Roy's First Machine

[roy_okc]

Saturday, July 2, 2011 progress:

Got some more tedious stuff done today plus a little bit of prepping and thinking for my Z axis, so that's good.

Based on louieatienza's post above, I went ahead and ground down an old 15 mm Western Auto (anybody remember them) wrench to use to adjust my Rollon truck bearings while loaded in the TLV railing. Took quite a bit of time to get it down to the needed thickness.

I also ground off a corner on each of my pinion assemblies so that they fit under the overhanging 1530. Now the pinion gear fully engages on the gear rack and there is still a bit of leftover space.

I cut down the TLV rails for my Y gantry and mounted them with a truck on each.

Now to figure out how I'm going to build my Z axis and connect to my Y Acme rod. (Before anyone calls me out on using 1-start rod on my Y, it is there only for mockup; I'll have 5-start there eventually.) I have an idea, but will probably mock it up in scrap wood first to make sure the concept is sound.

So far, this is going together much easier and quicker than I had anticipated. Normally, the only luck I have is bad luck and everything takes at least twice as long as I estimate. If I can figure out my Z this quickly I'll be ecstatic.

That's all for today.

Roy

[louieatienza]

Louie,

Thanks for confirming your experience with the scrapers. Have you noticed any debris accumulating in the rails without the scrapers?

Yes, my trucks were covered with grease in the bearing area. Did you get yours from an Ebay seller in Texas, 41" long?

So far all of the bearings that I've pulled off and looked at have been on eccentric shafts. There is a possibility that I haven't encountered the non-eccentric versions as I may have first taken apart trucks from a couple ULV rails that I initially bought; will definitely look through my loose bearings today. I took the opposite approach to preloading mine, bottoming out 1, 3, and 5, then installing and adjusting 2 and 4; sure doesn't take much to go from too loose to too tight.

I cut out a notch in a piece of thin aluminum for my wrench, however, it is too thick for the TLV and I cut the notch too wide so it tends to spread and slip. I need to take a look in my assortment of cheap metric wrenches to see if I have one that size and grind it down.

Are you using single rail pieces? I'm hoping to be able to butt pieces together and extend past the 41". Alternatively, if that doesn't work well, I may purchase a long piece or two of ULV43 and cut it down. I think the ULV43 would work fine, but really like that the TLV43 truck has no way to move/rotate in its track where the ULV43 can, although with great difficulty.

Thanks,
Roy

Roy, the best configuration would be a T or TK, and U rail, as the T or TK will constrain the axis, and the U will allow for any misalignment. You can use two T rails but you have to make sure the alignment is dead on. You do not want to use two U rails, as it woudln't constrict side play.

The trucks that come with the U rails are exactly the same, except for the different sweeps. My experience is that the rails will catch dust, so I make sure to use dust collection whenever possible.

According to the Rollon guys, longer lengths can be achieved by butting rails together, though they come in pretty long lengths. You would havev to grind a "ramp" or "bevel" on the tracks to allow the trucks to movev smoothly which is how the factory does it, but I don't know how easy it is to grind the hardened surface. Pretty easy to cut with an abrasive wheel however..

[roy_okc]

Roy, the best configuration would be a T or TK, and U rail, as the T or TK will constrain the axis, and the U will allow for any misalignment. You can use two T rails but you have to make sure the alignment is dead on. You do not want to use two U rails, as it woudln't constrict side play.

The trucks that come with the U rails are exactly the same, except for the different sweeps. My experience is that the rails will catch dust, so I make sure to use dust collection whenever possible.

According to the Rollon guys, longer lengths can be achieved by butting rails together, though they come in pretty long lengths. You would havev to grind a "ramp" or "bevel" on the tracks to allow the trucks to movev smoothly which is how the factory does it, but I don't know how easy it is to grind the hardened surface. Pretty easy to cut with an abrasive wheel however..

So far, with about 50-55" of rail (41" + gantry cutoffs), I'm not experiencing any binding using TLV on both X rails. Also, butting them together, without any effort yet to ensure straightness, seems to work fine. I do have some capability to adjust the rails side-to-side, so should be able to zero them in well enough to use TLV; however, I do have enough ULV should that not work well.

Roy

[roy_okc]

Monday, July 4, 2011 progress:

Didn't have a chance to work on my machine yesterday.

Happy Independence Day!

Another day of good progress, including figuring out how to build my Z axis. I see the end of the mechanical build in site, I estimate that I'll have this phase done by July 17 at the latest and perhaps even this coming weekend.

I will mount ~6" pieces of 1530 to my lower truck and 1545 to my upper truck. The upper and lower pieces will be tied together with some 1575. I'm attaching NB 15 rails to the 1575. To attach my Acme nut to the Z assembly, I'll use a thin piece of 1530 and drill out the holes to accept the 5/16" bolts; this will be attached to one of the pieces of 1575. I'll attach a piece of 6"x12"x3/8" aluminum to the trucks and attach that to my Z rod nut using a similar 1530 spacer.

I would have had both NB rails attached today if I wouldn't have snapped the only drill bit I had of that size.

It looks like I'll have enough 5-start rod left over from my Y rod to use for my Z rod.

Tomorrow morning, I'll run to the local Fastenal store to pick up a couple more drill bits and a few bolts. I'll also order some more parts from Ahren at CNCRP tonight, hopefully I'll get them by Friday.

Should be able to get several hours in tomorrow. I might even be able to get my router plate attached to the trucks and perhaps even attached to the Z nut.

Roy

[roy_okc]

Pictures for July 4. Didn't attach to previous post.

[roy_okc]

I'm seeking opinion on my router mounts. At present, I have no way, at least none that I'm highly confident about, to make router mounts out of aluminum. Would MDF work for a while? If so, would a pair be strong enough to use to slowly cut some 3/4" aluminum when I get the machine running?

My current fallback for aluminum would be to use a woodworking circle cutter in my drill press on a pair of 3" wide pieces clamped side-by-side. I believe the cutter blade would be able to get through the aluminum. However, my concern with this would be the cutter blade catching on the center seam.

Thanks,
Roy

[PaulRowntree]

I'm seeking opinion on my router mounts. At present, I have no way, at least none that I'm highly confident about, to make router mounts out of aluminum. Would MDF work for a while? If so, would a pair be strong enough to use to slowly cut some 3/4" aluminum when I get the machine running?

I cheated by using 2 or 3 hose clamps to secure the router body back against the Z slider, which was a piece of Al channel with a block of MDF in the back to provide a stable seat for the router body. The photos on on the 5th post of my build log. An inside chamfer on the MDF would have been better.

http://www.cnczone.com/forums/cnc_wo...ver_cnc-8.html

Cheers!

[roy_okc]

I cheated by using 2 or 3 hose clamps to secure the router body back against the Z slider, which was a piece of Al channel with a block of MDF in the back to provide a stable seat for the router body. The photos on on the 5th post of my build log. An inside chamfer on the MDF would have been better.

http://www.cnczone.com/forums/cnc_wo...ver_cnc-8.html

Cheers!

Paul,

Thanks for sharing your method. How sturdy is is your router held like this?

Thanks,
Roy

[roy_okc]

Tuesday, 5 July 2011 progress:

After a trip to the Fastenal for drill bits and bolts, I spent today working on my Z assembly. This was definitely a low progress day. Although a good amount of time was spent trying to figure out how much travel to allow -- I ended up with 3.5" maximum travel with the truck mounting bolts about 6" apart.

I got the router plate mounted to my Z trucks, only badly miss-measuring (measured more than twice--not sure what I did wrong) one hole. The heat beat me back in before I was able to get the holes drilled and tapped for my Z nut, though.

Having all three axes sliding makes me a happy boy.

Roy

[PaulRowntree]

Paul,

Thanks for sharing your method. How sturdy is is your router held like this?

Thanks,
Roy

I see no flex between the router shaft and the Z sled that it is hose-clamped to. No evidence of loosening with use, but it is easy to check too.
Cheers!

[louieatienza]

Roy, a lot of folks here use the K2CNC router mounts, they're made of aluminum and priced well... I've tried the hose clamps, but find they work best in conjunction with a wood cradle or two for the router. Depending on your router, you might be able to use clamps for mufflers; they have a metal cradle and a u-bolt that you can mount to an auxiliary plate that gets bolted onto your z axis plate...

[roy_okc]

@PaulRowntree: Thanks for the information on flex (or lack thereof). Not really the way I want to go on this build, but something I might keep in mind for a possible small/cheap/portable build I have in the back of my mind for the future.

@louieatienza: The K2CNC mounts may be my solution. I'll probably see if I can make my own aluminum mounts as I'll have at least a couple weeks between finishing the mechanicals before I can order the electricals, but if that doesn't work out easily and safely with the tools and materials I have on hand, will probably go ahead with these. They look well made. Hadn't even thought about muffler clamps although I'd have a heck of a time using them I think. I worked at a tractor dealer as my first real job when I was young, some of the larger diesel exhaust clamps that I recall would be big enough for even large wood routers.

Roy