[Silver-Fox]

Greetings everyone!
After reviewing several sets of plans and numerous forum posts I've decided to build the CRP4848 from CNCRouterParts. I've been into woodworking for a while and I've always wanted a large CNC router.

I have a little bit of experience with these machines. My first CNC was the PhlatPrinter III kit from Phlatboyz.com It is a great machine, but I've been pushing it to the limits and I want more.

I ordered the complete CRP4848 kit and NEMA 23 electronics. No matter how much I read, I don't think I'll really grasp everything until I get my hands on it. Even then, I'm sure I'll still have questions.

[Silver-Fox]

The base is 57"x60" and ~ 3' tall. There will be 2 storage areas underneath. One side will be able to store materials up to 2'x4' in size. The other side will have a couple of selves for random storage.

This base is gonna be heavy!

[cambosoup99]

Have fun. ahrens cnc kits should go together pretty smoothly, just remember to read the tips section on machine construction. As far as the other stuff, be prepared to hit snags here and there.

[DonFrambach]

Can't tell from your drawings. Are you going to skin both the top and bottom of your table top to make a torsion box?

[Silver-Fox]

I wasn't planning on skinning both sides of the top. The top surface will be 3/4 oak ply and the frame is 2x6s with 2x4s for supports. I think it will be strong enough.

Can't tell from your drawings. Are you going to skin both the top and bottom of your table top to make a torsion box?

I made some good progress today. The base is 75% completed. All that remains is to add the cross support 2x6s on the ends and Oak ply. I cleaned up all of the edges of the lumber before assembly, so you can see in the picture that I made a mess.

CNCRouterParts have been awesome. I've never ordered from them before, but I can assure you that I will order from them again. They processed my order and started shipping items within a couple of days. Their website states a 10-14 day lead time before shipping kits. I was very pleased to see the shipping notification emails so soon. I've received almost all of the parts that are required. Only 1 box left enroute, it should be here this week.

[Silver-Fox]

The construction of my CRP4848 is complete. Overall the build went very smooth. It took <12 hrs to assemble the machine. I only had problems with two components. 2 of the R&P plates needed to have one of the bolt holes tapped. The hole for the rack gear was not threaded all the way on two of my plates. Once i tapped those holes, everything was back on track.

The kit from CNCRouterParts.com is awesome. The machine was easy to assemble and adjust. I would definitely recommend them and their products.

I do have an issue that I need help with. Once the machine was assembled and Mach setup I started moving the axis around. That's when I noticed the problems.

My axis are making a loud thumping noise at random spots, jerking the machine. I thought that I had a mechanical issue, so I adjusted all of the linear components. The thumping was the same.

I disconnected the motors from the rack and ran them and the belts. Thump still there. Then I ran the motors without the belts. The thump is still there, it's just harder to hear.

The video shows what I'm talking about. At :03 and :12 you can hear the thump. This is happening on all axis.

What did I miss?

motorthump.3gp - YouTube


Thanks

[alan_3301]

I couldn't hear the thumps in the video, but I did notice something.
I'm not sure if its the sound of your camera or my computer, but the stepper should hold a single pitch when moving a constant speed.
I am hearing nah-nah-nah-nah-nah as it rotates. It should be naaaaaaaaaaaaaaaah.
I hope that technical explanation makes it clear.

Something with the wiring or drivers maybe? Is the motor pulley rubbing on the motor?

[ger21]

Could be that your PC is not putting out a good, clean pulse stream. Run Drivertest.exe in the Mach3 folder and see what you get. You want to see a smooth, flat line with no spikes.

[Silver-Fox]

Thanks for the replies Alan and Gerry.

The video I posted was a little deceiving. The pulsing sound must be from the camera, it sounds fine here.

I ran drivertest.exe and it looks fine to me. I attached a screenshot.

I also made another video with everything hooked up. When the motors thump, i can feel it.

I'm running windows 7, was there something about bios settings?

Thanks again for the help!

https://www.youtube.com/watch?v=wE81...e_gdata_player

[ger21]

What happens if you jog at about 50% of the speed in the video? It almost seems mechaniacal, as it appears to only do it right after you start jogging?

I would think that if it were the PC, it would be more random.

[Silver-Fox]

What happens if you jog at about 50% of the speed in the video? It almost seems mechaniacal, as it appears to only do it right after you start jogging?

I would think that if it were the PC, it would be more random.

It happens at all speeds and it's hard to show it on the videos, but it's definitely random. Sometimes the machine will travel to the end and only thump once, other times it's three or more times. I'm pretty sure it's not mechanical. I can run each axis through its full range by hand and it rides smooth. I've checked for square and adjusted all of the linear components. The reason i was starting and stopping in the video was because of a new problem. When i jog from the keyboard, the machine will pause for a second or two then continue. If i jog from the onscreen buttons, it's fine.

It has to be electrical or software, it does it with all four motors.
I'm really scratching my head here. I'm tempted to load Windows XP and try that.
I really appreciate you taking the time to help, especially during the holiday.

[BuckNaked31]

I built one of these machines, mine started thumping... Turned out to be a broken skate bearing... Just a thought...

[Silver-Fox]

I built one of these machines, mine started thumping... Turned out to be a broken skate bearing... Just a thought...

Thanks for the reply Buck, but I've checked all of my mechanical parts. Also, the problem happens on all 4 motors whether they are hooked up to the machine or not.

I installed Windows XP last night and I thought the problem was solved. I ran my X axis back and forward 3 times without a thump. Then it started again.

Could something be overheating? It was 40F last night in my garage, so it's not like I'm working in a hot environment.

I've checked the voltage coming out of the PS and it's a solid 47.7V.

Please keep the suggestions coming, I'll try anything.

Thanks

[BuckNaked31]

Sorry, I missed the all 4 motor part. Is the controllers computer a Dell?

[ger21]

Did you install any other software other than XP and Mach3?
What processor does the PC have?
Is the bios set to Standard or ACPI? You can chck the device manager to find out.

[Silver-Fox]

It is a Dell optiplex 740
Amd Athlon 64 X2 2.6ghz
4 Gigs of ram

I installed Windows XP and Mach 3, nothing else.
I'll double check the bios when i get home.

[ger21]

Go into the bios and see if there is a C1E setting, and disable it if there is.

[Silver-Fox]

Go into the bios and see if there is a C1E setting, and disable it if there is.

I could not find a C1E setting. Also, the computer is set to ACPI.

[ger21]

Try setting it to standard, but it may require a re install of XP.

[Silver-Fox]

Well thanks to all of your suggestions and a phone call from Ahren, my machine is running smooth. Just like Gerry suggested, I switched my pc from ACPI to Standard. I also updated the computer's bios, it was pretty old.

It took a little bit of work to get XP to boot up properly after switching the ACPI driver, but it seems that all is well now.

I ran through the calibration on all axis, then tried a few test files using a sharpie and they turned out great.

Thanks again for your help, I'm sure it will not be the last time!