David Sohlstrom Mods and build log

I’m starting this thread to document the Mods and building of my X-Carve.

My machine will not be your typical X-Carve. It will start out as a 1000 X 1800 X 117 machine. It will be controlled using a Linux computer and LinuxCNC control software. It will have 4 Nema 23 stepper motors at 280 oz and a 48 VDC power supply going to a Gecko G540 4 axis driver. It will be configured with full homing and limit switches.

The X axis for a standard machine will become the Y axis at 1000mm. The makerslides will have a 3/16" steel spline sandwiched between them.
The Y axis for a standard machine will become the X axis at 1800mm and will have at least 2 mid span supports. The drive belts will be replaced with 9mm wide belting and 9mm wide sprockets. There will be custom made end clamps that have positive clamping of the belting.The end plates will be new and be no less than 50mm taller than standard end plates. Plates will be .25" 1018 steel.
The Z axis will be a complete new design. It will be reversed with what would of been the makerslide traveling up and down. The V wheels will be replaced with linear slides and will be fixed to the carrage. The stepper motor will be direct coupled to a 10mm ball screw with 4mm pitch.

The 20X20 rails that tie the end rails together will be replaced with 3 20X40 rails. The work surface will be 25mm thick expanded PVC foam board. It will be drilled for a grid of clamping threaded inserts and will have a grid of reamed dowel pin holes for locating pins. I will build a custom mount to hold an electric drill with the ability to offset it both left and right of the Z axis center line.

This will not be your typical 8 hour assemble time. :grinning: There are several custom parts that have to be machined. I am lucky in that I have a complete machine shop including a Tormach 770 CNC milling machine that will be used to make most of the new parts.

Here is a PDF of what the gantry and new Z axis will look like not all of the parts are there yet.

Dave

x-carve_gantry.asm.1.7.pdf (3.4 MB)

5 Likes

I forgot the other important mod.

I will be designing and building a high speed spindle that will have a draw bar and R8 style collet. The brushless DC motor will set off to the side and belt drive the spindle. I will also build tooling similar to Tormachs TTS tooling system only smaller. Then I will be able to do multi tool jobs and use tool length offsets G43.

I would of liked to do an R8 spindle and use the tormach TTS that I have but I’m not sure that would be a good idea.

Dave

Hi Dave, I cant wait to see this come together ! :Looking forward to your updates

I can’t wait to read as you go along Dave. That spindle sounds like a big project just by itself! You got me to do some searching on the TTS system. Very nice indeed. Came across this video of a guy making his own tts tool holders, and he published the g-code!

Looks great! How much rigidity do you think the 20x40s and steel plate spine will add? What materials do you plan to cut?

Good morning David, it is nice idea. Looks like you are revolutionary brainy guy (in a good way). Have you ever think about working on changing this belt system to Ball Screw system setup. I’m always fascinated to have solid Ball screw running all X and Y axis equipment. Do you think it is possible.

Alan

The longer the axis the larger a ball screw has to be. The reason for this is to control screw whip as length and speed go up. The other way is to use traveling ball nut with a fixed screw. That is harder to do with the added bearings and belting to rotate the ball nut.

If you use rack and pinion gearing you have to control the backlash and that gets involved. There are companies doing it on there plasma cutters.

The next step is roller rack that eliminates the backlash but is very expensive.

Here are photos of the linear slides and ball screw that will be used on the Z axis.

Dave

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There are 4 of the linear rails on the Z axis. I would of liked to use 2 with longer rails and 2 trucks per rail but I have had these for a long time so they are getting used.

Dave

Eric

I think the combination of the 20X40 and the 25mm expanded PVC board will give me a nice solid work surface. Because of the cost of the PVC board it will not be a waste board. There will always be a 1/4" MDF board between it and the material being machined.

Material will be a lot of baltic berch plywood and styrene sheet making frames, hull plating and pilot house parts for model tug boats.

Dave

Thanks Dave. I was just wondering other machines running straight on slides driving by nice Acme Screw or similar.

By the way Dave, not to change the thread topic but those steam engines you build are amazing. How much time do you think one takes for you to make?

John

I don’t count the hours. The one for the W. T. Preston has been close to a three year project. I am getting very close to having it finished.

We started with some photos of the real engines and went from there.

Dave

But its likely a logarithmic function, you can never really get to “done” :smiley:

It shall be called: D-CARVE

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LOL that’s funny. thanks

Dave

Well My machine arrived with UPS yesterday. The box with the 1800 MS in it had one end crunched so I opened all the boxes to check for damage. All OK.
I brought a few small parts in the house. The MS for the Z axis, 1 V wheel, 1 smooth idler roller and 1 Y axis end plate.

Here in is the problem I found. When I held the V wheel against the MS and held it up to the light I could see a lot of light between the V wheel and the MS. The angle of the V wheel was not 90 degrees.

Today I took all of the V wheels out to the shop and checked every one. Of the 20 V wheels all were off. I got out my good protractor and a gauge that I could set to the angle of the wheels. They very between 87 degrees 20 minutes and 88 degrees 32 minutes.

They all contact the rail just at the very rim of the wheels. I can’t see this as being a good thing.

I’ll check with Inventables on Monday and see what they have to say about the problem.

Dave

Any update on this?

The information I was given was that they did not call out a tolerance on the angle of the wheels so what we get is what we get.

It is my opinion that the angle of the V of the wheel is important to good operation of the machine. I guess that if I want wheels with a much better tolerance on the angle of the V on the wheels then I will need to machine my own wheels. I’m lucky in that I have the equipment to do that.

Dave

Any new updates on this project?

Well I got casters in and mounted to the lift base I will mount my machine on.They give me the ability to lift the base onto the casters for movement and then let the feet back down to the floor when I get it where I want it. The base is from an old computer digitizer that has electric lift and will tilt for storage. Have to mount the rails for the machine.

Also I’ve been refining my Z axis in CAD and hope to start machining soon.

Dave