yes,the box will rattle, but resealing it may indicate it lost some parts. That happened with one other person, so check what’s in the box.
From the top of the sled to the bottom of the stainless arm, its 3 3/16". I tried to match the height I found worked well with my original sled. I used 4 layers of 3/4" plywood that I cut at the same time as the new sled. I had figured out the location of the pantograph arms in Fusion and wanted to just through-bolt the pantograph in place.
I didn’t even notice that. It was pretty late last night when I got this all assembled. I’ll have to check if that’s because of the twist. The right master link I used came from the Maslow kit, the left came from your hardware kit. I think they are slightly different, and that could be part of the problem. There may be a second master link that came with the original kit, I’ll have to do some digging in the mess that is my shop. Worst case, I can either sand down the face or widen the hole a little to get the clearances closer to what I need.
I had positioned my weights to get the center of gravity as close to the bit as possible. Is this necessary? I can shift them back down to where I had them on the original sled.
On my machine, this will probably be exaggerated a bit. The only space I have for the machine presently is in my shop trailer, and there’s only about 112" where it will fit. I had to make a smaller frame as a consequence, and I figure I probably lost about a foot or two of usable machining area.
I used the 1/4"-20 bolts and nylocks that came with the kit for connecting all the linkages. I did add 2 Oilite thrust bearings between the linkages to reduce friction between the joints. Not sure how necessary it is, but I figured it couldn’t hurt. I also cut down the bolts to reduce the amount of thread that was sticking out.
To connect the pantograph to the sled, I used 1/4"-20 x 5" carriage bolts, which I will admit was a HUGE mistake. I will be switching them out for regular hex cap bolts when I get the chance. The carriage bolt did not hold as well as I was hoping in the plywood while I was tightening the nylock, and it just spun. I ended up grinding a slot in the bolt head with a cut-off wheel, which allowed me to use a flat head screw driver to tighten down the nuts. I again used Oilite bearings between the plywood and the linkages, as well as between the linkages (I’ll post more pictures tonight when I get home). I used quite a few of them to get the height of the arms the same. Probably not entirely necessary, but I am a perfectionist, hence the username 
Yes, mine rattled quite a bit. I tried my best not to shake it like a 12 year old checking to see if his birthday gift is a new LEGO kit, but I only have so much self control. The box was packed inside a plastic bag, and as soon as I took it out some washers fell out. I’d imagine if you’re missing anything, it’s probably a couple of washers. Based on your other posts, I’d imagine you have some 1/4" washers floating around the Empire of Dirt. 
#4 to 3/4 iirc. Probably have 1/4 in steel, galvanized stainless, and brass. The trick will be to find any of them except the stock zinc flashed.
These days it’s the empire of cut concrete dust, those diamond saws sure make a big mess. We all wore HEPA dust masks
the bolts/washers I shipped are just the generic zinc coated ones. I thought about ordering stainless steel ones, but I wasn’t able to get good measurements of what the shoulders of the bolts would be, and I tried to size the shoulders so that none of the pivoting parts rub against thread (not that the thread will hurt the stainless steel as much as the thread will wear away faster and therefor have more slop.
All the parts except for 12 of the 25 washers were there. I might use it as an excuse to visit Fastenal to make sure that I have all washers the same thickness. I’ll check the bin in the cement dusty shop first, and see if I can dig out the box of 1/4 stainless washers - I think they were thinner than the bought by the pound zinc ones in the shop bin, although it’s a collection of multiple washers from multiple places. Wonder if nylon washers would work, think I have some of them too, from one of Grainger’s closeout sales (anybody need any 1/2x1" nylon SHCS, those might have been a little impulsive).
If I ever retire the Maslow those arms will make really good small prybars.
Winter showed up today, left a white dusting of the 4 letter word stuff on the ground. Too early for it to stick. Today’s rain and snow weren’t the best day off weather.
I envy your hardware collection. Anytime I need anything more than a 1/4"-20 or a 3/8"-16 in common sizes I need to run to the nearest hardware store to add to my collection.
Mmmm, Silicosis…
So photos. Had a bunch of photos I needed to work on from a hike last weekend, but I also got through the photos of the build process for the new sled.
The parts cut from 3/4" CDX. I have a lot of this left over from various projects, so I’m going to be using it a lot in the coming projects. I nested the risers with the sled to make use of corners of the sheet.
I got to try something new on this project, engraving! I wanted to add the Maslow Logo to my machine. I’m glad to be a part of this community! Another feature are all the hole locations that I marked with the engraving bit. One of the shops I used to work for did this a lot, and I thought it would be a good way to precisely locate all the needed holes.
Detail of the Maslow logo. I used a little flat black spray paint to make the logo a little more apparent, but got a bit of overspray in the grain. Oddly enough, I like the distressed look final result has.
Then it was a simple task of drilling out and countersinking all the holes. I took a notch out of the top of the sled to give clearance for the top carriage bolt, but the revised version I would extend the top a little more to give me a second hole location.
Once I had located the riser and therefore both of the mounting holes, I wanted to check to make sure the pantograph arm would line up as intended. I slid the arm over both of the bolt holes, and checked to make sure the chain hole is in line with the center hole of the sled.
Right on the money! Oh how much I love CAD.
Then its a matter of attaching the risers. I ran 4x 3" wood screws through the sled to secure it. I mean, there’s no kill like overkill, am I right? Also seen here are the cursed carriage bolts. I cannot stress how dumb of an idea this is. The nylock spun the carriage bolt quite easily and I had to cut a slot into it to make it a flat head screw (as I previously mentioned). I didn’t take any pictures of this hardware debauchery, I think I was too pissed off about it. Next time, hex cap bolts!
Plenty of thread to work with! I ultimately cut these down a little so there wasn’t so much thread poking through the nylock. Also, @dlang mentioned that he used partially threaded bolts so that the pantograph linkages didn’t wear down the threads. I didn’t think of that, and may use shoulder bolts or sex bolts in V2.
The pantograph all assembled. I hadn’t noticed it until now, but the linkages also make an “M”.
Out with the old, in with the new. After that, it was a simple matter of transferring my weights, Z-Axis, router base, and bungee anchors over. I got lazy in taking pictures after this point. I will have to go out an take a couple of pictures of the washer stacks tomorrow when I’m working on the machine. The video I posted earlier shows the final product.
I have included the nc files I used for this particular build. I will be making changes to these as I go along. Not saying that there will be an updated file tomorrow, but I will be updating these when I feel the need to make a new sled. I ran the engrave file first, and then the 6,35mm Down file with a 1/4" downshear bit (upshear bits will also work, the tool diameter is the important part).
PantographSled_Engrave.nc (9.3 KB)
PantographSled_6mmDown.nc (335.5 KB)
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Small farm, old equipment, long way to the closest hardware store - plus a tool junky and a little pack rat mixed with the moose genes. Why buy one bolt when you can buy them by the pound at Fleet Farm on those semi annual visits? Have everything but that one part you actually needed…
But can find one that can be made to fit 
How many four-bolt patterns have three different lengths of bolt and at least two different kinds of nut?
The washers are there for three reasons
- to keep the arms from rubbing against each other as they fold against each other,reducing the friction between the parts
2.on the outside to give a good solid surface to go against the sides of the arms rather than the possibly uneven nut and bolt heads, and eat up space so that the nuts can be tightened properly (I couldn’t find any bolts with just exactly the right amount of shoulder, so I got them a bit long and the washers make up the difference)
- in a setup like this where the horizontal arms are interleaved on the center wood spacer, to eat up space between the arms (in the next set I do, I may make a pair of spacers to include in the kit, eliminating this need)
for reason 1 above, nylon or other slick spacers work better than any metal that may eventually corrode in contact with the stainless steel
for the spacers, anything works.
I love all the pictures.
since you made the height of the arm from the sled 3 3/16 and the horizontal arm is 3/16, cutting down a 2x4 just a bit to make it 3" (or 3" minus the thickness of two washers) would work well for the mount to the sled.
There’s no need for the pantograph mounts to go all the way through the sled (and with a stock size sled, this put one right on the far edge)
but cutting the blocks on an accurate machine makes the rest of it really easy because you are just lining up the holes.
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I’ve had two reports of the packages being damaged in shipment to the point of loosing things out of them. In one case it was just some washers, in the other case it lost one of the long arms and almost all the small stuff.
Were there any other people who had trouble with their kits?
Mine arrived sealed up, no problems at all.
Thanks!
I think my motor mounts are roughly in the same place as the original design. I made a completely overbuilt steel tube frame for my Maslow. I can’t guarantee that it will necessarily match up with a normal machine.
For reference:
Quick view of the frame as I was test fitting it.
View of the motor mounts. I wanted as much adjust-ability as possible.
Mostly finished machine. This was just when I finished getting it built, and hadn’t even made my first circular sled.
Agreed, there isn’t a need for through bolting. I wanted to make the sled fairly easy to assemble, I like when I just have to bolt things up. I got pretty good results as far as accuracy with the original sled. In the middle, it was probably ±0.5mm, mostly due to the bit deviating a little as it moved.
Further updates:
Got a picture of the washer stacks I used:
I may end up switching out the literal washer tower on the center mounting points for sleeve bearings or some sort of bronze risers. At least that way it’ll look a little more intentional.
I also took the sled back off the machine and moved the weights down a little. After running it a little bit in the previous configuration, it seems like I want the sled to be a little bottom heavy.
I also ran a file over the attachment points for the chains. When I hooked everything back up, it didn’t catch like it did in the previous video. Still not sure if that was because of the twist in the chain or not enough clearance. If it comes back up, I may try to clearance it a little more and maybe even give it some silicone lubricant.
Quick video of one of my calibration tests:
So calibration. Do we have settings yet for what we should put into Ground Control? I figure that the “vertical” distance from chain to bit is 76.2mm, but I’m not sure what to use for distance between mounting points. Isn’t the point of the pantograph to make that value vary depending on where the sled is on the bed?
On the original sled, I would change the distance between mounting points to dial in the X/Y accuracy of the machine. So far, I’ve noticed that I can do the same with the pantograph, but I’m not sure if that level of accuracy will hold across the entire machine.
I wasn’t able to finish calibrating it this weekend, not enough time in the day. I hope I can get it to where I’m happy with it this week.
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Switch to triangular kinematics and you only give it one number (and it will find that through calibration) should be either 5.25 or 5.375 in
I did enable triangular kinematics., but now I think I was looking in the wrong place in the settings. I made the change in the advanced settings tab but then went back to “Maslow Settings” tab to change the values. Weird that I saw changes in calibration when I changed the other settings.
I need to change that value to 5.25" (133.35mm) or 5.375" (136.525mm)?
Yes.
Extra text tp satisfy the 20 char min
last week’s update also added support for triangular kinematics in the built in calibration process so if you want to keep it simple you have that option. If you do the built in calibration system I would love to hear your feedback because it’s new and I am sure there are ways we can improve it.
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Glad to hear it! I’ll have to update the firmware and Ground Control, but I can give it a try and let you know what I think.
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Finally got back in the shop! I was able to dial the accuracy of the machine near the center:
0.52mm off. Pretty close, but I’d like to get it closer. 136.525mm turned out to be the closest value. I may try to tighten the tolerance up a little more when I get the chance. I also would like to test the accuracy at the left top, left bottom, right top, and right bottom to see how well my calibration holds up across the bed.
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