[louieatienza]

Here in the Detroit area, the majority of Birch plywood sold at home depot is now made in China, and is absolute garbage. The glue joints are often poor, resulting in delamination, and it warps very quickly. I work in a cabinet shop, and we go through a lot of plywood. When we buy a bundle of Chinese plywood, as soon as we cut the metal straps off, it starts to warp. It's not uncommon for the top 3-5 sheets to have the corners curl up 2".

If you want decent cabinet grade birch ply, you'll probably need to go to a specialty plywood dealer, and expect to pay ~$60 (or more) for a 4x8 sheet.

I'm building a lot of my new router from Apple ply. It's not Maple core, it's alder and birch. But It sometimes will have maple face veneers, rather than birch. It can have a few very small voids, usually small knots. But you can see from the data here that's it's more than double the strength of regular birch plywood.
Appleply

As far as cost, it's comparable to baltic birch (per sq ft) when purchased from a wholesale distributor. But, if you're trying to buy just a few sheets, you probably will have to pay more.

I was fortunate enough to end up with a few hundred square ft of cutoffs from a large job we did, which required about 250 sheets of Apply Ply.

I believe the last time I bought baltic birch I paid $37 for 5 x 5 x 1/2" sheet. Not horrible at all, considering Home Cheapo sells 4 x 8 'asian' plywood for $44/sheet. Be prepared as they do weigh considerably more than regular plywood!

[momus_cnc]

I was considering capitalizing off Bob's plans and making some of the tougher to cut pieces available for purchase. My current clamps will be available when I rebuild since I will be cutting new ones so the spacers and washers are no longer needed. If anyone needs clamps or metal/wood parts cut contact me, I would never charge a hobbyist hundreds for parts.

I think this would be very cool. To have just a couple of the more complicated parts available for purchase would make the build go much quicker, especially if someone is building this with very basic tools.

Rayna- Yes, for the moment I'm just selling the plans on eBay. Hopefully I'll have a website up in the near future. But it actually seems to work well on eBay for now. It is mostly automated, so as soon as you pay via paypal you are emailed a download link. And if you have any difficulties with the download (95% of people don't, once in a while someone has trouble due to a slow internet connection) I'll make sure the file gets to you.

As bonzo_nz pointed out, it is all simple rectangular/square stock. One exception being the gantry, which is a length of rectangular aluminum tubing.

Maybe some folks from outside the US could chime in on metal availability in different countries? I've sold many plans to people in other countries, but they are not in metric and the design relies on accurate dimensions of the metal stock to position everything correctly. I have no concept of what is available for sizes, or how people might be modifying the plans to work with what they can get. Not that I have any immediate plans to offer a metric version, but it might help others to know what they are up against in sourcing metal. And I'm just curious.

I wasn't aware of that cutting fee policy at SpeedyMetals. That is very good to know. I like the idea of a pile of metal showing up in the mail that is already all cut to correct lengths. Now if only they would drill and tap holes...

-Bob

[bjesson]

I wasn't aware of that cutting fee policy at SpeedyMetals. That is very good to know. I like the idea of a pile of metal showing up in the mail that is already all cut to correct lengths. Now if only they would drill and tap holes...

-Bob

Bob,

I just checked with speedymetals again. Looks like there is only a fee charged on certain material not with how much or how little you order. So, all metal pieces in this kit can be cut close to the right size without any extra charge.

Bill

[bjesson]

All,

I created the g-code to cut clamps that better fit the 2401 model router. I only tested the program on 3/4" MDF since I dont have any 3/4" aluminum available. I was fine tuning the code a bit so you might be able to see the small should that was cut in a few areas because i changed offset a tiny bit. I also cut it out as one piece which i think I will do also with the aluminum stock but everything looked and measure good. Will post final pieces once I cut from aluminum. if they come out good I will make them available for a small fee. I also created the program to cut the clamps to plan specs.

Bill...

[bjesson]

pic of clamp being cut using the cnc

[kemper45]

bjesson,

That is so cool. Looking forward to seeing the results of these cut in aluminum. Will also be interested in what bits you use to make them.

Cheers, Dave

[bonzo_nz]

How well would this machine handle a router instead of a laminate trimmer? Or how necessary is the variable speed function? I've only managed to find fixed speed laminate trimmers where I am. My concern with a router is that it would be about twice as heavy as a laminate trimmer.

[antisubae]

That's fantastic, bjesson! I'll definitely be in line to grab a set of 2401 clamps. The time savings alone by not having to cut them by hand will be well worth the price.

[safaridog]

Just out of curiosity what is the approximate cutting area after being built?

[groswald]

Two quick questions,

1. Has anyone looked at using a Bosch Colt trim router instead of the spec'd Rigid? I have been planning on using the Colt based on the availability if high-precision collets.

2. Does anyone know how to request a sub-forum for Bob's design similar to those for the JGRO and Joe's designs? I suspect this topic could get rather lengthy otherwise.

Oh, I started cutting wood for mine yesterday. Should have the base pretty much completed this evening. I am trying to clean up my scrap pile and ended up using some 3/4" MDF for some of the interior torsion box members. Don't tell Bob!

MDF is actually great for this application. It adds some mass (portability is not an issue for me) and does a fine job of holding the skins apart - which is their primary function. And it beats throwing it away.

Regards,

Randy

[kemper45]

Just out of curiosity what is the approximate cutting area after being built?

From the Momus Design description on the eBay site new CNC 3 axis router table mill machine engraver PLANS | eBay

X travel - 16"
Y travel- 16"
Z travel- about 5.5" (depending on router mount configuration)

Overall footprint- 24" x 29"

Dave

[safaridog]

Thanks

From the Momus Design description on the eBay site new CNC 3 axis router table mill machine engraver PLANS | eBay

X travel - 16"
Y travel- 16"
Z travel- about 5.5" (depending on router mount configuration)

Overall footprint- 24" x 29"

Dave

[momus_cnc]

I am trying to clean up my scrap pile and ended up using some 3/4" MDF for some of the interior torsion box members.

Hey, I caught that! Actually, that's a good use for MDF.

[momus_cnc]

bonzo_nz- As long as it isn't a really heavy bulky router, it should be ok. Just a few things to keep in mind.

1. Yes, it will add some mass to the gantry, which might mean reducing the acceleration/deceleration settings in Mach3.

2. The small laminate trimmer comes pretty close to the cover plastic with the gantry in the far forward position. A larger router might hit it. This could be dealt with just by careful limit switch positioning.

3. The router essentially cantilevers off the front of the machine. A larger diameter one will move the cutting forces farther forward, putting a little more torsional stress on the gantry, and some of the bearings.

4. You'll need to figure out clamps. If it has a smooth body you should be able to come up with a version of the ones in the plans. I see a lot of other designs that attach the router shoe (is that the right term?) to a plate for mounting. This won't work well if you intend on doing highly contoured surfaces. It would be fine for simple 2 1/2 axis work, but might be very problematic if you are trying to reach down into a deep concave area.

5. It might just depend on what you are cutting. The fixed speed laminate trimmer might be fine for your needs?

Overall, a small compact router should be fine. I've contemplated mounting a Porter Cable router that I have to the machine. Don't know the model number of it.

Safaridog- Yep, 16 x 16. The Z has around 5 1/2" of travel , but keep in mind that usable Z will also depend on height of spoilboard and length of bit being used. It should be possible to install some simple riser blocks under the X axis rails to raise everything up and gain some Z clearance if necessary. That would make better use of the full Z axis travel in some situations.

-Bob

[raynorj]

Hi all, Thanks for input have purchased the plans and a few other bits.
Unfortunately all our stock sizes, bolts etc out here are metric so a few slight changes will be needed. Particularly the aluminium is not quite same. Not sure how we can connect Bonzo as would be good to talk about the project. i am not sure if allowed to add email so will check it out first. My plan at moment is to mke a 24" x 16" format.
regards
Rayna

[groswald]

Bob,

Have you seen any issues with the lag screws used to attached the X-axis plates to the base? I have a nagging concern about them working loose with time and vibration and ultimately wallowing out their threads.

I'm thinking about using bolts with t-nuts where the structure allows and threaded inserts set with epoxy where it doesn't. No fear of thread degradation that way, and I can use blue Loctite to eliminate vibration issues once everything is aligned. Any thoughts?

As far as progress, I'm still working on the base. The t-box is done and front and back plates are installed. I should get the sides done this evening along with the pre-paint sanding and filling.

I can't imagine anyone getting this right without a table saw! I have a pretty good one, and it has still been quite a challenge to get everything together with reasonable tolerances.

A suggestion for anyone who hasn't started yet - cut all of your inner torsion box members at one time on a good table saw if at all possible. You really need them to be the same width to less than a few thousandths! Cutting a few spares isn't a bad idea either.

I cut all of mine, cut the 1/2 laps, fitted everything, and then ran them all back through the t-saw shaving off about 1/128" of an inch (the blade was just kissing them as they ran through). The t-box came out dead flat.

Regards,

Randy

[safaridog]

Anyone here doing a build find 3/8-10 precision acme threaded rod in Canada? Since Mcmaster Carr does not ship up here anymore I'm having a hard time locating some.

If anyone has a chunk left over from their build I wil buy it off them.:banana:

[email protected]
Dennis

[groswald]

Dennis,

I have about 5 feet of 3/8" - 10 two start (I think) precision rod that I got from Roton for a design I was going to build before I saw this one. I am going to use about a foot for my Momus. Happy to sell you a chunk of the remainder for what it cost me ($0.80/inch) + whatever it costs to ship to you. I have a spare Dumpster anti-backlash nut, collar, thrust bearings, radial bearings, and motor adapter now too. There are yours at cost as well, although I don't remember right off what they cost. You can look on Dumpster's site to see though.

The two-start shouldn't be an issue as long as you account for in your Mach3 setup. The nut travels twice as far per rotation as a single start screw would.

Give me a holler if you are interested.

Regards,

Randy

[R_garza]

I've been gathering the parts and still shopping around for 3/8-10. I found this and wondered if it would be the same or make a lot of difference , I'm very new to cnc.

1/2-10 x 36" Acme Threaded Rod - Acme Threaded Rod - Threaded Rod

Thanks
Rick

[safaridog]

Hey Randy,

Thanks for the offer, but I already ordered the nut and thread coupling from dumpstercnc... I like to use what I already got. If I dont have any luck in the next week I'll send ya a Email.

I'm still trying to source out a supplier to Canada without getting raped by UPS.

So far I found this.
MSC Item Detail

3/8-10 acme thread(3' length)$47.57 + $20 shipping + $30 UPS brokerage fee( wont send it any other way)

Or go to Ronton

3/8 - 10 Right Hand Acme Lead Screws & Nuts for Power Transmission - Roton Products, Inc.

They sell buy the foot... only problem its a min $60 order and I haven't gotten to the shipping part yet.

Dennis