Nice video. Thanks. Since you mounted your struts vertically the upward force is different when the table is up (spring is fully extended) that when it is down and the spring gas is compressed more. If you were to move the bottom strut anchor out so that the angle of the strut varied as the knee went up and down the upward force would be more constant. Based upon the mill and strut dimensions you can calculate the best angles as well as those that might be allowed by the mill clearance constraints. I think this is the way a car hood or trunk springs work as the movement is on an arc. Just a suggestion... - - - Dave.
Dave, Thanks for the support. Actually a good point and I could explain myself better on camera, but there seems to be an antipathy for long videos on youtube. I've worked with automated machinery in the past and that's where I came up with the idea to do this. On that type of equipment there's normally there's an average two inch to 20 inch extended difference or 1:10 offset. Servo or Stepper motors like the constant. While filming you'll notice I was originally looking for an offset in near the dovetails and was trying to incorporate that offset. Mounting in that location would have strayed too far from my desire to keep it simple. If you notice the blocks I used to mount the lower end of the struts. There are two mounting holes. I used the lower ones but had already incorporated a higher set. This was in case I decided the movement did require a smoother action. I could simply move the blocks out away from the direct line of lifting to give me the needed offset. The struts used are rated at 200 pounds each of lifting force, but what they don't tell you is that this is an average. They actually have a (+-) of around 15 to 20%, but most of that is near the extremities of the stroke. My knee has 14" inches of movement and the struts have a 14.30 stroke. Starting at the full up position to mount them is the best way to go as you'll never run your table into the quill. So the strut realistically is operating in its 95 % full force at top (realistically) and would be capable of about 215 pounds (430) at bottom. I very seldom run to the bottom of the stroke unless I have something large (heavy) on the table, in which case the added lift is welcome. As of right now the direct throw of the strut is working beautifully, and my arm is taking a much needed break every time I go to use the mill. Precision depth cuts using the knee are Childs play at this point. Thanks for your astute observation, your point has not been lost on deaf ears. Don
Don, I’m about ready to do this mod on my 65 MV1. Have you had any thoughts on changes or advancements on the upgrade since you have had this working for a few months now? I really appreciate your content and time invested to share your info with us. Thank you. John in Mn
John. Yes this is an excellent question. If I were doing it again, Ide probably use 150 PSI cylinders instead of the 200 psi. The higher force causes the knee nut to lift when I'm cranking downward with low or no weight on the bed. So doing small parts you have an extra 4 rotations of crank before the bed starts dropping. With heavier parts its not an issue though. The added assist is amazing when you use the z axis to drill upward using the z axis. Its smooth and easy to move. You can sit there drinking a pina colada and watching the bikinis float by almost forgetting that you're doing a heavy - precision drill operation. I've thought about buying a set of lower psi cylinders and just swapping out depending on what job I may be doing. I definitely do more small light weight stuff on this mill, so it wouldn't be that often. If you need anything else, let me know. Good luck with the MV1. Great small knee mills no matter what the snob boys may think. Don
@@donsengine3158 Thanks for the update, I was concerned about that just a bit so I will look for 150 lb. lift. Your vision of daydreaming about bikinis…. That’s Florida stuff, snow boots and parkas up in the great state of Minnesota🤓
@@johnvandewege7607 Hay, I used to live in the great white North too. My son moved down here from MN/SP and my wife was quick to pack us up and follow. Don
Nice video. Thanks. Since you mounted your struts vertically the upward force is different when the table is up (spring is fully extended) that when it is down and the spring gas is compressed more. If you were to move the bottom strut anchor out so that the angle of the strut varied as the knee went up and down the upward force would be more constant. Based upon the mill and strut dimensions you can calculate the best angles as well as those that might be allowed by the mill clearance constraints. I think this is the way a car hood or trunk springs work as the movement is on an arc. Just a suggestion... - - - Dave.
Dave, Thanks for the support. Actually a good point and I could explain myself better on camera, but there seems to be an antipathy for long videos on youtube. I've worked with automated machinery in the past and that's where I came up with the idea to do this. On that type of equipment there's normally there's an average two inch to 20 inch extended difference or 1:10 offset. Servo or Stepper motors like the constant. While filming you'll notice I was originally looking for an offset in near the dovetails and was trying to incorporate that offset. Mounting in that location would have strayed too far from my desire to keep it simple. If you notice the blocks I used to mount the lower end of the struts. There are two mounting holes. I used the lower ones but had already incorporated a higher set. This was in case I decided the movement did require a smoother action. I could simply move the blocks out away from the direct line of lifting to give me the needed offset. The struts used are rated at 200 pounds each of lifting force, but what they don't tell you is that this is an average. They actually have a (+-) of around 15 to 20%, but most of that is near the extremities of the stroke. My knee has 14" inches of movement and the struts have a 14.30 stroke. Starting at the full up position to mount them is the best way to go as you'll never run your table into the quill. So the strut realistically is operating in its 95 % full force at top (realistically) and would be capable of about 215 pounds (430) at bottom. I very seldom run to the bottom of the stroke unless I have something large (heavy) on the table, in which case the added lift is welcome. As of right now the direct throw of the strut is working beautifully, and my arm is taking a much needed break every time I go to use the mill. Precision depth cuts using the knee are Childs play at this point. Thanks for your astute observation, your point has not been lost on deaf ears. Don
I just replaced the knee gears on my MVN about 3 months ago. This is a very well thought out modification and I'll have to do this now. Thanks.
The thought of wearing my gears prematurely is what got me to thinking about it. Glad you like. Don
Waiting for my gears now, will likely add your modification sometime soon. Thank you!
Sure thing John.. was really easy. I think you'll like the difference. Don
Great idea, Thanks
Interesting, dont think I would have thought of that. Thats an interesting Venturi vacuum. Which one is that? Do you like it?
The vacuum is from Matco.. Thanks for watching.. Don
Nice job! Do you still have full travel?
Could you post a link to the cylinders?
I think the Part # is ST320M200 on amazon
Yes, full travel for sure... Don
Don, I’m about ready to do this mod on my 65 MV1. Have you had any thoughts on changes or advancements on the upgrade since you have had this working for a few months now? I really appreciate your content and time invested to share your info with us. Thank you.
John in Mn
John. Yes this is an excellent question. If I were doing it again, Ide probably use 150 PSI cylinders instead of the 200 psi. The higher force causes the knee nut to lift when I'm cranking downward with low or no weight on the bed. So doing small parts you have an extra 4 rotations of crank before the bed starts dropping. With heavier parts its not an issue though. The added assist is amazing when you use the z axis to drill upward using the z axis. Its smooth and easy to move. You can sit there drinking a pina colada and watching the bikinis float by almost forgetting that you're doing a heavy - precision drill operation. I've thought about buying a set of lower psi cylinders and just swapping out depending on what job I may be doing. I definitely do more small light weight stuff on this mill, so it wouldn't be that often. If you need anything else, let me know. Good luck with the MV1. Great small knee mills no matter what the snob boys may think. Don
@@donsengine3158
Thanks for the update, I was concerned about that just a bit so I will look for 150 lb. lift. Your vision of daydreaming about bikinis…. That’s Florida stuff, snow boots and parkas up in the great state of Minnesota🤓
@@johnvandewege7607 Hay, I used to live in the great white North too. My son moved down here from MN/SP and my wife was quick to pack us up and follow. Don