Optimizing Danmar M6 2 Post Lift

I've been thoroughly enjoying having a 2 post lift in my home garage these past few months. It's seriously been awesome . If you've been on the fence about the quick jack or this, the Danmar M6 is what you want. (Not the maxjax) Out of the box it's a good set up, but there is definitely room for improvement. I would say these the biggest area for improvement is the hydraulic system and the lifting pads. My first project will address the lifting pads. For a truck, SUV, or most other vehicles, I'm sure this lifting pad works just fine. That's not really the case with the 996, as I've needed to add hockey pucks to make the lift arms clear the bottom of the body. I hate adding spacers between the car and the lift pads since you risk having those spacers slide out. As OCD as I am, it turns into a bit of a circus. After getting the hydraulic lines hooked up, the process goes something like this: Position arms under car Crawl around and place hockey pucks Lift arms a few inches Crawl around each corner for placement check Lower arms Crawl around each other to adjust lift arms a few inches Crawl around each corner for placement check Lift car to desired height I want to eliminate most of this. I would like to use the existing holes in the Porsche lifting points as a locator for a new lifting pad. This pad could slide upwards and downwards in the lift arm, that way the arm could be swung under the vehicle, and the lifting pad could slide up and locate into the lifting point to ensure a perfect, first time placement. I want it to be tall enough that it will be close to the bottom of the vehicle for ease of locating the pad to the lift point, but short enough that it will still clear the bottom of the side skirts on a lowered Porsche. I played around with the idea of making one height adjustable via threaded rod, but decided against it. So, a few minutes on Solidworks and McMaster and this is what I ended up with. The end that slides into the lift arm is ~ 2.1" long, and should be long enough so that I can slide the lifting pad upwards to ensure its lined up with the hole. After I got the initial design figured out, I made a second model that was optimized for 3D printing. I hallowed out the part and shortened the base to save materials and printer time. Here is what the first print looks like. It's difficult to tell, but I've decided to use a sealing washer as a consumable buffer between the lifting pad and the Porsche lift point. This is a nylon reinforced piece of rubber vulcanized to a steel washer. If you think this is too weak, let me put things in perspective. This washer is design for a 1" fastener. 30ftlbs of torque on a 1.00" fastener is going to produce a ~2200lb axial load. I'm not too worried about the washer, and it can be easily replaced for very little. Here is what the original lift pad looks like: Here is what the prototype lift pad look like: And here, you can see we will need a revision X2 for this part. I've shortened the part by roughly 5/8". I think that should do the trick.

Tomorrow I will print the second prototype. Depending on how that goes and my schedule, I'll be turning the final product out of 6061 aluminum on a CNC lathe at work.

Nice work....

Have you thought about making the top a different shape so you can lock it into the lifting points on the body then place the arms under the spacer rather than putting the spacers in the arms then lining them up with the lifting arms?

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Yes. That was actually what my initials thoughts were when beginning this project, but decided to go with the K.I.S.S. theory after modeling a few different renditions. The main thing was that I don't want to have to crawl under the car again to "unlock" anything, as I would be back to square one. The point of the lift is to not crawl around. The "peg" can easily locate the slot in the lifting point, eliminates the need for a spacer, and prevents the vehicle from sliding off the lift pad.

Cool. I’m interested to see how this shapes up. I have an M6 now (previously had a Maxjax) and agree that they are incredibly useful. I don’t have your skill or knowledge (or milling tools) so I went low tech and used the lift pucks sold by another rennlister (marketplace ad here: https://rennlist.com/forums/market/1107800 ). They fit in the lift holes and attach with a twist so they don’t move out of the way like hockey pucks do. They do have the downside of the extra step of putting them on and taking them off. When you finalize your design, will you be offering them for sale?

I have an atlas model 2 post (10k lbs, extra height version). For that lift, I have to have my 996 almost perfectly centered to get good contact on my lift pads. i bought the lift pads from one of our users that locks into the lift point so you are sliding a hockey puck in there. These pads are awesome. I think you idea is great as well except it would be difficult to use for my set up as I would be constantly adjusting the car to get the lift shaft of your design into all four of my lift points on the car. Probably lifts like the one you are talking about have a lot more adjustability to get "narrow" on the lift arms. i compromised on my lift to be able to handle larger vehichles as well, like larger trucks. In any case, I will be interested to see how this works out in practice as you have to be a bit more precise in lining up your arms than having a pad that locks into the car. Great idea and keep us posted!

Here is the shortened version next to the originals. I'll try to better illustrate my goal here. I want to be able to line up the pad perfectly, every single time, to create a repeatable processes that requires minimal effort. As an R&D engineer, I don't just design products, I design processes. You can visually locate the lift pad under the lift point using the peg and slot. You confirm the lift pad is directly under the lift point by sliding the lift pad upwards. I think I will tweak the design one more time. As you can see, it rubs the bottom of the lift point. I will shave off ~.20" or so. Also, I'm thinking that I will taper the peg instead having it straight with a chamfer. I think it will locate itself a bit easier in case there is a little movement when the arms are lifted.

Excellent!

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The M6 cost is at least 30% more than the maxjax. What makes it worth the premium over the MaxJax?

The big things I cared about are that the mx6 has automatic safety locks and is ALI certified. The maxjax has steel rods that need to be moved manually to provide safety. I sold my maxjax before I picked up the mx6, so I can�t be certain, but it also seems like the mx6 pump motor, reservoir and cart are more robust as well. I wish I had taken some measurements off the maxjax, since I suspect the mx6 also is made of thicker steel, but I didn�t measure so I may be way off.

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The safety locks vs. rods is a luxury bonus (not a big deal IMO) but the ALI certification seems like a really big deal. I didn't realize that the maxjax wasn't.

Would someone be so kind as to quoting Sweet Victory's picture posts? I can usually see the pictures at work in a quoted post, but not in the OP. Thanks in advance Mo

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picture post as requested

Sweet, i agree with your logic of shaping the top of the pin to help guide the post into the slot. The post itself plays very little roll once the weight of the car is on the pad. You could argue that the post adds some security from the car sliding off the pad but i think that's mostly a psychological safety net. I think the post guiding the lift arm so that the lift pad is squarely and fully under the lift point of the car is the real safety value and time saver when lifting. At that point you could really slope the pin from nearly a point at the top to a steep angle down to the base to provide maximum guide path vs. a post to "secure" the car once lifted. Just my $0.02

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Thanks cds.

Very cool. Is the purpose of the 3d printed version just to refine the design, or are you intending to lift the car with it? Also, I've been eyeing the maxjax product for several years. There was a second version branded under MaxJax with the automatic locking that I suspect they later re-branded as the M-6. So, if you're in the used market for one, you can still get those features under the MaxJax name - you just have to verify.

Very cool idea and work being done right here!

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The prints are just prototypes. I have CNC lathes at work, so will turn it from 6061 or 1018...whatever end cut we have that will work.

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Since the O.D. of the lift pad is only 2.0", it's critical that it's lined up perfectly. You can see in the photos that it's the same size as the lift point. On a normal lift pad, that pad might be 6" in diameter. In the event of an earthquake (I live in LA) or I'm doing something that transfer a lot of weight (dropping engine), I definitely want that peg there to mechanically retain the vehicle as I no longer have that large lift pad. In the latest model, the peg is tapered to help it better locate itself into the slot when the arm is lifted. (I mentioned this in my last update) Not sure when I can squeeze this project into a lathe at work, but I'll definitely keep you guys posted when it's completed.

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You would be surprised how convenient the safety locks are. I believe the MaxJax has 3 locations. With the safety locks, you have a ratcheting mechanism that gives you ~8 locations? (Never actually counted before) But this allows me to get the vehicle at the right spot depending what I'm doing. When I changed my coolant expansion tank, I raised the car to the right height so I wasn't hunched over for several hours. The ergonomics/usability alone is worth the cost. The certification gives peace of mind, but the quality of the install and your slab have more of a bearing on whether or not the car will kill you/cripple you for life...

I like what you're doing OP. If you spin a few of these, you'd probably have a few of us wanting copies. Any thoughts of making the OD just a little larger? I know the contact area probably won't change much, but maybe piece of mind.. Also, the taller version would probably be needed to clear the lower skirts on WB cars, I think. Nice work!

Got back home from a work trip to DC yesterday. Finally have time to work on this project again. Here are the first completed machined pieces. The initial trial was very good. I got the vehicle in the air in a fraction of the time. Pins located the lifting puck on the first try on every corner. No adjustment was needed. You'll see the pins have a taper on them rather than the small chamfer you saw on the printed prototype. This helps them locate themselves into the hole on the bottom of the lift point better. Also, I've got the tolerance on the shaft that slides into the lift arm perfect. When you let go of it, the air just barely slips through the puck and lift arm, so the puck slowly drops. I will have to use it for a while to see if I want to make any changes. With the protective washer. Here it is located under the lift point. Slide up to confirm location. You can see there is clearance between the top of the lift arm and the bottom of the vehicle.

Nice! Need any field testers?

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Had the car back in the air to take some measurements for a stud conversion. Really happy with how simple and effective they came out. Don't think I will need any field testers

Are these for sale?

I would love a set myself as I plan to buy one of these soon.

Question about 2 post lifts .. Has anyone made a set of runners that could be used to make the lift a drive on? Is that even possible? Is it a problem to leave the car stored for weeks at a time with the suspension "hanging"?

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Not really practical because even a few inches (or less) of variation in car position and the pick up points could be in very bad/dangerous spots. Once the car is lifted and the hydraulic pressure is relieved to rest the arms on their safety locks, the car can stay on the lift indefinitely. Read: don't leave hydraulic pressure doing the static work.

I've had a few inquiries about purchasing a set across a few forums. I've been really swamped at work and honestly haven't had time for a personal project for a few months. If we can get a minimum of 10 interested people, I might be able to knock out a bunch over a weekend. No promises.

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They exist. That being said, I would never store a vehicle on a danmar/maxjaxx.

^ Mohawk lifts make these wheel carriers for their lifts. I enquired about them and they are only 8 inches across which is a 205-225 tire. Mohawk rep ghosted on me when I pointed out that most vehicles that their lift weight capacity allows for run tires at least 10-12" or 265 and wider.

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At what price point? I'm definitely interested.

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That looks like a perfect solution if the arms on a 2 post are long enough...Who sells that. I want to store the 993 over my Macan. I am thinking that a "bolted down" 2 post may work..

Mohawk makes a sturdy two post with the tire lift arms, but they are costly. I wouldn't store another vehicle under my Maxjax mx-6 (if I could even fit one under it, which I doubt due to lift height). I went down the same road with storing two porsches at one point, and decided to get a Bendpak 4 post lift for storing two cars stacked. It takes up more space, but is a better solution, at least for me.

Price point is relevant but I would be interested in a set of these. Awesome design. Cool to see a good, useful project developed like this.

That extension creates a rotation force on the lift arm, looks like a bad idea.

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Would you care to elaborate as to why you wouldn't?

It might be fine, but I am not inclined to chance it, Here are my concerns: not enough height to fit a car under and it seems like a lot of weight put up high acting like a lever arm on the bolted connections. If it fails with a car underneath, you've doubled the amount of damage involved. Also, with my 4 post, I have trays to catch anything that might drip (not that Porsches would ever drip...), no such facility exists on the two post setup.

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CDS hit all the main points in his response. In addition to what he said, consider what may happen to this lift during an earthquake. (I live in SoCal)

Was just curious about pricing and found this: https://www.bestbuyautoequipment.com.../dannmarm6.htm Seems pretty competitive. You never worry about the anchor bolts? Doesn't seem like that would be enough.

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Would you be willing to share the dimensions or files so we can get them made ourselves if possible?

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We are in Los Angeles County and our recent earthquake had a rolling motion to the ground for about 30 seconds. Not good to have a vehicle on jacks or a lift during that. Best place to be in an earthquake.

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I just recently got a Dannmar M-6, not even installed yet. Hence I'm interested. Price sensitive also.

OP, you should see how much doing a small run is using 3dhubs.com, I use them all the time for low run machining stuff on the cheap.

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Do you have info on this wheel lift adapter?

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I'll give it a look. Thanks

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Sorry, I do not. I believe I found it on Garage Journal

If you decide just to release the specs to the wild,, one could send them to one of the online machine shop services to get them made relatively economically..

Yeah, just send a STEP file online to ProtoLabs or Xometry and you will have them in a few days for pretty cheap. Xometry will even do colored anodize. Price is better with more quantity, so get several sets and sell to other members!