Hardware store design CNC router #1

[Jimmy Southern]

Hello Everyone,

I just wanted to put in my vote.

NO to the drawer guides
YES!!!! to the pipe & bearing machine

I do believe that jgro's machine is a very good start but I have seen modifications that would make it better. The 24"x36" cut area is a perfect size for a starter machine. You could use the hobby CNC kit for the electrics IMHO. This would keep the learning curve low, especially for the electronic illiterate, like me.

One idea I saw that would make this easier, is the eccentric bolt for the bearings. This particular design was very easy to produce, even for the novice. You simply take a bolt 3/8"-1/2", whatever size we determine will be most suitable, and offset drill and tap a hole for a 5/16 flat(flush) head stove bolt in the head of the large bolt. This should all be available at the hardware store. It is also very simple to understand. This would give a great deal of play to take up errors, and give alignment ability.

If any one has a link to the pics of the bolt idea please post the picture. I saw it somewhere in the forum but did not save the link.

With a good torsion box bed and gantry, full support for the pipe or rod, whatever we end up with, I believe this will be the next starter machine for the newbie just coming to the zone.

I am going to try to build whatever we come up with. I really appreciate what jgro designed but I believe we can make it better.

Watching & waiting on pins & needles
Jimmy Southern

[mikeschn]

I'm looking for a good way to secure the black pipe to the torsion box. We could JB Weld it... but then we can never take it apart. We could drill some holes in the black pipe, and use socket hd cap screws. Is this still in the realm of entry level hardware store machine?

Any better ideas for fastening the black pipe to the torsion box?

Mike...

[Jimmy Southern]

Mike,

I like the capscrew idea but I would like to see a tee nut set in a pocket, or hole, like people have been doing on the jgro pipe supports. It would be easy to use a forstner bit to make the hole for the tee nut. You could even use a hole saw or spade bit, whatever you have. This would be much easier & stronger than tapping the MDF.

Everyone please jump in with any other Ideas,
Jimmy Southern

[ViperTX]

Don't you need some adjustability....some time back we came up with the idea of supporting the ends of the pipe with some adjustable bearing blocks.

[mikeschn]

You mean like this?

http://www.cnczone.com/forums/showth...8533#post98533

Mike...

[Jimmy Southern]

Viper,

If I am understanding you correctly, on the adjustability, I think if you use a master template to route all of the pieces then the only adjustment that should be necessary would be to the bearings on the gantry & the z carriage. Everything else should be very consistant. You may have to shim in a few areas but I don't think you would if you assembled the machine carefully, paying close attention to the alignment of the pieces and to the squareness of the parts.

If the design is well thought out it should go together almost like lego blocks. We should design this to have half lap joints in the torsion boxes so it goes together like a drawer divider. this will greatly eliminate the build errors.

Hope this sheds some light on the idea that I have
Jimmy Southern

[pminmo]

May I suggest that if your going with black/gas pipe that you size it to commercially available cutoffs. Usually available in 1' increments. For a machine base, consider using 3 sheets of MDF glued/laminated, that will give you strength and weight for stability. Those that don't have a table saw will be pressed to do a good torsion box. The only thing you need there is a flat surface or jigged support.

[chronon1]

what happened to the KISS principle .. and also First things First.. the simpler contains drawer slides, smaller, cheaper and less complex ..

it makes common damn sense to see how the simpler proof of concept can be completed before undertaking the whole gas pipe and roller blade bearing design..

start small and go forward.. remember, "He who is faithful in a little, can be faithful in alot."

[mikeschn]

Well actually, we are going to do both, the drawer slide and the black pipe designs. Both designs will be hardware store based, and also no mill required.

Here's what I am working on for the black pipe design. Each member of the torsion box will have an end like this, for adjustability over the entire length of the black pipe. Furthermore, if the holes are not perfectly centered, that's okay, you can center the pipe using the screws. The pipe is going to be 1 1/2" black pipe, currently 3.39 per foot, which has an od of 1.9". So you can drill a 2" hole, and have .10" to play with.

What do you think so far?

[woodworker2]

Hi, I am going to try and add a simple thought here, I think Jimmy is refering to a dado groove in the torsion box. Regarding the alignment of the pipe holes in the torsion box, once you measure, mark, and drill the first end piece accurately, you can lay it on top of the second piece and sqaure and clamp it. Then your first piece is a template for your second piece and should give you perfect matching holes.
As a possible substitute for the black pipe, has anyone looked at the ceiling fan drop rods that have a polished finish and are sized from 6" to 48"? If so, what did you think?
Thanks, woodworker21

[Jimmy Southern]

Hello everyone,

Just need to clear up a few things. First I am greatfull to Mike for taking the lead on this. There has been some discussion on the drawer guide vs black pipe and I was glad to hear that we are going to design two different machines. Personally I have no use for the drawer guide machine, it is just too small, so my mind is centered on the larger machine. So don't take my lack of interest as oposition. I am just posting the ideas I have had or seen.

Now to the specific misunderstandings: The half lap joints are nothing more than half depth dados. Please look closely at ger21's new machine thread. This will clear up alot of questions about what we are talking about.

Now to the difficulty: I am just guessing here but I think there would most likely be no more than 5 pieces that would have to be precision cut and all of this can be cut with hand tools if very diligent. More tedious than difficult. Once these pieces are cut you simply use a pattern bit, or flush trim bit, to follow the master template. It seems more daunting than it is.

I would like to see the design team take this machine to the level of ger21's machine just use a little less material and make the plans include either scalable master patterns or very precise measurements. The only variables that should exist would be the thickness of the MDF, Ply or whatever the builder uses, and the available pipe sizes. this will greatly reduce the work that the builder has to do. This design is very scalable up or down and very rigid. Ger21 says in his post that he put his entire weight 220lbs (I think thats right, sorry ger if it isn't) and it only deflected 1/64". Jgros machine has nowhere near this strength. This is why I am pushing very hard for that direction. In my opinion ger and spalm are on the right track for the perfect "usable" machine.

I am very open minded if anyone has a better idea for this machine, but I have not seen anything that for the price gives the same quality.

I really hope that no one has been offended by my enthusiasm. I really do plan on building this machine so I would like to be the guine pig(not sure that is spelled right).

Thanks to Everyone!!!
Jimmy Southern

P.S. Keep the ideas coming

[chronon1]

i DID A little CAD of that nice Rib Mike --- please find attached and see if you
how it looks ...