Is the MK4 or MK4i the better choice? Pros and cons to both?
Also, does anyone have contact information for SDS? I have reached out through the website and through here but haven’t had any luck contacting anyone.
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I’ve looked at both systems and I like the idea of the motors being protected and the wider wheelbase. In your opinion is the MK4i worth the extra $220?
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Those improvements are nice, but it’s going to cost you 1.1lbs per module, and it’s going to take a little more area on the chassis (although it’s shorter). It’s also slightly more expensive.
The Mk4 also allows you to get more ground clearance (without putting motors in danger) if that’s important in a particular game.
That said, we decided that the couple costs were worth it and went with the Mk4i modules this year. Don’t regret that decision.
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We are currently using Mk4s and they currently work great, but we really never had problems with Mk4s, that would cause us to make the switch.
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I think It’s certainly not the most needed, but it would be a great upgrade for lighter bots, So the weight increase wouldn’t effect them much.
Have you had any issues with the MK4i modules? This is our first step into swerve drive and is a significant cost so we want to do it right the first time.
No. They are fantastic. Make sure you give yourself plenty of code time before you try to run them in a season.
We are running the Neo configuration with a CANcoder and have been really happy. We used .1" thick 2x1 versaframe to connect the modules. L2 gear ratio
If you have the time to test preseason, I think those modules are fantastic. They open up a ton of potential for programmers, and for cool driving techniques.
We are trying to purchase a kit now so we can try them out before our top programmers graduate, but cannot get in contact with anyone from the company. 
this is something I have not seen people saying about the mk4is: they are bigger so if you don’t design around them then they probably wont fit.
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I’d be patient…pretty sure everyone involved with SDS is a team member/mentor as well, it’s a busy part of the season with PNW DCMP this past weekend.
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How is the NEO configuration working for you? It would be our preferred motor but the easier use of the Falcon encoder is tempting.
No issues so far. Obviously with a Neo there are more wires, but as long as you are careful with wiring, it all works.
We run all of our position PID loops on the Spark Max directly, with the built in Neo encoder. Works great, and gives us plenty of resolution. The CANcoder is just there to align the modules at the start of the match.
I didn’t know the falcon encoder was easier to use, but I’ve never used one. We standardized to Neo/neo 550 for everything and that works out great for us.
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from what has been said the falcons are easier due to no latency which the neos have built in
neos have a built in 112ms latency for the encoders
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Got it.
We using the Neo we are still able to do complex auto routines. So it’s not hurting our drive encoder too much.
Steering has no noticeable issues for us.
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I saw they were a mentor for a team and figured that they were in competition mode, but I also figured they’d check e-mail periodically. I’m not upset with them or the company, just getting antsy because our purchasing window is closing down as we approach the end of the school year.
This is only true for velocity measurements due to the filter used. Position measurements have no (measurement) latency.
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Coming from a first year swerve team that went with the MK4 we definitely regret not going with the MK4i. We mostly made the decision based on the fact that we already had a set of MK3s from an offseason project that were cheaper to upgrade than do full MK4i with spares.
Personally I wish we’d gone with the MK4i due to this year’s flat field and the fact that we’ve already had a falcon taken out by being driven on top of by a defense robot (we have since added falcon protectors) at our first competition
As mentioned earlier the MK4i takes up a larger footprint but less height where as the regular MK4 is the opposite, those seem to be the main contributing factors as to why teams made the choice they did this year. Although with a game like stronghold I personally wouldn’t want my falcons under my robot whereas this year the MK4is were perfect.
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Mk4
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Higher CoG
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More gear ratio options
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1.1 Lbs lighter per module
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Motors are at higher risk of being damaged
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Motors take up a decent amount of vertical space, enough that you may need to design intakes and other mechanisms around them
Mk4i
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Lower CoG
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Less gear ratio options
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1.1 lbs heavier per module
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Motors are at lower risk of being damaged
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virtually no vertical space is taken up, allowing for full width intakes
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Acts as a corner of your robot once mounted to tubing
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The L1, L2 and L3 gear ratios are the same between the MK4 and MK4i, so you could use MK4i’s on some corners of the robot and MK4’s on other corners of the robot. If you wanted the low module height on the “front” of the robot for a full width intake but needed the footprint space on the “back” of the robot for some mechanism, you could set up with MK4i’s on the front 2 corners and MK4’s on the back two corners. This would save you a little cost and weight over going with MK4i’s on all 4 corners.
Although this would not save you any money, you could buy the MK4 modules and then buy the conversion kits to go from MK4’s and MK4i’s and then select which style to use for each corner after kickoff.
We ran the SDS Mk4i L2 this season and absolutely love them. We’ve previously run the following in testing:
SDS Mk4
SDS Mk3
WCP Swerve X flipped corner config
WCP SS Falcon
WCP SS Original
While all modules have performed well in our testing, we really appreciate the advantages the Mk4i modules brings, most of which have been mentioned already.
Best,
-Mike
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