I made a chain guide out of half-inch ply cutting a 5 inch circle and then cutting it in half. One piece screws flat side up onto the motor mount behind both chains. The next one circle side up and you can screw it in at any point and adjust the chain tension or wrap around the sprocket as you like.
Meticulous Maynard's Chain Guide
How to Avoid Chain Wrapping?
Straight line curves down at top of the sheet (solved)
looks great! can you post a few more pictures from other angles?
awesome! thanks for sharing. Do you find that you can mount your motors farther out from the spoil board and still avoid the chains jumping the tracks? I am thinking it would be great if I could mount the motors at or near the maximum thickness of stock to be used. I’m still thinking I’ll try to make the motor mounts easily adjustable, but your solution would certainly help with not having to be exactly in line with the stock. I am also thinking that UHMW might also make good material for this to prevent wear and avoid dust buildup on the arcs.
Looks like you’ve got quite a few cuts under your belt judging by the stack of curves next to your machine
Yes a lot of firewood made here!!!lol
Those tear drops are part of a lamp I’m making.
I was trying to design a motor mount That swiveled and could be tightened it down with a wingnut, to adjust for the board thickness.
I am excited to get my kit and figure out a solution (or even determine if one is necessary) to adjusting motor placement. Thanks for the inspiration.
And look forward to seeing the lamp, if you decide to share it.
I will post it when done.
For movable mounts remember that the spacing between the motors has to say exactly the same when you adjust your mounts, or you will lose calibration. I suppose if the both move the same amount in the same direction you will just shift the cutting position on the work piece.
Yes that is the issue with individual swivel mounts. The top beam design could have an extra layer of 3/4 on top that could be clamped or bolted to the beam, then with slots where bolted, slid in and out to adjust both motors at once, keeping the distance, but adjusting for the thickness.
Also, I have not had troubles with how mounted currently. I have the back 3/4 board, and then a 1/2 spoil board, then the cutting object mounted. Since I put the semi circles on the motor mount, it have had no skipping or popping of the chain on the gear.
Thanks for the photos. Looks like a nice solution to the chain slippage. I will give it a try.
If you experience chain slippage, look into @mrfugu’s solution. It is simple, elegant, and completely eliminates the chance of slipping by not allowing the chain to disengage the sprocket. One thing it does not do, however, is ensure that the chain is not twisted as it approaches the sprocket (which @Blsteinhauer88’s solution does, and there are other variations people have come up with that also ensure that the chain is on the same plane as the sprocket), however I found that by moving the bottom pulley (for the bungie) out in the z direction to where it is on the same plane as the sprocket, the chain stays parallel without the need for something to ride on.
I tried this solution, but still got chain skip quite often, it probably because my frame was poorly build, or because my chain and sprockets were from 3rd party supplier, It seem like the sprocket was a bit thicker than it should be, or the chain is thinner or not stretched enough. I even tried mrfugu solution, and still got chain skipping. So I come out with my own solution, which seem like an overkill, but it doesn’t care of the chain and sprocket quality, not if the motor, chain and sled are positioned on one plan or not. It forces the chain to fit the sprocket at 3 points right at the place where the chain enter and exit. The only problem is it require 3D printer, or finding parts with appropriate size:
2 x rollers with D=11.5mm (larger than Delrin roler included in the kit)
1 x roller with D= 38mm
3x rollers of any sizes to lift other roller up to the position where chain fit to sprocket.
the key to solving chain skip is to make it so that the chain is not angled to
the sprockets. make sure that the chain is parallel to the workpiece. This may
mean that you need to make larger motor mounts to get them far enough out to get
the chain parallel.
One thing to watch out for is the large guide interfering with the chain when the sled is in the upper right portion of the cutting area. The program calculates how much chain to feed out based upon the chain not being interfered with. The net effect will be that the sled will be a little to the left (and very, very little high) of where you want it to be. This will affect your Maslow’s accuracy… still better than a chain skip though
Since I did this mod, I haven’t had a chain skip. Does not effect the chain length to the motor.
I just wanted to throw this up here. Found it on thingiverse and printed it off. Looks amazing. I’ll try and follow up on how well it works. Thanks for whoever put this together!
That is an awesome fix! Do you know what the sprocket specs are? Cheers.