[ger21]

Still, l left with an open question. While bigger is better, how big is big enough? At what size do I reach the point of diminishing returns?

I don't think you'll see a lot of difference between 12" and 15" or even 18". Once you get over 12", you're basically trying to keep the legs from flexing.
How good id good enough is one of those questions only you can answer.

I don't understand why decreasing the size of the resistor would correspond to reducing the output current.

I believe the value of the resistor is just telling the onboard processor what to limit the current to. It's not used or functioning like a normal resistor would be.

[davida1234]

UI could get them from Avid CNC, but I'm not enamoured with their use of oilite sleeve bearing. Fineline's have roller and needle bearings, which sounds like a better design and the prices is the same.

I believe that, some time ago and for a short time, CNCRP had them with needle bearings as well. Changed to oilites after bearing failures.

[ger21]

What to do next?

Run them and see if there are any issues.
Call Gecko and ask them about the resonance issue, and if there's a cure?

[GME]

I don't think you'll see a lot of difference between 12" and 15" or even 18". Once you get over 12", you're basically trying to keep the legs from flexing.
How good id good enough is one of those questions only you can answer.



I believe the value of the resistor is just telling the onboard processor what to limit the current to. It's not used or functioning like a normal resistor would be.

Run them and see if there are any issues.
Call Gecko and ask them about the resonance issue, and if there's a cure?

Thank you for weighing in again, Gerry.

Good information. I'll take your advice to (1) run the machine and see how it goes, and (2) to contact Gecko. I appreciate your help.

Gary

[GME]

I believe that, some time ago and for a short time, CNCRP had them with needle bearings as well. Changed to oilites after bearing failures.

Interesting information, David. I wasn't aware. Makes me wonder whether Fineline got a deal and took the bearing parts off of CNCRP's hands. Now, I'm wondering what I have. When I received my R&P drives, the gears were already installed. If I have a bearing model (vs oilite) I suppose early-stage bearing failure could explain my resonance issue. Also, early-stage bearing failure might not be readily detectable, unless you were specifically looking for it. Hmmm. Although I've resisted removing the R&P drives, I'm thinking maybe I should - that, and taking them apart. Ugh. Since Fineline was purchasing its R&P drives from CNCRP when I bought mine, I think I contact CNCRP and inquire. I'm not a fan of oilite sleeves (vs bearings), but if they are the most reliable right now, it is what it is.

Thanks for weighing in.

Gary

[GME]

Another update.




I decided to mount the 1530 extrusions on the sides in advance of cutting the gussets. In the near part of the photo, you will see some dark coloring at the end to the extrusion. It's marking fluid. I used it and a scribe to make where to make the cut for length.





Here is a closeup of how I mounted the extrusions. I could have used a 1.5" piece on the top an bottom for a cleaner install, but I had 3" pieces on hand. I will probably cut some 1.5" pieces after I get the gussets cut and installed.

Gary

[GME]

I used some really cheap 1/4" plywood to cut a prototype of the gusset.



This is a shot with the plywood mounted on a scrap of 3/4" MDF. Note that the MDF is clamped, but the plywood is not. Look closely. There are pieces of blue painter's tape sticking out on the right and left edges at the front and back. I used the blue tape and super glue method. For those who are not familiar with it, it's very simple and works great.

First, you lay down strips of tape on the MDF wherever you want the panel held down.. Then, you lay down strips on the underside of the piece you are going to cut. You place them to match the location of the strips on the MDF. I usually put tape on the edges. To establish the location on the MDF, I usually lay the stock down where I want it for cutting and draw lines on the MDF and use the lines to locate tape placement. Finally, you lay down beads of CA glue on the tape that's on the MDF and press the stock onto it. It all comes apart fine, because the CA glue only glues the tape together.

Here's Mark Lindsay's video demonstrating how to do it:








This photos shows the gusset in place. I'm pleased to say that it fit like a glove.

Design change. I decided to change the dimensions from 12" X 12" to 12" x 15". The 12" dimension is the vertical and the 15" is the horizontal. Here's why:

On the vertical dimension (on the leg), I have 8 total bolts. With as 12"x12", the leg would take up 3" of the horizontal length, and leave only have 9" to contact the horizontal extrusion. So it would be 8 bolts on the leg, and 6 bolts on the horizontal extrusion.. By extending the horizontal dimension to 15", I have the same number of bolts attaching the vertical and the horizontal - 8 per member. I cannot scientifically quantify that 12" X 15" is better, but it seemed to me that it would be no worse than 12" x 12". I reasoned the the extra 2 bolts and more contact area should be superior - even if only marginally so.

I am pleased to say that the gusset fit perfectly. That means I can use a "close fit" for the bolt holes. The closer the fit the better, IMO.


I have the toolpath for the 8 gussets in Aluminum, to be cut from a 42" x 48" piece of tread/diamond plate. While it might seem logical to cut the aluminum gussets next, I am considering a change of course and installing the spoilboard next. I don't like the idea of cutting aluminum with opening framing, because I can count on metal chips going everywhere. With the spoilboard and skirting in place, I should be able to contain the mess. Remember, my two control boxes are under my machine. So, with open framing, they will receive a deluge. Also, while I like the blue tape method for fixturing, it's not the most efficient method for fastening a 42" x 48" piece of aluminum. I'm thinking that I can clamp the edges, and cut the holes. Then, I can screw the gussets down through the holes, and make the profile (cutout) cut.

I'm still working out how to set up my Noga Mister. Mounting it is no problem; however, how to keep the spoilboard dry is an issue. Obviously, it won't due to get it wet with the soluble oil/water cooling/lubricating mix I use with my mill.

Even WD40 presents issues with the spoilboard. I'm thinking about sealing the MDF with a few coats of poly to protect it for this project, but have concerns that poly will make the surface slicker than I want. I thought about a piece of plastic countertop laminate (e.g., Formica), but it would probably be worse than the poly. Ditto for HDPE. On the plus side, an overlay sheet of .125" thick HDPE would be reusable for other aluminum cutting jobs and would cost around $100 (with tax). Not that bad. I'll have to give this more thought.

Gary

[GME]

Here's a video by NYC CNC showing the blue tape/CA glue hold down technique used on metal:



Gary

[wmgeorge]

Very nice work Gary, you might consider a piece of scrap Formica countertop for a temporary spoil board when cutting your aluminum.

[GME]

Very nice work Gary, you might consider a piece of scrap Formica countertop for a temporary spoil board when cutting your aluminum.

Thank you, Bill. I don't have any scrap countertop, or access to any. I would have to make up a countertop, or buy one. One of a variety of options. If I had my druthers, I'd make up a large 1/2" thick aluminum fixture plate with threaded holes that weren't cut all the way through. That way, the plate would contain the coolant, keeping it from reaching the spoilboard. The problem is both cost. Even a 24" x 48" X 1/2" would run me about $300 and a lot of time threading with a bottom tap. HDPE is about 1/2 the cost, and way lighter - about 20 pounds for a 24 x 48" X 1/2" piece (vs about 56 pounds for aluminum). I guess I'm leaning toward HDPE. My preference would be a 48"x48"x3/4" piece, but in that dimension the cost is a killer, even with going to pick it up (3 hours+ round trip). At about 60 pounds, the weight would just be manageable. On the other hand, I'm just not sure I will be cutting enough aluminum to justify the cost. A tough call and an issue I'm working through right now. The key will be coming up with a good way to protect the surrounding spoilboard area. I haven't figured out the part yet.

Gary

[ger21]

Bolt a sacrificial piece of MDF to your spoilboard. Add T nuts to the undersize to mount your aluminum to. When you're done, throw it away. That's what I do.

[wmgeorge]

Bolt a sacrificial piece of MDF to your spoilboard. Add T nuts to the undersize to mount your aluminum to. When you're done, throw it away. That's what I do.

And a handy person could just attach some boards to the sides to help contain the mess. Fast, easy & cheap. KISS

You can go to just about any construction dumpster and find scrap counter top from a tear out or demolition, I have seen new tossed out!

[GME]

Bolt a sacrificial piece of MDF to your spoilboard. Add T nuts to the underside to mount your aluminum to. When you're done, throw it away. That's what I do.

Thanks, Gerry. I may give it a shot. I thought about using MDF, but was concerned about it swelling while cutting and distorting my cuts. Maybe I'll try sealing it, or use some ply in place of the MDF. I've also thought of making judicious use of heavy plastic and duct tape to seal out most of the moisture.

And a handy person could just attach some boards to the sides to help contain the mess. Fast, easy & cheap. KISS

You can go to just about any construction dumpster and find scrap counter top from a tear out or demolition, I have seen new tossed out!

Thanks, Bill. Yeah, I have some cheap 1/4" ply laying around that would work to fill any open areas. As mentioned above, heavy plastic and duct tape might also work to contain the mess.

I don't have the time or inclination to go scrounging around for scrap Formica counter tops. Besides, in my area they use granite almost exclusively on new and remodel construction. Not many formica countertops around here. I've got some scrap Formica laying around. I suppose if I were to go that route, I could glue up my own on either MDF or ply. I don't have much use for particle board (mostly used for countertop substrate), so I don't keep it around and would want to store any left over from a sheet.

Gary

[ger21]

As long as you don't put water on it, it'll be fine.
If you use WD-40, it won't swell.

[GME]

I've decided to simplify the cutting process. I laid out my toolpaths to cut all 8 pieces from one of the plates I have. That means cutting parts from a 42" x 48" plate. I think I will cut the plate down for cutting individual pieces. That way, I reduce the bed support area. I can then use plastic sheeting and tape to mask off the rest of the bed. I can probably get away with using the tape method to hold each part down, which will eliminate fighting with clamps to get the plastic to cover everything else. I can mount the temporary spoilboard directly to the extrusion cross pieces, so I won't have to use any clamps. I have a non-ferrous blade for my Festool track saw, which will be safer then trying to man handle such a large piece on my table saw (I also have a non-ferrous blade for the TS).

I worry a lot about kickback, having experienced a particularly bad incident a 2 or 3 months ago on my chop saw. Just dumb luck that I wasn't injured. And yes, I had the material clamped down. Honestly, I don't know how it slipped, but slipping was what had to occur. Suffice it to say, the part I was cutting got pretty twisted up, and some of it went flying. It also damaged one of my pretty expensive Festool hold down clamps, and part of my saw fence aluminum casting was ripped off. Even with a featherboard in place on my cabinet table saw, a 42" x 48" piece can shift. Even a little bit of a shift could cause serious kickback and could prove fatal. I'm not comfortable going there. I built a vacuum fence for my table saw. I have to use a variable speed control on the vacuum, so it will hold so tight I can hardly move the stock through the blade Unfortunately, 1/2" is about as thin as I can go before I don't get enough vacuum to hold. The diamond plate I'm using only has a 1/8" base thickness.

The track on my track saw clamps to the material at each end, and a strip on the underside of the track grips very well to most everything. Short of using my plasma, my track saw is the safest way of making the cuts . For those who may be interested, I don't plan to use my hand operated plasma, because it's messier and far less accurate than my track saw. I would also have to move a lot of material around in my shop and do a very thorough clean up to eliminate fire hazards.

I should note that I plan to cut the aluminum a bit oversize. That will give me a hedge against any slight misalignment when mounting the plate to the temporary spoilboard.

Gary

[GME]

As long as you don't put water on it, it'll be fine.
If you use WD-40, it won't swell.

Thanks, Gerry. I had planed to use my mister from my mill, but I run a water/soluble oil mix through it. That wouldn't work with MDF. I've never tried WD40, but from what I've read, a lot of folks use it. It's definitely worth a try. It will be a lot easier to use, if I cut one piece at a time, rather than trying to cut 8 pieces in one go.

Gary

[GME]

Wow!!! Did I get a deal!!! :banana:

I just pulled out the sheet of tread/diamond plate I am going to use for my gussets. On the back, the price I paid was marked on the back - $43 for a 42" X 48" piece. I just looked the price up online (Online Metals in Seattle) for the same material - 1/8" 6061 tread plate. They charge $25.32 for a 12" X 12" piece and $193.28 (exclusive of tax or shipping) for a 36" X 48".

I bought it several years ago from Boeing's (the aircraft company) surplus store, when Boeing had a brick and mortar location. If memory serves, they sold surplus metals by the pound. As the price reflects, they were practically giving the stuff away. The diamond plate was in perfect condition. What I bought were offcuts.

Boeing moved its surplus sales to online only, and rather than fixing prices like they did in the past, they now auction off the stuff. When Boeing had a store, they had stuff in a warehouse type building and in a yard outside. It covered the better part of an acre in total, and was packed full of all sorts of stuff, e.g., computers, furniture, tooling, metals of all types, cabinets, office supplies, shelving - you name it. It was a candy store you could spend hours in. I got a lot of great deals there. Since they went online, they often have only a few items at a time. You have to be in the Seattle area, though. They don't ship. For anyone who might be interested, here's a link to the Boeing Surplus site: https://investmentrecovery.boeing.co...dAuctions.aspx

Gary

[Arjay]

Thanks for the link Gary. I live in Renton.

[GME]

Thanks for the link Gary. I live in Renton.

You're welcome. I live in Gig Harbor near the Fox Island bridge (across Hale Passage from Fox Island).

(I sure miss the old Boeing brick & mortar location. Hours of fun poking around. My heart sank when I last went there and found it closed. It was years ago).

Gary

[GME]

So Gary GME how goes your project?

The going is slow right now. My wife has a never-ending honey-do list and seems intent on keeping me from finishing the project.

I have made a little progress, though.

I've settled on how I'm going to do my spoilboard, created it in CAD and created the toolpaths for the base sheet. The spoilboard base is 18mm Baltic Birch - 60" x 60". To that I add my t-track spaced 4" OC. 1/2" MDF between each t-track, glued to the base sheet. Finally, 3/4" MDF cut to overlap the slot edges of of the t-track and glued to the 1/2" MDF. By overlapping the t-track slot edges, mechanical fastening of the t-track is unnecessary (I'll add a couple of screws in each piece to keep it from moving around). The Orange Aluminum t-tracks make the process easy, because they are 1/2" high. I don't need to cut rabbets (rebates for those not from the U.S.) in any of the pieces.

Bill, I recall that you have your t-tracks spaced at 6" OC. Since I cut directly on my spoilboard (versus using sacrificial pieces between the spoilboard and the stock), 4" OC will be more versatile for my purposes. I thought about variable spacing, but in the end, decided to go with fixed.

UPDATE ON RESONANCE ISSUE

I did some more fooling around with my homing speed. Using 5 ipm as my reference point, I incrementally increased and decreased the speed to see what would happen, i.e., at what point does the resonance start, and go away. Turns out that the unacceptable resonance was present at only 2 speeds - 5 ipm and 6 ipm. At 3 ipm, 4 ipm and 7 ipm everything was within an acceptable range. I decided to take ger21's suggestion and contact the folks at Gecko. However, before doing so, I tried to anticipate what diagnostics they might suggest and go ahead and perform them. I probably missed one or two things, but that's to be expected. I don't know what I don't know, if that makes sense.

One other thing I did was go back and regrease all of the bearing blocks and R & P parts. As expected, the blocks didn't take much additional grease, but I thought they might take some, given that I've been moving axes around and some of the grease may have settled in.

Where I actually saw a reduction in the resonance was with adding more grease to the R & P parts. That surprised me some. I thought I had lubed properly when I installed the parts. The post re-lube told me I hadn't. Don't get me wrong. There was still resonance, but the degree changed. Before lubing, there was enough to cause a 21mm wrench to move around. After, the wrench didn't move at all - no rattling noise, nothing. However, a pair of reading glasses and mechanical pencil still moved around at 5 ipm and 6 ipm. So, I am left to conclude that the lubing mitigated the effects of the resonance, but did make the resonance go away. Progress.

I detailed what I did in email to Gecko support. I suspect I will have a conversation with the folks at Gecko, but I wanted to make sure I communicated everything I've done first, so I didn't miss something if I started the dialog with a conversation. I just sent the email last evening, so I expect hear back in the next couple of days.

I think I've worked out how to cut the diamond plate braces. Rather than use a sacrificial piece of MDF, I think I will fasten a piece of HDPE to the spoilboard and tape plastic to it to keep the coolant from reaching the MDF spoilboard surface. I plan to cut some threaded holes in the HDPE for holding the diamond plate down, but I won't cut the threaded holes all the way though. That way, the coolant can't make its way around the threads and onto the MDF. If I do it right, I should be able to reuse the HDPE for future projects.

I am still toying with using WD40, instead of my water/soluble oil mix for cutting. I'd rather use with water/oil mix, but I'm reluctant to risk my spoilboard by exposing it to water. There is still a risk with WD40, though. If any of it gets on the spoilboard, it can later transfer to wood parts, which will create problems with finishing. nlancaster and I had some dialogue on this thread about cutting aluminum. I was pleasantly surprised to learn that whatever is used to cut aluminum tends to remain fairly localized to the cutting area. If I spray with a can of WD40 (vs using my mister), I can more easily minimize the amount of WD40 that's needed to do the job.

More to follow.

Gary