Starting long put off Gantry Rebuild

[Mountaincraft]

Been a while since I've been around...

Been making stuff, building up the shop, developing tips and tricks, trying to make a little money, dealing with health/money issues, getting old..

So there are a number of issues with my table, design issues, wear issues, and general improvements I've been wanting to make..

I've been collecting parts for more than a year, and planning in my head some of the things I want to do... and as of Yesterday, actually set upon the project, and began tearing things down this morning....

Murphy's law says someone will call and has an urgent project they need done, just about the time I get it torn down as far as it's gonna get torn down)

A 'partial' list of issues and upgrades...

1) I've been wanting to add a second limit switch on the second X axis rail, so that the table will auto square... So I bought 3 proximity sensors from CNCRP some time ago (2 for x and 1 for Y) and also a PC card for the PC to allows to parallel ports to control the BOB, allowing extra I/Os (no longer having to make choices, will have 'plenty' for virtually anything).. also bought a second cable, and a single gang panduit box to be mounted on the side of my control box, where a cover with (2) DB25 jacks will allow a much cleaner cable routing and connection method than what I have now...

2) I have had issues with pretty good sized 'round cut marks' that are left whenever the X or Y axis change direction during pocketing... These are near impossible to sand out (with hardwoods) and I have been 'hiding' this problem by using a texture after pocketing on things that will be visible... This limits what I am allowed to do, and adds a lot of time and effort and bit wear that is unnecessary... So, there are several issues that are allowing slop and flex in my design, that I plan to address in the rebuild.. There was no point in even attempting to adjust backlash until these significant mechanical issues were addressed.. In the mean time, I've just been living with it and accounting for it in design using things like texture.... One of the things that was a real problem is my wooden gantry mounts 'visibly flexed' when the router bit was pushed down into the material... Also, they were not constructed perfectly plumb, requiring some creative shimming (that I do not fully trust).. So I bought some of CNCRP's heavy duty steel gantry mounts and plan on replacing the wood ones with those...

3) When I assembled my machine, there were no drilling jigs available to drill the rails.. I did the best I could, but a couple of the holes drifted enough where there ended up being a situation where the distance between the outside of the rails 'could not' be pulled to within spec... as a result, there are a couple places where the bearings lose contact with the rail... I squeezed them together as best I could, but this resulted in over-clamping the bearings, and I am convinced caused some out of roundness on a couple of them, that over time resulted in a couple 'clunk' spots as the gantry moved back and forth that was getting worse over time... I am replacing the rails (drilled them with CNCRP's drilling jig), and also all of the bearings...

4) I have become tired of my dust shoe, and want to try something that moves with the router Z axis... I was thinking of getting Kent CNC's shoe, but I have grown fond of the LED lighting I installed allowing lighting of the work during routing, and providing the ability to see issues/mistakes/problems immediately and do something about it before they completely ruined a material.... His shoes do not allow room to do this, and also, his hose connection is 4", where as I need 2.5" (I know I could use an adapter), so I will probably make something 'similar' to his design (with the magnetically attached brush holder).. I have already bought one of the brushes and will be ordering the other 2 shortly...

5) My material bed/spoil board system... I tried to mimic Gerry's MDF cam system, but not realizing he had used nuts embedded below, I mistakenly thought that just the force of the cam was enough to hold things in place... It wasn't and as a result, I am constantly using jigs that have embedded nuts... this causes lots of hassle and other issues, so I want to redo the entire 4' x 8' spoil board using embedded nuts, and replaceable fences..

6) My router bearing overheat and this causes the bits to get pretty dang hot.... This has been an issue from the day I got this router, and I think I got a defective or remanufactured router that had bearing issues.. So I am going to tear it apart and replace the bearings and brushes...

7) I have loaded so much material in the storage area under the table, that the wheels I bought are overloaded.. At least one of them is crushed to way out of round and the table can not be moved... I plan to buy heavier duty rated casters, jack the table up, set it on blocks and replace the casters...

8) I want to add the functionality of auto corner finding to the system using Gerry's screen set.. I know he has also updated it at least once since I bought it, so I want to add that functionality and bring it all up to date and possibly even add a couple of custom buttons that would make life easier for me...

And so the journey begins....

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[Mountaincraft]

So the first thing I did yesterday was to drill/cut the new rails for the Y and Z axis...

I screwed up pretty much right off the bat... I put blue machinists marking dye every where I wanted to drill and used a scribe to mark the holes, and where I wanted to cut the rails to length...

I had marked the first holes on each end of the Y axis (gantry) so that they would be 1 inch from the ends of the new rails.. This was exactly where I had them on the existing ones... But when it came time to drill them, I found out that putting them that close to the ends of the rails would cause the jig's locating pins to be off of the rail, causing the jig to be ineffective.. so I moved them in to where the jig was flush with the end of the rail, resulting in them being an inch and a half in, instead of an inch.... all is well and good...

However, when I went to cut the excess steel off of the first rail, I saw a line where there was no hole, thinking this is the line I scribed for that purpose (forgetting that I had moved the end holes, and it turned out to be the original line that was to mark the holes 1" from the end... As a result, I cut one of the rails an inch short... This will not cause a problem with functionality, but ti will look weird... So now I'm brainstorming what I can mount in that one inch gap at one end of one rail so that it looks like this was 'intentional'...

[Mountaincraft]

Dust Shoe to be replaced

[Mountaincraft]

There was also an issues with the hose rubbing against the corner of the gantry riser causing it to eventually tear, so I will be replacing the hose and coming up with a better mounting method than just using wire to tie it to things.... (maybe I can use that 1" gap for a mount of some kind! )

[Mountaincraft]

The offensive Gantry mounts that are flexing...

[Mountaincraft]

Has anybody ever replaced the press fit bearing in the standard carriages before? I was thinking of using a drill press and inverted drill bit to do this? Will that work or do I need something with more 'oomph' to press the old pin out and the new one in?

[Mountaincraft]

The Mess...



- - - Updated - - -

[rusel]

Hi
I have used a vice and some sockets to make a press and die for removing bearings.
Hope this helps
R

[Mountaincraft]

that's what cory just said elsewhere... I'm gonna give it a try with a C clamp.... Easier than I thought... thanks!

[wizard]

Been a while since I've been around...

Been making stuff, building up the shop, developing tips and tricks, trying to make a little money, dealing with health/money issues, getting old..

Tell me about it, I spend enough on health and other issues to buy a 4x8 castiron router.

So there are a number of issues with my table, design issues, wear issues, and general improvements I've been wanting to make..

I've been collecting parts for more than a year, and planning in my head some of the things I want to do... and as of Yesterday, actually set upon the project, and began tearing things down this morning....

Murphy's law says someone will call and has an urgent project they need done, just about the time I get it torn down as far as it's gonna get torn down)

A 'partial' list of issues and upgrades...

1) I've been wanting to add a second limit switch on the second X axis rail, so that the table will auto square... So I bought 3 proximity sensors from CNCRP some time ago (2 for x and 1 for Y) and also a PC card for the PC to allows to parallel ports to control the BOB, allowing extra I/Os (no longer having to make choices, will have 'plenty' for virtually anything).. also bought a second cable, and a single gang panduit box to be mounted on the side of my control box, where a cover with (2) DB25 jacks will allow a much cleaner cable routing and connection method than what I have now...

While that may be helpful it sounds like your machine has so many weak spots it wouldn't matter. I'm of the general option also that if you can significantly square the machine with your servos/steppers then the machine isn't very stiff.

2) I have had issues with pretty good sized 'round cut marks' that are left whenever the X or Y axis change direction during pocketing... These are near impossible to sand out (with hardwoods) and I have been 'hiding' this problem by using a texture after pocketing on things that will be visible... This limits what I am allowed to do, and adds a lot of time and effort and bit wear that is unnecessary... So, there are several issues that are allowing slop and flex in my design, that I plan to address in the rebuild.. There was no point in even attempting to adjust backlash until these significant mechanical issues were addressed.. In the mean time, I've just been living with it and accounting for it in design using things like texture.... One of the things that was a real problem is my wooden gantry mounts 'visibly flexed' when the router bit was pushed down into the material... Also, they were not constructed perfectly plumb, requiring some creative shimming (that I do not fully trust).. So I bought some of CNCRP's heavy duty steel gantry mounts and plan on replacing the wood ones with those...

err there is always good reason to minimize backlash in your linear drives. It just makes it easier to address the rest of your issues. and frankly backlash can cause exactly the types of problems you are describing.

3) When I assembled my machine, there were no drilling jigs available to drill the rails.. I did the best I could, but a couple of the holes drifted enough where there ended up being a situation where the distance between the outside of the rails 'could not' be pulled to within spec... as a result, there are a couple places where the bearings lose contact with the rail... I squeezed them together as best I could, but this resulted in over-clamping the bearings, and I am convinced caused some out of roundness on a couple of them, that over time resulted in a couple 'clunk' spots as the gantry moved back and forth that was getting worse over time... I am replacing the rails (drilled them with CNCRP's drilling jig), and also all of the bearings...

4) I have become tired of my dust shoe, and want to try something that moves with the router Z axis... I was thinking of getting Kent CNC's shoe, but I have grown fond of the LED lighting I installed allowing lighting of the work during routing, and providing the ability to see issues/mistakes/problems immediately and do something about it before they completely ruined a material.... His shoes do not allow room to do this, and also, his hose connection is 4", where as I need 2.5" (I know I could use an adapter), so I will probably make something 'similar' to his design (with the magnetically attached brush holder).. I have already bought one of the brushes and will be ordering the other 2 shortly...

I'd strongly recommend staying with the larger hose fittings as they do remove dust and swarf better when coupled with a suitable dust collector. it can be a tough fit on smaller router designs though so you need to balance your collection abilities against physical size.

5) My material bed/spoil board system... I tried to mimic Gerry's MDF cam system, but not realizing he had used nuts embedded below, I mistakenly thought that just the force of the cam was enough to hold things in place... It wasn't and as a result, I am constantly using jigs that have embedded nuts... this causes lots of hassle and other issues, so I want to redo the entire 4' x 8' spoil board using embedded nuts, and replaceable fences..

6) My router bearing overheat and this causes the bits to get pretty dang hot.... This has been an issue from the day I got this router, and I think I got a defective or remanufactured router that had bearing issues.. So I am going to tear it apart and replace the bearings and brushes...

Some routers are beer than others in this regard. You may want to consider the value of the router plus part and time, against the purchase of a router known to do well on those machines.

7) I have loaded so much material in the storage area under the table, that the wheels I bought are overloaded.. At least one of them is crushed to way out of round and the table can not be moved... I plan to buy heavier duty rated casters, jack the table up, set it on blocks and replace the casters...

Well the good thing is all that material should provide you with considerable ballast.

8) I want to add the functionality of auto corner finding to the system using Gerry's screen set.. I know he has also updated it at least once since I bought it, so I want to add that functionality and bring it all up to date and possibly even add a couple of custom buttons that would make life easier for me...

And so the journey begins....

Sounds like you have a good project going here.

[Mountaincraft]

Yes, the wooden risers I had built were not very rigid at all... when I would screw up and hit something (leave something on the rails or forget to take the battery drill off the table, etc.) and knock the table out of whack (tweak the gantry system), it was a nightmare to get it all squared again.. and if I was in the middle of a project and in panic mode, then I'd often compound it by forgetting a step in the resquaring of the table and then just ruin the project when I restarted... So I want to automate that whole process...

So today I rebuilt 4 of the carriages and installed them, installed the new risers, and installed the gantry on the new risers.. Reinstalled the X axis motors, and installed the upgraded tensioners... Adjusted everything and squared it all up, and torques all the fasteners down... Ready to start on the Y axis...

I didn't order enough bearings (I guess I forgot how to count/multiply), so I won't be rebuilding the other four carriages until I get some ordered and they have time to ship (probably arrive Saturday at the earliest)

Tomorrow I can install the new Y axis rails, clean and reinstall the rack gear, and then while I'm waiting for the bearings, I can replace the limit switches with the new proximity switches and start rewiring things...

The gantry feels nice and stiff...

If everything goes well, with the exception of the dust shoe (still haven't decided what direction I'm going yet, and am kicking ideas around in my head), I should have the table back up and running sometime around the middle/end of next week... Then I can go about tramming the router and measuring/setting backlash....

Gonna be nice to have some of these nagging issues resolved...

[Mountaincraft]

Installed and adjusted the new Y axis Rails using the new aluminum spacer blocks.. From the measured rail to rail at about 10 places and it's with .006... 'WAY' better than before....

Rebuilt Y carriages and installed them... installed Z axis Riser plate and adjusted carriages... Cleaned and installed rack gear, Y axis motor and installed upgraded tensioner....

Ordered another 8 bearings...

Now, I will start fooling with the wiring while I wait for the bearings...

[Mountaincraft]

So, most of the way done.... here's a pictorial story of things..

Installed the new upgraded ACME nut, replaced the bearings on the Z Axis Carriages, and assembled them to the Z plate..




Installed the Z axis assembly and adjusted the bearing carriages... view from back side at the end of the 5 start ACME screw


front view




Reinstalled the bearing block and the nema 23 motor mount I have that I repurposed for the limit switch and also as a mount for the new Dust Shoe...




Since I originally built the machine, CNCRP now provides a transition block for the router mount... Bought one to try out to see if it helps in the alignment/tramming process... If it proves to not be a help, I can always go back to mounting the thing direct...


Installed the mount and router...

[Mountaincraft]

Next I replaced a couple of cables to reflect the change in the way I was going to do homing/limits, pulled them back in the W/T conduit, and mounted the conduit back to the Z Axis Carriage (but this time I did not reinstall the mounts for the old dust shoe) then tried it at both extremes of Y axis travel to make sure all was good...




Next I hooked up the Y axis proximity switch installed on the custom stop/mount I made for the Gantry (cut from a piece of angle iron and painted red)


Then I tapped the ends of the 80/20 rail supports installed standoff bolts, mounted the stops/proximity switches on both rails, and ran the wires for them to a terminal block where there were connections to the BOB already waiting for all three of the new switches.
X2 switch (A axis)


X1 switch (X axis)

[Mountaincraft]

I had installed a PCI parallel port card in the PC that I got from PMDX, and even though I had installed the drivers, carefully wired and assigned the ports and pins, verified that the PMDX was sensing the switches, etc, I could not get it to work..

So I called PMDX and had him help me through the set up.. Apparently, the new PCI card is not as plug and play as it appeared.. All that was needed was for him to manually walk me through assigning the port addresses in Mach 3..

Then the thing worked, and I tried out and adjusted the homing switches...

With the new risers, Gantry rails and all that. the thing is much quieter smoother than it was before.... the whole thing is a lot stiffer... It just feels better in general...

Plus, now I have increases X axis travel and am able to auto square the machine...

[Mountaincraft]

So now I am redoing the vacuum system....

I made a custom bracket out of unistrut, and attached it to the back of the Y axis carriages with some long bolts as standoffs... I ran some 2" ABS under the table, shortened the hose, and shortened the attachment point of the cables to the gantry so that neither will drag on the floor anymore... I am now waiting for some more hose, the brushes for the dust shoe, hose clamps and a couple pieces of flexible 1/4" fiberglass rod that I will use as 'stiffeners' for the hose and cable conduit that goes to the Z Axis carriage.... Hoping this will keep them from flopping over like they did before...

When the new hose comes, it will go from the ABS section at the end of the gantry and be attached with velcro straps to the flexible conduit.. The same things will happen with the cables and hose that goes to the gantry from the table base...

It's all just loosely fitted for now.. will be cleaning it all up when I get the parts...

[Mountaincraft]

So, to deal with how the liquid tight conduit carrying all the cables to the Z Axis carriage kept flopping over and causing issues with the vacuum hose becoming chaffed (and eventually tearing), I bought a couple 1/4" x 4' fiberglass rods (like are used for tent poles and fishing rods)... I cut (2) 20" long pieces from one and used ferrules to attach them to each end of the other 4' piece.. I strapped it temporarily to the conduit with tie wraps to see if/how it would work and what the best orientation would be... I ordered a bunch of double sided velcro that I intend to use for the permanent attachment, but I I might use hose clamps if necessary.... still waiting for hose/clamps, and fitting to arrive (hopefully all be here by Thursday evening)...

I think it's gonna do fine... so now I gotta make some standoffs to attach the hose to the conduit (and allow it to slide back and forth) with a pass through between them for the new rod...

will add a video in a bit of how it works... (gotta upload it to YouTube)

[Mountaincraft]

My first ever YouTube Video!

[nlancaster]

What is that diagonal bar on the back of your gantry for? Because it is severly limiting your travel.

[bhurts]

I think it is attached to the backside of the carriage and moves with the axis. Probably to load the bearing blocks together or for general support.

Ben