[DeadTom]

Don,
Looking real nice, please keep the pics coming.
Thanks for sharing,
Tom

[harryn]

Hi, nice stiff build - I am a big fan of fixed gantry setups.

I used 2 sets of bearing trucks to get the extended length stiffness, but on a 4x8 router.

You can go much longer with that plate and still be ok. cncrouterparts also makes a single longer truck.

Z axis travel is important for work - don't cut yourself short on it.

[RomanLini]

That's looking very respectable so far Don. Had you considered turning that Z plate upside down, so its side bearings are lower and closer to the tool (ie less deflection). Of course that depends on the length fo the spindle and tool.

On my machine I used a drilled plate with 10mm grid, so I can easily lift or lower the spindle by screwing it on at a different height, then set the max Z travel at 60mm. The result is that there is very little deflection distance when using short tools (as you do for heavy cutting) but if using long tools etc I can just re-mount the spindle higher up and still keep the bearings low and close to the cut for max rigidity. Hope that makes sense.

[DonFrambach]

Made the plate to allow the carriages to be mounted back to back. The first two photos show different views of the plate.

Mounted the plate using extended carriages available form CNCRouterParts.com. This reduced the Y travel from a theoretical 16 to a potential 14 inches. The potential travel is shown in the next two photos.

I then mounted the Z axis to the plate again using extended carriages. This severely reduced my Z travel to a little less than 2 inches. I'm going to get another steel plate to increase the Z travel but I haven't figured out how much I'll need.

Oops!, booboo shown in the last picture. I forgot to account for the height of the screw heads holding the Z carriages in place. I'll need to make a small relief in the plate for the two middle screws. darn!

[DonFrambach]

Cut the relief to regain full Y axis travel. The screw heads now clear the bearing block.

[DonFrambach]

Discovered another problem. The motor coupler that I purchased from CNCRouterParts.com is too wide to clear the 1/4" steel plate as I mounted it on my Y axis. The mount works just fine when the steel plate is offset from the mounting block as designed by CNCRouterParts.com. Clever me thought that it would be better to have the steel plate hold the smaller 8020 parts in alignment.

I was about to remove the portion of the steel plate that interfered but fortunately discovered that the parts from DumpsterCNC.com will fit over the plate. I purchased a motor coupler and two shaft couplers from DumpsterCNC.com.

The photo below shows an aluminum motor coupler from CNCRouterParts.com and a delrin motor coupler form DumpsterCNC.com

[DonFrambach]

Assembled the Y axis. Good news and bad news.

The good news is that I have 14" of Y axis travel.

Bad news is that I can't make Y axis moves faster than 30"/minute. At faster rates, the Y axis makes a terrible buzzing sound. Could I ask more knowledgeable folks a couple of questions?

Is the buzzing sound caused by lead screw whipping?

I have a 1/2" 10 tpi single start lead screw. Would I be better off with a 1/2" 10 tpi 5 start lead screw which would increase travel 5x for each turn of the lead screw?

[harryn]

Hi, most likely it is the stepper motors. At some frequencies, they will go into an oscillation / buzzer sound. Search for dampers on the forum, there are plenty of experiences with this.

[chimpera]

screw whip shouldn't be a problem. Try setting your acceleration really low. Otherwise its a matter of to much friction on the rail, or the screw. Is the g540 picky about the pulse length coming from the pc?

[DonFrambach]

Thanks! It was friction between the leadscrew and the delrin nut. With a little lubrication I'm up to 75"/min. Here's a YouTube video:
[nomedia="http://www.youtube.com/watch?v=0XNEnUm6S0w"]YouTube - Y axis movement.MP4[/nomedia]

[DonFrambach]

Z axis is assembled. There is about 5" of Z axis travel.

[acondit]

Don,

I was having problems with the Delrin nuts on my router, and a little lubrication solved my problems also.

Alan

[DonFrambach]

Alan,

What did you use to lubricate?

Don

[acondit]

I used a little tube called SuperLube. It has polytetrafluoroethylene (PTFE) , a strong, tough, waxy, nonflammable synthetic resin.

It works really well. But CarveOne and Khalid have given me a couple other ideas. CarveOne suggested Dupont's "Teflon Mulit-Use Dry, Wax Lubricant" spray. It sounds pretty good also. Available at Lowe's.

Alan

[ger21]

I use pneumatic tool oil. I found that it works better than the dry lubricants I tried.

[DonFrambach]

Made a plate to mount the spindle from some aluminum angle (6061-T6). A Taig ER-16 spindle is shown attached to the mount.

[acondit]

Don,

It is looking good.

Alan

[calgrdnr]

My 2 cents , I have found that liquid wrench - "Silicone Spray" works great
and no mess

Kent

[Jay C]

Thanks! It was friction between the leadscrew and the delrin nut. With a little lubrication I'm up to 75"/min. Here's a YouTube video:
YouTube - Y axis movement.MP4

How many starts are your leadscrews? I'm guessing single 10tpi right?

[DonFrambach]

How many starts are your leadscrews? I'm guessing single 10tpi right?

You're right, single start 10 tpi. I'm wondering if 5 start would be better.

Don