Telsta / Baker lifts

I'm looking for anyone who has used or maintained either of these arial lifts. Specifically looking at the Telsta 28c and comparable Baker model. Both are in the 28' range and are powered with the Onan genset w/ aux. hydraulic pump.
I'm looking at getting a used one and install it on my big service truck oposite the existing derrick. In order to do this, I will need to heavily modify the unit. Everything below the turntable is going to be replaced with a new tube steel structure between the cab and body mounted directly onto the front A-frame outriggers. Consequently, the operational valves, controls, and hyd. reservoir, normally located in the pedestal, will be remote mounted inside the truck body. May possibly use the existing hydrualic reservoir from the derrick to supply the bucket boom as well (depends if if the existing one has enough reserve capasity to handle the added loading).

Both are coming off of 1 ton utility chassis trucks and are midship mounted. I know I have some rorational clearance concerns because of the existing derrick and the derrick. Derrick is mounted on the curb side rear corner of the truck. Bucket boom needs to lay reverse of this on the street side, turntable facing forward and bucket facing rear. Rest for the derrick needs to be moved to the curb side about 16" to make room for the bucket turntable but the weight shift can be made up for by mounting the genset on the same side as the bucket boom. Truck has more than enough capasity to handle the added weight safely and balanced as not to make it heavy to one side.

I'm going to be replacing the fiberglass bucket with one made of aluminum tubing and expanded metal. (Fire resistant and lighter since I don't require electrical insulation.)

I'd to get any and all input on these lifts, good or bad. They both seem to be pretty basic units with electric over hydraulic controls. The base designs also seem to be much alike with only minor differences between them (I'm going on outward appearance only). I don't plan on just swapping it from one vehicle to the other. The entire system will be ripped down, inspected and repaired or replaced with new parts as necessary (it's my butt that'll going up in it and since I did not come equipped with wings, it's gonna be right). Are there any internal differences that would make one better than the other, stability, ect... I have my choice of units at the same price but what about prices of parts and availability? Is there a better place to post this question?

Thanks in advance,
Mark Kw

The only thing I'd add to what you plan to do (which all makes excellent sense) is to inspect the pivots of the various boom sections, cylinder mounts, etc, etc, for cracks. A dye-penetrant test might be money well spent. From what I've seen, truck-mounted lifts suffer a lot from vibration just from going down the road.

I don't have a great deal of experience with either brand you mention, but I share your impression, both seem to be basic, reliable hardware with nothing much to choose between them.

If it were me, and if time and money were no object, I would do away with the genset/pump rigging and run the thing off a PTO pump on the truck motor. I would say that 90% of our service attentions on gas-engine manlifts are associated with the motor or the pump. But that may be more fun than you were planning to have.

HTH

llater,

llamas

In addition, when I plumb this in, I'm going to add a bypass loop into the existing truck / derrick hydraulic system. Should I experience a failure in the truck PTO system, I can open two valves and supply limited hydraulic power to the derrick and outriggers to get them stored for travel. Likewise, I can do the reverse as well by adding flow / pressure regulators to operate the bucket boom from the truck system.

I've studied the maint. manual for the derrick for months learning everything about it. The PTO pump supplies too much pressure and volume for the bucket lift but it can be controlled as above for emergency operation but not daily use.

I was more concerned with the guts of the Baker / Telsta systems themselves. I'm not real fond of the on-off controllers used but they make for adding a couple spare switches in the control panel rather easy. (just in case I get in the air and a switch fails, can change it in a matter of minutes with a screwdriver that you can bet will be chained to the bucket)

As for the pedestal, I have to make a whole new one. I have contemplated welding the turntable base directly to the pedestal tower against using a sub-plate on the tower and bolting the turntable to it. The latter affords easier removal of the boom and turntable as whole unit without having to remove the tower from the truck or splitting the rotation joint.

The one thing that's bothering me is that both of these lifts use a hydrualic cylinder to stabilize and level the bucket. Altec uses a gravity leveler with a closed circuit hydraulic motion snubber and hand applied disk brake. I don't have info on this particular part of the system but I'm assuming these lifts have a similar closed circuit system but neither has a positive lock brake. How dependable are these non-locking snubber systems and will they be allow the bucket to be carried pinned in the horizontal position when stored?

I'd suggest, if you're going to be buidling your own basket anyway, that you consider building a more permanent cradle arrangement for it, and plumb a bypass valve into the hydraulic leveller circuit. That way, you can lower it into the cradle, open the bypass to let it find its place in the cradle, then dog it down. Terex, for example, has used a rather neat cam-and-wedge lock for this.

You're right about switches. The engineers who design the control boxes used on manlifts should hang their heads in shame. Cheap and chintzy seems to be the order of the day, and they are a royal pain to fix. We carry several rebuilt control boxes in the service van, because they are virtually impossible to repair on site - you need a bench, and good light, and watchmakers tools.

I'm guessing you have just toggle switches, which are not too bad, but they do go south eventually. We've been replacing the stock $2 switches with higher-grade sealed units at $7 and $8 a shot, plus silicone-rubber toggle covers at $3 a pop, and are still ahead on service costs. If you have controllers with microswitches, you're in for fun times also. These are a continual source of problems, especially in multi-axis joystick controllers, which may have 8 of them. We found a hermetically-sealed switch made by Cherry (# DC3) which is almost double the price of the generic switch, but which wears like a pig's nose.

If the control box doesn't have a weatherproof cover, you might consider making one. Also sealing the control box, and going through the insides of it with a can of conformal coating. But, like I said, any engineer with any pride in his work would blink at some of the junk that manufacturers put out as control boxes.

HTH

llater,

llamas

I take it this unit is for your personal use only?

Re-engineering and modifications, no matter how well done, will void any safety certifications.

If at some point insurance underwriters or safety certification is going to be involved with this unit there may be major hassles. (If you are using this for business purposes this will very likely come into play.)

Here's another chilling thought.

If you should ever sell this modified unit, you may be leaving a liability trail that could bankrupt you some day should anything ever go wrong... even if it had nothing to do with your modifications.

The way the legal system in this country works, I shudder at the thought.

Sorry if I'm bringing up some real nasty issues to think about, hopefully you've already considered them.

-- bbott

I don't have to deal with OSHA or MSHA because I have no employees. MSHA also only requires I notify the customer and post signs to keep other workers away.

As far as selling the unit, it can never be sold as is. I have to remove and or destroy the derrick and any other boom before the truck can be sold since it is over 20 years old. I get around a lot of liability being the only one using the unit since, in the eyes of the government, it's ok if I waffle myself using junk. Personally, I ain't using it if there is even a hint of a problem with it.

I actually went so far as to reduce the safety settings on the derrick to less than half its rated capasity. Normally set for 8 tons, I reduced the safety cut-out (HOP system) to stop operation at 3 tons. I don't need to lift anything over that and if I do, that's what the crane service company up the street is for.

I mostly use the derrick for positioning dozer blades, excavator buckets and assembling machinery and nowhere near exposed power lines. Too easy to get myself killed doing what I do let alone running the cable or boom into a live power line. As for the bucket, it'll only be me going up in it so you can bet it'll be perfect before I get in it.

Sometimes folks put all kinds of labor and money into a project like this and come up with something they'd find out was unusable due to the regulators.

I wanted to make sure it wasn't going to happen to you.

Post a few pictures when you're done !

-- bbott

bb