in the top piece of the holder allows you to push down on the knife holder so it will stick out to remove it from the magnetic knife holder.

    Click image for larger version

Name:	comgrow75.jpg
Views:	58
Size:	164.5 KB
ID:	988049

    So that's it for now. Next will be the material holding table. Right now, I've got in mind to use two 1/2" thick MDF boards. One as a mounting surface and the other to hold the material. Kind of like I did with the window frame jig I made previously.

    I'm going to draw up the tool holder in CAD and offer them to modelers who, if they decide to try one of these machines, might want to 3D print a holder or machine one like I did and can make one without having to figure out dimensions.

    That's it for now. Have to start on the windows on the engine house and get those done.

    Until next time.

    Bernd

    Leave a comment:


  • Bernd
    replied
    Thanks for the birthday wish Rich. Much appreciated.

    I know what I know due to over 30 years in working in the machining business, plus many years from Dad being a tool and die maker. I think that has a lot to do with it, plus I enjoy working with stuff like this. Kind of like you and building buildings in wood and other materials. It's fun and challenging. You always learn something new.

    Come up for class, information is free, what you do with it will at times save you money. I like to share (show off ) what I can do and hope others can learn something or even try the same.

    Bernd

    https://railroad-line.com/member/5164-pennman hey read my reply.
    Last edited by Bernd; 03-05-2022, 05:37 PM.

    Leave a comment:


  • Pennman
    replied
    Wow... Bernd.. you are the Professor !! I might come up with the $$$ to join your class, but with my very limited schooling.. I doubt that I would succeed as well as you have shown with your work here. Will you be working in your shop today, or just enjoying your progress? BTW... HAPPY BIRTHDAY !!

    Rich

    Click image for larger version

Name:	BB.jpg
Views:	72
Size:	92.2 KB
ID:	987921

    Attached Files

    Leave a comment:


  • Bernd
    replied
    Thanks Bruce. Part of that perseverance and patience was learned at work when working on bringing machines to life after they had been assembled. It was always a great pleasure to find something wrong with a machines performance and run the engineer through the wringer. I really don't get frustrated. It's a challenge to find the problem and getting it fixed. That part of the job I enjoyed working with A-holes was something else and the political air made me want to leave the place many times.

    Bernd

    Leave a comment:


  • Dutchman
    replied
    Bernd, your perseverance and patience is admirable!

    Leave a comment:


  • Bernd
    replied
    This will close out this portion of the new machine for now. I did a run of 13 windows. Ya, lucky number 13.

    I was getting terrible vibration even with the feed rate cut back to 30% of one inch per minute. I still haven't figured out if that's what my CAM software means. Anyway this seemed to work for a while. I still had an annoying vibration at certain spots in the cut. I tightened down the motor clamp a bit more and that seemed to help, but the brass still vibrated a bit. Only being held down by the clamps on the outside of the piece seemed to be causing the problem. So on the next piece I used the 3M adhesive. That seemed to quiet it down even more. Only problem was I had to totally remove the clamps to pry the piece off the jig with a putty knife. So on the 13th piece I just stuck it down with the adhesive. I figured if the cutter broke I already had my 12 window frames. And that's how I got the 13th piece. It worked out great.

    Now came the next problem. Cleaning the adhesive off the cut part. Duck (yes that's what it says on the roll Duck Tape) works wonders. I stuck it on to the side with the adhesive still on it and pulled it off. I had to do that once or twice to remove all the adhesive. Worked great. Then I used a sharp box cutter knife and separated all the frames. Pictures of the procedure follow.

    Click image for larger version

Name:	comgrow63.jpg
Views:	101
Size:	134.8 KB
ID:	987271

    Click image for larger version

Name:	comgrow64.jpg
Views:	85
Size:	87.2 KB
ID:	987272

    Click image for larger version

Name:	comgrow65.jpg
Views:	83
Size:	240.8 KB
ID:	987273

    Click image for larger version

Name:	comgrow66.jpg
Views:	94
Size:	81.5 KB
ID:	987274

    Click image for larger version

Name:	comgrow67.jpg
Views:	91
Size:	84.2 KB
ID:	987275

    Click image for larger version

Name:	comgrow68.jpg
Views:	82
Size:	152.6 KB
ID:	987276

    Click image for larger version

Name:	comgrow69.jpg
Views:	80
Size:	232.5 KB
ID:	987277

    Click image for larger version

Name:	comgrow70.jpg
Views:	310
Size:	197.5 KB
ID:	987278

    So this closes out the first chapter on getting this machine to perform. This is not a milling machine, yes it can be used as a mill but only small projects. Anything over an 1/8" cutter would vibrate this machine off the table. I think I've located all the spots that cause the vibration. One being the motor. The stator is not balanced as is the plastic fan inside it. You can see the runout when turned by hand. At 10,000 RPM that sets up quite a bit of vibration. Plus the long spindle of the motor that is also used as the tool holder. It's way to long for any kind of heavy work. Plus the machine is not a ridged machine like a cast iron milling machine weighing several thousand pounds. It can do the kind of work I've tasked for it, but any heavy milling will be reserved for the Grizzly mini-mill and the Bridgeport. I think it will do well for engraving, an adventure I need to go on yet. You can also add a laser cutter to it for cutting and engraving. One problem here is it will need some kind of enclosure to contain the smoke. Before I even think of getting a laser for this machine I have three other items lined up for it. One will be using a Deep Cut knife from the Cricut that the scrapper crowd uses to cut styrene, cardboard and possibly thin wood. A second test will be to use the machine to make rivets in brass or styrene and the third test will be to see if I can get it to emboss thin aluminum for corrugated siding. I'll document the work in this thread as the adventure continues.

    Hope who that read this little adventure found it useful and interesting. Stay tuned more to come.

    Bernd

    Leave a comment:


  • rrladmin
    commented on 's reply
    Bernd, looks like you are making good progress... and you are learning the idiosyncrasies of the machine... next part will be easier, you can only build on it from here, looks like fun !

    Joe

  • Bernd
    replied
    I last left off with the addition of a base plate to mount jigs/fixtures on to machine parts. Once that was done I needed a few of these plates for projects. The first being the window frame of the Suydam Two Stall engine house.

    This is how I mass produced those plates using my 10" table saw and 1/4" thick aluminum plate.

    I mounted a 38 tooth carbide tipped blade in the machine.

    Click image for larger version  Name:	comgrow39.jpg Views:	0 Size:	146.1 KB ID:	987119

    Next I set the height of the blade just so the small portion of the teeth would be above the aluminum plate.

    Click image for larger version  Name:	comgrow40.jpg Views:	0 Size:	163.2 KB ID:	987120

    I place a piece of foam, it could be anything that the blade will cut, over the top. This keeps the spray of chips to a minimum on top.

    Click image for larger version  Name:	comgrow41.jpg Views:	0 Size:	159.8 KB ID:	987121

    And the first jig plate.

    Click image for larger version  Name:	comgrow42.jpg Views:	0 Size:	162.7 KB ID:	987122

    I also cut up a bunch of strips that will be used for tie downs. You'll see in a later picture where they go.

    Click image for larger version  Name:	comgrow43.jpg Views:	0 Size:	176.3 KB ID:	987123

    I fly-cut both top and bottom surfaces to make sure the plate is nice and flat.

    Click image for larger version  Name:	comgrow44.jpg Views:	0 Size:	201.1 KB ID:	987124

    Here I'm fly-cutting the sides of the hold down strips. That's the fly-cutter mounted in the spindle. It's a single point tool that you take about a .005" deep cut at a slow feed rate to get and nice surface finish like on the plate in the previous picture.

    Click image for larger version  Name:	comgrow45.jpg Views:	0 Size:	207.1 KB ID:	987125

    Notice the difference in surface finish from the last picture. The tool is spinning at about 800 to 1000 rpm.

    Click image for larger version  Name:	comgrow46.jpg Views:	0 Size:	202.6 KB ID:	987126

    Back to the router. I drilled and reamed a hole in the exact center of the base plate for 1/4 for a 1/4" dowel. The jig plate also has 1/4" reamed hole an it already has some 3M adhesive applied to hold the plate in place.

    Click image for larger version  Name:	comgrow47.jpg Views:	0 Size:	179.4 KB ID:	987127

    A close look at the applied adhesive and the dowel installed ready for mounting on the base plate.

    Click image for larger version  Name:	comgrow48.jpg Views:	0 Size:	185.6 KB ID:	987128

    Using a square to align the jig plate perpendicular on the base plate.

    Click image for larger version  Name:	comgrow49.jpg Views:	0 Size:	188.2 KB ID:	987129

    Here you can see the hold down strips I made that will hold down the brass sheet. I'm using a printed out CAD drawing to line up where the cutter will start. I've installed a 1/16" dia. cutter to mill out a groove in the aluminum so when the tiny 1/32" dia. cutter cuts out the frame it won't have to cut out the aluminum too.

    Click image for larger version  Name:	comgrow50.jpg Views:	0 Size:	195.3 KB ID:	987130

    Milling out the aluminum with 1/16" dia. cutter.

    Click image for larger version  Name:	comgrow51.jpg Views:	0 Size:	218.6 KB ID:	987131

    A piece of approximately 2" X 1.75" sheet brass clamped down ready for cutting out the frame.

    Click image for larger version  Name:	comgrow52.jpg Views:	0 Size:	182.8 KB ID:	987132

    And we're off.

    Click image for larger version  Name:	comgrow53.jpg Views:	0 Size:	192.3 KB ID:	987133

    So how did I get to this point? Several software packages and a lot of hair pulling, not only in design work but machine performance. I'll get into the machines performance after showing what it takes to make a part with this method.

    First you will need a CAD program that puts out a DXF file for the next program. I use DraftSight Standard. No it's not free. I pay an annual fee to use. I didn't find it very difficult to use. No really steep learning curve on this software.

    Click image for larger version  Name:	comgrow54.png Views:	0 Size:	79.5 KB ID:	987134

    Once the DXF file is exported the next program I use is BamCam. This is a CAM program that takes your DXF file and after telling it what you want to do it'll produce the G-code file the machine needs to cut out he part. This is what it looks like when you first import a DXF file. Back in the CAD program you need to tell the CAD program to start or place a corner of you project on the "origin point". That's where the bottom left hand corner of the frame is located. This will be where you G-code program will start from.

    Click image for larger version  Name:	comgrow55.png Views:	0 Size:	56.4 KB ID:	987135

    This is what the finished CAM file looks like. It has been told what tool to use, where to cut, how deep, what feed, what spindle speed and so forth. Those green blocks are what is known as "tabs". They will hold the frame in place as it gets cut out. The tabs keep the part in place so it doesn't get wrapped up in the cutter or thrown off the machine. Hard to fathom, but I’ve seen both things happen.

    Click image for larger version  Name:	comgrow56.png Views:	0 Size:	86.5 KB ID:	987136

    Now that it's all finished and the software has done it's calculations to produce a G-code list that will then be loaded into the machine software. This is what a G-code file looks like for a simple project such as this. Note it runs off the bottom of the page.

    Click image for larger version  Name:	comgrow57.png Views:	0 Size:	108.6 KB ID:	987137

    You can physically go into the G-code and change parameters. It's nothing more than a text file. You could also write your own G-code by typing it into a text file format and load that in the machine.

    So here's what I start with. A 2" square piece of sheet brass. Yes I changed the size to better fit in the jig.

    Click image for larger version  Name:	comgrow58.jpg Views:	0 Size:	233.9 KB ID:	987138

    And here are some of the disasters. Five broken cutters, some unfinished cut's due to machine failure. This is what makes you a machinist. Just don't break the machine. That makes you a failed machinist.

    Click image for larger version  Name:	comgrow59.jpg Views:	0 Size:	121.8 KB ID:	987139

    But you feel like a real machinist when the part comes out good, except for one part that wanted to get into this picture instead of the last one. The machine almost finished when it lost the USB connection. I'll get into the all that a bit later. Note the tiny tabs left to hold the frame. These can be cut with a sharp box cutter or spur nippers.

    Click image for larger version  Name:	comgrow60.jpg Views:	0 Size:	136.3 KB ID:	987140

    Here's the frame has been separated from the rest of the brass sheet. A little bit of filing and it'll be ready for use.

    Click image for larger version  Name:	comgrow61.jpg Views:	0 Size:	150.5 KB ID:	987141

    And I quickly applied it to one of the windows to see what it would look like and for the purpose of this write up.

    Click image for larger version  Name:	comgrow62.jpg Views:	0 Size:	108.8 KB ID:	987142

    I need to cut out nine more for the engine house.

    Now the gory details of learning this machines idiosyncrasies. As I was working on getting the base and jig/fixtures designed and made I was having trouble with the machine. It kept giving errors will in a cycle. One problem was me. If the E-stop button is pushed in it actually start a cycle and run for a bit and then stop due to an error. I always kept getting he same error code as to why it stopped. I finally found out what it was from a guy on the Comgrow Face Book group. Make sure your E-stop button isn't on. Yup, that was the first problem solved. The next occurred while actually trying to cut parts. The machine kept stopping randomly anywhere along the cut path when it lost the USB connection. Having previously purchased a newer computer with more horsepower to learn Fusion 360 on, I hooked the machine to it and have not had a problem with it since. One other issue is that the machine has a lot of vibration whether it is cutting or just running through a dry cycle (not cutting anything). I've traced it down to the motor. This motor runs at 10,000rpm. It can be slowed down through programming, but when you're using a 1/32" dia. cutter you want to run at a high RPM. These types of motors are small and built to run fast but lack the balancing of the rotor to alleviate vibration. I'm looking into seeing if I can find a more suitable motor. Another short coming of a small machine as this is rigidity. Only weighing in a around 17 pounds you can't expect it to perform like a 2000lb Bridgeport. It will do for what I want to do with it. My next test subject for this machine will be the milling out of brass sides for a East Broad Top RR caboose. But this will be a while before that happens.

    My next adventure is to design a holder for the Cricut deep cut housing and deep cut blade. But first I need to finish the engine house before the April 15 finish date of a build challenge on another forum.

    Questions and comments welcomed.

    Until next time.

    Bernd
    Last edited by Bernd; 02-25-2022, 02:12 PM.

    Leave a comment:


  • Bernd
    replied
    Originally posted by k9wrangler View Post
    I just heard something fly right by, WAY over my head….

    Glad you’re having fun Bernd terrific patience….
    Keep following and you'll pick it up. It' my way of having fun modeling.

    Bernd

    Leave a comment:


  • Bernd
    replied
    joe Well you got to have the tooling in order to do the job.

    Bernd

    Leave a comment:


  • k9wrangler
    replied
    I just heard something fly right by, WAY over my head….

    Glad you’re having fun Bernd terrific patience….

    Leave a comment:


  • rrladmin
    commented on 's reply
    Bernd, looks like you are setting up a bridgeport there... LOL

  • Bernd
    replied
    Originally posted by rrladmin View Post
    Bernd, always a nice shop project !
    Joe
    Yes, it is when you have the tools to do it with too.

    Today I got the base plate installed and bolted down. It's with in .005" in 11" of travel. I'm happy with that. Next comes the jig that will hold the brass sheet metal.

    Click image for larger version

Name:	comgrow36.jpg
Views:	56
Size:	193.5 KB
ID:	986262

    Also got some tooling today. Finally ordered the right ER collets. The last set I ordered were ER16. A bit big for this machine. I figure I'll get an arbor for them and see if I can mount them on the Sherline. Along with those I got a surfacing bit. That ought to vibrate the router really good.

    Click image for larger version

Name:	comgrow37.jpg
Views:	52
Size:	178.5 KB
ID:	986263

    Click image for larger version

Name:	comgrow38.jpg
Views:	49
Size:	188.1 KB
ID:	986264

    Until next time.

    Bernd

    Leave a comment:

Working...
X