Shark HD4 bed - can you add to the bed?

[IDBD]

Has anyone tried to upgrade/add to the bed to make it longer?

If so how would you do it?

[Kayvon]

This would be interesting to do. It's not just expanding the bed, but lengthening (replacing) the rails and lead screws. You're pretty close to rebuilding the machine at that point, which could be fun.

[sharkcutup]

I could not say that it would be fun but I would definitely say that it would be quite a challenge!!! And as Kayvon pointed out it would also require

lengthening (replacing) the rails and lead screws

You do realize that you can use tiling feature for your project parts? In fact, you would probably spend less time tiling the project parts rather than spending time and money on extending the bed.

Good Luck!!!

Have a GREAT DAY!!!

Be SAFE around those AWESOME machines!!!

Sharkcutup

[cjablonski]

THIS is a great topic and idea. So much so that it made me get up off the couch and go down to the shop to formulate a plan how. Thats not as easy as its sounds Realistically it's entirely feasible if you think about the simplistic differences between a standard shark and a shard HD extended bed. I say this with some basic assumptions. Those are as follows;
1). A regular shark and shark HD extended use the same post processor and g-code (which I'm not sure but feel fairly confident they do)
2) The bushings that cap the end of the lead screw on Y axis are the same between each of the 2 different types of machines and can be reused.
3) in extending the bed the existing gantry structure would also be reused.

Looking at it in the simplist of ways you are realistically only modifying 1 axis of the machine, the Y axis. Z and X would remain the same using the same components. Now, structurally the base of the machine would need to be extended to support the greater travel distance along with the bed itself. Additionally , the the Y axis lead screws TPI (threads per inch) would need to be figured out so as to maintain the proper rotational calculations for the machines post processor and the correct mechanical movement of the gantry. And after a quick peek post-couch sitting the 2 guide rails on that axis would also need to be lengthened /changed. All told, completely doable (as evidenced by the existence of a hd extended bed). One could also assume from a production stand point of view reusing proven existing components make complete sense to a manufacturers perspective to ensure proper operation of a new machine and additional cost saving measure. Hence it's my belief that between the 2 most parts would be interchangeable.

Now for the drawbacks (otherwise known as fine print lol). If you have read this far, fine print is your thing so bad news is your norm , BTW- it's mine too so no worries .

1) doing this would almost certainly void any and all warranties in any universe.
2) Ensuring all 3 rails remained perfectly parallel to each other on that critical Y axis would be paramount to its future operation. Binding would most certainly occur.
3) Finding the exact match for the lead screws TPI would also be critical. Off by a shade and ANY Y axis movement and accuracy would be lost
4) Cost and risk. Although new machine is 3-4k, what you have, well, already works. No fiddling. And tech support at the ready from NWS whenever needed. Gone in a flash if the machine is modified. Plus lead screws ( not too too expensive.) and lower guide rails ( cost unknown ) are simply an expense no matter how you look at it.
5) Ultimately unnecessary. In theory ( yeah that place again, theory ) this problem is resolved through tool path tiling in V-carve.
You can ( again theory) run an infinite length of material beneath the gantry and reposition it using tiling. So the cost of doing it is eliminated by simple software we all own

There's my 2 cents, or more like 35 dollars worth

[tonydude]

I have the HD mako shark which I took off the gantry and bought the extended bed from nextwaveautomation for $1500.00 and it works great. Had the extended bed for over a year and had no problems with it. I can carve a 25 x 52 inch plaque on it.

Tony

[IDBD]

Wow!

Thank you all for all the info.
This forum and the people on are so great. I enjoy reading and looking at the forum everyday.

[rungemach]

For what its worth, once you extend the Y axis, you start thinking about making a new x axis, then a better z, and before you know it, you have built a second machine.

The linear bearings and lead screws are usually an industry standard item. I used Roton for the screws and Glacern Machine for the linear bearing rods and carriers.

If you just redo your Y, fully supported bearing rods (not just the ends and center) and a sturdy base will help immensely. IMHO, When you get to longer y machines, just making the bearing rod diameter larger is not the way to get rigidity. Fully supported bearing rods are.

This older thread has some info on machine building and rebuilding. http://www.cncsharktalk.com/viewtopic.p ... 2&start=20

[Kayvon]

A regular shark and shark HD extended use the same post processor and g-code

This is true. There are a lot of misconceptions on the forum surrounding post processors, but when you look into them they're not that complicated. It's just a way of making sure the proper commands are issued to the Shark Control Panel.
For instance, I commonly see people say that using mm instead of inch would completely change the size of the result. I believe this is incorrect. Using mm instead of inch would merely change your units in the .tap file, but they would still be accurate. Instead of moving 3 inches in a direction, you'd move 76.2mm.

[meb]

Don't forget you need to re-build the bed also and that is an added expense. You can contact Next Wave and find out how much they would charge for everything to convert your machine into the extended bed version or source the parts yourself. It might just cost you about the same amount but doing it yourself you will have parts you will have to make like the supporting structure that need to be made correctly or all you will have is one big headache that you are constantly working on and not producing any projects. The control box will work.

Post processors need to be correct for the units you are using. If you have 3 inches and use a inch post processor it cuts 3 inches. If you have 3 inches but use a mm post processor it cuts 3 mm. The post processor looks at the value and does not convert between inch and metric.

[cjablonski]

Kayvon is absolutely correct regarding the units change. I find myself in agreement with K a lot . Again though, keep in mind that this all could be for not as tool path tiling is a cheaper, less risky and less expensive option. For what it's worth, the gantry with is a greater obstacle to overcome, and at that point a new machine is more in order. A competitor, Gryphon CNC offers an off the shelf cnc with a 4ft wide gantry an capable of cutting 8 ft lengths for 3-4 k depending on options. Additionally it's transverse travel speed is at least 10x faster. When you start to factor in the sharks current limitations and the cost to upgrade it almost (stress "almost") seems to be a better option to upgrade.