[arrio]

Well, I am finally getting back to building this LC50B. I bought the basic kit from Lionclaw a couple years ago. I assembled the parts that came in the box, but stopped when I had to start on the table portion. and its been sitting collecting dust since then.
A conversation with a close friend and an agreement to allow me to build it in his garage, fired my renewed interest in completeing the project.

I have collected all the hardware materials for the router like the acme screws, Dumpster nuts, HobbyCNC controller, 305oz steppers and more assorted hardware bits. Actually I purchased the acme screws twice. The first time I bought 1/2x10, then I read where some folks were having great results with the 1/2x10 2-start. So I bought the 2-start rods and nuts and clamps to go with it.

Currently I am painting the Gantry parts. I have decided to go with a nice clear finish. The birch wood looks too darned nice to cover up with regular color paint. I now have 3 coats on them and the sheen is really coming out. I'll take some pics tomorrow (hopefully).

I have the table skins cut and fitted. Found some decent 12mm birch ply at Home Depot. Now I need to plot and drill all the 1/4-20 nut plate holes and bottom access holes in the skins.

The black Gas Pipe has been chucked in a lathe and sanded/filed smooth.

The HobbyCNC controller is near completed and housed in a nice steel electronic cabinette/box.

This pic is from when I first started, assembled sanded and ready for paint. I couldn't decide wether to paint a solid color (white) or clear coat it.

[arrio]

Well I had a nice long day in the garage today. Moving along on the LC50B. I did manage to bring out the camera today.
I put the last coats of clear on the gantry parts, as I'm now pretty satisfied with the depth of shine.
I epoxied the steel tubes to the gantry cross beam, useing 30 minute epoxy. Finally got all the main table parts trimmed and fitted. Most of the interlocking ribs fit pretty well with just a little cleaning up of the slots with some 150 sandpaper. Some of them required a good bit more to get them to slide together with a light push.
The table skins were pulled back off to have the holes drilled for the 1/4-20 blind nuts and the series of large access holes in the bottom skin. Tomorrow I hope to try to glue the top and bottom skins.

Alfred

[arrio]

Another fine day in the shop. Progress on the gantry and the main table. Not so much on the table. Those bottom holes were giving my hands a workout. Decided to hold off on cleaning up/ sanding the holes in the bottom skin till I get my drum sander out. The large holes were drilled with a "hole saw and hand drill. They turned out pretty clean, but they still need a bit of work to get them smooth. And theres a lot of them.
Assembled more of the gantry and the Z axis. Not happy with the Z slide. The plastic bushings called out in the drawing were terribly sloppy. I managed to snug them up somewhat, but they will have to be replaced. Will be looking into some Thompson linear flanged bearings.

Not looking forward to glueing the skins to the table frame. Wood glue dries way too fast to be able to paint all the contact surfaces.

I am on the lookout for another computer&monitor to run this thing.

I need some more long 1/4-20 all thread rod, and hardware to mount the steppers.
Not quit sure what to do for the stepper mounts. There is a lot of peices to glue together for a standoff. But does a long bolt go all the way through, or just a short screw throught the stepper to the mount?

[arrio]

I'm getting the main table ready to glue up. But I have a problem.
There is so much contact area with the rib structure, what glue should I use that will allow enough working time to coat everything and not start cureing before I'm ready to lay the skin down? Also the same question for gluing together all those ribs? I have used regular "Wood Glue" on the other parts, and I know that stuff starts skinning over in about a minute.

Thanks,
Alfred

[harryn]

You sure do nice work. How the heck people hand drill holes that nice I have no idea. It makes me embarressed to show my project. Oh well.

I know what you mean about glue dry time. Here is a link to Rockler's site and their glue selection. I wonder if a veneer type adhesive would help?

http://www.rockler.com/CategoryView.cfm?Cat_ID=1511

I remember my Dad used to use contact cement for large parts sometimes. He would put the glue on each side, let it dry, then use paper to keep them separated until it was all aligned. It was a one shot / no corrections trick, so that would be perhaps high risk.

[arrio]

I have had mixed results using contact type adhesives. Sometimes they held very well and others seem to seperate after a while. Not sure I want to experiment with this project. Also. there is no fudging the positioning of the parts. Once contact is made, you're committed.
I am thinking Elmers white glue. Should have plently of work time to coat all the contact surfaces. It also dries clear, so that is a plus.
Not sure I can do it, but I'm concidering deviseing a vacume bag setup to clamp the skins. Otherwise I'll need lots of weights.

[radcliffe]

Stay away from the contact glues not good for stress joints or torsion box constructions.

The slow-plastic resin glues such as weldwood and cascamite are good to use, need long clamping time. Need about 24 hours to cure. Work best with vacuum press.

Another plastic resin glue is Resorcinol. This glue is used in boat buliding and repairs complete water proof after cure, but leaves dark glue line on light color woods.

Titebond/Titebond II extend has been formulated for slower set and longer open time 15 minutes.

Hope this helps,
Harold

[CarveOne]

I would recommend Tightbond or Titebond II also. Any brand of yellow Carpenters glue I have used has always been stronger than the plywood or MDF I have used it on. Especially when spread on with a roller on both pieces and clamped or weighted heavily.

With the aliphatic resins and thin veneers, you can even put it on both pieces, let it dry. and then use a heat iron to apply it. The glue will melt and polymerize when it cools. I used to use it this way to apply birch plywood or balsa wing skins to foam r/c model wings. The glue was thinned with 10% to 20% water to glue ratio.

CarveOne

[arrio]

Well, Moving forward, I went to Lowe's and looked at all thier wood glues. I settled on the Titebond3 because it said it had longer open time for multiple part assemblies.
I first glued each table rib by pulling it from the assembly, applying the Titebond3 and reinserting it back into the structure. Asuring level fit and wipeing away the excess glue. Each interlocking piece was done this way. When finished, all parts had glue on them and good contacting fit.

The building table used for this operation is a solid core door 32"x80". I cut off the 80" side to 72". It sits on a sturdy 2x4 constructed 24"x50" table. The door was leveled on the table with shimms and a good bubble level. This serves as my straight surface to build the main table upon. These doors are constucted on big machined flat surface, and pressed together. They are very straight, and stiff.

I also progressed some on the gantry. I installed the 1/2x10 2-start Acme screws in the Z and Y axis. I had some issue with the alignment of the hole position provided for the Dumpster acme nuts. I elected to move the acme nut to the outboard side so I could more easily adjust the nut and screw for best alignment.

Also installed the Z axis acme screws and Dumpster nut. The provided holes were much closer here and required only minor hole resizing to bring the acme screw and Dumpster nut into alignment. I debated wether or not to use the stacked wood stepper motor motor stand-offs, and decided to go ahead and use them. I still need to glue them together and clear finsh them.

This morning I glued up the bottom skin to the frame. A milestone for me, as I was really dreading the operation. (No pics yet, forgot the camera) I simply squeezed a bead a glue on all the edges of the framework and laid the skin down. The glue seemed to be still fresh, and it had a good squeez out on the edges. Several clamps and weights, and then clean up the dripps. Ready to do the top skin now....

[CarveOne]

Good choice of glue.

Just in case you need to break a 90 degree joint you made in plywood or MDF, don't try to pry it apart. Put the larger piece in a vise and knock the smaller piece away from the larger piece using a no nonsense hard, fast whack with a hammer. If it is fully cured it usually breaks apart fairly cleanly and you can sand and re-glue the parts again. Just prying it apart will usually tear out more wood or MDF.

In the next photo you should aim the camera a little higher and show us the heli-chopper hanging above the CNC machine. It looks like a serious machine all by itself. Nice collection of R/C transmitters too.

CarveOne

[arrio]

CarveOne, Thanks for the tip on breaking a glue joint.
I bonded the top table skin thin morning, useing pretty much the same technique as yesterday. Got a pic of the bottom skin clamped and weighted and also of the top skin secured in place.
As I mentioned the shop belongs to my friend Gene, and he allowed me to snap a couple pics of his beautiful helicopter designs and machine work. He crafted/machined almost every piece on them and designed them too. He's been building and designing RC helicopters since the 60's.

Alfred,

[CarveOne]

Thanks for including the helicopter photos Alfred. Gene does some intricate machining of parts for those models. Nice workmanship.

Your table is coming along nicely. Dead sealed gel cell batteries from R/C flight boxes and emergency lighting fixtures work well for weighting down projects like your LC50B table skins. I cut off the stake-on terminals so they will stack better when needed. Any size I can get for free I will collect. My boss has 3-1/2 solid lead bricks that we use all the time for various duties.

Cheers,
CarveOne

[arrio]

I do have a few dead gell-cell batteries. But did not have them at the build location. I forgot about them anyway. Will have to remember that next time.

Couple more hours this morning yeilded some light sanding on the table and its first coat of Clear. the wood darkened up niceley. looks a lot like Luan wood instead of Birch. It has a redish glow to it. Still looks nice though.
Also glued up the the stepper motor stand-offs. Will sand and clear finish them tomorrow.

[BobF]

arrio,
Nice looking build.
I use titebond III for all my woodworking now. I like it better than any of the alternatives.
I have used the iron on technique that carveone mentions to apply veneer. Works well. I used titebond I for that.

[arrio]

Things are getting close to being able to assemble the whole machine. This last bit of painting and I can set up the mechanics. Though, It will take a few days to get through this painting sequence. One coat per day per side. I have one coat on the bottom and two on the top right now. Three to four coats is what it will get, and of coarse razor scraping and sanding in between coats. The sanding takes longer than the painting.
I bought a computer system for the Router on eBay the other day. Its a 3.2 Ghz P4, Dell Optiplex GX620, small format system. Got the whole system, 19" monitor, keyboard, mouse etc for $321 shipped.

Going to have to start thinking about a dust collection system. Several options out there to concider.

[arrio]

BobF, thanks for the feedback. I appreciate the comments.

Moving along on the build. The table is finished with painting, and the tube rails mounted. I have meant to take some pics this morning, but forgot to bring my camera again. Thankfully Gene was taking some pics of his own stuff and snapped a shot of the installed gantry/table.
I'm having some difficulty similar to the issue with the gantry Y axis drive screw/nut alignment. Its like the the parts were drawn in Cad but perhaps a later revision was not fully accounted for in the bearing rack offset. The mounting provisions for the Dumpster nut is off to one side by about 3/16". nearly the depth amount of the grooves that the bearings Alu angle stock rests in to maintain alignment. I'll have to either shim out the the bearing racks or re-do the dumpster nut mount holes. I know, pics would great here, but I'll get some during my next session.

Alfred

[arrio]

Well, The router structure is about done. What I have left to do now is install the motors and controller.

A couple pics here of the assembled machine, less electronics. and a couple pics of the gantry and table bearing assemblies. I had to make provisions to move the gantry over a bit to get the acme scews to align with the predrilled holes in the table. You can see the gantry Z-box is not aligned very well on the acme rod. But it just clears the hole and new mount holes were made for the Dumpster nuts.

Now working on wireing up the motors with connectors and assembling the controller box.

[CarveOne]

It's looking very good arrio. You're going to have fun with that machine.

CarveOne

[arrio]

Thanks CarveOne, I'm looking forward to cutting out lots of radio control stuff.

Just a little update. I've had some health issues that took me away from the project for a while. Feeling a lot better now, so its back on.
Finally got all the electronics installed and functioning. Using Mach-3 and Vcarve Pro5. Still sorting out the programs though. Just have the steppers jogging manually so far.
Had an incident which burned up my cnc controller and Computer. One of the connectors for the stepper motors had the wire positioned incorectly and the 34v stepper power was fed back into the computer. We smelled smoke eminating from the back of the computer and quickly shut down the system. But it was too late. A check with a multimeter at the parallel port found the 34v pin.
I had another cnc board from a mini mill project with its computer, to finish testing the system, after correcting the cable connector pin-outs.
I have another computer like the original on the way from eBay at a resonable price. Its the complete computer box less perifials. So I will be ready to run some sample cuts very soon.

Alfred